Campylobacters, Helicobacters and related organisms (CHRO’s)

1. Campylobacters, Helicobacters and related organisms (CHRO’s)

2. Veterinary pathogens • Ovine/Bovine abortion • C. fetus ss fetus • C. jejuni • A. cryoaerophila • Bovine infectious infertility • C. fetus ss venerealis • A. skirrowii

3. 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

4. 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

6. 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

7. 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)

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

9. 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)

10. 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

11. Campylobacter abortion

12. 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

14. 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

15. 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

16. 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)

17. 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)

22. 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

23. Antibiotic resistance and human Campylobacter infection

24. 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

25. Adhesion to intestinal tissue

27. 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

28. 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

29. 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

30. 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.

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

32. 20% Superficial chronic gastritis 1%

33. 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