Vegetable salads available at retail stores, supplied by various producers, were analyzed in the study to determine the counts of aerobic mesophilic bacteria, coliforms and spore-forming Bacillus species, as well as the presence of Staphylococcus aureus, Clostridium perfringens and Listeria monocytogenes. Strains of Gram-negative rods and Bacillus cereus were isolated and identified. None of the salads contained S. aureus, Cl. Perfringens or Listeria monocytogenes. It was found that in 88% of samples the population size of aerobic mesophilic microbes was of the order of 4 to 5 log cfu g⁻¹; higher and lower counts were recorded sporadically only. In 58% of samples the population size of coliforms and Bacillus species ranged from below 2.00 to 2.90 log cfu g⁻¹, and from 2.00 to 3.95 log cfu g⁻¹ respectively. Gram-negative rods isolated from the examined salads were identified to the following genera: Citrobacter, Providencia, Escherichia, Enterobacter, Klebsiella, Serratia, Yersinia, Pseudomonas and Flavobacterium. The species Providencia retgeri, Citrobacter freundii and Enterobacter aerogenes were the most frequent among them. A total of 84 salad samples were tested in the experiment, of which 3 were found to contain strains of Y. enterocolitica, and 6 – strains of E. coli. The presence of spore-forming Bacillus cereus was confirmed in 34% of salads.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.