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

Thomai Lazou,Chrysostomos Dovas,Eleni Iossifidou

doi:10.2478/acve-2021-0017

Abstract

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.

Highlights

The awareness of the genuine population of foodborne pathogens that could be released and recovered from meat surfaces is necessary for the accurate evaluation of data relevant to veterinary public health
Lazou et al.: Method-related impacts on Campylobacter coli recovery from sampling materials and meat the real bacterial contamination is unknown, results normally rely on the ratio of colony forming units (CFU) obtained from destructive and non-destructive sampling methods in order to compare the relative bacterial recovery between them
An overall low bacterial recovery (3.2 – 28.9%) from the artificially inoculated samples was determined by qPCR, with cellulose sponge and polyester bud being superior to cotton bud, and direct homogenization of meat more efficient than swabbing (Figure 2)

Summary

Introduction

The awareness of the genuine population of foodborne pathogens that could be released and recovered from meat surfaces is necessary for the accurate evaluation of data relevant to veterinary public health. Lazou et al.: Method-related impacts on Campylobacter coli recovery from sampling materials and meat the real bacterial contamination is unknown, results normally rely on the ratio of colony forming units (CFU) obtained from destructive and non-destructive sampling methods in order to compare the relative bacterial recovery between them. The meat industry favours the use of non-destructive methods, such as swab sampling, since they neither damage the carcass surface nor affect its commercial value in contrast to excision methods [1,3,5]. Recovery of bacteria from swabbing materials is dictated by the specimen uptake into and its subsequent release from the adsorbing material. Excision typically yields higher counts of bacteria recovered from sampled meat surfaces compared to swab sampling [1,5,7]

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Conclusion