Lab 6. Salmonella, citrobacter, shigella, proteus, providentia, yersinia, serratia, edwardsiella, anaerobic gram negative rods Flashcards
Salmonella
- Taxonomy
Species:
- S. enerica
- S. bongori
Within S. enterica:
- 6 subspecies
- S. enterica subsp, enterica
- S. enterica subsp. arizonae
Within subspecies:
- serovars/serotypes: 2500
- eg: S. entrica subsp enterica serovar Typhimurium
Salmonella
- habitat, morphology, staining,
Habitat:
- gut, feed, food
- sewage, water
Morphology:
- 1-5um rod, flagella
–> except S. gallinarum/S. pullorum
Staining:
- gram negative
Salmonella
- culture
not fastidious
selective and differential media are used
- low selective capacity: MacConkey, Drigalski: lactose negative
- medium selective capacity: Brilliant green-lactose-phenol red (lactose negative, XLD (lactose negative), Rambach agar (fermentation of propylene glycol)
- High selective capacity: bismuth-sulphite agar (reduction)
Selective enrichment - Aim:
- isolation of salmonella from mixed flora
- low number of salmonella
Media:
- Na-seleite, cysteine
- Na-tetrathionate, bile salts
- rappaport-vassiliadis
Salmonella
- Biochemistry
Lactose negative, H2S positive
Differentiation of antigenically uniform types: sugar fermentation
S. Typhysuis:
- Arabinose +, Dulcitol +, Mannitol -
S. Choleraesuis:
- Arabinose -, Dulcitol -, Mannitol +
Salmonella
- antigens
Kauffmann-White system: O-Vi-H antigens
- composite antigens
- O antigens: 35 groups
- K (Vi): S. typhi, S.dublin etc
- H antigens
–> specific (phase 1 flagellar antigens)
–> non specific (phase 2 flagellar antigens)
–> monophasic serotypes: only H specific antigens
–> diphasic serotypes: not only H specific antigens
- Cross reactions: factor sera are used
Salmonella
- resistance, classification within serotypes
Resistance: medium
Classification:
- phage typing
- examination of the genome: restriction endonucleases, sequencing, plasmid
Salmonella
- pathogenicity
Only humans:
- S. typhi: typhoid fever
- S. paratyphi A, B, C, S.sendai: paratyphoid
Only animals:
- S. typhisuis: swine typhoid
- S. gallinarum: fowl paratyphoid
Human-Animal:
- s. enteridtidis, S. Typhimurium, S. Thompson, S. choleraesuis
- paratyphoid: swine, ruminants, horse, poultry
- human: gastroenteritis, septicaemia
Abortion:
- S. abortusequi, S. abortusovis, S. abortusbovis
Citrobacter
- habitat, biochemistry, pathogenicity
Habitat:
- mammals, birds, gut, water, environment
Biochemistry:
- Lactose negative, KCN+, lysine decarboxylase negative
Pathogenicity:
- saprophytic, sometimes secondary pathogen
Shigella
- habitat, morphology, culture, biochemistry, pathogenicity
Habitat:
- intestine (primates), sewage
Morphology:
- no flagella
Culture:
- DC (deoxycholate citrate) agar
Biochemistry:
- resembles E.coli, but lactose negative or late fermentation
Pathogenicity:
- S. dysenteriae, S. flexneri, S. sonnei, S. boydii: human bacillary dysentery
Proteus, Providentia
- habitat, staining, culture, biochemistry, pathogenicity
Habitat:
- intestine, urine, water
- rotting materials
Staining: gram neg
Culture: swarming!
Biochemistry:
- lactose neg
- phenylalanine-deaminase +
- indole +/-
- urease +
Pathogenicity:
- saprophytic, sometimes UTI
- P. vulgaris, P. mirabilis, P. morganii, Prov. stuartii
Yersinia
- species
Y. pestis
Y. pseudotuberculosis
Y. enterocolitica
Y. ruckeri
Y. pseudotuberculosis
- habitat, morphology, staining, culture, biochemistry
Habitat:
- intestine, water
Morphology:
- 1-2 um coccoid rods
- flagella 22*C
Staining:
- gram neg
- bipolar staining
Culture:
- not fastidious
- optimal temp 30*C
- replication: 4-42 *C
- small colonies
- selective culture: on low selective capacity media for Enterobacteriaceae
Biochemistry:
- lactose neg
Y. pseudotuberculosis:
- antigens, pathogenicity
Antigens:
- O antigens: 8 serogroups
- 5 H antigens
- composite antigens
Pathogenicity:
- rodents (rodentiosis)
- turkey, pheasant, quail (septicaemia, abcesses)
- cattle, swine, sheep (abortion)
- human
Y. enterocolitica
- habitat, morphology, staining, culture, antigens, pathogenicity
Habitat:
- intestine, water
Morphology, staining
- middle sized rods, Gram neg
Culture:
- optimal temp: 22*C
- selective culture: Na-oxolate + bile salts
Antigens:
O-antigens:
- 34 O groups
- O9: cross reaction with Brucella species
H-antigens: 20
PAthogenicity:
- human: gastro-intestinal infection, abscesses
- swine, rabbit: intestine, mesenterial lymph nodes, resembles ruberculosis
Y. ruckeri
- pathogenicity, biochemistry
Biochemmistry:
- inactive
Pathogenicity:
- trout septicaemia, kidney (red mouth disease)
Serratia:
- habitat, culture, pathogenicity
Habitat:
- soil, water
Culture:
- lower optiamal temperature, pigment
Pathogenicity:
- saprophytes
- S. marcescens: food contamination
Edwardsiella:
- habitat, culture, pathogenicity
Habitat:
- intestine (fisk, amphibians, birds, mammals), water
Culture:
- fastidious (vitamins, amino acids needed)
Pathogenicity:
- E. tarda: eel
- E. ictaluri: septicaemia, ascites (channel catfish)
Gram negatie anaerobic rods
- genera
fusobacterium
bacteriodes
dichelobacter
prevotella
Gram negatie anaerobic rods
- habitat, pathogenicity
habitat:
- mucous membrane: alimentary tract, respiratory airways, genital tract
- components of the anaerobic gut flora
Pathogenicyt:
- facultative pathogenic: inflammation of the mucous membranes, wounds, abscesses
- minly mixed infections
Fusobacterium
- morphology, staining, culture
Morphology:
- polymorph: chain, filaments. Generally no flagella
Staining:
- gram neg
- irregular staining
Fusobacterium:
culture, biochemistry, resistance, pathogenicity
Culture:
- fastidious: blood agar, protein is needed, yeast extract.
- obligate anaerobic
- CO2, haemolysis
- selective culture: crystal violet, brilliant green, vancomycin
Biochemistry:
- carbohydrates are generally not utilised
- gelatine, casein are decomposed
- extracellular enzymes (lipase, DN-ase, hyaluronidase)
Reistance: low
Pathogenicity:
- facultative pathogenic
- anaerobic wounds, abscesses, gangrene
Fusobacterium
- species
F. necrophorum:
- F. necrophorum subsp. necrophorum: Hemolysis +, haemagglutination +, leukotoxin +, synergism +
- F. necrophorum subs. funduliforme: haemolysis -, haemagglutination -, leukotoxin -, synergism -
- F. nucleatim
F. necrophorum subsp. necrophorum
Calf, sheep, rabbit:
- necrobacillosis, calf diphteria, bovine liver abscess
Sheep:
- involved in the pathogenesis of foot rot
Cattle: mastitis
Dog cat: gingivitis, peritonitis
Wound infections, abscesses
F. nucleatum:
- mainly human, dog, cat
- abscess, mastitis, metritis
- peritonitis
- wound infection
Bacteroides, dichelobacter, prevotella
- habitat, morphology, staining, culture, biochemistry
Habitat:
- alimentary tract, respiratory way, genitals, mucous membranes, water
Morphology:
- 3-5 um rod, fimbria
Staining:
- gram neg, Irregular staining
Culture:
- fastidius, obligate anaerobic
Biochemistry:
- more active, proteases, keratinase
Bacteroides, dichelobacter, prevotella
- pathogenicity, species
Pathogenicity:
- facultative pathogens, necrosis, abscesses
Species:
- B. fragillis: mainly human, gut flora, appendicitis, wounds
- Dichelobacter nodusus: fimbria, proteolysis, keratinase, sheep foot rot
- Prevotella melaninogenica: dog, cat putrid inflammations
