Medical Microbiology

306 4 BacteriaasHumanPathogens

Campylobacter,Helicobacter,Spirillum............................

&Campylobacter,Helicobacter,andSpirillumbelongtothegroupofspiral,

motile,Gram-negative,microaerophilicbacteria.C.jejunicausesaformof

enteritis.Thesourcesofinfectionarediseasedanimals.Thepathogensare

transmittedtohumansinfood.Thediseasesaresometimesalsocommunic-

ableamonghumans.Thepathogensareidentifiedfordiagnosticpurposesin

stoolculturesusingspecialselectivemediums.Helicobacterpyloricontribute

tothepathogenesisoftypeBgastritisandpepticulcers.Spirillumminus

causesratbitefever,knownassodokuinJapanwhereitisfrequent. &

ThegeneraCampylobacter,Helicobacter,andSpirillumbelongtothegroupof

aerobic,microaerophilic,motile,Gram-negativerodbacteriawithahelical/

vibrioidform(p.220).Humanpathogensarefoundinallthreegenera.

Campylobacter.........................................

Classification.Forseveralyearsnow,Campylobacterbacteriahavebeenclas-

sifiedtogetherwithArcobacter(medicallyinsignificant)inthenewfamily

Campylobacteriaceae(fam.nov.).ThegenusCampylobactercomprisesnumer-

ousspecies,amongwhichC.jejuni(morerarelyC.coli,C.lari)aswellasC.

fetushavebeenobservedascausativepathogensinhumaninfections.

Morphologyandculture.Campylobacterareslender,spirallyshapedrods

0.2–0.5lmthickand0.5– 5 lmlong.Individualcellsmayhaveonespiral

windingorseveral.Asingleflagellumisattachedtoeitheroneorbothpoles.

Campylobactercan,undermicroaerophilicconditions,andinanatmo-

spherecontaining 5 %O 2 and 10 %CO 2 ,beculturedonbloodagarplates.

TheoptimumproliferationtemperatureforC.fetusis 258 CandforC.jejuni

428 C.

Pathogenesisandclinicalpictures.Thedetailsofthepathogenicmecha-

nismsofthesepathogensarelargelyunknown.C.jejuniproducesanentero-

toxinsimilartotheSTaproducedbyE.coliaswellasanumberofcytotoxins.

C.jejunicausesaformofenterocolitiswithwatery,sometimesbloodydiar-

rheaandfever.Theincubationperiodistwotofivedays.Themanifestillness

lastslessthanoneweek.

C.fetushasbeenidentifiedinisolatedcasesasapathogeninendocarditis,

meningitis,peritonitis,arthritis,cholecystitis,salpingitis,andsepsisinim-

munocompromisedpatients.

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Kayser, Medical Microbiology © 2005 Thieme