Modified enrichment strategies coupled with molecular and conventional methods to detect and quantify Campylobacter jejuni in chicken meat from the market.

摘要

C ampylobacter spp. are currently the bacterial foodborne pathogen that causes the highest number of gastrointestinal diseases in developed countries, according to the World Health Organization. The aim of this study was to compare the performance of four C ampylobacter enrichment broths: Bolton broth, Bolton broth with blood, Preston broth and Preston broth with blood using both culture-dependent methods and an optimized quantitative polymerase chain reaction (qPCR) protocol. The enrichment in Bolton broth with blood allowed most positive samples for C ampylobacter jejuni to be detected when 40 chicken meat samples from the market were tested. Correlation between cultural methods and molecular methods was poor. Only in a few cases could C. jejuni and C ampylobacter spp. be identified by PCR. Out of 480 colonies isolated throughout the enrichment process, only seven colonies could be identified as C ampylobacter spp., three of which were C. jejuni. Enrichment of chicken meat samples with Bolton broth added with blood, coupled with qPCR resulted to be the most suitable method to detect samples contaminated with C. jejuni. Practical Applications. Detection and identification of C ampylobacter spp. in food is still a challenge and there is lack of consensus on the methodology that should be used in order to recover these fastidious microorganisms. The application of molecular methods, such as the amplification of a target gene sequence by PCR, in order to rapidly and inequivocally detect and identify foodborne pathogens in foodstuff, offers a valid alternative to traditional microbiological testing. In this study, we investigated the performances of combined enrichment strategies with a specific C. jejuni qPCR protocol. The molecular approach resulted to be superior with respect to traditional plating and was able to detect a higher number of C. jejuni positive samples. Among the enrichment broths tested, Bolton broth added with blood resulted to be the most suitable for the detection of C ampylobacter spp. in poultry meat