NTA Level 5 • Semester 1 • PST05103

Neisseria, Gonorrhoea and Meningococcal Meningitis

Pharmaceutical Microbiology • Source Session/Topic 12

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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

|2 | 25 |Presentation |Characteristics of Neisseria |

|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) that covers the brain and spinal

cord.

• The disease is caused by the bacterium Neisseria meningitidis

• Humans are the only natural hosts for whom meningococci are pathogenic

• N. meningitidis is transmitted through respiratory droplets

• The bacteria enter through the nasopharynx attach to epithelial cells

(by using pili)

• From the nasopharynx, organisms may reach the bloodstream, producing

bacteremia and produce symptoms which may be similar to those of an

upper respiratory tract infection

• Fulminant meningococcemia is more severe and lead to disseminated

intravascular coagulation and circulatory collapse (Waterhouse-

Friderichsen syndrome)

• Other causes of bacterial meningitis include Haemophilus influenza

type b and Streptococcus pneumoniae

STEP 7 Signs and Symptoms of Meningococcal Meningitis (10 minutes)

• Signs and symptoms include;

o Headache, high fever

o Nausea and vomiting

o Photophobia

o Neck stiffness (rigidity of the neck muscles)

o Confusion, convulsions, coma

• In infants under 1year diagnosis is much more difficult but may

present with;

o Refusal to eat and or suckle

o Drowsiness and weak cry

o Focal or generalized convulsions

o Fever may be absent

o Irritability

o Hypotonia, neck is often not stiff

o Bulging fontanel

STEP 8: Treatment, Prevention and Meningococcal Meningitis (20 minutes)

• Supportive therapy

o Control of fever and pain

o Control convulsions

• Pharmacological management

o Either of the following antibiotics

▪ Chloramphenicol

▪ Penicillins e.g. Benzyl penicillin G, ampicillin, meropenem

▪ Cephalosporins e.g. ceftriaxone, cefpodoxime, cefepime,

cefotaxime

o Combination of antibiotics is also used especially where

identification of the causative agent is not done for bacterial

meningitis

STEP 9: Key Points (5 minutes)

• The Neisseriae are gram-negative, nonmotile, kidney-shaped diplococci

• 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

• Some neisseriae are normal inhabitants of the human respiratory tract,

rarely if ever cause disease, and occur extracellularly

• Medically important Neisseria are Neisseria gonorrhoeae (gonococci),

which causes gonorrhoea and Neisseria meningitidis (meningococci)

which causes Meningococcal meningitis

STEP 10: Evaluation (5 minutes)

• What is bacterial meiningitis?

• What is the causative agent for meningococcal meningitis?

• How is gonorrhoea transmitted?

• What are the treatment options for gonorrhoea?

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

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