campylobacters helicobacters and related organisms chro s n.
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Campylobacters, Helicobacters and related organisms (CHRO’s). Veterinary pathogens. Ovine/Bovine abortion C. fetus ss fetus C. jejuni A. cryoaerophila Bovine infectious infertility C. fetus ss venerealis A. skirrowii. Campylobacter species. Gram negative ‘seagull’, spiral shaped

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slide2

Veterinary pathogens

  • Ovine/Bovine abortion
  • C. fetus ss fetus
  • C. jejuni
  • A. cryoaerophila
  • Bovine infectious infertility
  • C. fetus ss venerealis
  • A. skirrowii
campylobacter species
Campylobacter species
  • Gram negative ‘seagull’, spiral shaped
  • Motile
  • Microaerophilic (reduced oxygen)
  • Like enriched medium
  • Non fermentative
  • Oxidase positive
  • Commensals of the intestinal tract of animals
  • Pathogens in reproductive and enteric tracts
laboratory identification
Laboratory identification
  • Wet mount of faeces  corkscrew-like darting motility
  • Use of selective media containing antibiotic cocktail to suppress faecal commensals (Poly/Rif/Tri/Cyclo)
  • Grow at 37 or 42 degrees
  • Microaerophilic atmosphere
  • Colonies small (1-2 mm), round, smooth, mucoid, translucent, dewdrop-like appearance on blood agar (C.fetus)
  • Confirm by smear and Gram stain
  • Identify using API
  • Antimicrobial sensitivity testing
c jejuni and c coli in animals
C. jejuni and C. coli in animals
  • C. jejuni is part of normal intestinal flora in birds
  • No disease association in poultry
  • C. coli – normal intestinal flora in pigs.
  • C. jejuni and C. coli may cause acute diarrhoea in very young animals but not older animals
  • 1970’s it was discovered these organisms cause acute diarrhoea in humans
intestinal campylobacteriosis in dogs
Intestinal Campylobacteriosis in dogs
  • C. jejuni causes acute diarrhoea in puppies
  • Typically develops diarrhoea after acquisition
  • Typical history of recently acquired puppy develops bloody or watery diarrhoea followed by owner or child in the household getting diarrhoea
  • Get isolates from both dog and owner to establish transmission!
  • Healthy animals may shed C. jejuni with no symptoms
  • May be part of mixed infection (+ enteric virus, Giardia, helminths etc)
slide8

CAMPYLOBACTERIOSIS - Campylobacter jejuni colitis, gross lesions of focal congestion and mucus production, dog.

campylobacter fetus sub species fetus
Campylobacter fetus sub species fetus
  • Sporadic abortion in sheep often late in gestation
  • Transmitted by contaminated food or water
  • Bacteraemia ensues, organism spreads to distal sites including placenta
  • Abortion in the 3rd trimester of ovine gestation results from placentitis
  • Sporadic abortion in cattle, goats, pigs and horses
  • Bloodstream infection in man (usually but not always with underlying immunocompromise)
campylobacters in sheep abortion
Campylobacters in sheep abortion
  • Present in intestine
  • Invades tissues
  • Invades uterus
  • Invades foetus
  • Kills foetus
  • Aborted mummified foetus
  • Campylobacter in foetal liver
  • Campylobacter in discharges
pathogenesis ovine abortion
Pathogenesis (ovine abortion)
  • C. fetus ss fetus
  • High molecular weight protein S-layer on the surface of the bacterium
  • S-layer fails to bind C3b of complement and prevents phagocytosis by neutrophils
  • S-layer mutants are of reduced virulence in disease model
  • S-layer shields LPS as a means of decreasing immunogenicity
campylobacter fetus sub species venerealis
Campylobacter fetus sub species venerealis
  • The cause of bovine venereal campylobacteriosis (BVC – sexually transmitted bovine infectious infertility)
  • Transmitted by infected bulls through normal breeding or artificial insemination
  • Organism recovered from glans penis and distal urethra of infected bulls
  • Ascending infection in cows from vagina to cervix to uterus then oviducts
  • Tempory infertility
  • Abortion in small proportion of infected cows (<10%)
  • Protective immunity eventually develops via IgA in vaginal mucous and IgG in uterus
pathogenesis bvc
Pathogenesis (BVC)
  • C. fetus ss venerealis persists in the vagina of the cow due to antigenic shifts in the immunodominant antigens of the S layer proteins (sapA)
  • Genomic re-arrangements of this locus in weekly isolates
  • sapA promoter on invertible segment that can flip and allow change in expression from S-layer protein gene cassettes
slide16

Campylobacter enteritis in man

  • Incubation 3 days
  • Abdominal pain (severe)
  • Diarrhoea (small volume bloody diarrhoea, watery with blood, watery no blood)
  • Fever
  • Myalgia, malaise
  • (Rigors, high fever delirium)
slide17

Most frequently identified cause of acute infective diarrhoea in man

  • Campylobacter jejuni
  • C. coli (5-15%)
  • Zoonosis – acquired from animals via food (or direct contact)
control in poultry production
Control in poultry production
  • Bio-security

- Hygiene barriers, dedicated footwear, clothing, restriction on numbers entering, boot dipping, hand washing!

  • Thinning
  • Competitive exclusion
  • Inhibitory flora
  • Worse husbandry, more Campylobacter
  • Carcass freezing
pathogenic mechanisms
Pathogenic mechanisms
  • Tissue invasion
  • (GI biopsies of infected patients, primates, animal models, tissue culture cells) –
  • pVir plasmid, type IV secretion system, invade cultured cells
  • Cia proteins secreted via flagella and translocate effector proteins into host cell
  • transcytosis
  • Reduced adhesion/invasion correlates with lack of diarrhoeal disease in ferret models
  • Glycosylation of flagella, LOS, OMP’s
  • Toxins (cytotoxins)
  • LPS – LOS (molecular mimicry, GBS)
  • Activation of host inflammatory mediators IL-8, LTB4, PGE2
  • Understanding advanced by Genome sequence of C. jejuni NCTC 11168
arcobacters
Arcobacters
  • Arcobacters have Campylobacter like morphology
  • Aerotolerant
  • Grow at 30 degrees
  • A. cryoaerophilus, A. nitrofigilis (environmental), A. skirrowii and A. butzleri
  • Possible disease association only just being defined
arcobacters disease association
Arcobacters – disease association
  • A. cryaerophilus – late term abortion in cattle, horses, sheep, and dogs -Mastitic milk, ovine faeces
  • A. butzleri – diarrhoeal disease in humans and animals – potentially zoonotic
  • A. skirrowii – diarrhoeal disease in man, lambs, calves, abortion in swine and cattle
helicobacters in animals
Helicobacters in animals
  • Widely documented in mammals and birds due to frenzy generated by H. pylori! (18+ species)
  • Helicobacter hepaticus is a mouse pathogen and common in breeding colonies from commercial facilities
  • Focal hepatic necrosis leading to chronic disease and hepatocellular tumours
  • H. bilis causes hepatitis in mice, other helicobacters associated with gall bladder disease & gall stones
helicobacter pylori
Helicobacter pylori
  • In 1983, Marshall and Warren described the bacterium now known as Helicobacter pylori
  • Suggested that it may be important in the pathophysiology of chronic active gastritis and peptic ulceration in man
  • They were proved correct (after much controversy) and it is now accepted that H. pylori infection:

■ causes chronic active gastritis;

■ is the main cause of duodenal and gastric ulceration; and

■ is an important risk factor for gastric adenocarcinoma and lymphoma.

slide31

H. pylori prevalence in Westernized versus developing countries. (Adapted from Marshall BJ (1994). , S116–118

slide32

20%

Superficial chronic gastritis

1%

gastric cancer
Gastric cancer
  • The World Health Organization has classified H. pylori as a gastric carcinogen.
  • Infection is associated with an approximately eightfold increased risk of gastric cancer.
  • Eradication of H. pylori from Japanese patients with early gastric cancer greatly diminished the risk of recurrent cancer after endoscopic resection.
  • Whether to eradicate from individuals without ulcers—an issue which is currently unresolved.
  • USA treats anyone over 40 found to have H. pylori whether symptomatic or not in order to prevent gastric cancer