Antimicrobial Resistance and Virulence Factors of Escherichia coli in Cheese Made from Unpasteurized Milk in Three Cities in Brazil.

The production of cheeses from unpasteurized milk is still widespread in Brazil, even with a legal ban imposed on its marketing. The manufacture of this cheese is a public health problem, due to the use of raw milk and the poor hygienic conditions throughout the supply chain process. Contamination may occur from several sources and involve several different pathogenic microorganisms, such as Escherichia coli. The latter can cause different clinical manifestations depending on the pathotype involved. Furthermore, some isolates manifest antimicrobial resistance and may be a risk for public health. The purpose of the current study was to investigate the presence of potentially pathogenic E. coli in raw-milk cheese in Brazil and their possible risk to public health. A total of 83 cheeses were collected from three different cities and 169 E. coli isolates were characterized for the presence of enteropathogenic E. coli, Shigatoxigenic E. coli, enterotoxigenic E. coli, extraintestinal pathogenic E. coli (ExPEC) virulence genes, phylogenetic type, antimicrobial resistance, O serogroup, and pulsed-field gel electrophoresis. The number of samples positive for E. coli was highest in Aracaju (90.32%, 28/31). The prevalence of samples positive for potential ExPEC genes was similar for Uberaba and Aracaju (23.07%); the most prevalent ExPEC virulence genes were tsh, iucD, and papC. Isolates from Uberaba had a higher prevalence of resistance to tetracycline (38.46%), amoxicillin/clavulanic acid (58.85%), and ampicillin (61.54%) than the other cities. Overall, antimicrobial resistance genes tetB, blaTEM, and blaCMY-2 were the most prevalent genes (26.32%, 15.79%, and 28.95%, respectively) and the most prevalent serotypes were O4 (8%), 018 (12%), and O23 (8%). Clones originating from the same regions and from different regions were observed. These results emphasize the presence of a potential danger for humans in the consumption of raw-milk cheeses in three cities in Brazil due to the presence of antimicrobial resistance, which should be monitored.

Comparação dos testes de virusneutralização contra os genótipos 1 e 2 do vírus da diarreia viral bovina (BVDV-1 e BVDV-2) em bovinos de rebanhos naturalmente infectados / Comparison of virusneutralization tests against genotypes 1 and 2 of the bovine viral diarrhoea virus (BVDV-1 and BVDV-2) in cattle of naturally infected herds

Os resultados dos testes de virusneutralização (VN) contra os genótipos do vírus da diarreia viral bovina (BVDV-1 e BVDV-2), bem como os respectivos títulos de anticorpos, foram comparados em 1.925 amostras de soro sanguíneo obtidas de rebanhos bovinos naturalmente infectados e não vacinados contra o BVDV, provenientes dos Estados de São Paulo e Minas Gerais. A proporção de amostras reagentes entre os genótipos foi analisada pelo Teste de McNemar, e os títulos de anticorpos das amostras reagentes ao BVDV-1 e ao BVDV-2 foram comparados pelo Teste de Wilcoxon. Não foi verificada discordância na proporção de bovinos reagentes ao BVDV-1 e ao BVDV-2 (P>0,05). No entanto, houve discordância entre os títulos de anticorpos detectados nos testes de VN contra os genótipos 1 e 2 do BVDV (P<0,0001). Embora a proporção de animais reagentes contra ambos os genótipos do BVDV tenha sido semelhante, resultados falso-negativos seriam obtidos se 67 amostras (3,5 por cento) tivessem sido submetidas apenas ao teste de VN, para o BVDV-1, e em 51 amostras (2,65 por cento), apenas para o BVDV-2. Alguns rebanhos apresentaram títulos de anticorpos superiores para o BVDV-1, enquanto outros para BVDV-2, demonstrando assim a ocorrência da infecção pelos diferentes genótipos do vírus entre os rebanhos analisados. Portanto, tais resultados demonstraram a necessidade da inclusão de ambos os genótipos do BVDV nos testes de VN.

The virusneutralization test (VN) results against bovine viral diarrhoea virus genotypes (BVDV-1 and BVDV-2), and the respective titers of antibodies, were compared in 1,925 serum samples collected from unvaccinated and naturally infected cattle herds, located in the states of São Paulo and Minas Gerais, Brazil. The proportion of reagent samples among the genotypes was evaluated by McNemar test and the antibody titers against BVDV-1 and BVDV-2 were compared by Wilcoxon test. There were no disagreement in the proportion of BVDV-1 and BVDV-2 reagent samples (P>0.05). However, there was a disagreement among titers of antibodies detected in the VN tests against BVDV genotypes (P<0.0001). Although the proportion of reagent animals to BVDV genotypes was similar, false negative results would be obtained if 67 samples (3.5 percent) had been submitted only to VN test against BVDV-1, and 51 samples (2.65 percent) only against BVDV-2. Some herds had higher titers of antibodies for BVDV-1, while others for BVDV-2, thus demonstrating the occurrence of infection by different virus genotypes among the analyzed herds. Therefore, these results demonstrated the need for inclusion of both BVDV genotypes in VN tests.