PST05103 Pharmaceutical Microbiology

NTA Level 5 • Semester 1 • PST05103 Introductory Parasitology Pharmaceutical Microbiology • Source Session/Topic 36 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 36: Introductory Parasitology Total Session Time: 60 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Define common terms used in parasitology • Classify and list general characteristics of parasites Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 | 15 minutes|Presentation |Common Terms used in Parasitology | |3 |30 minutes |Presentation |Classification of and General | | | | |Characteristics of Medical | | | | |Parasites | |4 |5 minutes |Presentation |Key Points | | 5|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Common Terms used in Parasitology (15 minutes) • Parasitology o Parasitology is the study of parasites that infect humans. Parasitology deals with characteristics, transmission, clinical features and diagnosis, treatment and prevention of diseases caused by the parasites. • Parasite o A parasite is an organism that depends on another organism (a host) for food, shelter or other benefits and which receives these benefits is such a way that the host experience detrimental effects as a consequence. It is simply an organism that depends on other organisms and at the same time causing harm to that organism. o Examples of parasites included in parasitology are protozoa, helminthes, and some arthopods. • Host o A host is an organism that harbours the parasite • Intermediate host o Is a host that harbours the larval or asexual stages of the parasite. Sometimes larval development is completed in two different intermediate hosts, referred to as first and second intermediate hosts • Definitive host o Is a host that either harbors the adult stage of the parasite or where the parasite utilizes the sexual method of reproduction. In the majority of human parasitic infections, man is the definitive host except for example in malaria however, man acts as the intermediate host. • Ectoparasite o A parasite that lives on the outer surface of its host e.g. lice, ticks. • Endoparasite o A parasite that lives inside the body of its host e.g. Entamoeba histolytica • Obligate parasite o Is a parasite that completely depends on the host during a segment or all of its life cycle e.g. Plasmodium species. • Facultative parasite o Is an organism that exhibits both parasitic and non-parasitic modes of living and therefore does not absolutely depend on the parasitic way of life but is capable of adopting it if placed in a host • Erratic parasite o Is a parasite that wonders in to an organism in which it is not usually found e.g. Entamoeba histolytica in the liver or lungs of humans • Symbiosis o Is an association in which both the parasite and the host are so dependent upon each other that one cannot live without the other and none suffers any harm from the association • Commensalisms o This is an association in which only the parasite derives benefit from the association but without causing injury to its host. • Parasitism o This is an association in which the parasite derives benefit and the host gets nothing in return but always suffers some injury • Encystation o This is the transformation of a parasite from an active (trophozoite) to an inactive stage through losing its power of motility and enclosing itself within a tough wall (cyst). o The cyst is the resistant stage of the parasite and is also infective to its human host. • Extrinsic incubation period o This is the interval between the acquision of an infectious agent by a vector and the vector’s ability to transmit the agent to other susceptible vertebrate host • Carrier state o A perfect host-parasite relationship where tissue destruction by a parasite is balanced with host’s tissue repair STEP 3: Classification and General Characteristics of Medical Parasites (30 minutes) General Characteristics • Parasites have multiple life stages o Because of this they exhibit different immune response, makes it difficult to formulate vaccines and are difficult to control • Parasites spend part of their life cycle within or on a host body; • Parasites require sustenance from the host in order to survive in the period it is within or on the host • Parasites can be ectoparasites or endoparasites • Some parasites are unicellular parasites (protozoa) while others are multicellular (helminths and arthropods) Classification of Medical Parasites • Medical parasites can be grouped into protozoa, helminths, and ectoparasites. • Protozoa o Protozoa are microscopic, unicellular organisms that can be free- living or parasitic in nature o Protozoans are eukaryotic o They are made up of cytoplasm and nucleus ▪ Cytoplasm is differentiated into endoplasm and ectoplasm ▪ Nucleus contains karyosome and peripheral chromatin o They are able to multiply in humans, which contributes to their survival and also permits serious infections to develop from just a single organism o Transmission of protozoa that live in a human’s intestine to another human typically occurs through a fecal-oral route (for example, contaminated food or water or person-to-person contact). o Protozoa that live in the blood or tissue of humans are transmitted to other humans by an arthropod vector (for example, through the bite of a mosquito or sand fly) o The protozoa that are infectious to humans can be classified into four groups based on their mode of movement; ▪ Sarcodina (pseudopods) • Belong to phylum Sarcomastigophora • Move by pseudopodia, e.g. Amoeba such as Entamoeba

NTA Level 5 • Semester 1 • PST05103 Blood and Tissue Protozoal Infections Pharmaceutical Microbiology • Source Session/Topic 37 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 37: Blood and Tissue Protozoal Infections Total Session Time: 120 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Describe causative agents, transmission, life cycle, signs/symptoms of Malaria, Toxoplamosis andTrypanosomiasis Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 | |Small group |Malaria | | |40 minutes |discussion/ | | | | |Presentation | | |3 | 35 |Presentation |Toxoplasmosis | | |minutes | | | |4 |30 minutes |Presentation |African Trypanosomiasis | |5 |5 minutes |Presentation |Key Points | | 6|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Malaria (40 minutes) Cause and Transmission • Malaria is a life-threatening mosquito-borne blood disease caused by various species of Plasmodium • Species of Plasmodium causing malaria include: o Plasmodium falciparum o Plasmodium vivax o Plasmodium ovale o Plasmodium malariae o Plasmodium knowlesi • Severity of malaria depends on the species involved • Malaria is transmitted by the bite of an infected female Anopheles mosquito. • Life cycle of Plasmodium o The malaria parasite life cycle involves two hosts. o During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host o Sporozoites infect liver cells and mature into schizonts, which rupture and release (merozoites (In P. vivax and P. ovale a dormant stage (hypnozoites) can persist in the liver and cause relapses by invading the bloodstream weeks, or even years later.) o After this initial replication in the liver (exo-erythrocytic schizogony), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony). o Merozoites infect red blood cells. o The ring stage trophozoites mature into schizonts, which rupture releasing merozoites o Some parasites differentiate into sexual erythrocytic stages (gametocytes) o Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal o The parasites’ multiplication in the mosquito is known as the sporogonic cycle o While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes o The zygotes in turn become motile and elongated (ookinetes) which invade the midgut wall of the mosquito where they develop into oocysts o The oocysts grow, rupture, and release sporozoites, which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle. [pic] • Types of malaria o The disease presentation will vary according to patient’s state of immunity, the intensity of the infection and the presence of accompany conditions such as malnutrition, anaemia and other diseases. ▪ Uncomplicated Malaria • Uncomplicated malaria is defined as symptomatic malaria without signs of severity or evidence (clinical or laboratory) of vital organ dysfunction. • In this type of malaria, symptoms are present, but there are no signs to indicate severe infection or dysfunction of the vital organs. • This form can become severe malaria if left untreated, or if the host has poor or no immunity. ▪ Severe Malaria • Severe malaria is symptomatic malaria with signs of severity of vial organ dysfunction. Severe Plasmodium falciparum malaria is a medical emergency. • In severe malaria, clinical or laboratory evidence shows signs of vital organ dysfunction • Delay in diagnosis and provision of appropriate treatment may lead to serious complications and even death Signs and Symptoms • Signs and symptoms of uncomplicated malaria o Fever, headache, nausea, vomiting, o Malaise, fatigue, muscle pain, o Anorexia, chill, rigors, sweats, cough and diarrhea • Signs and symptoms of severe malaria o Fever and chills o Impaired consciousness o Change in behavior o Prostration/extreme weakness o Respiratory distress o Circulatory collapse/shock o Vomiting everything o Multiple convulsions o Deep breathing and respiratory distress o Abnormal bleeding and signs of anemia o Clinical jaundice and evidence of vital organ dysfunction o Severe malaria can be fatal without treatment o Inability to drink or breastfeed o Complications of severe malaria include; ▪ Hyperpyrexia, convulsions, shock, hypoglycaemia, metabolic acidosis, acute renal failure or pulmonary oedema o In Tanzania the commonest presentations of severe malaria are; ▪ Severe anaemia ▪ Coma (cerebral Malaria) Treatment and Prevention • Treatment of Uncomplicated Malaria o Artemisinin-based combination therapy (ACT) is recommended by the WHO to treat uncomplicated malaria. o ACT is artemisinin combined with a partner drug. The role of artemisinin is to reduce the number of parasites within the first 3 days of infection, while the partner drugs eliminate the rest. o These drugs include; ▪ Artemether-Lumefanthrine ▪ Dihydroartemisinin with Piperaquine ▪ Uncomplicated malaria in first trimester of pregnancy is managed by quinine tablet • Treatment of Severe Malaria o Hypoglycaemia is the major problem in the management of severe malaria especially in young children and pregnant women. Hypoglycaemia should be looked and treated accordingly. Other features like anaemia should also be addressed ▪ Medications include: • Quinine injection • Artesunate injection |Activity: Take home Assignment (10 minutes) | | | |DIVIDE students in groups or individual. | | | |ASK the students to work on the following assignment | | | |Explain the dose and dosing schedule for antimalarial drugs used in | |the treatment of uncomplicated and severe malaria in Tanzania | | | |ALLOCATE time for students to do the assignment and submit | | | |REFER students to recommended references | • Prevention of Malaria |Activity:

NTA Level 5 • Semester 1 • PST05103 Herpes Virus Infections Pharmaceutical Microbiology • Source Session/Topic 25 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 25: Herpes Virus Infections Total Session Time: 120 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Describe common viral diseases (causative agents, transmission, signs and symptoms) • Describe treatment, prevention and control of common viral diseases Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 |25 minutes |Presentation |Characteristics of Herpes viruses | |3 |30 minutes |Presentation |Herpes Simplex Infections | |4 |30 minutes |Presentation |Varicella (Chickenpox) | |5 |20 minutes |Presentation |Herpes Zosters (Shingles) | |6 |5 minutes |Presentation |Key Points | | 7|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Characteristics of Herpes Viruses (25 minutes) • Herpes viruses belong to the family Herpesviridae • They are a group of virus that are widely spread in human population • They are among the leading cause of human viral diseases • They can cause overt disease or remain silent for many years, then reactivated • These viruses contain double-stranded DNA which is located at the central core • All herpesviruses establish latent infection within tissues that are characteristic for each virus, reflecting the unique tissue trophism of each member of this family • There are over one hundred viruses in the family but only eight are pathogenic to humans. These are known as human herpes viruses and they are; o Herpes Simplex Virus -1 –causes oral herpes o Herpes Simplex Virus -2 –causes genital herpes o Varicella zoster virus (VZV) –causes chickenpox and herpes zosters o Cytomegalovirus (CMV) –causes cytomegalovirus retinitis o Epstein-Barr virus (EBV) –causes infectious mononucleosis o Hhuman herpesvirus 6 (HH6) o Human herpesvirus 7 (HH7) o Human herpes virus 8/Kaposi's Sarcoma virus causes cancers • Members of herpes viruses are grouped into three subfamilies namely alpha herpesviruses, beta herpesviruses and gamma herpesviruses • After initial infection, all herpesviruses remain latent within specific host cells and may subsequently reactivate • Antiviral drugs that have activity against herpesviruses include acyclovir, cidofovir, famciclovir, fomivirsen, foscarnet, ganciclovir, idoxuridine, penciclovir, trifluridine, valacyclovir, valganciclovir, and vidarabine STEP 3: Herpes Simplex Virus Infections (30 minutes) Cause, Transmission and Manifestations • Herpes simplex viruses (HSV-1 and HSV-2) commonly cause recurrent infection affecting the skin, mouth, lips, eyes, and genitals • Common severe infections include encephalitis, meningitis, neonatal herpes, and, in immunocompromised patients, disseminated infection • Both types of herpes simplex virus (HSV), HSV-1 and HSV-2, can cause oral or genital infection • Most often, HSV-1 causes gingivostomatitis, herpes labialis, and herpes keratitis • HSV-2 usually causes genital lesions • Transmission of HSV results from close contact with a person who is actively shedding virus o HSV -1 is transmitted by respiratory droplets or direct contact with infected saliva and the infection usually limited to Oropharynx o HSV -2 is transmitted through sexual contact and from maternal genital infections to newborn during delivery or in utero • Viral shedding occurs from lesions but can occur even when lesions are not apparent. • After the initial infection, HSV remains dormant in nerve ganglia, from which it can periodically emerge, causing symptoms • Recurrent herpetic eruptions are precipitated by overexposure to sunlight, febrile illnesses, physical or emotional stress, immunosuppression and some unknown stimuli • Generally, HSV infection presents with the following signs and symptoms o Preceding tingling sensation, discomfort and itching o Grouped vesicles forming on the skin, and mucous membranes, particularly the buccal area, gentalia, conjunctivae, and cornea Treatment and Prevention • Antiviral drugs o Acyclovir o Valacyclovir o Famciclovir • Prevention o Hygiene o Treatment of mothers o Safe sex practices STEP 4: Varicella (Chickenpox) (30 minutes) • Chickenpox is an acute, systemic, usually childhood infection caused by the varicella-zoster virus (VZV) • Chickenpox is an acute invasive phase of the infection with VZV which lies dormant and reactivate later in life to cause shingles • It usually begins with mild constitutional symptoms that are followed shortly by skin lesions appearing in crops and characterized by macules, papules, vesicles, and crusting • Patients at risk of severe neurologic or other systemic complications (e.g. pneumonia) include adults, neonates, and patients who are immunocompromised or have certain underlying medical conditions • In immunocompetent children, chickenpox is rarely severe but in adults and immunocompromised children, infection can be serious • Generally, chickenpox presents with the following signs and symptoms o Red macular rash with a central vesicle (blister) on the trunk, oral mucosa and scalp o Pustules and crusting o Intense pruritus o Fever o Occasional regional lymphadenopathy • Treatment options for chickenpox include; o Antiviral drugs e.g. acyclovir o Antipyretic/analgesic e.g. Paracetamol o Antipruritic agent i.e. Calamine lotion with phenol STEP 5: Herpes Zosters (Shingles) (20 minutes) • Herpes zosters is an infection due to resurgence or reactivation of the Varicella zoster virus (VZV) which also causes chickenpox • Signs and Symptoms of Herpes zosters o Severe burning pain o Grouped vesicles overlying erythematous skin following a dermatomal distribution o Typically, lesions do not cross the midline • Treatment options o Antiviral drugs e.g. acyclovir o Antiseptics for the wounds e.g. Potassium permanganate 1:4000 solution o Antibiotics for secondary bacterial infections ▪ Topical gentamycin ▪ Mupirocin STEP 6: Key Points (5 minutes) • Herpes is a group of over hundred viruses that belong to family herpesviridae • Eight of the herpes are pathogenic to humans and they cause an initial illness then lie dormant in

NTA Level 5 • Semester 1 • PST05103 Taeniasis and Schistosomiasis Pharmaceutical Microbiology • Source Session/Topic 39 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 39: Taeniasis and Schistosomiasis Total Session Time: 120 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Describe taeniasis and schistosoniasis basing oncausative agents, transmission, life cycle, signs/symptoms of common diseases caused by helminths (Taenia, Schistosoma, pinworm, whipworm, hookworm, intestinal roundworm, filarial worm) • Describe treatment,prevention and control of taeniasis and schistosomiasis Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 | 15 minutes|Presentation |Taeniasis and Cysticercosis | |3 |30 minutes |Buzzing/ |Schistosomiasis | | | |Presentation | | |4 |5 minutes |Presentation |Key Points | | 5|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Taeniasis and Cysticercosis (15 minutes) Cause and Transmission • Taeniasis is a tapeworm disease caused by Taenia saginata (beef tapeworm), Taenia solium (pork tapeworm), Diphyllobothrium latum (fish tapeworm) and Hymenolepsis nana. Teaniasis leads to chronic malnutrition or multi-organ dissemination and dysfunction (Cysticercosis) • Humans are the only hosts for these Taenia tapeworms. • Taeniasis is transmitted through consumption of raw or undercooked beef or pork containing infective cysticerci of the worms. • T. solium also causes cysticercosis which is a parasitic tissue infection caused by larval cysts of the tapeworm and is transmitted by consumption of eggs of the worms. Life cycle • Taeniasis is the infection of humans with the adult tapeworm of Taenia saginata or Taenia solium • Humans are the only definitive hosts for T. saginata and T. solium. Eggs or gravid proglottids are passed with feces; the eggs can survive for days to months in the environment. • Cattle (T. saginata) and pigs (T. solium) become infected by ingesting vegetation contaminated with eggs or gravid proglottids • In the animal’s intestine, the oncospheres hatch, invade the intestinal wall, and migrate to the striated muscles, where they develop into cysticerci. • A cysticercus can survive for several years in the animal. Humans become infected by ingesting raw or undercooked infected meat. • In the human intestine, the cysticercus develops over 2 months into an adult tapeworm, which can survive for years. • The adult tapeworms attach to the small intestine by their scolex and reside in the small intestine • Length of adult worms is usually 5 m or less for T. saginata (however it may reach up to 25 m) and 2 to 7 m for T. solium. • The adults produce proglottids which mature, become gravid, detach from the tapeworm, and migrate to the anus or are passed in the stool (approximately 6 per day). T. saginata adults usually have 1,000 to 2,000 proglottids, while T. solium adults have an average of 1,000 proglottids. • The eggs contained in the gravid proglottids are released after the proglottids are passed with the feces. T. saginata may produce up to 100,000 and T. solium may produce 50,000 eggs per proglottid respectively. Taeniasis (T. saginata and T. solium) [pic] Cysticercosis (T. solium) [pic] • Signs and Symptoms of Taeniasis o Most people have no symptoms or have mild symptoms o Colicky abdominal pain o Body Weakness o Loss of or increased appetite o Constipation or diarrhea o Mild epigastric discomfort o Nausea o Weight loss o Abdominal pain o Pruritus ani o Hyperexcitability • Infection with T. solium tapeworms can result in human cysticercosis • Cysticercosis is a parasitic tissue infection caused by larval cysts of the tapeworm Taenia solium. The larval cysts infect brain, muscle, or other tissue (see life cycle). Cysticercosis is transmitted by swallowing eggs found in the feces of a person infested with T.solium, e.g. autoinfection with own fingers o The cysticerci are most often located in subcutaneous and intermuscular tissues, followed by the eye and then the brain. o The CNS is involved in 60-90% of patients i.e. Neurocystercosis (cysticercosis of the brain) which may manifest as; ▪ Convulsions and/or seizures ▪ Intracranial hypertension • Headache, nausea, vomiting, vertigo, and papilledema • Personality and mental status changes (Neuropsychiatric changes) • Behavioral changes and learning disabilities more marked in children and immunocompromised adults • Treatment and Prevention o Taeniasis ▪ Praziquantel or Niclosamide with Magnesium sulphate (oral) o Cysticercosis ▪ Praziquantel or Albendazole with Dexamethasone and Carbamazepine (oral) • Taeniasis and cysticercosis are prevented by; o Health education o Avoid eating raw pork o Sanitary inspection of slaughter houses STEP 3: Schistosomiasis (30 minutes) • Cause and Transmission o Schistosomiasis (also known as bilharzia) is a parasitic disease caused by blood flukes (trematodes) of the genus Schistosoma ▪ Three species of Schistosoma are commonly found in Tanzania; • Schistosoma haematobium –responsible mainly for urogenital Schistosomiasis • Schistosoma mansoni –responsible mainly for intestinal Schistosomiasis. • Scistosoma japonicum responsible for both of intestinal and urinogenital schistosomiasis o Schistosoma parasites are transmitted to humans through skin penetration of the cercariae (infective forms of Schistosoma) when humans are in contact with contaminated freshwater. o Life cycle; ▪ Eggs are eliminated with feces or urine and hatch to release miracidia, which swim and penetrate specific snail (Bullinus) intermediate hosts ▪ The stages in the snail include 2 generations of sporocysts and the production of cercariae, which are the infective forms. Upon release from the snail, the cercariae swim, penetrate the skin of the human host and shed their forked tail, becoming schistosomulae. ▪ The schistosomulae migrate through several tissues and stages to their residence in the veins ▪ Adult worms in humans reside

NTA Level 5 • Semester 1 • PST05103 Pinworm, Whipworm, Hookworm and Roundworm Infestations Pharmaceutical Microbiology • Source Session/Topic 40 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 40: Pinworm, Whipworm, Hookworm and Roundworm Infestations Total Session Time: 120 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Describe causative agents, transmission, life cycle, signs/symptoms of common diseases caused by helminths (, pinworm, whipworm, hookworm, intestinal roundworm, filarial worm) • Describe treatment, prevention and control of pinworm, whipworm, hookworm, intestinal roundworm, filarial worm) • Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 |25 minutes |Presentation |Pinworm infestation (Enterobiasis)| |3 |25 minutes |Presentation |Whipworm infestation | | | | |(Trichuriasis) | |4 |25 minutes |Presentation |Hookworm infestation | | | | |(Ancylostomiasis) | |5 |30 minutes |Presentation |Roundworm infestation (Ascariasis)| |6 |5 minutes |Presentation |Key Points | | 7|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Pinworm Infestation –Enterobiasis (15 minutes) Cause and Transmission • Pinworm infection (also known as enterobiasis), is a human parasitic disease caused by the pinworm Enterobius vermicularis. • E. vermicularis is an intestinal nematode that is tiny, white and spindle-shaped with a large, bulbar esophagus • Enterobiasis is transmitted by the faecal-oral route, either directly or indirectly via contaminated hands or objects such as clothes, toys, and bedding. • The disease is more common in children • Females usually migrate out the anus at night and depositeggs on the perianal skin. • The eggs embryonate quickly and, if ingested, hatch and mature in the intestines. • Life cycle o Eggs are deposited on perianal folds. Self-infection occurs by transferring infective eggs to the mouth with hands that have scratched the perianal area. o Person-to-person transmission can also occur through handling of contaminated clothes or bed linens. o Enterobiasis may also be acquired through surfaces in the environment that are contaminated with pinworm eggs (e.g. curtains, carpeting). o Some small number of eggs may become airborne and inhaled. These would be swallowed and follow the same development as ingested eggs. o Following ingestion of infective eggs, the larvae hatch in the small intestine and the adults establish themselves in the colon o The time interval from ingestion of infective eggs to oviposition by the adult females is about one month. o The life span of the adults is about two months. Gravid females migrate nocturnally outside the anus and oviposit while crawling on the skin of the perianal area. o The larvae contained inside the eggs develop (the eggs become infective) in 4 to 6 hours under optimal conditions. o Retroinfection, or the migration of newly hatched larvae from the anal skin back into the rectum, may occur [pic] • Signs and Symptoms o Enterobiasis is most common in children, who usually present with ▪ Pruritus ani ▪ Insomnia (sometimes) ▪ Abdominal pain ▪ Anorexia, and pallor ▪ Genitourinary infection may occur in females. • Treatment and Prevention o Antihelminthic drugs ▪ Mebendazole ▪ Pyrantel pamoate ▪ Albendazole o Preventive measures include; ▪ Treatment of the sick and carriers ▪ Improved personal hygiene, including washing the perianal region and changing nightclothes STEP 3: Whipworm Infestation –Trichuriasis (30 minutes) Cause and Transmission • Trichuriasis is a parasitic disease caused by infection of the large intestine by Trichuris trichiura (also known as the human whipworm), which is an intestinal parasitic nematode. • Adult whipworms mainly live in the caecum, but can be seen throughout the colon and rectum. People infected with whipworm can suffer light or heavy infections. • T. trichjura belongs to the family Trichuridae. The worms are known as "whip-worms" because they have a broad short posterior end and a very long narrow whip-like anterior end • Trichuriasis is transmitted by the faecal-oral route, involving the ingestion of eggs with contaminated food, water or soil. • Life cycle o The unembryonated eggs are passed with the stool. In the soil, the eggs develop into a 2-cell stage, an advanced cleavage stage, and then they embryonate; eggs become infective in 15 to 30 days. o After ingestion (soil-contaminated hands or food), the eggs hatch in the small intestine, and release larvae that mature and establish themselves as adults in the colon. o The adult worms (approximately 4 cm in length) live in the cecum and ascending colon. The adult worms are fixed in that location, with the anterior portions threaded into the mucosa. o The females begin to oviposit 60 to 70 days after infection. Female worms in the cecum shed between 3,000 and 20,000 eggs per day. The life span of the adults is about 1 year. [pic] Signs and Symptoms • Heavy infections may cause dysentery, anaemia, malnutrition, and occasionally rectal prolapse Treatment and Prevention • Anthelminthic medications o Albendazole o Mebendazole • Infections are generally treated for 3 days. • Trichuriasis is prevented b; o Sanitary disposal of faeces o Effective sewage disposal systems o Personal hygiene e.g. washing hands o Thorough washing of vegetables, salads and fruits with clean water prior to consumption STEP 4: Hookworm Infestation –Ancylostomiasis (30 minutes) Ancylostomiasis • Human hookworm or ancylostomiasis is a hookworm disease caused by infestation of the small intestine with Ancylostoma duodenale or Necator americanus. It is one of the main causes of anaemia in the tropics which is also the major clinical feature. • Life cycle o Eggs are passed in the stool and under favorable conditions (moisture, warmth, shade), larvae hatch in 1 to 2 days to

NTA Level 5 • Semester 1 • PST05103 Introduction to Antisepsis, Disinfection and Sterilization Pharmaceutical Microbiology • Source Session/Topic 42 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 42: Introduction to Antisepsis, Disinfection and Sterilization Total Session Time: 60 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Define sterilisation • Distinguish between sterilisation, disinfection and, antisepsis • Outline procedures for disinfection and sterilisation of pharmaceutical equipment • List factors affecting sterilisation and disinfection Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 |15 minutes |Presentation |Antisepsis and Disinfection | |3 |30 minutes |Presentation |Sterilization | |4 |5 minutes |Presentation |Key Points | |5 |5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Antisepsis and Disinfection (15 minutes) • Antisepsis o Antisepsis is defined as destruction or inhibition of microorganisms on living tissues having the effect of limiting or preventing the harmful results of infection o Antisepsis is not a synonym for disinfection • Disinfection o Disinfection is the process of removing microorganisms, including potentially pathogenic ones, from the surfaces of inanimate objects o The British Standards Institution further defines disinfection as not necessarily killing all microorganisms, but reducing them to a level acceptable for a defined purpose, for example, a level which is harmful neither to health nor to the quality of perishable goods • Chemical disinfectants are capable of different levels of action o High level disinfection ▪ High level disinfection processes destroy vegetative bacteria, mycobacteria, fungi and enveloped (lipid) and nonenveloped (nonlipid) viruses, but not necessarily bacterial spores. High level disinfectant chemicals (also called chemical sterilants) must be capable of sterilization when contact time is extended. Items must be thoroughly cleaned prior to high level disinfection o Intermediate level disinfection ▪ indicates destruction of all vegetative bacteria including Mycobacterium tuberculosis but may exclude some viruses and fungi and implies little or no sporicidal activity o Low level disinfection ▪ Low level disinfectants kill most vegetative bacteria and some fungi as well as enveloped (lipid) viruses (e.g., hepatitis B, C, hantavirus, and HIV) ▪ Low level disinfectants do not kill mycobacteria or bacterial spores ▪ Low level disinfectants are typically used to clean environmental surfaces • Procedures for disinfection o Selection of appropriate disinfectant o Washing with clean water to remove visible soil e.g. pus, blood o Diluting disinfectant appropriately (according to manufacturer’s recommendations) using sterile water o Immersing the items to sterilized in the disinfectant solution for the recommended time o Removing disinfected items from the disinfectant solution using gloved hands or disinfected/sterilized forceps o Rinsing the disinfected using sterile water (or water previously boiled for 20 minutes and cooled) to remove traces of disinfectants o Placing the disinfected items in a previous sterilized/disinfected container with lid STEP 3: Sterilization (30 minutes) • Sterilization is the process where all the living microorganisms, including bacterial spores are killed or removed from a particular product, package or a medical equipment • The product being sterilized becomes sterile i.e. devoid of any viable form of microorganisms • Acceptable performance for sterilization is that a sterilization process should provide for a probability of finding a nonsterile unit less than 1 in 1 million • Sterilization is absolute, the sterilized item is either sterile or not, there is no semi sterilized or almost sterilize phenomena • Sterility is therefore absence of viable forms of life • Sterilization can be achieved by physical, chemical and physiochemical means • Chemicals used as sterilizing agents are called chemisterilants • Sterilization is an essential stage in the processing of any product for parenteral administration, or for contact with broken skin, mucosal surfaces, or internal organs, where the threat of infection exists • Sterilization processes involve the application of a biocidal agent or physical microbial removal process to a product or preparation with the object of killing or removing all microorganisms • Main methods used in sterilization include; o Heat sterilization o Chemical sterilization o Irradiation sterilization o Filtration sterilization • Sterilization may therefore involve elevated temperature, reactive gas, irradiation or filtration through a microorganism-proof filter • The success of the sterilization process depends on a suitable choice of treatment conditions, e.g. temperature and duration of exposure • Factors that affect sterilization include; o Number of microbes ▪ The more microorganisms are present the more difficulty it is to eliminate them. It takes more time or stronger sterilization effect o Type of microbes ▪ Endospores are very difficult to eliminate ▪ Vegetative bacteria have different susceptibility to sterilization methods o Environmental influence ▪ Presence of organic matter e.g. blood, pus, faeces affect sterilization o Time of exposure ▪ Chemical and radiation sterilization are more effective at longer times of exposure. ▪ In heat sterilization, longer times compensates for lower temperatures • Procedure for sterilization of instruments o Cleaning of instruments as per procedure for cleansing of instruments ▪ Instruments that are not clean cannot be sterilized o Performing hand hygiene and apply gloves ▪ Hands should be as clean as possible to prevent contamination of clean instruments/equipment. o Placing the clean instruments/equipment in the appropriate sterilization package and sealed ▪ Sealed packaged items will maintain sterility after sterilization has been achieved until opened for use. If packaging becomes wet or damaged, sterility cannot be ensured. Instruments in damaged packages must be re-sterilized or discarded. Packaging should be appropriate for type of sterilizer used. o Placing temperature sensitive chemical indicators for each load to be sterilized ▪ Temperature sensitive chemical indicators provide an

NTA Level 5 • Semester 1 • PST05103 Antiseptics and Disinfectants Pharmaceutical Microbiology • Source Session/Topic 43 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 43: Antiseptics and Disinfectants Total Session Time: 120 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • List criteria for selection of antiseptics • Explaincriteria for selection of disinfectants • Identify factors affecting action of antiseptics and disinfectants • Describe chemical groups of antiseptics and disinfectants Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 | |Presentation |General Properties of Antiseptics | | |15 minutes | |and Disinfectants | |3 |50 minutes |Presentation |Chemical Agents Used as | | | | |Antiseptics and Disinfectants | |4 |20 minutes |Presentation |Factors affecting action of | | | | |antiseptics and disinfectants | |5 |20 minutes | |Criteria for selection of | | | |Presentation |antiseptics and disinfectants | |6 |5 minutes |Presentation |Key Points | | 7|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: General Properties of Antiseptics and Disinfectants (15 minutes) Antiseptics • Antiseptics are chemicals that are applied to animate surfaces (skin, mucous membranes and wounds) to kill or inhibit the growth of microorganisms • The ideal antiseptic has to have similar properties as an ideal disinfectant • But the primary importance for antiseptics is the selective toxicity o Toxicity to microorganisms but not to human cells • The degree of selectivity of the antiseptic agents can change depending on the tissues they contact • Chemical used as antiseptics have sufficiently low toxicity for host cells that they can be used directly on skin, mucous membranes or wounds • Ideal Characteristics of Antiseptics o They must have adequate antimicrobial activity o The must not be toxic or irritating for skin o Antiseptics are mostly used to reduce the microbial population on the skin before surgery or on the hands to help prevent spread of infection by this route. Antiseptics are often lower concentrations of the agents used for disinfection • Uses of antiseptics o The treatment of skin infections o Prevention of infections in cuts and wounds o Cleaning the skin area of surgery from microorganisms o Prophylaxis and treatment of infections in mucosal areas such as mouth, nose and vagina that are open to environment o As a scrub for surgeons and the medical personnel Disinfectants • Disinfectants are used on inanimate surfaces • They may be the same agents used for antisepsis but at higher concentrations • Ideal characteristics • Should be soluble in various solvent especially water. • Should have high potency. • Should be compatible with organic matters. • Should be stable on storage. o Effective at room temperature o Non-corrosive and nontoxic o Inexpensive STEP 2: Chemical Agents Used as Antiseptics and Disinfectants (50 minutes) • Classes of chemicals used as antiseptics and disinfectants o Alcohols o Acids and Esters o Aldehydes o Biguanides o Halogens o Hydrogen peroxide and peroxygen compounds o Phenols • Alcohols o The aliphatic alcohols (ethanol and isopropanol) are used for disinfection and antisepsis o They are bactericidal against vegetative forms, including Mycobacterium species, but are not sporicidal o Cidal activity drops sharply below 50% concentration o Alcohols have poor penetration of organic matter and their use is therefore restricted to clean conditions o They possess properties such as a cleansing action and volatility, are able to achieve a rapid and large reduction in skin flora and are widely used for skin preparation before injection or other surgical procedures o Ethanol (CH3CH2OH) ▪ Ethanol is widely used as a disinfectant and antiseptic ▪ The presence of water is essential for activity; hence 100% ethanol is ineffective ▪ Concentrations between70% and 90% are best bactericidal and a 70% solution is usually employed for the disinfection of skin, clean instruments or surfaces ▪ At higher concentrations, e.g. 90%, ethanol is also active against most viruses, including HIV ▪ Ethanol is also a used in pharmaceutical preparations and cosmetic products as a solvent and preservative o Isopropyl alcohol (isopropanol, CH3. CHOH.CH3) ▪ Has slightly greater bactericidal activity than ethanol but is also about twice as toxic ▪ It is less active against viruses, particularly nonenveloped viruses, and should be considered a limited-spectrum virucide ▪ Used at concentrations of 60–70%, it is an acceptable alternative to ethanol for preoperative skin treatment and is also employed as a preservative for cosmetics • Aldehydes o Many aldehydes have antimicrobial properties, including sporicidal activity, o Glutaraldehyde (CHO(CH2)3CHO) ▪ It is the most widely used for disinfection ▪ It is a highly effective biocide and it is also used as ‘chemosterilant’ ▪ It has a broad spectrum of antimicrobial activity and rapid rate of kill, most vegetative bacteria being killed within a minute of exposure, although bacterial spores may require 3 hours or more. ▪ It is not affected significantly by organic matter ▪ The glutaraldehyde molecule possesses two aldehyde groupings which are highly reactive and their presence is an important component of biocidal activity ▪ At a pH of 8, biocidal activity is greatest but stability is poor due to polymerization ▪ In contrast, acid solutions are stable but considerably less active ▪ In practice, glutaraldehyde is generally supplied as an acidic 2% or greater aqueous solution, which is stable on prolonged storage ▪ This is then ‘activated’ before use by addition of a suitable alkalizing agent to bring the pH of the solution to its optimum for activity ▪ The activated solution will have

NTA Level 5 • Semester 1 • PST05103 Sterilization Methods and Criteria for Selection Pharmaceutical Microbiology • Source Session/Topic 44 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 44: Sterilization Methods and Criteria for Selection Total Session Time: 120 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • List methods used for sterilization • Explain (dry and moist) heat sterilization • Explain gaseous sterilization • Explain radiation sterilization • Explain sterilization by filtration • List the criteria for selecting sterilization method Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • Handout 48.1: Sterilization Methods SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 |15 minutes |Presentation |Introduction to Sterilization | |3 |30 minutes |Presentation |Heat sterilization | |4 |20 minutes |Presentation |Gas sterilization | |5 |15 minutes |Presentation |Radiation sterilization | |6 |15 minutes |Presentation |Sterilization by filtration | |7 |10 minutes |Presentation |Criteria for selecting | | | | |sterilization method | |8 |5 minutes |Presentation |Key Points | | 9|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Introduction to Sterilization (15 minutes) • Microorganisms cause contamination, infection, and decay • In order to prevent contamination of pharmaceuticals and infection, it is necessary to remove microorganisms • Sterilization is the process of killing or removing all viable organisms by by physical, chemical and mechanical means. • Physical sterilization employs the use of heat and radiation to kill the microorganisms • Chemical sterilization uses chemical agents in form of liquid or gases to kill the microorganisms • Mechanical methods involve removal of microorganisms by filtration • In sterilization all micro-organisms both pathogenic and non- pathogenic including spores are killed or removed. • All sterilization methods must be validated and monitored e.g. bacillus stearothermophilus is used to monitor moist heat sterilization process STEP 3: Heat Sterilization (30 minutes) Heat Sterilization • Heat sterilization is the killing of all organisms from an item by the use of heat. • Heat sterilization is the safest and most common method of sterilization • Types of heat sterilization o Dry heat sterilization o Moist heat sterilization Dry Heat Sterilization • Dry heat sterilization involves use of dry heat to kill microorganisms. Organisms are killed by oxidation effects • Dry heat sterilization is divided into flaming, incineration and hot air sterilization o Flaming ▪ It is the oldest and the simplest method of sterilization ▪ The item to be sterilized is held in an open flame. ▪ Example of sterilization by flaming is the heating of a loop wire to a red glow on a Bunsen flame before using it to transfer microorganisms [pic] ▪ Advantages of Flaming Method • Flaming is a convenient way of killing many, but not necessarily all, microorganisms • It can be used to kill all microorganisms in meat ▪ Disadvantages of Flaming • Does not necessarily kill all microorganisms o Incineration ▪ This is an excellent method of destroying or disposing of materials such as heavily contaminated cloth, animal carcasses and pathological materials [pic] ▪ Advantages • Incineration destroys 100% of microorganisms and reduces the volume of waste significantly. • It's also the ideal way to prevent contaminated items from being reuses ▪ Disadvantages • Incineration completely the object/item being incinerated • It is expensive method (repair, maintenance and operation) o Hot air sterilization (Hot air oven) ▪ Is a sterilization method in which organisms are killed by oxidation effects ▪ In this process, the various items need to be sterilized are duly kept in an electric oven, preferably with a stainless- steel chamber inside, and duly maintained at 170°C for a duration of approximately 2 hours (to ensure complete sterilization) ▪ Dry heat sterilization requires raising the temperature of an object to a controlled 170° C for approximately 2 hours to kill all microorganisms ▪ The items to be sterilized is exposed at higher temperature for prolonged duration of time ▪ Dry heat is the ideal way to kill microorganisms attached to fats, oils and powders, which can't be sterilized in an autoclave because they either resist water or are destroyed by it. ▪ The Hot Air Oven is the equipment used for this type of sterilization. This oven has; • A thermostat controlling the temperature • Double walled insulation keeps the heat in and conserves energy ▪ Hot air oven is used for sterilization of; • Medical equipment resistant to heat e.g. forceps, scissors, scalpels, swabs • Thermal stable and moisture-labile pharmaceuticals products o Nonaqueous Liquids (Liquid paraffin, fats and grease o Solids (powders) Moist Heat Sterilization • This is a sterilization method that uses heat in moisture to kill microorganisms • In this method microorganisms are killed by coagulating or denaturation of their proteins • Moist heat sterilization methods include boiling, autoclaving and pasteurization • Boiling o Boiling at 100°C at 760 mm atmospheric pressure kills particularly several varieties of vegetative states of microbial strains, many viruses and fungi usually within a period of 10 minutes o This method cannot destroy endospores and certain viruses o This method is mainly used for making food products safer for human consumption • Autoclaving o This is a sterilization method that is operated in a special equipment called Autoclave o The process of moist heat sterilization is also known as Autoclaving o Items to be sterilized are heated and maintained at temperatures of 120 ± 2°C and high positive pressure in an autoclave o Autoclaving is used for items/products that are not sensitive to moisture and thermostable An autoclave [pic] Schematic diagram

NTA Level 5 • Semester 1 • PST05103 Introduction to Immunology Pharmaceutical Microbiology • Source Session/Topic 45 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 45: Introduction to Immunology Total Session Time: 60 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Explain e terms used in immunology and immunization • Describe types of immunity Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Presentation |Common Terminologies used in | | | | |Immunity | |3 |10 minutes |Presentation |The Immune System | |4 |25 minutes |Presentation |Types of Immunity | |5 |5 minutes |Presentation |Key Points | | 6|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Common Terminologies Used in Immunology (10 minutes) • Immunity o Immunity is the ability of the body to defend itself against diseases • Immunology o Immunology is the study of immunity • Immune response o A response generated against a potential pathogen • Granulocytes o Are leukocytes that contain densely staining granules • Monocytes o Are small leukocytes that circulate in the blood • Phagocytosis o Is a process whereby cells of the immune system known as phagocytic cell e.g. a neutrophil, recognize, ingests and destroys a pathogen • Antigens o Are substances that are capable of stimulating the immune system to produce specific immune response against them • Antibodies o Are specific substances produced by the immune system in response to exposure to an antigen STEP 3: The Immune System (10 minutes) • The immune system is the system of specialized cells and organs that protect the body from diseases • The immune system functions to protect the body against bacterial and viral infections and destroy cancer cells and foreign substances • When the immune system is weakened, its ability to defend the body also weakens. This allows pathogens to grow and flourish in the body, and cause diseases • The immune system also performs surveillance of tumour cells, and immune suppression has been reported to increase the risk of certain types of cancer • The immune system protects the body from infection through various lines of defence. • The immune system is a complex system of structures and processes that work together to protect the body • The immune system is made up of two components derived from the central (bone marrow and thymus) and peripheral (spleen, lymph nodes and lymphatic channels, tonsils, adenoids, Peyer's patches, and appendix) lymphoid organs; o The molecular component ▪ This component uses specific and nonspecific molecules to protect the body against foreign substances and pathogens ▪ Molecules of the immune system; • Immunoglobulins • Lymphokines o The cellular components ▪ This component consists of immune cells that protect the body ▪ Cells of the immune system are white blood cells • Granulocytes • Lymphocytes • Monocytes • Macrophages STEP 4: Types of Immunity (25 minutes) • There are basically two types of immunity, innate immunity and acquired immunity • Innate immunity o It is an immunity that an individual is born with, it is pre- existing in the body o It is the first line of defence o It is non-specific and non-adaptive ▪ It produces the same responses for all potential pathogens o Innate immunity includes; ▪ Physicochemical barriers (e.g. skin, saliva, lysozymes etc.) • These physical barrier kills or prevent entry of pathogens ▪ Cells (e.g. macrophages, neutrophils, basophils, mast cells etc.) • These cells attack and kills foreign organisms and toxins ▪ Processes • Processes such as inflammatory reactions and phagocytosis limit spread of infection o These components protect the body for the first few days of an infection o Sometimes innate immunity is enough to clear the pathogen • Acquired immunity o This is the type of immunity that is not present at birth o It is the second line of defence which involves building up memory of encountered infections so can mount an enhanced response specific to the pathogen or foreign substance o Acquired immunity is adaptive o It involves ▪ Antibodies • which generally target foreign pathogens roaming free in the bloodstream ▪ T cells • which are directed especially towards pathogens that have colonised cells and can directly kill infected cells or help control the antibody response o Acquired immunity has two components; humoral immunity and cell- mediated immunity o Humoral immunity is mediated by antibodies while cell-mediated immunity is mediated by immune cells o Acquired immunity is either active or passive o Active acquired immunity; ▪ It is induced after contact with a foreign substance or pathogen (antigen) ▪ After exposure the body actively produces antibodies and immune cells that will fight against the pathogens ▪ Active acquired immunity is acquired either artificially e.g. by injection of antigen (e.g. vaccines) or naturally e.g. after a clinical or subclinical infection ▪ Advantage: • Produces long term immunity ▪ Disadvantages; • Slow onset of immunity • Requires prolonged contact with antigen o Passive acquired immunity ▪ Passive acquired immunity is naturally acquired from the mother or artificially produced e.g. by injection of an antibody containing preparation ▪ Advantage: • Immediate action ▪ Disadvantages • Short lived • Hypersensitivity reaction STEP 5: Key Points (5 minutes) • Immunity is the ability of the body to defend itself against invading pathogens or toxin • The immune system consists of innate and acquired components of the immunity • The innate component is pre-existing, comprised of physical barriers such as skin and mucous membrane together

NTA Level 5 • Semester 1 • PST05103 Antigens and Antibodies Pharmaceutical Microbiology • Source Session/Topic 46 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 46: Antigens and Antibodies Total Session Time: 120 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Differentiate between antigens and antibodies • Explain sources of antibodies • Classify antibodies Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 | 35 minutes|Presentation |Antigens | |3 |35 minutes |Presentation |Antibodies | |4 |25 minutes |Presentation |Classification of antibodies | |5 |10 minutes |Presentation |Differences between antigens and | | | | |antibodies | |6 |5 minutes |Presentation |Key Points | | 7|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Antigens (35 minutes) Definition of Antigens • Antigens are substances that induce a specific immune response and subsequently react with the products of a specific immune response. • An antigen is a molecule that stimulates an immune response. • The definition encompasses all substances that can be recognized by the adaptive immune system. • Antigens differ from allergens • An allergen is a substance that causes the allergic reaction. The (detrimental) reaction may result after exposure via ingestion, inhalation, injection or contact with skin • The name “antigen” is derived from the term “ANTI’body GEN’erator” • Superantigens are class of molecules that can interact with antigen presenting cells and T-cells in nonspecific way e.g. staphylococcal exotoxins, Toxic shock syndrome toxins and some viral proteins Classification of Antigens • Antigens can be classified in order of their origins into exogenous antigens, endogenous antigens and autoantigens. o Exoantigens ▪ Exogenous antigens are antigens that have entered the body from the outside, for example by inhalation, ingestion, or injection. ▪ These antigens enter the body by endocytosis or phagocytosis • The antigens are taken into the antigen-presenting cells (APCs) and processed into fragments. o Antigen-presenting cells (APCs) are a heterogeneous group of immune cells that mediate the cellular immune response by processing and presenting antigens for recognition by certain lymphocytes such as T cells. Classical APCs include dendritic cells, macrophages, Langerhans cells and B cells. o Endogenous antigens ▪ Endogenous antigens are antigens that have been generated within the cell, as a result of normal cell metabolism, or because of viral or intracellular bacterial infection. o Autoantigens ▪ An autoantigen is usually a normal protein or complex of proteins (and sometimes DNA or RNA) that is recognized by the immune system of patients suffering from a specific autoimmune disease. ▪ These antigens should under normal conditions not be the target of the immune system, but due to mainly genetic and environmental factors the normal immunological tolerance for such an antigen has been lost in these patients. o There are antigens that are known as tumor antigens ▪ Tumor antigens are those antigens that are presented by the major histocompatibility complex class I (MHC I) molecules on the surface of tumor cells. ▪ These antigens can sometimes be presented only by tumor cells and never by the normal ones. In this case, they are called tumor-specific antigens (TSAs) and typically result from a tumor specific mutation. • Antigens can also be classified as Thymus-dependent antigens (TD-Ag) and Thymus independent antigens (TI-Ag) • Characteristics of Antigens o Immunogenicity ▪ The capacity to stimulate the production of antibodies or cell- mediated immune responses ▪ It is the ability of the antigen to stimulate an immune response from the immune system o Antigenicity ▪ The ability to bind antibody ▪ An incomplete antigen that cannot elicit an immune response is known as a hapten o Foreignness ▪ this an antigen being recognized as non-self. It is important feature because self-responsive cells are eliminated during lymphocyte activation leaving only cells that respond to non- self o Specificity ▪ This is the uniqueness of an antigen. ▪ Antigen specificity depends on epitopes • An epitope is the region or part of the antigen that is active immunogically i.e. it binds to antibodies and products of immune response o Chemical and structural complex ▪ Proteins are the most potent immunogens ▪ Polysaccharides are less immunogenic ▪ Nucleic acids and lipids do not elicit good immune response ▪ Molecules with simple chemical structures e.g. a simple sugar are less immunogenic than complex molecules o Molecular size ▪ Large molecular weight proteins are highly antigenic ▪ Smaller molecular weight molecules are less antigenic o Stability ▪ Highly stable and non-degradable substance are not immunogenic o Biological systems ▪ Some substances are immunogenic in one individual but not immunogenic in others o Dose of antigen ▪ Very low dose does not stimulate immune response ▪ Repeated accumulation may be needed to stimulate immune response in some cases e.g. booster doses in immunization such as in diphtheria o Route of entry ▪ Antigens entering through parenteral route produce good levels of antibodies o Adjuvants ▪ A substance that increases immunogenicity of an antigen when mixed with that antigen and then injected ▪ Adjuvants increase the strength and duration of immune response • Aluminium potassium sulfate STEP 3: Antibodies (35 minutes) • An antibody (or an Immunoglobulin) is a specialized immune protein produced because of the introduction of an antigen into the body, and which possesses the ability to combine with the very antigen that triggered its production. • The production of antibodies is a major function of the immune system and is carried out by B-lymphocytes • Antibodies can be triggered by and directed at