03 Gram-Negative Cocci Flashcards
What are the Gram-Negative Cocci?
Neisseria meningitidis. N. gonorrhoeae. Moraxella catarrhalis
What are the characteristics of N. meningitidis?
Transmitted by airborne droplets. 2-10% of healthy people - part of normal oropharyngeal flora. 5% become chronic carriers –> source of infection for others. Complement deficiency –> recurrence, bacteremia
What are the Virulence factors for N. meningitidis?
Polysaccharide capsule (antiphagocytic). Endotoxin (fever, shock, purpuric skin lesions (DIC)). IgA protease (mediate attachment to membranes of upper respiratory tract)
What are the clinical findings of N. meningitidis?
Meningococcemia, meningitis. Once of 3 most common causes of meningitis in age > 2 months
What are the top 2 causes of Meningitis?
N. meningitidis and S. pneumoniae
What is the diagnosis for N. meningitidis?
Smear and culture of blood and CSF
How is N. meningitidis prevented?
Rifampin for household and close contacts (will not eliminate carriage in 10-20% of colonized individuals). Vaccine for serogroups A, C, Y, W135 (no coverage for serogroup B - 50% of invasive cases)
What is N. gonorrhoeae?
Transmitted sexually, newborn acquired from mother. Localized infections in the genital mucosal surfaces (urethra, vagina) tract; disseminated. Mixed infection with Chlamydia trachomatis - common
What are the virulence factors of N. gonorrhoeae?
Pili, IgA protease, endotoxin
What are the common side effects Gonorrhea?
Men (urethritis). Women (endocervical infection). Anorectal infections. Pharyngitis. Neonates (purlent conjunctivitis). Disseminated (rash and septic arthritis)
What is the diagnosis for N. gonorrhoeae?
Gram stain: gram-negative diplococci within PMNs (urine, urethral, or cervical specimens). Generally not recovered from culture due to media and incubation conditions used (require enriched medium and incubation)
What is the treatment for N. gonorrhoeae?
Ceftriaxone PLUS Rx for chlamydia for patient and sexual contact(s); PCN-R strains increasing
