Development of isolation and identification methods for emerging species of Campylobacteraceae

Abstract

Recently, a number of emerging species of Campylobacteraceae have been isolated from clinical samples using antibiotic-free isolation media and a hydrogen-enriched incubation atmosphere, questioning their importance in human disease.

This PhD study was carried out as part of an EU collaborative project to investigate existing methods for isolation of emerging Campylobacteraceae species and to improve current isolation and identification procedures.

Evaluation of a range of currently used selective isolation media indeed showed that a number of selective media and antibiotics contained in these media inhibited the growth of a number of Campylobacteraceae species.  Subsequently, a novel medium, ABA VAT, containing minimal levels of antibiotics was developed to allow the isolation of all Campylobacteraceae species.  Commercially available incubation atmospheres were also shown to be sub-optimal for the growth of many Campylobacteraceae species.  A novel, universal incubation atmosphere, containing low levels of oxygen and supplemented with hydrogen (3%, O_2, 10% CO₂, 7% H₂), permitted the growth of all Campylobacteraceae species.  It was demonstrated that even the species thought to grow only under anaerobic conditions could grow in this atmosphere and that hydrogen was essential for growth of a number of species.  A range of identification methods was also evaluated, including phenotypic tests, EDIC microscopy, latex agglutination, fluorescence in situ hybridisation and a typing method using a 2D gel electrophoresis approach.

The novel isolation methods developed were incorporated into protocols so that recovery of Campylobacteraceae species from sewage and salad vegetable samples could be investigated.  Results showed that a number of non jejuni/coli Campylobacter species could be isolated from sewage and salad vegetables.  An important and previously unreported finding was the high isolation rate of the emerging pathogen, A. butzleri, from processed salad vegetables, which is potentially of public health concern.

More information

Identifiers

Catalogue record

Export record

ASCII CitationAtomBibTeXData Cite XMLDublin CoreDublin CoreEP3 XMLEndNoteHTML CitationHTML CitationHTML ListJSONMETSMODSMPEG-21 DIDLOpenURL ContextObjectOpenURL ContextObject in SpanRDF+N-TriplesRDF+N3RDF+XMLRIOXX2 XMLReferReference ManagerSimple Metadata