Neisseria species

Background:

——————————————————————————
Gram-Negative Cocci & Coccobacilli
——————————————————————————
>Aggregatibacter aphrophilus (formally known as Haemophilus aphrophilus)
>Bordetella pertussis (Causative agent of pertussis or whooping cough. )
>Brucella species:
     1] Brucella abortus
     2] Brucella canis
     3] Brucella melitensis
     4] Brucella suis
>Eikenella corrodens
>Haemophilus species:
     1] Haemophilus influenzae
     2] Haemophilus ducreyi
     3] Haemophilus avium
>Moraxella catarrhalis (formerly known as Branhamella catarrhalis)
>Neisseria species: (frequently colonize mucosal surfaces.)

1] Neisseria gonorrhoeae
2] Neisseria meningitidis
>Pasteurella multocida

Neisseria:

Large genus of commensal bacteria that colonize the mucosal surfaces of many animals.
Of the 11 species that colonize humans, only two are pathogens. N. meningitidis and N. gonorrhoeae often cause symptomatic infections, a commensal-like behavior.
Most gonoccocal infections are asymptomatic and self-resolving, and epidemic strains of the meningococcus may be carried in >95% of a population where systemic disease occurs at <1% prevalence.
Neisseria species are Gram-negative bacteria included among the proteobacteria, a large group of Gram-negative forms. All the medically significant species of Neisseria are positive for both catalase and oxidase.
Neisseria diplococci resemble coffee beans when viewed microscopically.
This genus (family Neisseriaceae) of parasitic bacteria grow in pairs and occasionally tetrads, and thrive best at 98.6°F (37°C) in the animal body or serum media.
The genus includes:
- N. gonorrhoeae (also called the gonococcus), which causes gonorrhea.
- N. meningitidis (also called the meningococcus), one of the most common causes of bacterial meningitis and the causative agent of meningococcal septicemia.

Therapy:

Important considerations: The choice of an agent should be based on local antimicrobial sensitivities, site of infection, cost, and comorbid conditions. Generally, the most common agents/regimens are listed first. Listed dosages may need to be adjusted for renal dysfunction.

Neisseria gonorrhoeae:

Ceftriaxone 250 mg IM x 1 + Doxycycline 100mg orally twice daily x 7 days (for possible C. trachomatis)
Azithromycin 2 grams po x 1.

Neisseria meningitidis:

Ceftriaxone 2 grams IV q12h
Cefotaxime 2 grams IV q4-6h.
Penicillin G 3 to 4 million units q4h IV
Chloramphenicol 100 mg/kg/day in divided doses every 6 hours (Maximum daily dose is 4 grams e.g. 1 gram q6h)