Neisseria

Neisseria gonorrhoeae (gonococcus):
Important properties:
• Gram negative cocci in pairs (diplococci) and kidney shape.
• It is non-capsulated.
• It is non-motile bacteria.
• Aerobic or facultative anaerobes.

Antigenic structure and Virulence factors:
• Endotoxin is lipooligosaccharide(LOS). The toxicity of gonococcal infections is largely due to endotoxic LOS effect.
• IgA protease: it mediates attachment to cells by hydrolysis of IgA at mucous membranes.
Source and transmission :
• Natural habitat is genital tract of human only(obligate human pathogen).
• The organism is usually transmitted from person to person by sexual contact.
• Also the organism can be transmitted from infected mother to her newborn during birth.

Diseases and clinical findings:
1. Venereal diseases (VD):.
a-Genital VD(gonorrhea):
GC causes gonorrhoea (means flow of semen) after I.P 1-2 days:
• In males are characterized by urethritis with yellow and creamy pus (purulent discharge) , and painful urination with accompanied by dysuria. The process may extend to prostate and epididymis. Untreated infection, fibrosis occurs, sometime leading to urethral stricture and infertility.
• In females , the primary infection is in endocervix and extends to urethra (urethritis) and vagina(vaginitis) , causing a purulent vaginal discharge and intermenstrual bleeding (cervicitis). It may then progress to uterine tube , causing salpingitis and fibrosis , which can result in sterility or ectopic pregnancy.