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NTA Level 5 • Semester 1 • PST05103 Introduction to Bacilli Pharmaceutical Microbiology • Source Session/Topic 13 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 13: Introduction to Bacilli 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: • Describe medical bacilli 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 |Characteristics of Bacilli | |3 |20 minutes |Presentation |Classification of Gram Positive | | | | |Bacilli | | |15 minutes |Presentation |Classification of Gram Negative | | | | |Bacilli | |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: Characteristics of Bacilli (10 minutes) • Bacilli are rod shaped bacteria. They are not spherical as cocci. • Bacilli should not be confused with bacillus which is a genus in the spore forming gram positive bacilli • Bacilli are groped into two major groups depending on their staining properties with Gram stain o Gram postive bacilli o Gram negative bacilli • Bacilli consist of a large number of bacteria some of which cause serious diseases in humans and others are normal flora of humans STEP 3: Classification of Gram Positive Bacilli (25 minutes) • Spore forming Gram Positive Bacilli o These bacilli are ubiquitous, and because they form spores, they can survive in the environment for many years o The gram-positive spore-forming bacilli are the Bacillus and Clostridium species ▪ Genus Clostridium • Anaerobic spore-forming bacilli • Members of the genus Clostridium are obligate anaerobic to spore forming bacilli • Found in soil as well as in normal intestinal flora of man and animals • There are both gram-positive and gram-negative species, although the majority of isolates are gram-positive • Produce exotoxin(s) which play an important role in disease production • Pathogenic members include; o Corynebacterium perfringes which causes gas gangrene o Clostridium tetani which causes tetanus o Clostridium botulinum which causes botulism o Clostridium difficile which causes pseudomembraneous colitis o Clostridium perfringes which causes food poisoning and necrotizing enteritis ▪ Genus Bacillus • Consists of aerobic or facultatively anaerobic gram positive spore-forming bacilli • Some may turn Gram negative with age • Most members of the genus bacillus are saprophytic • They are able to survive in harsh environment • They include thermophilic, psychrophilic, acidophilic, alkaliphilic, halotolerant, and halophilic representatives, which are capable of growing at temperatures, pH values, and salt concentrations at which few other organisms could survive • Pathogenic bacteria in this genus include o Bacillus anthracis which causes anthrax o Bacillus cereus which causes bacillus food poisoning • The non–spore-forming gram-positive bacilli are a diverse group of aerobic and anaerobic bacteria o They are grouped into acid-fast bacilli and non-acid fast bacilli o The acid fast bacilli include Mycobacterium and Nocardia ▪ Mycobacterium e.g. Mycobacterium tuberculosis that cause tuberculosis, Mycobacterium leprae that causes leprosy • The non-acid fast bacilli include regular bacteria and pleomorphic bacteria o The regular acid fast bacilli include Lactobacillus and Listeria ▪ Listeria e.g. Listeria monocytogenes which causes meningitis and sepsis o The pleomorphic acid fast bacilli include Corynebacterium and Propionibacterium ▪ Corynebacterium e.g. Corynebacterium diphteriae causes Diphtheria ▪ Propionibacterium acnes is associated with acne vulgaris STEP 4: Classification of Gram Negative Bacilli (15 minutes) • The Gram negative bacilli are grouped into two groups; the aerobic non enteric bacilli and the enteric bacilli • Aerobic Gram-Negative Nonenteric Bacilli o Do not ferment sugars o They include ▪ Pseudomonas e.g. Pseudomonas aeruginosa, a dangerous opportunistic pathogen ▪ Brucella e.g. Brucella species which cause brucellosis ▪ Francicella e.g. Francicella tularensis which causes Tularemia ▪ Bordetella e.g. Bordetella pertussis which cause whooping cough ▪ Legionella e.g. Legionella pneumophilia which causes legionnaire’s disease • Enteric Gram-Negative Bacilli (Enterobacteriaceae) o These are gram negative rods o They ferment glucose with acid production o Reduce nitrates into nitrites o They are oxidase positive o They are catalase positive o They are facultative anaerobic o They are motile except Shigella, Klebsiella, and Yersinia o They are non-capsulated except Klebsiella o They are non-fastidious o They grow on bile-containing agar (MacConkey agar) o Most members are opportunistic or cause secondary infections of wounds, the urinary tract and the circulatory system o They are grouped into two groups ▪ Lactose fermenters e.g. E. coli ▪ Lactose non fermenters e.g. Salmonella, Shigella, Proteus, Yersinia STEP 5: Key Points (5 minutes) • Gram positive bacilli are grouped into spore forming and non spore forming • The spore forming gram positive bacilli are grouped into bacillus and clostridia, all are pathogenic to humans • The non-spore forming are grouped into acid fast and non acid fast • Gram negative bacilli are grouped into two groups namely non enteric gram negative bacilli and the enterics (enterobacteriaceae) • Non enteric gram negative bacilli do ferment any sugar while the enterobacteriaceae ferment a varieties of sugar STEP 6: Evaluation (5 minutes) • What are the features of gram positive bacilli? • List some bacteria that are gram positive bacilli • Mention some diseases caused by gram positive bacilli • Differentiate non enteric gram negative bacilli from the enteric gram negative bacilli References Hugo and Russell (2011), Pharmaceutical Microbiology 8th Edition, Willey- Blackwel publications Karen C. Carroll et al (2013); Jawetz, Melnick and Adelberg’s Medical Microbiology 26th Ed. McGraw Hill Co. Inc. Greenwood et al (2012); Medical Microbiology, 18th edition Churchill Livingstone ← Previous TopicNext Topic →View all Pharmaceutical Microbiology topicsOpen Complete Full Notes PDF / OFFLINE

NTA Level 5 • Semester 1 • PST05103 Neisseria, Gonorrhoea and Meningococcal Meningitis Pharmaceutical Microbiology • Source Session/Topic 12 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 12: Neisseria, Gonorrhoea and Meningococcal Meningitis 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 bacterial diseases (causative agents, transmission, signs and symptoms) • Describe treatment, prevention and control of common bacterial 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 |Presentation |Characteristics of Neisseria | | |minutes | | | |3 |10 minutes|Buzzing/ |Cause and Transmission of | | | |Presentation |Gonorrhoea | |4 | |Small group |Signs and Symptoms of | | |15 minutes|discussion/ |Gonorrhoea | | | |Presentation | | |5 |10 minutes|Brainstorming/ |Treatment, Prevention and | | | |Presentation |Control of Gonorrhoea | |6 | |Presentation |Cause and Transmission of | | |15 minutes| |Meningococcal Meningitis | |7 |10 minutes|Presentation |Signs and Symptoms of | | | | |Meningococcal Meningitis | |8 |20 minutes|Presentation |Treatment, Prevention and | | | | |Control of Meningococcal | | | | |Meningitis | |9 |5 minutes |Presentation |Key Points | | |5 minutes |Presentation |Evaluation | |10 | | | | 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 Neisseria (25 minutes) • The genus Neisseria belongs to the family Neisseriaceae • The typical Neisseriae are gram-negative, nonmotile, kidney-shaped diplococci • The neisseriae grow best under aerobic conditions, but some grow in an anaerobic environment. o Most neisseriae oxidize carbohydrates, producing acid but not gas, and their carbohydrate patterns are a means of distinguishing them ▪ N. gonorrhoeae does not oxidize maltose (only oxidizes glucose) but N. meningitides does o They are oxidase positive • Some neisseriae are normal inhabitants of the human respiratory tract, rarely if ever cause disease, and occur extracellularly • Medically important Neisseria are; o Neisseria gonorrhoeae (gonococci), which causes gonorrhoea o Neisseria meningitidis (meningococci) which causes Meningococcal meningitis o Both are typically found associated with or inside polymorphonuclear cells • Gonococci and meningococci are closely related (70% DNA homology) o Meningococci have polysaccharide capsules but gonococci do not o meningococci rarely have plasmids but most gonococci do o Meningococci typically are found in the upper respiratory tract and cause meningitis, but gonococci cause genital infections STEP 3: Cause and Transmission of Gonorrhoea (10 minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What are the cause and transmission of gonorrhea? | | | |ALLOW few pairs to respond and let other pairs to add on points not | |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | • Gonorrhoea is a sexually transmitted infection (STI) caused by the bacteria Neisseria gonorrhoeae • The disease is transmitted through unprotected sexual intercourse with an infected person and from an infected mother to the baby during delivery • Gonococci attack mucous membranes of the genitourinary tract, eye, rectum, and throat, producing acute suppuration that may lead to tissue invasion • The infection may progress to the epididymis • In women, primary infection is in the endocervix and entends to the urethra and vagina. It may progress to the uterine tubes and cause salpingitis, fibrosis and obliteration of the tubes. Infertility occurs in 20% of women with gonococcal salpingitis STEP 4: Signs and Symptoms of Gonorrhoea (15 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the signs and symptoms of gonorrhoea? | | | |ALLOW few students to respond? | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARIZE by using the content below | • Female are usually asymptomatic but may have the following signs and symptoms; o Most infections are asymptomatic o Cervicitis ▪ Abnormal vaginal discharge, intermenstrual bleeding, dysuria, lower abdominal pain, or dyspareunia ▪ Mucopurulent or purulent cervical discharge, easily induced cervical bleeding ▪ At least 50% of women with clinical cervicitis have no symptoms o Urethritis ▪ Dysuria however, most women are asymptomatic • Ii male Incubation period is commonly 2-5 days and the following are common signs and symptoms; o Typically, purulent or mucopurulent urethral discharge (Yellow, creamy pus from the penis) o Often accompanied by dysuria o Urethral infection in men can be asymptomatic o Symptoms associated with epididymitis ▪ Unilateral testicular pain and swelling ▪ Infrequent, but most common local complication in males ▪ Usually associated with overt or subclinical urethritis • Gonococcal bacteremia leads to skin lesions (especially hemorrhagic papules and pustules) on the hands, forearms, feet, and legs and to tenosynovitis and suppurative arthritis, usually of the knees, ankles, and wrists STEP 5: Treatment, Prevention and Control of Gonorrhoea (10 minutes) • Treatment o Antibiotics ▪ Fluoroquinolones e.g. ciprofloxacin ▪ Cephalosporins e.g. ceftriaxone ▪ Macrolides e.g. Azithromycin or Tetracyclines e.g. doxycycline should be added if chlamydial infection is not ruled out. • Prevention and control o Avoiding multiple sexual partners o Early diagnosis and treatment o Mechanical prophylaxis e.g. condoms o Gonococcal ophthalmia neonatorum is prevented by local application of 0.5% erythromycin ophthalmic ointment or 1% tetracycline ointment to the conjunctiva of newborns STEP 6: Cause and Transmission of Meningococcal Meningitis (15 minutes) • Meningococcal meningitis is a serious bacterial infection that causes inflammation of the layers (meninges)

NTA Level 5 • Semester 1 • PST05103 Pneumonia Pharmaceutical Microbiology • Source Session/Topic 11 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 11: Pneumonia 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 cause of pneumonia (causative agents, transmission, signs and symptoms) • Describe treatment, prevention and control of common bacterial 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 |20 minutes |Brainstorming/|Introduction to Pneumonia | | | |Presentation | | |3 |10 minutes |Presentation |Signs and Symptoms of Pneumonia | |4 |15 minutes |Presentation |Treatment, Prevention and Control | | | | |of Pneumonia | |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: Introduction to Pneumonia (20 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is pneumonia? | | | |ALLOW few students to respond? | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARIZE by using the content below | • Pneumonia causes inflammation in the alveoli of one or both lungs. The alveoli fill with fluid or pus, making it difficult to breathe. • Pneumonia is caused by bacteria, viruses, fungi, aspiration and chemicals (chemical pneumonia) • Bacterial pneumonia is the most common type of pneumonia. o The common causative organisms for pneumonia are bacterial (e.g. Streptococcus pneumoniae, Hemophilus influenza, Staphylococcus aureus, and Mycoplasma pneumoiae) viral or parasitic e.g. Pneumocystis jirovecii o Streptococcal pneumonia is caused by the bacterium Streptococcus pneumoniae • Aspiration pneumonia is lung infection caused by inhaling mouth secretions, stomach contents, or both –these contents usually contain microorganisms • Chemical pneumonitis is lung irritation caused by inhalation of substances toxic to the lungs • Pneumonia can be community acquired or hospital (nosocomial) acquired o Community acquired pneumonia is the type of pneumonia that is acquired outside hospital settings o Hospital acquired (nosocomial) pneumonia is pneumonia that occurs more than 48 hours after hospital admission but that was not incubating at the time of admission. • Pneumonia is transmitted through respiratory droplets, aspiration of particles containing microorganisms into the lungs or inhalation of chemicals into the lungs which cause irritations (and hence inflammation) of the lung tissue • Pneumonia has different clinical presentations in children and in adults • In children pneumonia is classified into no pneumonia, pneumonia and severe pneumonia depending on age, rate of breathing and presence of chest in-drawing STEP 3: Signs and Symptoms of Pneumonia (10 minutes) • The important clinical features are o High fever 39°C o Chills o Dry or productive cough o Central cyanosis o Respiratory distress o Chest pain and tachypnea o Chest in-drawing (in children) STEP 4: Treatment, Prevention and Control of Pneumonia (15 minutes) Treatment • General management o Oxygen therapy o Lowering fever e o Bronchodilators • Medications o Antibiotics ▪ Penicillins • Benzyl penicillin • Ampicillin • Amoxicillin • Cloxacillin ▪ Aminoglycosides • Gentamycin ▪ Other antibiotics • Clindamycin • Chloramphenicol Preventive and control measures • Immunization • Practicing Good hygiene • By avoiding or stopping to smoke STEP 5: Key Points (5 minutes) • Pneumonia causes inflammation in the alveoli of one or both lungs. The alveoli fill with fluid or pus, making it difficult to breathe. • Pneumonia is caused by bacteria, viruses, fungi, aspiration and chemicals (chemical pneumonia) • Streptococcal pneumonia is caused by S. pneumonia STEP 6: Evaluation (5 minutes) • What is pneumonia? • Mention the types of pneumonia • How is pneumonia treated? • How is pneumonia prevented? References Hugo and Russell (2011), Pharmaceutical Microbiology 8th Edition, Willey- Blackwel publications Karen C. Carroll et al (2013); Jawetz, Melnick and Adelberg’s Medical Microbiology 26th Ed. McGraw Hill Co. Inc. Greenwood et al (2012); Medical Microbiology, 18th edition Churchill Livingstone ← Previous TopicNext Topic →View all Pharmaceutical Microbiology topicsOpen Complete Full Notes PDF / OFFLINE NOTES Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP WhatsApp: 255620339260

NTA Level 5 • Semester 1 • PST05103 Pharyngitis Pharmaceutical Microbiology • Source Session/Topic 10 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 10: Pharyngitis 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: • Describe common pharyngitis (causative agents, transmission, signs and symptoms) • Describe treatment, prevention and control of pharingitis 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 |Cause and Transmission Pharyngitis| |3 |15 minutes |Presentation |Signs and Symptoms of Pharyngitis | |4 |15 minutes |Presentation |Treatment, Prevention and Control | | | | |of Pharyngitis | |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: Cause and Transmission of Pharyngitis (15 minutes) • Pharyngitis (or sore throat) is an inflammation of the pharynx involving lymphoid tissues of the posterior pharynx and lateral pharyngeal bands • Pharyngitis can be caused by bacterial, viral and fungal infections as well as noninfectious etiologies such as smoking • Most cases are due to viral infections and accompany a common cold or influenza. • Type A coxsackie viruses can cause a severe ulcerative pharyngitis in children (herpangina), and adenovirus and herpes simplex virus, although less common, also can cause severe pharyngitis • Pharyngitis is a common symptom of Epstein-Barr virus and cytomegalovirus infections. • Group A beta-hemolytic streptococcus or Streptococcus pyogenes is the most important bacterial agent associated with acute pharyngitis and tonsillitis o These bacteria attach the mucosa of the upper respiratory tract STEP 3: Signs and Symptoms of Pharyngitis (15 minutes) • Pharyngitis usually presents with a red, sore, or “scratchy” throat • Discomfort or pain in the throat, especially in the morning • Sensation of foreign body in the throat • An inflammatory exudate or membranes may cover the tonsils and tonsillar pillars o Cough • Vesicles or ulcers may also be seen on the pharyngeal walls • Depending on the pathogen, fever and systemic manifestations such as malaise, myalgia, or headache may be present • Anterior cervical lymphadenopathy is common in bacterial pharyngitis and difficulty in swallowing may be present. STEP 4: Treatment, Prevention and Control of Pharyngitis (15 minutes) • Symptomatic treatment e.g. Paracetamol to control fever is recommended for viral pharyngitis • The exception is herpes simplex virus infection, which can be treated with acyclovir if clinically warranted or if diagnosed in immunocompromised patients • The specific antibacterial agents will depend on the causative organism, but penicillin G is the therapy of choice for streptococcal pharyngitis • Warm saline gargle (especially in the morning) is also useful to sooth and relieve discomfort • Mycoplasma and chlamydial infections respond to erythromycin, tetracyclines and the new macrolides • \Preventive measures include personal hygiene STEP 5: Key Points (5 minutes) • Pharyngitis is an inflammation of the pharynx involving lymphoid tissues of the posterior pharynx and lateral pharyngeal bands • Pharyngitis can be caused by bacterial, viral and fungal infections as well as noninfectious etiologies such as smoking • Group A beta-hemolytic streptococcus or Streptococcus pyogenes is the most important bacterial agent associated with acute pharyngitis and tonsillitis • Pharyngitis usually presents with a red, sore, or “scratchy” throat STEP 6: Evaluation (5 minutes) • What is sore throat? • How is sore throat treated? • How is pharyngitis transmitted? References Hugo and Russell (2011), Pharmaceutical Microbiology 8th Edition, Willey- Blackwel publications Karen C. Carroll et al (2013); Jawetz, Melnick and Adelberg’s Medical Microbiology 26th Ed. McGraw Hill Co. Inc. Greenwood et al (2012); Medical Microbiology, 18th edition Churchill Livingston ← Previous TopicNext Topic →View all Pharmaceutical Microbiology topicsOpen Complete Full Notes PDF / OFFLINE NOTES Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP WhatsApp: 255620339260

NTA Level 5 • Semester 1 • PST05103 Diseases Caused by Staphylococcal infection and Toxin Pharmaceutical Microbiology • Source Session/Topic 9 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 9: Diseases Caused by Staphylococcal infection and Toxin 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: • Describe common bacterial diseases (causative agents, transmission, signs and symptoms) • Describe treatment, prevention and control of common toxin mediated staphylococcal infection 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 | 15 minutes|Presentation |Staphylococcal Food Poisoning | |3 |15 minutes |Presentation |Toxic Shock Syndrome | |4 |15 minutes |Presentation |Signs and Symptoms of Syphilis | |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: Staphylococcal Food Poisoning (15 minutes) • Cause and Transmission o Staphylococcal food poisoning is caused by ingesting food containing a preformed heat-stable staphylococcal enterotoxin o Food can be contaminated by staphylococcal carriers or people with active skin infections o In food that is incompletely cooked or left at room temperature, staphylococci reproduce and elaborate enterotoxin o Many foods can serve as growth media, and despite contamination, they have a normal taste and odor o Common food products are meat, fish, milk or milk products • Signs and Symptoms o Incubation period is 1-8 hours after ingesting contaminated food o Severe nausea and vomiting o Abdominal cramps and diarrhea o Resolves in 24 hours • Treatment and Prevention o Treatment ▪ Symptomatic • Adequate fluids • Rest o Prevention ▪ Refrigeration of food ▪ Hygienic handling of food STEP 3: Toxic Shock Syndrome (15 minutes) • Cause and Transmission o Toxic shock syndrome is a rare, life-threatening complication of certain types of bacterial infections o Often toxic shock syndrome results from toxins produced by Staphylococcus aureus ▪ Staphylococcal Toxic Shock Syndrome (STSS) o Group A streptococci (Streptococcus pyogenes) also produce toxin that causes toxic shock syndrome ▪ Streptococcal toxic shock o Disease occurs following production of exotoxin by the bacteria infecting a wound or colonizing a device or tampon in the body (vaginal tampons or tampon to control nose bleeding) o TSS may also occur following staphylococcal or streptococcal soft tissue infections. The toxin enters bloodstream through skin/mucosal break or via the uterus o Toxic shock syndrome can affect anyone including men, children and postmenopausal women o Women who have preexisting staphylococcal colonization of the vagina and who leave tampons or other devices such as contraceptive sponges or diaphragms in the vagina. o Also, skin wounds and surgery are risk factors for staphylococcal toxic shock syndrome • Signs and Symptoms o Onset of Toxic Shock Syndrome is sudden, with ▪ Fever (39 to 40.5° C, which remains elevated) ▪ Hypotension (which can be refractory) ▪ A diffuse macular erythroderma ▪ Multiple organ dysfunction (involvement of at least 2 other organ systems) o Staphylococcal TSS is likely to cause vomiting, diarrhea, myalgia, mucositis, hepatic damage, thrombocytopenia, and confusion. ▪ Staphylococcal TSS rash is more likely to desquamate, particularly on the palms and soles, between 3 and 7 days after onset o Streptococcal TSS commonly causes acute respiratory distress syndrome (ARDS), coagulopathy, and hepatic damage and is more likely to cause fever, malaise, and severe pain at the site of a soft-tissue infection o Renal impairment is frequent and common to both. The syndrome may progress within 48 h to syncope, shock, and death. Less severe cases of staphylococcal TSS are fairly common • Treatment and Prevention o Local measures ▪ Decontamination • Decontamination includes re-inspection and irrigation of surgical wounds even they appear healthy • Repeated debridement of devitalized tissues • Irrigation of potential naturally colonized sites (sinuses, vagina) o Fluid resuscitation and circulatory support ▪ Fluids and electrolytes are replaced to prevent or treat hypovolemia, hypotension, and shock o Empiric antibiotic therapy ▪ Clindamycin plus vancomycin ▪ Daptomycin ▪ Beta lactamase resistant penicillin e.g. nafcillin, Oxacillin o Preventive measures ▪ Frequent change of tampons ▪ Hygienic wound care ▪ Debridement of infected site STEP 4: Staphylococcal Scalded Skin Syndrome (15 minutes) • Cause and Transmission o Staphylococcal Scalded Skin Syndrome (SSSS) is an acute epidermolysis caused by a staphylococcal toxin o Infants and children are most susceptible o Staphylococcal scalded skin syndrome (SSSS) is caused by coagulase- positive staphylococci which produce a toxin (exfoliatin or epidermolysin) that separate the upper part of epidermis from underlying tissue o The primary infection often begins during the first few days of life in the umbilical stump or diaper area ▪ In older children, the face is the typical site ▪ Toxin produced in these areas enters the circulation and affects the entire skin. • Signs and Symptoms o The initial lesion is usually superficial and crusted o Within 24 hours, the surrounding skin becomes painful and scarlet, changes that quickly spread to other areas o The skin may be exquisitely tender and have a wrinkled tissue paper–like consistency o Large, flaccid blisters arise on the erythematous skin and quickly break to produce erosions o Blisters are frequently present in areas of friction, such as intertriginous areas, buttocks, hands, and feet o Intact blisters extend laterally with gentle pressure (Nikolsky sign) o The epidermis may peel easily, often in large sheets o Widespread desquamation occurs within 36 to 72 hours and patients become very ill with systemic manifestations (e.g. malaise, chills, fever) o Desquamated areas appear scalded o Loss of the protective skin barrier can lead

NTA Level 5 • Semester 1 • PST05103 Staphylococcal and Streptococcal Skin Infections Pharmaceutical Microbiology • Source Session/Topic 8 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 8: Staphylococcal and Streptococcal Skin 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 bacterial diseases (causative agents, transmission, signs and symptoms) • Describe treatment, prevention and control of common staphylococcal and streptococcal 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 | 30 minutes|Presentation |Impetigo | |3 |25 minutes |Presentation |Folliculitis | |4 |20 minutes |Presentation |Farunculosis | |5 |15 minutes |Presentation |Erysipelas | |6 |10 minutes |Presentation |Cellulitis | |8 |10 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: Impetigo (30 minutes) • Cause o Impetigo is a superficial skin infection with crusting or bullae caused by Streptococci, Staphylococci, or both. o Impetigo is commonly caused by Staphylococcus aureus o It affects the subcorneal layer of the epidermis with characteristic honey-colored serous crusts. Ecthyma is an ulcerative form of impetigo o Impetigo commonly occurs in school children, usually starting on the face, especially around the mouth or nose o Impetigo may be bullous or nonbullous ▪ Staphylococcus aureus is the predominant cause of nonbullous impetigo and the cause of all bullous impetigo ▪ Bullae are caused by exfoliative toxin produced by staphylococci • Signs and Symptoms o Nonbullous impetigo typically manifests as clusters of vesicles or pustules that rupture and develop a honey-colored crust (exudate from the lesion base) over the lesions o Bullous impetigo is similar except that vesicles typically enlarge rapidly to form bullae. The bullae burst and expose larger bases, which become covered with honey-colored varnish or crust o Ecthyma is characterized by small, purulent, shallow, punched-out ulcers with thick, brown-black crusts and surrounding erythema o Impetigo and ecthyma cause mild pain or discomfort o Pruritus is common, scratching may spread infection, inoculating adjacent and nonadjacent skin • Management o Remove crusts ▪ Washing with water and soap o Wet dressings with; ▪ Potassium permanganate 1:40000 (0.025%) solution ▪ 0.5% GV paint o Topical therapy (Mupirocin 2%, Fusidic acid, Retapamulin o Systemic antibiotics (if systemic symptoms e.g. pyrexia are present) ▪ Penicillins ▪ Macrolides • Main preventive measure is personal hygiene STEP 3: Folliculitis (25 minutes) • Cause o It is the inflammation of the hair follicle which may be caused by bacteria, fungi, viruses or parasites. o Bacterial folliculitis is usually caused by Staphylococcus aureus and occasionally Pseudomonas aeruginosa ▪ The bacteria enter the hair follicle and cause inflammation • Signs and Symptoms o Mild pain, pruritus, or irritation o Superficial pustule or inflammatory nodule surrounding a hair follicle o Infected hairs easily fall out or are removed, but new papules tend to develop o Deep follicular inflammation often occurs in the bearded areas of the face (Sycosis barbae) • Management o Avoiding suspected irritants o Antiseptics o Topical antibiotics (Neomycin, gentamycin, tetracyclines or mupirocin) o Systemic antibiotics (in systemic manifestations) ▪ Penicillinase resistant penicillins ▪ Clindamycin (topical –lotion or gel) ▪ Cephalosporins • Cephalexin • Main preventive measure is personal hygiene STEP 4: Furunculosis (20 minutes) • Cause and Manifestations o Farunculosis is deep follicular infection that starts as a firm red nodule which rapidly becomes painful and fluctuant in a few days o Furunculosis form furuncles (or boils) that are skin abscesses caused by staphylococcal infection. o Furuncles involve a hair follicle and surrounding tissue o A cluster of furuncles forms a carbuncle. Carbuncles are clusters of furuncles connected subcutaneously, causing deeper suppuration and scarring. o Furuncles are common on the neck, breasts, face, and buttocks o They are uncomfortable and may be painful when closely attached to underlying structures (e.g., on the nose, ear, or fingers) o Appearance is a nodule or pustule that discharges necrotic tissue and sanguineous pus. Carbuncles may be accompanied by fever and prostration • Management o Usually resolves spontaneously, but improved by placing hot compresses over the boil until it breaks o Incision and drainage o Antibiotics (those effective against MRSA) ▪ Clindamycin ▪ Linezolid ▪ Daptomycin ▪ Flucloxacillin ▪ Macrolides e.g. erythromycin STEP 5: Erysipelas (15 minutes) • Cause and Manifestations o Erysipelas is a bacterial infection of upper half of dermis with lymphatic vessel involvement, caused by Group A β-haemolytic Streptococci (rarely by Group C, G and B) o The disease occurs most frequently on the legs and face o Erysipelas begins as a small break in the skin or umbilical stump (infants) o The affected area has growing redness, accompanied by high fever and pains o Erysipelas is characterized clinically by; ▪ Shiny, raised, indurated, and tender plaques with distinct margins ▪ High fever, chills, and malaise • Management o Rest o Lifting affected part o Antiseptics ▪ Potassium permanganate solution 1:4000 o Topical antibiotics ▪ Mupirocin o Systemic antibiotics ▪ Penicillins • Phenoxymethylpenicllin • Amoxycillin ▪ Macrolides • Erythromycin o In recurrent erysipelas treatment should be prolonged (10 to 14 days) STEP 6: Cellulitis (10 minutes) • Cause o Cellulitis is acute bacterial infection of the skin and subcutaneous tissue most often caused by streptococci (S. pyogenes) or staphylococci (S. aureus) o Cellulitis is a deep inflammation and involves lower half of dermis and subcutaneous tissue o Cellulitis differ from erysipelas by; ▪ Raised, sharply demarcated margins from uninvolved skin ▪ Indistinct borders – acute cellulitis and accompanied with systemic symptoms • Signs and Symptoms

NTA Level 5 • Semester 1 • PST05103 Introduction to Streptococci Pharmaceutical Microbiology • Source Session/Topic 7 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 7: Introduction to Streptococci 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: • List characteristic of the medical Staphylococci 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|Buzzing/ |Characteristics of Streptococci | | | |Presentation | | |3 |15 minutes |Presentation |Classification of Streptococci | |4 |5 minutes |Presentation |Human Streptococcal Pathogens | |5 |10 minutes |Presentation |Epidemiology and Pathogenesis of | | | | |Streptococcal Infections | |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 Streptococci (15 minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What are the characteristics of Streptococci? | | | |ALLOW few pairs to respond and let other pairs to add on points | |not mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | • Streptococci belong to the genus Streptococcus • Streptococci are Gram positive, non motile, non spore forming cocci that grow in pairs or in chains • They lose their Gram-positive character as the culture grow old • Most are facultative anaerobic but some are obligate anaerobic • Most require enriched media (e.g. blood agar) for their growth • All Streptococci are catalase negative (this distinguish them from Staphylococci which are catalase positive) i.e. Streptococci cannot break down hydrogen peroxide • Streptococci exhibit various degree of red blood cells haemolysis. o Complete haemolysis –β-haemolytic streptococci o Partial haemolysis –α-haemolysis o No haemolysis –γ-haemolysis STEP 3: Classification of Streptococci (15 minutes) • Based on Haemolysis of red blood cells o Three different types of streptococci are initially differentiated by their appearance when they are grown on sheep blood agar ▪ β-haemolytic streptococci • Produce zones of clear haemolysis around each colony ▪ α-haemolytic streptococci • produce partial haemolysis or show green discoloration resulting from incomplete haemolysis ▪ γ-haemolytic streptococci (also known as the Viridans Streptococci) • they are non-haemolytic. • Based on the presence of a specific carbohydrate in their cell wall, streptococci are subsequent classified into Lancefield groups A through H and K through T • Viridans streptococci form a separate group that is difficult to classify by the Lancefield grouping method • In the Lancefield classification, enterococci were initially included among the group D streptococci but now have been classified as a separate genus [pic] Refer students to Figure 9.1: Medically important Streptococci for detailed information on the classification of various Streptococci into Lancefield classification STEP 4: Human Streptococcal Pathogens (5 minutes) • Various members of the Streptococci are normal flora of humans and other animals • Some Streptococci are pathogenic to humans causing acute and chronic diseases • Some pathogenic Streptococci include; o Streptococcus pyogenes o Streptococcus pneumoniae o Streptococcus agalactiae -causes neonatal disease o Viridans streptococci ▪ S. sanguis ▪ S. mutans ▪ S. milleri STEP 5: Epidemiology and Pathogenesis of Streptococcal Infections (10 minutes) • Pathogenic Streptococci cause diseases that range from subacute to acute or even chronic • In humans, diseases associated with the streptococci occur chiefly in the respiratory tract, bloodstream, or as skin infections • Most significant human diseases caused by streptococci are scarlet fever, rheumatic heart disease, glomerulonephritis, and pneumococcal pneumonia • The most significant streptococcal pathogen is S. pyogenes, which is beta-hemolytic and in Lancefield group A and is thus denoted as group A beta-hemolytic streptococci (GABHS)???? o The most common acute diseases due to GABHS are ▪ Pharyngitis (or sore throat) ▪ Skin infections such as impetigo, cellulitis and necrotising fasciitis o In addition, delayed, nonsuppurative complications (rheumatic fever, acute glomerulonephritis) sometimes occur ≥ 2 weeks after infection • Disease caused by other streptococcal species is less prevalent and usually involves soft-tissue infection or endocarditis (Some non-GABHS infections occur predominantly in certain populations (e.g. group B streptococci in neonates and postpartum women) • GABHS can spread through the affected tissues and along lymphatic channels (causing lymphangitis) to regional lymph nodes (causing lymphadenitis) • GABHS can also cause local suppurative complications, such as peritonsillar abscess, otitis media, sinusitis, and bacteremia • Suppuration depends on the severity of infection and the susceptibility of tissue. • Other serious GABHS infections include septicemia, puerperal sepsis, endocarditis, pneumonia, and empyema • Streptococcal infections are transmitted through contact, droplets, food or formites • Portal of entry for the infections are generally the skin or pharynx • Children are predominantly affected for cutaneous and throat infections • Systemic infections and progressive sequela are possible if local infections are left untreated STEP 6: Key Points (5 minutes) • Streptococci are gram positive spherical bacteria (cocci) that occur in chain • Streptococci are catalase negative • Streptococci are classified by their ability to haemolyse red blood cells and presence of specific carbohydrate in their cell walls • Pathogenic streptococci cause a variety of infections due to direct invasion of tissues and toxin-mediated infections • Many skin infections caused by Streptococci are also caused by Staphylococci. STEP 7: Evaluation (5 minutes) • How are streptococci classified? • How do streptococci differ from staphylococci? Figure 9.1: Medically important Streptococci [pic] Source: Medical Microbiology. 4th edition. Baron S, editor. Galveston (TX): University of Texas

NTA Level 5 • Semester 1 • PST05103 Introduction to Staphylococci Pharmaceutical Microbiology • Source Session/Topic 6 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 6: Introduction to Staphylococci 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: • List characteristic of the medical Staphylococci 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 |Characteristics of Staphylococci | |3 |10 minutes |Presentation |Human Staphylococcal Pathogens | |4 |20 minutes |Presentation |Epidemiology and Pathogenesis of | | | | |the Staphylococci | |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: Characteristics of Staphylococci (15 minutes) • Staphylococcus is a genus of Gram-positive spherical bacteria (cocci) which grow in grape-like clusters • Staphylococci are catalase positive (this distinguishes them from Streptococci which are catalase negative). The enzyme catalase breaks down hydrogen peroxide into water and oxygen. • Staphylococci are widely distributed; some are normal flora while others are pathogenic to humans causing many forms of infections. • Staphylococcus aureus colonizes the nasal passage and axillae while Staphylococcus epidermidis is a common human skin commensal. Other species of staphylococci are infrequent human commensals and other animals. • Staphylococci are salt tolerant and often hemolytic • S. aureus and Staphylococcus intermedius are coagulase positive. Coagulase enzyme clots blood plasma • All other staphylococci are coagulase negative STEP 3: Human Staphylococcal Pathogens (10 minutes) • Most staphylococci are not pathogenic to humans • Human pathogens include; o S. aureus ▪ which is the most pathogenic of the staphylococci ▪ leading cause of nosocomial infections o S. epidermidis ▪ Causes infections of prosthetic heart valves and hips ▪ It is a common member of the skin normal flora o S. saprophyticus ▪ Which causes urinary tract infection STEP 4: Epidemiology and Pathogenesis of the Staphylococci (20 minutes) • Infections caused staphylococci include; o Skin infections, pneumonia, endocarditis, osteomyelitis and septic arthritis which are due to direct tissue invasion by the bacteria o Toxic shock syndrome, staphylococcal scalded skin syndrome, staphylococcal food poisoning which are toxin-mediated • S aureus causes many forms of infection in humans; o Superficial skin lesions (boils, styes) and more serious skin infections e.g. furunculosis o Toxin-mediated infections e.g. food poisoning o Localized abscesses o Deep-seated infections, such as osteomyelitis and endocarditis • S. aureus expresses many potential virulence factors o Surface proteins that promote colonization of host tissues o Factors that probably inhibit phagocytosis e.g. capsule, immunoglobulin binding protein o Toxins that damage host tissues and cause disease symptoms • Coagulase-negative staphylococci are normally less virulent and express fewer virulence factors o S. epidermidis are skin normal flora that readily colonize implanted devices e.g. prosthetic heart valves • Pathogenic staphylococci are transmitted by shedding from human lesions and contaminated formites such as clothing and bed linens. Heavily contaminated environment and compromised immunity favour infection by members of the genus • Manifestations of disease caused by Staphylococci are inflammatory and toxin-mediated o Inflammatory manifestations range from superficial skin lesions to deep osteomyelitis to septicaemia • Multiple antibiotic resistance is increasingly common in S. aureus and S epidermidis • Methicillin resistance indicates multiple resistance • Methicillin-resistant S aureus (MRSA) causes outbreaks in hospitals and can be epidemic • Infections acquired outside hospitals can usually be treated with penicillinase-resistant β-lactams • Hospital acquired infections are often caused by antibiotic resistant strains and can only be treated with vancomycin STEP 5: Key Points (5 minutes) • Staphylococci can cause many forms of infection • Staphylococci are Gram-positive cocci 1μm in diameter and grown in grape-like clusters • Staphylococci are catalase positive • S. aureus and S. intermedius are coagulase positive while all other staphylococci are coagulase negative STEP 6: Evaluation (5 minutes) • Mention four characteristics of staphylococci • S. causes which diseases in humans? • How are staphylococcal infections acquired? References Hugo and Russell (2011), Pharmaceutical Microbiology 8th Edition, Willey- Blackwel publications Karen C. Carroll et al (2013); Jawetz, Melnick and Adelberg’s Medical Microbiology 26th Ed. McGraw Hill Co. Inc. Greenwood et al (2012); Medical Microbiology, 18th edition Churchill Livingstone ← Previous TopicNext Topic →View all Pharmaceutical Microbiology topicsOpen Complete Full Notes PDF / OFFLINE NOTES Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP WhatsApp: 255620339260

NTA Level 5 • Semester 1 • PST05103 External structures and drug targets in prokaryotic cells Pharmaceutical Microbiology • Source Session/Topic 5 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 5: External structures and drug targets in prokaryotic cells 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 the structure of a bacterial cell • List functions of different bacterial organelles/structures • Describe various drug targets in the bacterial cell 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 |50 minutes |Presentation |External structures of prokaryotic| | | | |cells | |3 |25 minutes |Presentation |Drug Targets in Bacterial Cell | | | | |Wall | |4 |30 minutes |Presentation |Acid fast Bacilli | |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: Bacterial External Structures and Drug Targets (50 minutes) • Bacterial External Structures o External structures include the cell wall and structures external to it • Bacterial Cell wall o A cell wall is a layer located outside the cell membrane found in plants, fungi, bacteria, algae, and archaea. o The bacterial cell wall is a rigid structure outside the cell membrane (and inner to the capsule for capsulated bacteria) composed of peptidoglycan layers making up a cell envelope around the cell o Peptidoglycan is composed of disaccharides and amino acids which gives structural support to the bacteria o Peptidoglycan is unique to bacteria Figure 5.1: Structure of Peptidogycan [pic] ▪ Molecules making up the peptidoglycan include; • Alternating NAM and NAG chains • A tetrapeptide chain • A petaglycin chain [pic] o Bacteria are classified as being either Gram-positive or Gram- negative based in differences in the structure of their peptidoglycan cell wall o Gram-positive bacteria are stained dark blue or violet by Gram staining o In Gram-positive bacteria, the cell wall is thick and consists of several layers of peptidoglycan o Gram negative bacteria lack the outer membrane envelope found in Gram-negative bacteria ▪ They contain teichoic acids in the peptidoglycan. • Teichoic acids are unique to the Gram-positive cell wall • Teichoic acids are linear polymers of polyglycerol or polyribitol substituted with phosphates and a few amino acids and sugars ▪ immune response when the bacteria infect animals o Functions of the bacterial cell wall; ▪ To enclose and protect the internal structures ▪ To protect the bacteria from osmotic lysis ▪ Provide shape to the bacteria • Structures external to the cell wall include; ▪ Flagella • Flagella are long protein filaments of uniform length that are responsible for cell motility • They are whip-like structure that allows a cell to move • Types and examples of flagella o Monotrichous –Single polar flagellum e.g. Vibrio cholerae o Amphitrichous –Single flagellum on both sides e.g. Alkaligens faecalis o Lophotrichous –Tufts of flagella at one or both sides e.g. Spirillum o Peritrichous–Numerous flagella all over the bacterial body ▪ Pili • Pili (singular: pilus) are hair-like appendages found on the surface of some bacteria. They are made up of proteins called pilins • Pilli are classified into Ordinary pili or Sex pili according to their morphology, distribution, and function • The pilus is found on the surface of many gram-positive bacteria and some gram-negative bacteria • Pili function as adhesive factors for mucosal surface attachment ▪ Capsule • A capsule is a discrete detectable layer of polysaccharides deposited outside the cell wall • Capsule is attached tightly to the bacterium and has definite boundaries • Capsules are considered virulence factors because they protect a bacterial cell from ingestion and destruction by white blood cells (phagocytosis) ▪ Slime layer • • A slime layer in bacteria is an easily removable (e.g. by centrifugation), unorganized layer of extracellular material that surrounds bacteria cells • A slime layer is loosely associated with the bacterium and can be easily washed off • The slime layer is usually composed of polysaccharides and it may serve to trap nutrients, to aid in cell motility, to bind cells together or to adhere to smooth surfaces STEP 3: Drug Targets in Bacterial Cell Wall (25 minutes) • Cell Biosynthetic Enzymes o Fosfomycin o Cycloserin • Carrier Molecules o Bacitracin • Cell wall substrates o Vancomycin • Enzymes that Catalyse Crosslinking of peptidoglycan subunits (Transpeptidases) o Penicillins o Cephalosporins o Carbapenems o Monobactams STEP 4: Acid-fast Bacteria (30 minutes) • Acid-Fast Bacteria possess a unique cell wall architecture different from both gram negative and gram positive bacteria • The Acid-Fast cell wall consists of a thick, outer lipid-rich layer composed primarily of the fatty acid "Mycolic Acid" • This lipid layer lies on top of a layer of peptidoglycan and the sugar arabinogalactan which in turn invest the inner lipid membrane common to all bacteria • The thick outer mycolic acid layer renders acid-fast bacteria resistant to gram stain. • When stained with alternative dyes, the cell wall is resistant to decolorization with acid alcohol, thus their name "Acid-Fast” • The cell wall is characterized by; o A thin layer of peptidoglycan [pic] • Function of the Cell wall components of Acid-fast bacilli o The peptidoglycan prevents osmotic lysis o The arabinogalactan layer is linked to both the peptidoglycan and to the mycolic acid outer membrane and probably provides additional strength to the cell wall o The mycolic acids and other glycolipids also impede the entry of chemicals causing the organisms to grow slowly and be more

NTA Level 5 • Semester 1 • PST05103 Internal structures and drug targets in prokaryotic cells Pharmaceutical Microbiology • Source Session/Topic 4 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 4: Internal structures and drug targets in prokaryotic cells 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 the structure of a bacterial cell • List functions of different bacterial organelles/structures • Describe various drug targets in the bacterial cell 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 |80 minutes |Group |Description of Internal Structures| | | |discussion/ |of Bacteria | | | |Presentation | | |3 |25 minutes |Presentation |Drug Targets | |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: Internal Structures of Prokaryotic Cells (80 minutes) • Bacteria are one group of prokaryotes, the other group is the archaea • Bacterial structure can be described in terms of external and internal structures • Internal structures of bacterial cells are those internal to the cell wall • The bacterial cell wall and its associated structures comprise the external structures of the bacterial cell |Activity: Small Group Discussion (40 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |Draw a labeled diagram showing internal structures of a bacterial | |cell | |List the function(s) of each of the labeled structure | | | |ALLOW students to discuss for 30 minutes | | | |ALLOW few groups to present and the rest to add points not | |mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • The internal structure of a prokaryotic cell consists of the cytoplasm which contains enzymes needed for metabolic reactions. [pic] Source: https://www.slideshare.net/mdsalaadx1/anatomy-and-physiology- of-bacteria The Cytoplasm • The cytoplasm is an aqueous thick fluid enclosed by the cell membrane • It is made up of 80% water, and proteins (enzymes), carbohydrates, lipids, inorganic ions and many low-molecular-weight compounds • Fills the cell and it is where most cellular reactions and activities take place • It is the internal environment of the cell The cell membrane • The cell membrane is located immediately beneath the cell wall • The cell membrane is a thin membrane around the cytoplasm • The cell membrane is also called the cytoplasmic membrane or plasma membrane • It contains phospholipids, proteins and polysaccharides • The cell membrane is a vital structure and critical barrier that separates the inside of the cell from the outer environment • The gram positive bacteria have one plasma membrane while the gram negative bacteria have two plasma membranes –one is internal and the second is known as an outer membrane separated from the inner membrane by the periplasmic space Figure 4.1: Cell membrane in Gram positive and Gram negative bacteria [pic] • Functions of plasma membrane; o The plasma membrane retains the cytoplasm, particularly in cells without cell walls, and separates it from the surroundings o Plasma membranes serve as a selectively permeable barrier; it allows particular ions and molecules to pass, either into or out of the cell, while preventing the movement of others o Transport systems can be used for such tasks as nutrient uptake, waste excretion, and protein secretion o The plasma membrane also is the location of a variety of crucial metabolic processes; respiration, photosynthesis, the synthesis of lipids and cell wall constituents, and probably chromosome segregation. Mesosomes • In gram positive bacteria, the plasma membrane forms in folding • The infolding form structures called mesosomes within cytoplasm • The mesosomes are associated with bacterial nuclear material and its replication • Respiratory enzymes are also associated with mesosomes • Functions of mesosomes o They are imvolved in cell wall formation during cell division. o They play a role in replication of chromosome and distribution to daughter cells. o They are also involved in secretary processes Nucleoid • Nucleoid is an area within the cytoplasm of a prokaryotic cell where DNA is located • It is equivalent to the nucleus in eukaryotic cells • It is not enclosed in a membrane i.e. no nuclear membrane (not a true nucleus) but it is visibly separate from the rest of the cell interior. • The bacterial DNA is single-stranded, circular and haploid Plastids • Prokaryotic cells do not have mitochondria or chloroplast o The electron transport enzymes are located in the cytoplasmic membrane o Photosynthetic pigments (Carotenoids, bacterial chlorophyll) of photosynthetic bacteria are located below the cell membrane o In some Cyanobacteria (blue-green algae), the photosynthetic structures are called Thylakoids o Thylakoids contain light harvesting pigments called phycobilins o Plastids provide energy for the prokaryotic cell as well as carrying out photosynthesis process in cyanobacteria Inclusion or storage granules • Inclusion granules are storage structures within the bacterial cytoplasm • There are several types of storage granules for nutrients in prokaryotic cells o i.e. they serve as energy and nutrient reservoirs • Nutrients may be stored in the cytoplasm in the form of lipids, glycogen, polyphosphate (and sometimes sulphur (volutin granules) or nitrogen • When source of nitrogen, sulphur, or phosphorus is limited or when pH is low, excess CO2 in the medium may be converted to “Poly-β- hydroxybutric acid, starch and glycogen which are used as energy sources Endospores • Some bacteria (e.g. Clostridium) form spores that are very resistant to drought, high temperatures and other hazards of