Term
| causes of bacterial meningitis |
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Definition
-S. PNA (g. +)
-H. Influenzae Type B (g. -)
-N. Meningitidis (g. -)
*all are encapsulated and can survive in the blood |
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Term
| causes of neonatalbacterial meningitis |
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Definition
-S. Agalactiae (g. +)
-E. Coli (g. -)
-L. Monocytogenes (g. +) |
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Term
| gram + bacteria causing meningitis |
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Definition
| Strep PNA and Strep Agalactiae |
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Term
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Definition
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Term
| Bacteria causing Botulism |
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Definition
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Term
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Definition
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Term
| clincal features of Bacterial (Acute/Purulent) Meningitis in Adults |
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Definition
-SUDDEN fever
-SEVERE HA
-STIFF neck
-pt may have flu like sxs initially and can be associated with n/v, AMS, photophobia, PETECHIAL rashes |
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Term
| clinical features of bacterial meningitis in Newborns/Children |
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Definition
| -constant crying, poor feeding, sleeping constantly, irritability (all non-specific sxs) |
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Term
| S. PNA is the leading cause of: |
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Definition
| -URI otitis media, pneumococcal PNA and Meningitis and conjunctivitis |
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Term
| S. PNA distinguishing features |
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Definition
-No Lancefield Ags
-Alpha hemolytic
-grows in pairs (cocci)
-Optochin sensitive |
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Term
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Definition
-Polysaccharide capsule
-Autolysins (in cell wall)
-Pneumolysins (in cytoplasm) |
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Term
| Disease Mechanism of Pneumococcal Meningitis (caused by S. PNA) |
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Definition
-usually in kids <2 and adults over 60
-starts as a focal infection in lungs, moves to blood, passes into CSF eliciting a strong macro/CK/Il-1 response |
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Term
| distinguishing feature of Pneumococcal Meningitis |
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Definition
Prolonged fever
-sequelae: hearing loss and hydrocephalus |
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Term
| Dx for Pneumococcal and Meningococal Meningitis |
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Definition
-gram stain of CSF and f/u w/ bacterial culture
-rapid test for Ags if pt has been tx'd with Immediate Abx Therapy |
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Term
| Vaccine for Pneumococcal Meningitis |
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Definition
Vaccine Conjugate Prevnar
-2,4,6 12 months admin- very successful in kids under 2 yrs |
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Term
| Characteristics of genus Neisseria |
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Definition
-Gram Negative diplococci
-non motile
-Oxidase/Catalase positive
-Aerobic- increased CO2 |
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Term
| N. Meningitidis distinguishing features |
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Definition
-ferments glucose AND maltose
-can grow on standard media
-POLYSACCHARIDE capsule with 13 serogroups |
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Term
| N. Meningitidis serotypes: |
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Definition
A: in developing countries- AFRICA/ASIA
B: on the decline in the US
C: increasing in the US
W-135 and &
*all can cause PNA, often the focal infection is unnoticed. Most ppl are just carriers; lives on MMM in URT |
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Term
| N. Meningitidis virulence factors |
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Definition
-Polysaccharide capsule
-pili for adherence to nasopharynx
-LOS; sialic acid addition (innactivating complement)
-iGa portease and OMP's |
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Term
| N. Meningitidis epidemiology |
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Definition
-5-15% carrier rate
-outbreaks common in winter, esp in dorms, military |
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Term
| Disease Mechanism of Meningococcal Meningitis (caused by N. Meningititis) |
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Definition
| -spread by resp droplets (many healthy adults are carriers in URT and have protective Abs), the org adheres to non-ciliated columnar epithelium over 1-4 days causing a focal infection. Bacteria gets endocytosed , multiplies in submucosa and enters blood. Leads to meningitis or Septicemia (DIC) with hallmark PETECHIAL RASHES |
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Term
| Vaccine for Meningococcal meningitis |
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Definition
-Quadrivalent Vaccine (MCV4-2005)
-for kids 11-12 yrs old and at risk pops
-doesnt include serotype B bc its too similar to self proteins. |
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Term
| H. Influenzae distinguishing features and dz mechanism |
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Definition
-Pleomorphic gram neg. rod
-growth on Chocolate agar with NAD and factor X
-colonizes URT, transmitted by resp secretions often in NON_IMMUNIZED KIDS 1 mo-3 yrs often w/ otitis media then enters blood and eventually meninges |
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Term
| H. Influenzae type B virulence factors |
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Definition
-Polyribose capsule (not polysaccharide!)
-IgA protease |
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Term
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Definition
-Gram stain CSF then f/u with culture on choc agar
-immunological test for Abs to capsular ag
-35% of isolates are resistant to ampicillin |
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Term
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Definition
| Hib polyribose phosphate vaccine conjugate |
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Term
| S. Agalactiae distinguishing features |
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Definition
-gram + cocci
-Beta hemolytic
-Group B cell wall Ag (GBS)
-ARROWHEAD streak on a plate with s. aureus
-leading cause of neonatal sepsis and meningitis
-resistant to bacitracin |
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Term
| S. Agalactiae dz mechanism |
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Definition
-colonies GI and vaginal/cervical MM w/o any sxs
-transmitted to baby during birth (50%) |
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Term
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Definition
-Early onset in neonates causing focal PNA--> bacteremia <7 days old
-late onset >7 days--> meningitis |
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Term
| E. Coli distinguishing features |
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Definition
-Gram Neg rod
-Facultative Anaerobe
-Oxidase negative
-ferments lactose; turns pink on MacConkey Agar |
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Term
| E. Coli Virulence factors |
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Definition
-Lipopolysaccharide O Ag
-Flagellum H Ag
-Capsule K Ag*
-toxin production |
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Term
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Definition
| E. Coli moves from GI to vagina and transmitted to baby during delivery. Main presentation is meningitis (not PNA. the K Ag allows for adherence to brain endothelial cells) |
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Term
| Listeria Monocytogenes distinguishing features |
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Definition
-short, non spore forming, gram + rods
-ubiquitous in the environment, intracellular parasite
-tumbling motility at 23 deg C
-contaminates cold cuts, soft cheeses
-generally does not cause dz in healthy ppl (pregnant women are mildly immunocompromised) |
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Term
| L. Monocytogenes dz mechanism |
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Definition
| -ingested by mother, expresses INTERNALIN to enter cells, makes LYSTERIOLYSIN O to destroy phagolysosomes, then multiplies and uses ActA to make actin to push through to neighbor cells and keep multiplying. |
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Term
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Definition
-Gastro in healthy pts 48 hrs post ngestion
-Bacteremia in pts with risk factors; fever, chills, myalgias
-Meningitis in 5-10% of pts |
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Term
| Listeriosis sxs in pregnant women |
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Definition
-Bacteremia; flu like illness w/o CNS sxs
-70-90% transmission to baby w/ 30 % mortality sue to disseminated dz and sepsis
-if baby acquires it at birth, will dev meningits in 3-4 wks |
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Term
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Definition
-use fermentation to make energy
-damaged by O2
-colonize in gut, distal ileum, lower genital tract, distal urethra, oral cavity and follicles of the skin |
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Term
| characteristic of group Clostridum |
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Definition
-Gram + rods
-found in soil and GI tract
-Anaerobic spore formers |
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Term
| features of both C. Tetani and C. Botulinum |
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Definition
-produce potent neurotoxins that exhert systemic effects
-may cause death due to respiratory failure |
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Term
| Clostridium Tetani distinguishing features |
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Definition
-'tennis raquet' shaped spores; large rods
-motile 'swarming' action on a plate
-strict anaerobe- culture on blood agar
-spores common in soil
-cause dz in older ppl with waning immunity |
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Term
| Clostridium Tetani virulence factors |
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Definition
| -Tetanospasmin toxin; has mealloproteinase that blocks release of inhibitory NTs. acts by cleaving synaptobrevin and increasing resting firing rate of motor neurons causing rigidity |
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Term
| Clostridium Tetani disease mechanism |
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Definition
| Organism gets innoculated via a puncture wound, incubate 4-21 days. Spores release tetanospasmin toxin which gets taken up by retrograde transport into CNS. Toxin's heavy chain allows entry into neuron and light chain allows acts on synaptobrevin |
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Term
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Definition
| -lock jaw, progressing to opisthotonos, paralysis of chest muscles, respiratory failure and death |
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Term
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Definition
| goal is to neutralize toxin with HTIG and abx. May need to debride the wound and give active immunization. |
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Term
| Clostridium Botulinum distinguishing features |
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Definition
-7 serotypes
-spores found in soil, fresh water, surface of fruits/vegetables; like neutral and alkaline environments
-produces Botulinum toxin |
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Term
| Features of Botulinum Toxin |
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Definition
-Most potent natural toxin, resistant to gastric enzymes
-produces metalloproteinase to act on presynaptic membranes to block ACh release in PNS
-inactivate by heating
-commonly found contaminating home canned foods |
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Term
| Botulism Intoxication sxs in an adult |
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Definition
-present 12-36 hrs post ingestion
-GI sxs, blurred vision, aphagia, progressive, bilateral, descending paralysis
-NO FEVER OR AMS |
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Term
| Botulism sxs in an infant 3 wks to 8 months |
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Definition
-constipation, lethargy, poor sucking, paralysis 'floppy baby syndrome'
-spores are able to germinate in the gut due to the alkaline environment then elaborate the toxin
-up to 10 week incubation |
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Term
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Definition
-clinical presentation
-reportable dz
-isolate and culture organism from specimens
-the antitoxin is an equine trivalent and has the risk of hypersensitivity rxns |
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Term
| Mycobacteria group distinguishing features |
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Definition
-acid fast bacilli-stain pink with Ziehl Neelson Method
-60% of their cell wall is lipid/mycolic acid; appears waxy when grown
-grow slowly- 4-12 weeks on a plate
-obligate AEROBES
-non motile, non spore forming |
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Term
| Mycobacteria group distinguishing features |
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Definition
-acid fast bacilli-stain pink with Ziehl Neelson Method
-60% of their cell wall is lipid/mycolic acid; appears waxy when grown
-grow slowly- 4-12 weeks on a plate
-obligate AEROBES
-non motile, non spore forming |
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Term
| Mycobacterium Leprae distinguishing features |
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Definition
-causative agent of leprosy (Hansens dz)
-low infectivity- need PROLONGED contact
-CANNOT be grown in culture, only in armadillos and mouse foot pad at 30 degrees
-can isolate from skin |
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Term
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Definition
| -transmitted via nasal secretions, enters body through mucosa or skin lesions. org gets taken up by macros- replicates and eventually enetrs schwann cells elaborating its PGL 1 virulence factor preventing fusion of phago/lysosome. body responds by bringing in lots of macros and lymphoctyes forming a granuloma |
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Term
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Definition
-chronic granulomatous dz
-affecting PNS
-Tuberculoid or Lepromatous Leprosy |
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Term
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Definition
-STRONG cell mediated immune response (few bacilli)
-formation of granulomas ; large, flattened plaques on face, trunk and limbs with pale hairless centers.
-Patchy anesthesia
-Lepromin skin test will be + |
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Term
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Definition
-WEAK cell mediated immune response
(lots of bacilli in skin and MM)
-infectious
-multiple skin lesions causing disfigurement; anesthesia, resporption of bone, thick and folding skin
-NEGATIVE lepromin skin test bc T cell levels are so low |
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