Purpose: The aim of the present study was to evaluate RAPID’Campylobacter agar (RAPID; Bio-Rad, France) for quantification of Campylobacter in poultry samples and to compare results with those from the widely used modified Charcoal Cefoperazone Deoxycholate Agar (mCCDA) and Campy Food®Agar (CFA; bioMérieux, France).
Methods: Analysis of 12 artificially and 36 naturally contaminated samples was performed in parallel on RAPID, mCCDA and CFA plates. One ml from each homogenized sample was spread plated on 2 agar plates (0.5 ml on each plate), while 0.1 ml of further dilutions was plated using a spiral plater. After incubation, at least 4 presumptive positive colonies were confirmed by microscopic examination and PCR test. The agreement between Campylobacter counts obtained by the different agars was calculated using Lin’s concordance correlation coefficient (CCC) and by Bland–Altman plot.
Results: Concordance correlation coefficient (CCC) between overall (artificially and naturally contaminated samples) Campylobacter counts on RAPID and on mCCDA agars was 0.973 (95% CI: 0.949 - 0.986). When plotting overall Campylobacter counts obtained by CFA against counts from RAPID plates, the CCC was 0.978 (95% CI: 0.961 - 0.988). Further, the Bland-Altman plot showed low variation in Campylobacter counts obtained between RAPID and the other two agars mCCDA and CFA.
Significance: RAPID agar is a highly sensitive and selective medium for the recovery of Campylobacter. The results obtained are in agreement with other commonly used agars, and therefore, RAPID media is a reliable tool for the Campylobacter enumeration in poultry meat samples.