Lab 5 Flashcards
Enterobacteriaceae:
- habitat, morphology, staining
40 genera, > 180species
Habitat:
- Gut, mucous membranes
- normal gut flora, environment
Morphology:
- 1-3 um rod
- flagella (except: Shigella, Klebsiella)
Staining:
- gram negative
Enterobacteriaceae:
- Culture
- simple, aerobic, facultative anaerobic
- 10-45 (37) *C
- selective and differential media; isolation from mixed culture
- chromogenic media; Detection of specific enzymes
- selective enrichment; Isolation of salmonella
- combined media; examination of more. characteristic in one medium
Enterobacteriaceae:
Culture capacity
Low selective capacity: (Enterobacteria)
- crystal violet - lactose - litmus (Drigalski)
- crysta violet - bile salts - lactose - neutral red (MacConkey)
- eosin - lactose - methylee blue - Na lauryl sulphate
Medium selective capacity: (some genera of Enterobacteriaceae:)
- brilliant green - lactose - phenol red
- deocycholate citrate - lactose - neutral red (DC)
- XLD: xylose lysine deoxycholate - lactose - phenol red (isolation of E.coli and salmonella)
High selective capacity:
- bismuth sulphate agar (Highly selective. Only salmonella can grow on it)
Enterobacteriaceae:
- chromogenic media
Rambach agar:
- fermentation of propylene glycol: salmonella
Chromocult Coloform Agar: differentiate coliform and E.coli
- beta D galatosidase: coliforms
- beta D glucuronidase: E.coli
Enterobacteriaceae:
- Biochemistry, Antigens, resistance
Biochemistry:
- catalase +, oxidase -, fermentative (acid + gas) (carbohydrate production)
Antigens:
- O: Cell wall (LPS)
- K: capsule (polysaccharide) (virulence factor. used for serotyping)
- H: flagella (protein)
- F: fimbria (protein)
Resistance:
- medium
Enterobacteriaceae:
- pathogenicity
Saprophytic: normal flora (gut, mucous membranes) (the majority!)
Pathogenic:
- facultative
- obligate (only a few)
Enterobacteriaceae:
- grouping
- Genus: biochemical characteristics
- Species: biochemical and serological characteristics
- Serogroups: O antigens
- Serotype: O-K-H-F antigens
- Biotypes: fermentation pattern
Enterobacteriaceae:
- lactose postivie
- Echerichia
- klebsiella
- enterobacter
Enterobacteriaceae:
- lactose negative
- salmonella
- shigella
- yersinia
- proteus
- providencia
- edwadsiella
- serratia
- citrobacter
Escherichia:
- habitat, morphology, staining
E. coli
Habitat:
- gut, component of normal gut flora
- aerobic, facultative anaerobic gut flora
Morphology:
- 2-3 um rod
- flagella, capsule (some of them), fimbria (only in the pathogenic E.coli, virulence factor)
Escherichia:
- culture
- simple, not fastidious (following the general principles of Enterobacteriaceae)
- selective and differential media (grows on low and medium selective media)
- Capsule (E.coli strains from Calf)
- Beta Heamolysis (E.coli strains from swine)
- Lactose positive –> acids
Escherichia:
- biochemistry, resistance
- Biochemistry: lactose +, indol +
- Resistance: medium
Escherichia:
- antigens
- O: type specific (187 types)
- K: polysaccharide (60 types)
- F: 30 types (virulence factors)
–> F1: common fimbria
–> F2, F3, human
–> F4 (K88), F6 (987p), F18 ab/ac: swine
–> F5 (K99), F17, F41: cattle
–> F7 - F16: Urinary tract infection (UTI) in: human, poultry
- H: 53 types (NOT virulence factors)
Escherichia:
- pathogenicity
Sprophyte:
- normal gut flora, normal flora of mucous membranes
Facultative pathogenic:
- cattle, swine, sheep, goat, rabbit, poultry, foal, dog, cat, mink, fox, nutria, chinchilla, human
Genetic variety
Escherichia:
- pathogenicity Cattle
- calf coli-diarrhoea (neontal)
- calf coli-septicaemia
- cow; mastitis
Escherichia:
- pathogenicity Swine
- Coli diarrhea of noental piglets
- weaned piglets: coli diarrhea
- weaned piglets: oedema disease
- sow: mastitis, metritis
Escherichia:
- pathogenicity Lamb, kid and Rabbit
Lamb, Kid:
- coli diarrhea (neontal)
- watery mouth
Rabbit:
- diarrhea
Escherichia:
- pathogenicity Poultry
- day-old-chicken: septicaemia
- chicken: septicaema, respiratory disease
- adult: lesions in organs (airsacculitis, peritonitis, coli-graulomatosis)
Escherichia:
- pathogenicity foal, dog, cat, mink, fox, nutria, chinchilla AND human
foal, dog, cat, mink, fox, nutria, chinchilla:
- coli-diarrhea, septicaemia
Human:
- neontal enteritis, septicaemia
- urogenital infections
- enteritis
- haemorrhagic enteroclitis, haemolytic uraemic syndrome
Escherichia:
- Virulence fanctors of the pathogenic E.coli strains:
- Enteropathogenic strains: (EPEC or AEEC)
- intimin
- damage of enterocytes and microvilli (decreased absorption = diarrhea) - Enterotoxigenic strains (ETEC)
- Adhesive factors: fimbria, surface proteins (will excrete water into the gut = diarrhea)
- Enterotoxins:
–> LT (het labile) toxin: protein 88.000 D
–> ST (heat labile) toxin: polypeptide 1.500-2000 D
–> damage of fluid absorption
- Verotoxigenic strains:
- verotoxins (shiga-like toxins):
–> VT1 (Stx2), VT(Stx2). -> Damage of endothelial cells
- inhibit protein synthesis of the endothelial cells –> odema, haemorrhages will be formed, .
- Vero = monkey cell line
4. Necrotoxic (cytotoxic necrotic factor producing) strains - cytotoxic necrotic factor (CNF1 + CNF2 strains)
5. Enteroinvasive strains: - human, dysentery, like Shigella
- they can enter the mucous membrane of large intestine, necrosis, diarrhea
6. Enteroadhesive-aggregative strains (human)
7. Septicaemic strains - invasivness
- survival in blood
Klebsiella:
- habitat, morphology
K. pneumonia
Habitat:
- Gut, respiratory way, genital tract
- environment
Morphology:
- Rod, capsule, NO flagellum
Klebsiella
- culture, biochemistry
Culture:
- large, merging, mucoid colonies
- rapid change of the colour of the indicator
Biochemistry:
- Lactose +, Vogues-Proskauer test +, Urease +
Klebsiella
- antigens, pathogenicity
Antigens:
- 82 serogroups (capsule)
Pathogenicity:
- Saprophytic - facultative pathogenic
- Cattle: Calf (bronchitis, bronchopneumonia), Cow (mastitis, metritis)
- Mare: metritis
- Human: pneumonia, urogenital infections
Enterobacter:
- habitat, morphology, culture, biochemistry
Habitat:
- Gut, environment
Morphology:
- Rod, capsule
Culture:
- mucoid colonies
Biochemistry:
- Lactose +, Voges-Proskauer test +
Biochemical characteristics of E.coli, Klebsiella and Enterobacter:
Enterobacter:
- Pathogenicity, species
Pathogenicity:
- saprophytic,
- rarely respiratory infection in humans
Species:
- E. cloacae, E. aerogenes
