Neisseria
General: Consists of 10 species found in humans, though only two are strictly human pathogens (Neisseria gonorrhoeae and Neisseria meningitidis); the remaining are common commensals but rare pathogens.
Clinical:
- Normal:
- Abnormal:
Resistance: Some strains of N. gonorrhoeae produce beta-lactamases (penicillin resistance).
Morphology: Usually encapsulated gram- diplococcus, often with adjacent sides flattened together (resembling coffee beans). Not motile and do not form endospores. Pili are common and promote antigenic variation, thus a general lack of immunity to re-infection and inability to develop a vaccine thus far.
Growth characteristics: Oxidase+, aerobic, and most are catalase+. Nonpathogenic species grow on nutrient agar at 35-37C.
Common/important pathogens: