Review of current methodologies to isolate and identify Campylobacter spp. from foods. (Special Issue: Update on methodologies to study Campylobacter species.)

摘要

This article summarizes the most effective protocols to isolate Campylobacter spp. (mainly Campylobacter jejuni and Campylobacter coli) from food, primarily poultry products, and includes a summary of the current methods recommended by the Food and Drug Administration and the U.S. Department of Agriculture in the USA, and ISO in Europe. The recommended temperature for incubation of the samples throughout the isolation procedure is 42 degrees C. The enrichment of the samples for 48 h, which can be performed under aerobic conditions, is recommended to achieve a detectable number of Campylobacter cells. Bolton broth or buffered peptone water supplemented with cefoperazone and amphotericin B is commonly used enrichment broths. The transfer of the enriched samples to plate media using membrane filters helps to obtain pure Campylobacter colonies. Charcoal cefoperazone deoxycholate (CCDA) is the best choice among all plate media. There is no need to add oxygen quenching substances or blood to enrichment broth for the isolation of Campylobacter spp. However, the addition of blood to plate media aids in differential identification of presumptive colonies. Phase contrast microscopy and latex agglutination tests are confirmatory tests for presumptive Campylobacter isolates. The use of multiplex polymerase chain reaction (mPCR) assays is the simplest and most rapid method to identify isolates to the species level. mPCR assays, or other methods assessing DNA sequence variations, will probably become the confirmation procedure of choice in the future. Recent work with retail broiler meat has revealed that the rinsing of meat is more sensitive for the recovery of naturally contaminated retail broiler meat than current reference methods and requires less time for preparation and processing of the samples. This protocol could be coupled with DNA-based methods for a fast screening of positive samples.