Occurrence and antimicrobial resistance of E. coli non-O157 isolated from beef in Mato Grosso, Brazil.

Shiga toxin-producing Escherichia coli (STEC) is an important public health concern pathogen, as it produces two toxins, Stx1 and Stx2, with cytotoxic capacity. In addition, STEC strains are frequently involved in food outbreaks worldwide, leading to public health challenges and economic losses. In this context, the occurrence and antimicrobial resistance profile of the STEC isolated from fresh beef produced in Mato Grosso, Brazil, were estimated. One hundred seven retail beef under vacuum-packaged produced by 13 different slaughterhouses were submitted to microbiological, molecular, and antimicrobial resistance analyses. STEC occurrence in beef was of 4.67%, and five strains presented the stx2 gene. The O111 serogroup, reported in several outbreak cases worldwide, was detected, and other serotypes (O8:H20, O22:H16, and O141:H49) were also isolated. All isolated strains displayed sensitivity to 12 antibiotics, except for two strains, which where streptomycin-resistant. The presence of STEC in retail beef samples indicates public health risks with significant economic impact throughout the retail beef chain.

Listeria monocytogenes in beef: a hidden risk.

Listeria monocytogenes in beef receives less attention compared to other pathogens such as Salmonella and Escherichia coli. To address this gap, we conducted a literature review focusing on the presence of L. monocytogenes in beef. This review encompasses the pathogenic mechanisms, routes of contamination, prevalence rates, and the laws and regulations employed in various countries. Our findings reveal a prevalence of L. monocytogenes in beef and beef products ranging from 2.5% to 59.4%. Notably, serotype 4b was most frequently isolated in cases of beef contamination during food processing, with the skinning and evisceration stages identified as critical points of contamination.