6 CampylobacterFive different species of Campylobacter may be isolated from clinical specimens.C. sputorum, biovar sputorum – is part of the normal oral flora of humansC. fetus, ssp. fetusC. fetus, ssp. venerealisC. jejuniC. coliThey are so small that they will pass though .65 uM filters that filter out most enteric bacteriaThey grow best at reduced O2 and increased CO2 concentrations of 10% (is capnophilic)
7 CampylobacterThe enteric species (C. coli and C. jejuni) are best isolated at 420 C since this is their optimal growth temperature and the higher temperature will suppress the growth of many other enteric organisms.The organisms grow well on CBA a chocolate, and poorly on Mac plates.It may take 48 hours for the small, translucent colonies to appear.
8 Campylobacter Biochemistry Selective agar may be used to isolate the enteric Campylobacter sp.CampyBAP – Brucella agar base with 10% sheep blood, vancomycin, trimethoprim, polymyxin B, amphotericin B, and cephalothin to supress NF.Skirrows media – contains lysed, defiriinated horse blood and vancomycin, polymyxin B, and trimethoprim.BiochemistryOxidase +Catalase + (except sputorum)ID by above, growth requirements, and G stain morphology
10 Campylobacter sp Virulence factors Clinical significance Enterotoxin EndotoxinAdhesionsIntracellular survivalAbility to penetrate cellsClinical significanceGastroenteritisCaused mainly by C. jejuni and C. coli
11 Campylobacter spAcquired by ingestion of contaminated food or water or contact with an infected animal (bird or mammal).The organism invades the epithelium of the lower small intestine and multiplies.The invasion produces an inflammatory response that may be responsible for many of the symptoms.Symptoms start 1-10 days after ingestion with vague abdominal cramps that progress to crampy abdominal pain, bloody diarrhea, chills, and fever for 3-6 daysUntreated patients may excrete the organism for several monthsErythromycin is used in severe cases
12 Campylobacter sp Campylobacter-like organisms – Helicobacter pylori Systemic infectionsUsually due to C., fetus ssp. FetusOccur in debilitated or immunocompromised individualsCampylobacter-like organisms – Helicobacter pyloriSmall, gram-negative, curved rodGrown on same media and under same conditions as Campylobacter, but may take 5 days to grow.Differentiated from Campylobacter based on strong urease + test (may become - in as short as 10 minutes)
14 Helicobacter pylori Virulence factors Adhesions – BapA and HpaA Vacuolating Cytotoxin (VacA) - forms a pore in host cell membranes and induces apoptosisNeutrophil-Activating protein (NAP) - activates neutrophils and mast cells that damage local tissuesEndotoxinUrease – facilitates survival in the stomach by raising the pH, provides access to nitrogenous nutrients needed by the bacteria for growth, and the NH4+ endproduct may cause cell damage and inflammationFlagella – allow bacteria to penetrate through gastric mucousCollagenase/Mucinase –degrades gastric collagen and mucous,exposing gastric epithelium to gastric acidCagA – is injected into host epithelial cells where it activates host signal transduction pathways that can stimulate growth→ cancer?
15 Helicobacter pylori Clinical significance Responsible for chronic, active gastritis and peptic ulcers – symptoms include nausea, vomiting, anorexia, and epigastric painThere is an association between H. pylori and carcinoma of the stomachpossibly due to chronic inflammationPossibly due to the activity of CagA.Activates signal transduction pathways that cause an increase in cell cycling that can contribute to the development of cancer.
17 Helicobacter pylori Neutrophil activatiing protein Plus neutrophil activating protein
18 Helicobacter pylori Diagnosis – BiopsyNon-invasive urea breath test – oral 14C labeled urea is given and the breath is monitored for 14CO2Treatment – administration of several antimicrobial agents, including meteonidazole, tetracycline, amoxicillin, and clarithromycinNew ecological studies with H. pylori:Has been a part of normal human flora as far back as been studiedChanges associated with modern life have lead to a decrease in the number of humans who harbor the organism
19 Helicobacter pyloriThe decrease in H. pylori is associated with an increase in esophageal adenocarcinoma!
20 Summary of Campylobacter and Helicobacter infections