| Congresso Brasileiro de Microbiologia 2023 | Resumo: 176-1 | ||||
Resumo:Campylobacter spp. is an important causative agent of human diarrheal diseases worldwide. Consumption of improperly prepared poultry meat has been the main transmission route of Campylobacter. Although Brazil is the largest exporter of poultry meat in the world, campylobacteriosis has been a neglected disease in this country. Therefore, the aims of this study were to verify the presence of prophages, frequency of several virulence genes and to analyze the effect of freeze-thaw and pasteurization process in the survivability of 80 C. coli strains isolated from humans (12), animals (34), the environment (20) and chicken meat (14) between 1995-2019 in Brazil. The presence of prophages and virulence genes were evaluated in silico using the whole genome sequencing of strains in PHASTER and Virulence Factors Database, respectively. For the phenotypic tests, the strains were analyzed for their tolerance to incubation at −20 °C for 3 and 7 days (freeze-thaw) and their tolerance to heat and cold treatment by using a thermocycler at 75°C for 15s and 4°C for 15s which mimicking the pasteurization process. The phenotypic experiments were conducted in three independent replicates and two control strains, Campylobacter jejuni ATCC 3329 and Salmonella Typhimurium ATCC 14028, were included for comparisons. The prophages detected were: PPpW-3 in 25%, Escher vB EcoM ECO1230 10 in 11.2%, Campyl PC14 in 8.7%, Vibrio VP58.5 in 7.5%, Campyl CP81 in 3.7%, Campyl vB CjeM Los1 in 2.5%, Escher vB EcoM ep3 in 2.5% and Campyl CP21 in
1.2% of the strains studied. The 80 C. coli showed 138 virulence genes related to adherence, biofilm, capsule synthesis, chemotaxis, hemin uptake, immune modulation, invasion, ion metabolism, motility, post-translational modification and toxin production. Five out of the 80 strains showed a survival percentage of 87.5%, 68 strains a survival of 75.0% and 7 strains a survival of 62.5% after an incubation at −20 °C for 3 days. After 7 days at -20oC, 64 strains showed a survival percentage of 75.0% and 16 strains a survival of 62.5%. The control strains, ATCC 3329 and ATCC 14028 showed a survival percentage of 75.0% and 100% in both incubation periods, respectively. Likewise, after the assay mimicking the pasteurization process 18 out of the 80 strains remained 100% viable, 24 strains showed a survival of 87.5%, 23 strains showed a survival of 75.0%, 10 showed a survival of 62.5%, four showed a survival of 50% and one showed a survival of 37.5%. The ATCC 3329 and ATCC 14028 showed a survival percentage of 87.5% and 100%, respectively. In conclusion, the pathogenic potential of the strains studied was reinforced by the presence of some prophages and important virulence genes. Furthermore, once freeze-thaw and pasteurization process are methods widely used to control bacterial growth the survival rates obtained might suggest that more rigorous control measures may be needed given the importance of contaminated food as vehicles of Campylobacter coli. Palavras-chave: Campylobacter coli, WGS, Tolerance to stress conditions, Food Safety Agência de fomento:FAPESP and CNPq | |||||