Listeria monocytogenes in sliced cheese and ham from retail markets in southern Brazil

Abstract

The aims of this study were to evaluate the occurrence of Listeria monocytogenes and Salmonella spp. in sliced cheese and ham from retail markets in southern Brazil, as well as to perform molecular characterization and to assess the antimicrobial resistance profile of the isolates. Samples (n = 160) of sliced cheese and ham were collected at retail level from the city of Pelotas, Brazil. The isolation of L. monocytogenes and Salmonella spp. was performed and the isolates were confirmed by PCR, submitted to antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE). Listeria monocytogenes was found in 9.4% (15/160) of the samples. All L. monocytogenes isolates were positive for the prs, inlA, inlC and inlJ genes. Salmonella spp. was not isolated. Regarding the antimicrobial susceptibility, one (6.6%) L. monocytogenes isolate was resistant to streptomycin and four (26.6%) to clindamycin. Macrorestriction analysis with ApaI and AscI enzymes yielded two major PFGE groups I and II. All L. monocytogenes isolates showed virulence genes, and some of them were resistant to clinically used antimicrobials, representing a risk to public health. Moreover, PFGE patterns with high similarity were visualized in L. monocytogenes isolates at different times, demonstrating adaptability of the pathogen at retail level in the region.

Antimicrobial Resistance and Virulence Characterization of Listeria monocytogenes Strains Isolated from Food and Food Processing Environments

“…Its mechanism of action is similar to that of erythromycin, i.e., it is responsible for the inhibition of protein synthesis due to the binding with the 50S subunit of bacterial ribosomes [ 49 , 56 ]. There are several studies indicating a high level of clindamycin resistance among the L. monocytogenes isolates derived from food and production facilities [ 45 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ]. According to studies conducted by Şanlıbaba et al, 2018 [ 49 ] and Escolar et al, 2017 [ 56 ], the strains’ resistance to clindamycin may be associated with the action of the clindamycin structure-modifying enzyme that contributes to the inactivation of the antibiotic action.…”

Antimicrobial Resistance of Listeria monocytogenes Strains Isolated from Humans, Animals, and Food Products in Russia in 1950–1980, 2000–2005, and 2018–2021

“…Here our data are in line with results obtained by other authors. In particular, 26.6% L. monocytogenes isolated from sliced cheese and ham in Brazil, 81% of L. monocytogenes isolated from raw milk, milking equipment and dairy workers in Egypt, and 90% L. monocytogenes isolated from ready-to-eat products of animal origin in Spain were resistant to clindamycin [32][33][34].…”

PRINCIPAIS ASPECTOS DE Listeria monocytogenes E SUA IMPORTÂNCIA PARA A SAÚDE PÚBLICA

“…Neste sentido, diversos estudos foram realizados com o intuito de isolar a bactérias nestes produtos, tanto nas indústrias como no varejo. Jamali et al (2013), relatou que 4,0% das amostras de leite cru coletadas de diversos tanques de leite foram positivos para o microrganismo, além de demonstrar resistência à tetraciclina e penicilina G. Corroborando com Campos et al (2021) e Maia et al (2019), nos quais L. monocytogenes foi detectada em 4,5% dos queijos tipo Canastra e 9,4% em queijo fatiado pronto para comercialização, respectivamente. Estes estudos demonstram a importância do tratamento térmico no leite antes de sua comercialização ou produção de derivados, além de enfatizar as falhas higiênicossanitárias observadas em toda a cadeia produtiva do leite.…”

“…A presença do microrganismo em alimentos em diferentes etapas da cadeia produtiva tem relação direta com medidas higiênicossanitárias tomadas na indústria e no varejo (JAMALI et al, 2013;BRANDÃO et al, 2013;ANDRADE et al, 2014;MAIA et al, 2019;SERENO et al, 2019;SOUZA et al, 2020;SOARES et al, 2021;CAMPOS et al, 2021). A ocorrência da bactéria está inserida em toda a cadeia produtiva, fazendo-se necessária a implementação de ações conjuntas dos múltiplos setores envolvidos na produção dos alimentos com o objetivo de eliminar o agente da cadeia de produção.…”