1. Chapter 30 “Don’t eat chocolate agar!”
Neisseria
Chapter 30
“Don’t eat chocolate agar!”

2. Neisseria 2 important species: Neisseria gonorrhoeae
Neisseria meningitidis
Gram -, diplococci
Figure 30-1
Virulence factors – Table 30-1

3. Gonorrhea Primary site of infection Boxes 30-2 and 30-4
Males – urethra (Fig. 30-2)
Purulent discharge, dysuria,
2-5 day incubation
95% of men show symptoms
Females – cervix
Can progress to PID in 10-20% of women
Vaginal discharge, dysuria, abdominal pain
Only ~50% of women show symptoms
Boxes 30-2 and 30-4

4. Disseminated Gonococcal Infection
In a few persons, the organism gains access to the blood stream and spreads throughout the body. This serious complication is characterized by elevated temp., joint pain, multiple small abscesses in the skin, and sometimes infections of the joints, tendons, heart valves, and meninges
Fig 30-3

5. Other N. gonorrhoeae Syndromes
Purulent conjunctivitis, particularly in newborns infected during vaginal delivery (ophthalmia neonatorum—Fig 30-4)

6. Meningitis Site of infection Symptoms Meninges Headache Fever
Confused/Disoriented/Agitated
May lead to neurologic damage, hearing problems, and arthritis

7. Meningococcemia Site of infection Symptoms Blood stream
Thrombosis of small blood vessels
Multiple organ involvement
Small skin lesions (Fig 30-5)
Shock as a result of disseminated intravascular coagulation with destruction of adrenal glands

8. Epidemiology of Gonococci
Gonorrhea occurs only in humans; there is no other reservoir
Major reservoir is asymptomatically infected person
Second to chlamydia as most commonly reported STD in US
Rates in males and females are equal
Highest in southeastern US

9. Epidemiology cont. Occurs most often between ages of 15-24
Decreased between ’75-’98 but has leveled out since then; 310,000 new cases were reported in 2004
It is believed by officials that an accurate measure would double this number

10. Epidemiology cont.
Women have a 50% chance of becoming infected per single exposure
As many as half of infected women are asymptomatic
Men have approximately 20% chance of becoming infected
Most men (95%) are symptomatic

11. Epidemiology of Meningococci
Endemic throughout the world
Epidemics commonly occur in developing countries as a result of introducing a new virulent strain
Transmitted by respiratory droplets among people in prolonged close contact
Carriage is typically transient
Humans are only natural carriers

12. Other Facts About Meningococcal
Total of 1254 cases of meningococcal disease were reported in the US in 2004
Most were meningitis
Mortality approaches 100% without treatment, but is less than 10% in patients who quickly receive appropriate antibiotic treatment

13. Laboratory Diagnosis-Gonorrhea
Gram stain is effective in men with purulent discharge
Not quite as effective in asymptomatic men
Difficult to use as proof of infection in women; depends on the skills of the microscopist
Must be proven by culture

14. Laboratory Diagnosis-Meningitis
Easily seen by stain of cerebrospinal fluid (Fig 30-6)
Unlike most bacteremia, meningococcal bacteremia has enough cells in the blood to identify

15. Treatment Prevention and Control
Penicillin is no longer used for Gonorrhea due to resistance
Beta-lactamase—plasmid transfer of genes
Mutations in penicillin-binding proteins and cell wall permeability
Ciprofloxacin resistance is common in Asia, the Pacific Islands, California, and in the male homosexual population in some US cities

16. Treatment Prevention and Control
N. meningitidis is susceptible to penicillin

17. Vaccine For Gonorrhea? Multiple infections are still common
Variability in POR proteins, LOS, and Pili antigens make it difficult to create a vaccine
There is antigenic diversity among strains
Protection for infants against eye infections
1% silver nitrate, 1% tetracycline, or .5% erythromycin