Microbiological Assessment of Dairy Products Produced by Small-Scale Dairy Producers in Serbia

Abstract

The microbiological quality of dairy products from small-scale producers in Serbia was analysed. A total of 302 dairy products [raw (n = 111) and pasteurized milk cheeses (n = 79) and kajmak (n = 112)], were collected and tested for the presence of pathogens, Listeria monocytogenes and Salmonella spp., and enumerated for Coagulase-positive staphylococci (CPS), Escherichia coli, and yeasts and moulds. None of the samples tested positive for Salmonella spp., while L. monocytogenes was recovered from one raw milk cheese and five kajmak samples. Raw milk cheese and kajmak also had higher levels of indicator microorganisms, namely E. coli and yeast and moulds. Molecular serotyping grouped L. monocytogenes isolates into serogroups 1 (1/2a and 3a) and 3 (1/2b, 3b, and 7). When exposed to eight antibiotics, L. monocytogenes isolates were mostly sensitive, with the exception of oxacillin and reduced susceptibility to clindamycin, penicillin G, and trimethoprim/sulfamethoxazole, emphasizing the importance of continuous surveillance for antimicrobial resistance. Samples that tested positive for Listeria spp. also had higher loads of indicator microorganisms, namely E. coli and yeast and moulds, suggesting lapses in hygiene practices during production. Collectively, these data emphasize the need for improved food safety and hygiene practices among small-scale dairy producers. This is crucial to reduce the microbial contamination and improve both the quality and safety of dairy products in the Serbian market.