Method-Related Impacts on Campylobacter coli Recovery From Sampling Materials And Meat

Abstract

A defined Campylobacter coli (C. coli) suspension was inoculated on sterile sampling materials (cotton bud, polyester bud, cellulose sponge) and pieces of lamb meat. Various combinations of diluents (phosphate buffer saline ± Tween®80) and sampling methods (direct homogenization, simulating the excision method for meat, and swabbing) were investigated for the recovery (detachment) of C. coli cells from the inoculated samples. The obtained C. coli bacteria, as quantified by real-time PCR with respect to the dilution factors and the initial inoculum, were used for the calculation of the recovery (%) per sampling material and method. Regarding artificially inoculated sampling materials, the lowest recovery was observed for cotton buds (2.8%) and the highest for cellulose sponge (28.9%), and the differences between the obtained results were statistically significant (P < 0.05). As regards lamb meat, the lowest recovery was observed for swabbing with cotton buds (3.2%) and the highest for direct homogenization (10.7%). The results indicate an overall low rate of bacterial recovery from contaminated samples, with cellulose sponges and polyester buds being significantly superior to cotton buds, and direct homogenization of meat with diluent better than swabbing. The type of sampling materials and methods applied for the quantification of C. coli entails a key impact on determining the actual contamination of the examined samples.

Keywords

• campylobacter
• microbiological sampling
• bacterial recovery
• lamb meat