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33 Cards in this Set
- Front
- Back
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Neisseria genus features
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- gram (-) diplococci w/ flat sides
- OXIDASE POSITIVE |
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2 bugs of medical importance
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- n.meningitidis
- n. gonorrheae |
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N. meningitidis
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capsule: yes
vaccine: yes entry: resp. glucose fermentation: yes maltose frmnter: yes b-lactamase prdcr: RARE |
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N. Gonorrheae
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capsule: NO
vaccine: NO entry: GENITAL glucose frmntr: yes maltose fermenter: NO b-lactamase prdcr: COMMON |
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N. menigitis features
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- gram (-) kidney bean diplococci
- large capsule ; latex particle agglutination - chocolate agar growth @ 5% CO2 - MALTOSE FERMENTER |
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n.meng reservoir?
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human nasopharynx
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transmission?
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resp. droplets; oropharyngeal colonization --> spreads to meninges via BLOOD STREAM
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clinical vignette clues for n. meng
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- gram (-) diplococcus in CSF
- young adult w/ meningitis - fast onset w/ signs of ENDOTOXIN toxicity |
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N.Meng pathogensis
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- antiphagocytic CAPSULE ; 5 common serotypes ; Bstrain is mcc in u.s.a. (not covered by vaccine)
- IGA protease - endotoxin release (LPS b/c g(-) bacteria) - pili - DEFICIENCY in LATE PHASE MAC PROTEINS (c5-c8) increases risk for bacteremia |
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N. Meng diseasesss
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-meningitis
- meningiococcemia |
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s&s of meng and menigiococcemia
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- fast onset of chills, fever, malaise, prostration, and petechial rash
- once rash shows up --> rapid decline of the patient |
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fulminant cases of n. meng , what can happen quickly
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DIC, shock, coma and death --> WATERHOUSE-FRIDERICHSON SYNDROME
- adrenal collapse/ hemorrhage --> death 10-12 hours later |
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differential for n. meng
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- s.pneumo
- picornaviruses (enteroviruses) - arboviruses - HSV - measles |
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n. meng diagnosis ?
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- gram stain of CSF --> look for g(-) cocci
- latex agglutination --> look for capsules |
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N. meng Rx
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neonates --> ampicillin + cefotaxime
old infants/kids/adults --> cefotaxime OR ceftriaxone W/ or W/O vanco |
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n. meng prevention?
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vaccine: Y, w-135, c and a strains
- type B seen in 50% of cases b/c not covered in vaccine - prophylaxis with RIFAMPIN for close contacts (or cipro) |
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NEISSERIA GONORRHEAE distinguishing features
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- gram(-) kidney bean shaped diplococi
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gon reservoir ?
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human GENITALS
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transmission?
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sexual contact
birth sensitive to drying and cold |
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pathogensis factors of gonorrhea
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- pili --> attachment to mucsl srfaces
- inhibit phagocytic uptake - ANTIGENIC variation -OUTER MMBRNE PROTEINS - IGA Protease - INVADES mucosal surfaces --> inflammation! |
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disease caused by gonorrhea
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men: urethritis, proctitis
women: ENDOCERVITIS, PID, arthritis infants: OPTHALMIA (leads to blindness if not treated quickly) -prophylactic blindness treatment is silver nitrate or erythromycin ointment @ birth |
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differential for gonorrhea
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- chalmydia
- garnderella vaginalis - trich |
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diagnosis of gonorrhea
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- intracellular g(-) diplococci in PMN's on urethral smear
- genetic probes - thayer martin medium (choclate agar + antibx) - NO MALTOSE FORMED - NO CAPSULE - OXIDASE POSITIVEEEE |
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Gonorrhea Rx
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- ceftriaxone
- test for c.trachomatis or rx w/ doxy - plasmid mediated b-lactamse produces HIGH LEVEL PENICILLIN RESISTANCE |
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prevention of gonorrhea ?
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adult: no vaccine ; use condoms
noenatal : silver nitrate or erythromycin |
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MORAXELLA CATARRHALIS features :)
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g(-) diplococcus
- close relative of neisseria |
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moraxella reservoir?
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normal upper respiratory tract flora
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transmission? pathogenesis?
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resp. droplets / endotoxin MAY cause disease...not sure
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Vignette clues for N. Gonorrheae
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- sexually active
- urethral/vaginal discharge - arthritis - neonatal opthalmia - gram (-) diplococcus in neuts |
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COMLEX note for n. gonorrheae
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if see PMN'S WITHOUT an organism...think of C. TRACHOMATIS!
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M. catarrhalis diseases caused...
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- otitis media
- sinusitis - bronchitis/ bronchopneumonia in elderly pats w/ COPD |
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Differential for m. cat
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- s. pneumo
- h. influenza |
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M. Catarrhalis treatment ?
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Augmentin or 2nd/3rd gen ceph OR bactrim
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