Entero: E. coli (Ex2) Flashcards
Where does Enterobacteriacae normally reside?
What are the benefits of it being there?
- Resides in the GI tract
- Microbial antagonism
- Breakdown and absorption of food
- Waste processing
- Vitamin K production
General features of Enterobacteriacae
gram, oxygen requirements, shape, oxidase
- Gram negative
- facultative anaerobe
- rods or coccobacilli
- oxidase negative
What are Coliform Bacteria?
Name the three included
- Lactose positive bacteria
- E. coli
- Klehsiella
- Enterobacter
General features of Escherichia coli
lactose, oxidase, motility, shape
- lactose positive
- oxidase negative
- motile
- rods
Virulence Factors of E. coli
- capsule
- fimbrial and non-fimbrial adhesions
- endotoxin (LPS)
- enterotoxins
- cytotoxins
- siderophores
What do these stand for? ETEC EHEC VTEC/STEC EPEC RPEC APEC NTEC
ETEC - enterotoxigenic EHEC - enterohemorrhagic VTEC/STEC - verotoxigenic/shiga-like toxic EPEC - enteropathic RPEC - rabbit pathogenic APEC - avian pathogenic NTEC - nectrotoxigenic
General Features of ETEC in pigs
symptoms, age affected, adhesion factors, enterotoxins
- watery diarrhea
- neonatal, weanlings
- adhesion factors: F4, F5, F6, F18, F41
- enterotoxins: LT, Sta, Stb, EAST1
Adhesion factors of ETEC in pigs
F4 - on plasmids, specific receptors, mannose resistant, genes expressed at body temp, solely in pigs, neonates to weanlings
F5 - on plasmids, in pigs and bovines, mannose resistant, expression temp dependent, in young animals
F6 - extrachromosomal, neonatal
F41 - chromosomal, mannose resistant, pigs and bovines, freq with F5, rare, neonatal
Describe LT enterotoxin in ETEC in pigs
- heat labile
- high molecular weight
- strong antigen
- Na absorption, Cl and HCO3 secretion
- activation of adenlyate cyclase
Describe the heat stable enterotoxins in ETEC in pigs
- low molecular weight
- little antigen
- Sta: activation of guanylate cyclase, Na absorption, Cl and HCO3 secretion
- Stb: prostaglandin E2, secretion of water and electrolytes, stimulation of 5-H secretion
- EAST1: closely related to Sta
Characteristics present at each age (neonatal, neonatal till 4 wks, weanling) in ETEC in pigs
(adhesion, enterotoxins, hemo/non)
Neonatal: F5, F6, F41; Sta, Stb; non-hemolytic
Neonatal - 4 wks: F4; LT, Sta, STb, EAST1; hemolytic
Weanling: F4, F18; LT, Sta, Stb, EAST1; hemolytic
What are the causes of ETEC in pigs?
- increase infection pressure
- lowering of maternal immunity (MMA, first delivery, low birth weight, too many piglets)
- appearance of new type
What are the symptoms of ETEC in pigs?
- remain drinking
- smelly feces
- dehydration
- diarrhea
How do you diagnose ETEC in pigs?
- agglutination tests
- PCR
Treatment of ETEC in pigs
- hydration
- antimicrobials
Prevention of ETEC in pigs
- keep infection pressure low and maternal immunity high
- hygiene
- vaccination of sows
- selection of receptor free piglets
Virulence factors of VTEC in pigs
- adhesion in small bowel: F18
- exotoxin: VT2e or Stx2e: media necrosis
- endotoxin: acute mortality
What are the symptoms of VTEC in pigs?
- acute mortality in some
- diarrhea in some
- anorexia
- edema (hoarse voice, dyspnea, swollen eyelids, CNS)
- CNS signs
How do you treat VTEC in pig?
- fasting to eliminate toxin
- increases intestinal peristalsis
- antimicrobial therapy
How do you prevent VTEC in pigs?
- reduce stress
- feed restriction, increase fiber content, starter feed before weaning
- adaptation of intestinal flora (probiotics, organic acids, zinc oxide, antimicrobials, vaccination)
- selection of F18 receptor negative animals
What are the symptoms of UTI E. coli in pigs?
- anorexia
- hematuria
- vaginal exudate
- general malaise
What is MMA of PPDS?
What are the possible etiologies?
- Metritis-Mastitis-Agalactiae
- Post Partum Dysgalactiae Syndrome
- problem in milk production
- E: hereditary, hormonal, feed, infectious agents
What are the symptoms of ETEC in bovines?
What age is affected?
- watery diarrhea leading to dehydration
- less than 3 days old, neonates
Virulence factors of ETEC in bovines
- fimbriae (F5, F41, F17, CS31A)
- toxins (Sta and Stb)
EPEC in pigs
symptoms, mechanisms, diagnosis
- diarrhea at weaning
- attachment to enterocytes, effacement of microvilli
- type 3 secretion system: injection of effector proteins into host cell
- diagnose by isolation and PCR
How to treat bovines with ETEC.
On milking farms?
- separate ill animals
- hydration
- antibiotics
- NSAID (for shock)
- MF: separate calves from mother, colostrum from another, antibiotics, vaccinate moms
What age does VTEC (Edema disease) affect piglets?
post weaning
What media necrosis by the toxin produced by VTEC in each chronicity of infect?
(hyperacute, acute, chronic)
Hyperacute: enterorrhagia
Acute: permeability of blood vessels leading to edema
Chronic: intravascular coagulation
Describe the pathogenesis of ETEC in bovines
- oral uptake
- multiplication
- enterotoxin production
- secondary septicemia
Diagnosis of ETEC in bovines
- ELISA
- culture+virulence factors (agglutination or PCR)
EPEC and EHEC in bovines
age, virulence factors, symptom, location, therapy
- 1-8 weeks
- muccoid diarrhea +/- blood
- large intestine
- antibiotics
- EPEC: eae
- EHEC: eae, VT, zoonotic
Virulence factors of NTEC in bovines
- serum resistance
- iron uptake
- endotoxin
- capsule
- adhesion factors
- CNF toxins
How does the cow become infected with NTEC?
- per os via lymphoid tissues of head and throat or intestine
- via umbilical cord
- too little colostrum
Symptoms of NTEC in bovines at each level of chronicity
Hyperacute: acute mortality, shock
Acute: general symptoms, fast mortality
Chronic: slow with organ localization
How do you treat NTEC in bovines
- NSAID (shock)
- antibiotics
- gamma globulins
Describe the pathogenesis of Neonatal colibacillosis (in avians)
- contamination of egg shell (shrinking of content and entrance of bacteria), neonatal contamination, manipulation of chicks
- yolk rest infection
- sepsis (then death), polyserositis, airsac, pericad (growth retardation)
