Gram - Cocci

Question 1

Neisseria general features (7)

Answer 1

• Gram negative diplococci
• Pyogenic
• LOS instead of LPS (short outer membrane)
• Oxidase positive
• Thayer Martin again (VPN-vanc, myastatin, polynycin)
• Problems if have C5-C9 def-no MAC complex
• Pillus (antigenic variation and IgA protease and Fe extraction

Question 2

N. meningitides

• natural habitat
• virulence
• ID
• Spread
• Disease
• Tx
• Prevention

Answer 2

A shocking death on campus

• Nasopharangeal mucosa
• Capsular polysac (serotypes-B is most common), outer membrane has meningeal activity, pilli, OpA proteins
• Gram stain of CSF and blood culture, capsular antigen test, Oxidase positive, PCR
• REspiratory root tonasopharynx, submucosa, blood stream possibly meninges/skin/pericardium/joints
• Fulminant meningococcal sepsis, Waterhouse Friderichsen syndrome if adrenal collapse, shock, DIC 9disseminated intravascular coagulation (adrenal failure), blotchy rashes
• Ceftriaxon
• Vaccinate nearby people with rifampicin, at risk population get conjugated polysaccharide

Question 3

Neisseria gonorrhoaea

• nautral habitat
• ID
• virulence
• spread
• disease
• Tx

Answer 3

The Violinists Last Clap

• nasopharyngeal mucosa
• Male (purulent discharge with gram negative diplococci and neutrophils), Female and carriers (positive cultures needed for diagnosis), Both-oxidase +, GM-, diplocci, NAAT
• STI
• NO CAPSULE, outer membrane with endotoxin activity (LOS), Pili+OpA (opacity) proteins, IgA protease, transferrin receptor
• GU tract infection, Female-urethritis, dysuria, cervicitis with discharge, PID, Male-Acute onset urethritis, dysuria, purulent yellow discharge; Neonates-OPthalmia neonatorum (severe conjunctivitis-give silver nitrate or ceftriaxone); HIV risk up, pharyngitis
• Cefriaxone (but often comes with Clap so give macrolide or doxycycline too)