Term
| Neisseria Meningitidis (MC) Apperance |
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Definition
Gram - diplococci
Pyogenic
Oxidase +
Catalase +
Fastidious (needs chocolate agar, Thayer-Martin agar)
Ferments glucose and maltose (distinguishes from Neisseria gonorrhoeae)
Facultative intracellular pathogen |
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Term
| Neisseria Meningitidis (MC)Virulence |
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Definition
Type IV Pili: primary adhesion, extensive phase and antigenic variation
PI: porin, adhesion and invasion: resists phagolysosomal fusion and oxidative burst
PII: Opa, adhesion and invasion, extensive phase and antigenic variation
PIII: Rmp, blocks antibodies
Iron-binding proteins
Lipooligosaccharide (LOS): endotoxin, lacks the O-antigen of LPS
IgA 1 proteases
Peptidoglycan: cytotoxic
CAPSULE: anti-phagocytic, phase variable |
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Term
| Neisseria Meningitidis (MC) Disease |
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Definition
1. Direct contact leads to attachment in nasopharynx
2. LOS and peptidoglycan damage surrounding epithelium, inflamm repsonse
3. Multiply and spread into systemic blood, leading to menigococcemia
OR can cross blood-brain barrier and lead to menigitis
Endotoxin LOS: fever, petechial skin rash, thrombocytopenia, DIC, endotoxic shock |
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Term
| Neisseria Meningitidis (MC)Toxin |
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Definition
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Term
| Neisseria Meningitidis (MC) Transmission |
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Definition
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Term
| Neisseria Meningitidis (MC) Reservoir |
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Definition
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Term
| Neisseria Meningitidis (MC) Treat/Prev |
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Definition
No antibiotic resistance (unlike N. gonorrhoeae)
Penicillin
Chloramphenicol
Prophylactic: rifampin, sulfonamide
Vaccine: capsular polysaccharide subunit vaccine |
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Term
| Neisseria Meningitidis (MC) Mortality |
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Definition
| Life-threatening, high mortality rate untreated (unlike N. gonorrhoeae) |
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Term
| Similarites of N. gonn and N. men |
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Definition
| Colonize mucosal cells, adhere via pili, invade via opacity proteins, have IgA 1 proteases, similar Fe-acquisition, toxic LPS, antigenic variation of pili and outer membrane proteins, sialyation of LPS blocks complement mediated killing, can survive w/in host cells |
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Term
| Differences of N. gonn and N. men |
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Definition
N gon: always pathogenic, sexual direct contact transmission, localized infection, rarely fatal, no vaccine, no capsule, no hemolysin, no antigenic variation in capsule (no capsule)
N. men: usually commensal, airborne transmission, menigitis and menigococcemia, life threatening, vaccine available, has capsule, keep it, has hemolysin, HAS antigenic variation in capsule serotypes |
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Term
| Shigella Dysenteriae Apperance |
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Definition
Gram - rod
Facultatively anaerobic
Ferments glucose but NOT lactose
Oxidase -
Does not produce H2S
Strict pathogen, never normal flora |
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Term
| Shigella Dysenteriae Virulence |
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Definition
Ipa: adherence, invasion and escape from endocytic vesicle, secreted by Type III
IscA, IscB: contact hemolysin (IscB), intracellular spread on actin tails
Shigatoxin: enterotoxin, neurotoxin, cytotoxin
LPS: inflammatory repsonse |
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Term
| Shigella Dysenteriae Disease |
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Definition
1. Ingested: only needs small amount
2. Attaches to M cells: uptake via trigger mechanism and membrane ruffling
3. Pass thru M cells to LP, inflamm response
4. Trigger uptake into epithelial cells from basal side
5. Escape phagosome to cytoplasm, multiply there, spread laterally on atin tails
Causes dysentery (diarrhea w/blood and mucous) |
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Term
| Shigella Dysenteriae Toxin |
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Definition
| Shigatoxin: AB subunit toxin, inhibits protein synthesis, neurocytotoxin |
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Term
| Shigella Dysenteriae Trasmission |
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Definition
| Ingested, only need small amount |
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Term
| Shigella Dysenteriae Reservoir |
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Definition
Human intestinal tract
Contaminated water and food |
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Term
| Shigella Dysenteriae Treat/Prev |
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Definition
Antibiotics somewhat helpful
Rehydration |
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Term
| Shigella Dysenteriae Prevention |
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Definition
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Term
| Salmonella (Typhi) Apperance |
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Definition
Gram - rod
Facultatively anaerobic
Ferments glucose but NOT lactose
Oxidase -
Produces H2S |
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Term
| Salmonella (Typhi) Virulence |
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Definition
LSP: multiple antigenic types
Flagella: multiple antigenic types
Invasins: invA-H
Vi antigen: capsular polysaccharide
Survive in macrophage (type III secretion)
Acidic stomach turns on multiple virulence genes |
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Term
| Salmonella (Typhi) Diesase |
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Definition
1. Ingested: only need small amount
2. Attaches thru M cells in large intestine, triggers its own endocytosis
3. Pass thru M cells to submucosal layer to be ingested by macrophages
4. Multiply inside macrophages, carried to lymphatics then bloodstream and gallbladder
Diarrhea: not watery like cholera or bloody like shigella
Food poisoning
Typhoid fever: flushed apperance, anorexia, chills, convulsions, delirium
Reinfectino: was stored in galbladder, leads to severe ulceration |
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Term
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Definition
No exotoxins
LPS endotoxin: responsible for many systemic symptoms of typhoid fever |
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Term
| Salmonella (Typhi) Transmission |
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Definition
| Ingested of contaminated food/water by human feces |
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Term
| Salmonella (Typhi) Reservoir |
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Definition
Humans
Contaminated food/water |
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Term
| Salmonella (Typhi) Treat/Prev |
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Definition
Antibiotics that get inside macrophages
Vaccine for international travelers |
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Term
|
Definition
Gram - rods
Facultatively anaerobic
Oxidase -
Ferments glucose and lactose |
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Term
| ETEC: enterotoxigenic E. Coli Virulence and Disease |
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Definition
Heat-labile toxin LT
Heat-stable toxin ST
Toxin-mediated: cause cholera-like diarrhea |
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Term
| EIEC: enteroinvasive E. coli virulence and disease |
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Definition
No shiga toxins
Ipas: invasion proteins (like shigella)
Plasmid encoded
Diarrhea: similar to shigella but not usually bloody |
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Term
| EPEC: Enteropathogenic E.coli Virulence |
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Definition
Type IV class pili attaches first
Type III secretion happens next
LEE locus: pathogenicity island encoding for Type III secretion system
Tir: protein injected by type III: creates receptor for intimin
Intimin: binds to tir to bring bacteria close |
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Term
| EPEC: Enteropathogenic E Coli Disease |
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Definition
Colonize small intestine
Fever, nausea, vomiting
Diarrhea (especially in infants) |
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Term
| EHEC: Enterohemorrhagic E Coli Virulence |
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Definition
Effectively = EPEC + shiga toxin (AB subunit toxin)
Acid-resistant, low infection dose
Sorbitol -
LEE locus: pathogenicity island encoding for Type III secretion system
Encodes cryptic prophage |
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Term
| EHEC: Enterohemorrhagic E. Coli Disease |
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Definition
Colonize large intestine
From undercooked or contaminated meat
Don't treat with antibiotics! Will retaliate more strongly! Use hydration!
Hemorrhagic colitis: very bloody, watery diarrhea |
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Term
| UPEC: Uropathic E coli: Virulence |
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Definition
Type I pili: mannose-sensitive, stick inside urinary tract
Pap pili: helps to urinary tract
Hemolysin: creates pores to lyse cells
CNF-1: cytotoxic necrotizing factor: affects bladder cells |
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Term
| UPEC Uropathognic E. Coli Disease |
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Definition
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Term
| SEC: Septic E Coli Virulence |
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Definition
Capsule: antiphagocytic, poorly immunogenic
Adhesins: Type I Pili, same as UPEC, S-fibriae used to bind within brain
Invasins: Ibe (invasion of brain endothelium) |
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Term
| SEC: Septic E Coli Disease |
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Definition
| Neonatal sepsis and meningitis |
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