1. Neisseria

2.  Aerobic  Gram-negative cocci often arranged in pairs (diplococci)  Oxidase positive  Most catalase positive  Nonmotile General Characteristics of Neisseria spp.

3. Neisseria gonorrhoeae Neisseria meningitidis Important Human Pathogens

4. Neisseria Associated Diseases (ophthalmia neonatorum)

5. Neisseria gonorrhoeae (gonococcus)

6. Gonorrhea Sexually transmitted disease Infection Rate depends on – socioeconomic class – Age Increasing antibacterial resistance Transferred from mother to infant through infected birth canal

7. Neisseria gonorrhoeae in Urethral Exudates

8. Epidemiology of Gonorrhea  Seriously underreported sexually-transmitted disease 350,000 reported cases in USA in 1998 Down from 700,00 cases in 1990  Found only in humans with strikingly different epidemiological presentations for females and males  Asymptomatic carriage is major reservoir  Transmission primarily by sexual contact  Lack of protective immunity and therefore reinfection, partly due to antigenic diversity of strains

9. IN MEN:  Urethritis; Epididymitis  Most infections among men are acute and symptomatic with purulent discharge & dysuria (painful urination) after 2-5 day incubation period  The two bacterial agents primarily responsible for urethritis among men are N. gonorrhoeae and Chlamydia trachomatis Differences Between Men & Women with Gonorrhea

10. Differences Between Men & Women with Gonorrhea (cont.) IN WOMEN:  Cervicitis; Vaginitis; Pelvic Inflammatory Disease (PID)  Women often asymptomatic or have atypical indications.serious complication in case of untreated infection ranging from PID complications to infertility  Pelvic Inflammatory Disease (PID) May also be asymptomatic, but difficult diagnosis accounts for many false negatives Can cause irreversible damage (scarring ) of fallopian tubes leading to infertility or ectopic pregnancy (egg trapped in fallopian tube and fetus begin to develop here)

11. FemalesMales 50% risk of infection after single exposure 20% risk of infection after single exposure Asymptomatic infections frequently not diagnosed Most initially symptomatic (95% acute) Genital infection primary site is cervix (cervicitis), but vagina, urethra, rectum can be colonized Genital infection generally restricted to urethra (urethritis) with purulent discharge and dysuria Ascending infections in 10-20% including salpingitis, tubo-ovarian abscesses, pelvic inflammatory disease (PID), chronic infections can lead to sterility Rare complications may include epididymitis, prostatitis, and periurethral abscesses Disseminated infections more common, including septicemia, infection of skin and joints (1-3%) Disseminated infections are very rare Gonorrhea

12. Gonoccocal Infectious process The life cycle of Neisseria gonorrhoeae consists of five primary stages: Entry – The bacterium invade the mucous membrane of the contacted tissue. Attachment – The bacterium attach to the microvillus of epithelial cells, which will act as the host throughout the multiplication process of this infection. Endocytosis – Vacuoles are formed as the bacterium are engulfed by the host cell’s membrane by way of endocytosis. Transportation – These infected vacuoles directly transport the bacterium to a place where it can safely multiply—the bottom membrane of the host cell. Accumulation and Self-Defense –After the infected mucous membrane dies, the accumulated bacterium will inhabit the dead connective tissue and secrete a serum that reduces antibody activity, further lowering the body’s ability to fight against the infection.

14. Infection N. gonorrhoeae attaches to mucosal cells via pili and other surface proteins Induces production of inflammatory cytokines by epithelial cells http://www.brown.edu/Courses/Bio_160/Projects1999/av/gonorrhea.html

15. If left untreated, the infection as well as the inflammation can spread and become so severe as to cause pelvic inflammatory disease. The bacteria may be engulfed and killed by a macrophage, but most will evade the macrophage through antigenic variation strategies. The yellowish pus associated with gonococcal infection is a result of the macrophage killing.

16. Diagnosis not easy Three levels of diagnosis are defined on the basis of clinical findings or the results of laboratory diagnostic tests. A definitive diagnosis of gonorrhoea must be obtained for medico-legal purposes.

17. Diagnosis of Gonorrhoea Suggestive diagnosis is defined by the presence of: A mucopurulent endocervical or urethral exudate on physical examination and sexual exposure to a person infected with N. gonorrhoea.

18. Presumptive diagnosis of gonorrhoea is made on the basis of one of the following three criteria: Typical gram-negative intracellular diplococci on microscopic examination of a smear of urethral exudate from men or endocervical secretions from women*; Growth of a gram-negative, oxidase-positive diplococcus, from the urethra (men) or endocervix (women), on a selective culture medium, and demonstration of typical colonial morphology, positive oxidase reaction, and typical gram- negative morphology;

19. Definitive diagnosis of gonorrhoea requires: Confirmation of isolates by biochemical, enzymatic, serologic, or nucleic acid testing e.g., carbohydrate utilization, rapid enzyme substrate tests, serologic methods such as coagglutination or fluorescent antibody tests supplemented with additional tests that will ensure accurate identification of isolates, or a DNA probe culture confirmation technique.

20. Screening “Gold Standard” – Nucleic acid amplification assays Polymerase chain reaction Cell culture to confirm diagnosis – Oxidase positive