Campylobacter

2. Campylobacter

3. Campylobacter • Comma shaped ,gram (-) rods,0.2-0.5μm wide ₓ 0.5-5.0 μm • Motile by a polar flagellum • Most species microaerophilic • 25 species and 11 subspecies • Different O antigens, heat-labile capsular and flagellar antigens are used for epidemiological classification of clinical isolates • C.jejuni : gastroenteritis • C.coli : gastroenteritis • C.upsalensis: gastroenteritis • C.fetus: systemic infections (bacteremia, septic thrombophlebitis, arthritis, septic abortion, meningitis)

4. Campylobacter jejuni • Structure :Thin ,gram (-) rods with comma , S or gull wings shapes, motile with a single polar flagellum. • Culture: Charcoal or blood (remove toxic oxygen radicals) with antibiotic added media is required • grows at 37-42°C in a microaerophilic conditions ( 5%-7% oxygen) and 5%-10%CO2 on selective Skirrow`s medium contains vancomycin ,polymyxin B , and trimethoprim . Colonies are colorless to gray. • Growth characteristics : oxidase (+), catalase (+) • Small size of Campylobacter is used for recovering by filtration of stool specimen ( 0.45 μm filter) • Do not oxidize or ferment carbohydrates • Antigenic structure : LPS , enterotoxins

7. Campylobacter (Virulence) • cytotoxic enzymes , enterotoxins, adhesins are detected • Factors that regulate adhesion, motility and invasion into intestinal mucosa are poorly defined. • Guillain – Barre syndrome believed to be an autoimmune disorder of the peripheral nervous system characterized by development of symmetrical weakness over several days and recovery requiring months . caused by antigenic cross-reactivity between oligosaccharides in bacterial capsule and glycosphingolipids on surface of peripheral nerve gangliosides • Reactive arthritis: immune-related late complication ; painful joint swelling that may last for weeks to a year

8. Campylobacter jejuni • Pathogenesis : • Is acquired by the oral from food, drink or contact with infected animals and animal products. • Is susceptible to acids, 100-500 organisms is need for infection. • Risk of disease is influenced by infectious dose. • Patient`s immune status affects the severity of disease • Patients with hypogammaglobulinemia have prolonged , severe disease

9. Campylobacter jejuni(Pathogenesis) • Multiply in the small intestine, invade the epithelium, produce inflammation. • Mucosal surface appears: - ulcerated, edematous, bloody - crypt abscesses in epithelial glands - infiltration of the lamina propria with neuthrophils, mononuclear cells, and eosinophils

11. Campylobacterjejuni(Pathogenesis) • Gastrointestinal disease produces histologic damage to the mucosal surfaces of the jejunum, ileum, colon • Rarely , the bloodstream is invaded (like enteric fever) (1.5/1000) • Role of cytopathic toxins, enterotoxins and endotoxic activity have not been defined • Are killed rapidly by complement and antibody- mediated serum killing

13. Campylobacter( epidemiology) • Zoonotic infection ; improperly prepared poultry is a common source of human infections • Infections acquired by ingestion of contaminated food (poultry), unpasteurized milk, or contaminated water • person- to- person (fecal-oral) spread is unusual • Worldwide distribution, with enteric infections most commonly seen in warm months.

15. Campylobacter (diseases)

16. Campylobacter jejuni(diseases) • Acute enteritis with diarrhea, malaise, fever, and abdominal pain. More than10 bowel movement per day , bloody stools • Most infections are self-limited but can persist for a week or more • Colitis, abdominal pain mimicking acute appedicitis, bacteremia • Chronic enteric infection develop in immunocompromised patients (AIDS) and difficult to treat. • Extraintestinal infections are uncommon • Complications: - C.jejuni ( serotype O:19)and C.upsalensis are associated with Guillain-Barre syndrome(1/1000) - reactive arthritis

17. Campylobacter jejuni(Diagnosis) • Specimens :stool • smears: typical “gull wing “shaped rod in Gram strain ,Darkfield ,phase contrast microscopy • Culture :requires use of selective media ( Skirrow ) or incubated in 5-10 CO2 (5-7% O2 , microaerophiliccondition) and 42 °C ; requires incubation for 2 or more days. • Identification: catalase (+). Oxidase(+)

18. Campylobacter ( diagnosis )

19. Campylobacter jejuni(Diagnosis) • Antigen detection: immunoassay detection of C.jejuni and C.coli • Sensitivity 80%-90% , specificity >95% • Antibody detection: serologic testing for IgM and IgG are useful for epidemiological survays

20. Campylobacter ( treatment, prevention ,and control) • Treatment : for gastroenteritis , infection is self-limited and is managed by fluid and electrolyte replacement • Serve gastroenteritis and septicemia are treated with erythromycin, azithromycin (drugs of choice) , tetracycline, clindamycin, amoxiclave, imipenem, or fluoroquinolones. • More strains are resistant to penicillin, cephalosporins and sulfanamide • Prevention: Gastroenteritis is prevented by proper preparation of food and consumption of pasteurized milk; preventing contamination of water supplies also controls infection.

21. Campylobacter fetus • C.fetus is associated with septicemia and is disseminated to multiple organs and causes diarrhea (uncommon disease) • Spread from the gastrointestinal tract to the blood and distal foci. • Spread is common in debilitated and immunocompromised patients (liver disease, diabetes mellitus, chronic alcoholism, malignancies) • S protein (heat-stable S layer) in C.fetus inhibits C3b binding and subsequent complement and antibody -mediated phagocytosis and killing (resistant to serum killing)

22. Campylobacter fetus • Diseases: - intravascular infections (septicemia, endocarditis, septic thrombophlebitis) - extraintestinal infections (meningoencephalitis, abscesses) Diagnosis: like C. jejuni, but cannot grow at 42 C

23. C.upsalensis • Catalase (-) or weakly (+). • Growths at 42C • Highly susceptible to drugs in selective media (skirrow ) • Filter method is suitable for isolation • Domestic pets and cats are reservoir • Opportunistic agent of infections in children • Present as acute enteritis with diarrhea , fever and abdominal pain • Isolates from stool, blood , fetoplasental material of human • Is associated with Guillain-Barre syndrome

25. Arcobacter

26. Arcobacter • The genus Arcobacter which is related to Campylobacter was introduced in 1991. • Are aerotolerant • Optimal growth temperature is at 30oC. • Members of this genus inhabit very diverse environments • Distinguishing from Campylobacter: - Hydrolysis of indoxyl acetate - growth at 15-36◦ C ,but not at 42◦ C - Inability to hydrolyze hippurate • separated to 5 major groups: • A.cryaerophilus (2 subgroups) • A.nitrofigilis • A.butzleri • A.skirrowii • A. halophilus

27. Arcobacter • A.cryaerophilus: grows well under aerobic conditions. May require microaerophilic conditions for initial isolation • Optimal growth at 30◦ C • Resemble C.fetus but is Indoxyl acetate (+) • Sensitive to nalidixic acid, resistant to cephalothin • Growth in CIN agar is better than Skirrow • A. cryaerophilus has been found both in association with diseased as well as healthy humans and animals caused that these bacteria were considered to play a role as food borne or waterborne agents

28. Arcobacter • A.nitrofigilis: • a nitrogen fixing bacterium • a cryophilic species • Grows optimally at 25◦ C • Urea (+) • Non pathogenic for human • A. skirrowii: • isolates from fluids of bulls, aborted fetuses and diarrheal feces from cows , pigs and sheep.

29. Arcobacter • A.butzleri: aerotolerant both at 30◦ C and 36◦C ( separatation from A. cryaerophilus ) • Grows on MacConkey and glycine and nitrate containing media and in 1.5% and 3.5% NaCl • Isolated from stools of patients with diarrheal illness. • Rarely isolates from abdominal contents , peritoneal fluid and blood

31. Helicobacter

32. Helicobacter • First isolated by Marshal and Warren in1983 • Spiral , G(-) rods resembling campylobacter (0.5-1.0μm wide*2-4 μm long) , coccoid form in older cultures • Motile (polar flagella) • catalase and oxidase (+) - 30 species are characterized according to: • sequence analysis of their 16S rRNA genes • cellular fatty acid , (different from Campylobacter with high % of O:14 and low O:16 and presence of O:18-OH-3) • presence of polar flagella

33. Helicobacter ( diseases) • H.pylori : (gastric) Gastritis , peptic ulcer, gastric adenocarcinoma, gastric mucosa-associated lymphoid tissue (MALT) B-cell lymphomas • H.cinaedi: enterohepatic (isolated from homosexual men with HIV) Gastroenteritis, septicemia, proctocolitis, cellulitis • H.fennelliae :enterohepatic(isolated from homosexual men with HIV) Gastroenteritis, septicemia, proctocolitis • Helicobacter species flexispira taxon 8: bactermia with cellulitis in immunocompromised patients • H.canadensis : Gastroenteritis • H.canis:Gastroenteritis • H.pullorum:Gastroenteritis

34. Helicobacter pylori • Morphology : Curved, gram- negative rods , motile by multiple flagella at one pole • Lipid A has low endotoxin activity compared with other (-) bacteria • O side chain is antigenically similar to Lewis blood group antigens, which may protect the bacteria from immune clearance

35. H.pylori • Culture: require complex medium supplemented with 5% defibrinated horse or sheep blood, serum, charcoal, starch, egg yolk( Brucella agar ,BHI,or TSB mediums with supplements and antibiotics ) . • Microaerophilic conditions( 10% CO2, 5% O2 and 85% N2 or 10%CO2 with air ). • Grows in 3-6 days at 37°C in a microaerophilic environment in Skirrow`s medium with vancomycin, polymyxin B and trimethoprim ; and in chocolate medium

37. H.pylori • Growth characteristics : oxidase- positive , catalase-positive, do not ferment or oxidase carbohydrates, metabolize amino acids by fermentative pathways -Urease production at very high levels is typical of gastric helicobacters, and uncommon in intestinal helicobacters - Flagella and urease are important for survival in gastric acids and rapid movement through the viscous mucus layer towards a natural pH environment

38. H.pylori ( Virulence factors)

39. H.pylori (pathogenesis) • Virulence factors: • A-Initial colonization of H.pylori facilitate by: 1- blockage of acid production by acid inhibitory protein 2- Urease activity ; -neutralization of gastric acids by production of the ammonia - stimulate monocytes and neuthrophils chemotaxis - stimulate production of inflammatory cytokines - stimulate production of high amount of gastrin and acid

41. H.pylori (pathogenesis) • B- H.pylori can pass through the gastric mucus by actively motility of flagella • C- adhere to the gastric epithelial cells by multiple surface-adhesion proteins - haemagglutinins ; binding to N-acetyl-noraminil-lactose - sialic acid- binding adhesin - pili; adhere to phosphatidyl-ethanol amin and laminin - Lewis blood group adhesin; may protect the bacteria from immune clearance • Surface proteins can also bind host proteins and help the bacteria evade immune detection.

42. H.pylori (pathogenesis) • D- Localized tissue damage is mediated by: 1- Urease byproducts 2-Mucinase; disrupts gastric mucus 3-Phospholipases; C,A1,A2 ; disrupts gastric mucus 4-Vacuolating cytotoxin A (VacA); after endocytosis by epithelial cells, damage the cells by producing vacuoles - 60% of H.pylori strains produces Vac A but toxin production is not seen in strains of Patient with long time non-ulcerative gastritis

43. H.pylori (pathogenesis) • E- Cag A protein ; interferes with the normal cytoskeletal structure of the epithelial cells - an important virulence factor of H.pylori is the Cytotoxin-associated gene (cagA) that resides on a pathogenicity island containing approximately 30 genes. - These genes encode a structural (type IV secretion system) that acts like a syringe to inject the Cag A protein into the host epithelial cell • The cag PAI (phosphoribosylanthranilate isomerase) genes also induce IL-8 production, which attracts neutrophils. • Release of proteases and reactive oxygen molecules by the neuthrophils is believed to contribute to gastritis and gastric ulcers

44. H.pylori (pathogenesis) • F- Superoxide dismutase; prevent phagocyting killing by neutralizing oxygen metabolites • Catalase; prevent phagocyting killing by neutralizing oxygen peroxides • Heat- shock proteins; enhances expression of urease

45. H.pylori (pathogenesis) • Long life colonization in the antrum of stomach of untreated humans • Grows at pH = 6-7 • Gastric mucus is impermeable to acid and has a buffering capacity. • On the lumen side of the mucus pH is low (1-2) ;on the epithelial side pH is about 7.4 • H.pylori produces a protease • urease activity produces ammonia • TNF-α, IL-6 and IL-8 , urease activity and cytokines are caused Chronic inflammation of stomach

46. H.pylori (pathogenesis) • H.pylori infection (weeks to months) chronic superficial gastritis ( years to decades ) - peptic ulcer disease; - chronic superficial gastritis; - chronic atrophic gastritis gastric adenocarcinoma

47. H.pylori ( epidemiology) • Infections are common, particularly in people in a low socioeconomic class or in developing nations (70%-90%) • Humans are the primary reservoir; Incidence of carriage in developing nations (70%-90%) most before age 10 years. • Person-to-person spread is important (typically fecal-oral) • is worldwide with no seasonal incidence of disease • 70%-100% of patients with gastritis, gastric ulcer, duodenal ulcers are infected with H.pylori • Colonization with H.pylori appears to offer protection from gastroesophagal reflux disease and adenocarcinoma of the lower esophagus and gastric cardia

48. Diseases • Gastritis ; infiltration of neutrophils and mononuclear cells in to gastric mucosa. • Acute phase: feeling of fullness; nausea; vomiting; hypochlorhydria ( decreased acid production ); • Chronic phase: disease confined to the gastric antrum in individuals with normal acid secretion, or involve the entire stomach (pangastritis) if acid secretion is suppressed.

50. Diseases • Peptic ulcer (10-15%) in chronic gastritis. Developing to gastric ulcer (isolate 85%) or duodenal ulcer(isolate 95%) • Gastric cancer; replacement of normal gastric mucosa with fibrosis and proliferation of the epithelium in chronic gastritis. (high risk for cancer is associated with cagA positive strains and high levels of IL-1 production) • MALT lymphoma; monoclonal population of B cells