POLYMERASE CHAIN-REACTION DETECTION AND SPECIATION OF CAMPYLOBACTER-UPSALIENSIS AND C-HELVETICUS IN HUMAN FECES AND COMPARISON WITH CULTURETECHNIQUES

A polymerase chain reaction (PCR) assay based on the 16S rRNA gene and an improved DNA extraction procedure were developed for the direct de tection and differentiation of Campylobacter upsaliensis and C. helvet icus in seeded human faeces, The PCR assay was compared with culture d etection by a membrane filter (MF) technique and on selective agar (SA ) containing 8 mg l(-1) cefoperazone, Both MF culture and the PCR assa y detected 10(5) colony-forming units (cfu) g(-1) faeces. Selective ag ar culture of some strains could detect as few as 10(3) cfu g(-1) faec es, However, some strains were susceptible to cefoperazone and either Failed to grow or were detected only with reduced sensitivity in the p resence of the antibiotic. Detection by MF and SA both required 48-96 h incubation in a microaerobic atmosphere and did not specifically ide ntify the isolate. By contrast, the PCR assay could be completed withi n 8 h and accurately identified the two phenotypically similar species , C. upsaliensis and C. helveticus.