Eliana Guimarães Abeid Ribeiro

Quantification of Listeria monocytogenes in minimally processed leafy vegetables using a combined method based on enrichment and 16S rRNA real-time PCR

Modern lifestyle markedly changed eating habits worldwide, with an increasing demand for ready-to-eat foods, such as minimally processed fruits and leafy greens. Packaging and storage conditions of those products may favor the growth of psychrotrophic bacteria, including the pathogen Listeria monocytogenes. In this work, minimally processed leafy vegetables samples (n = 162) from retail market from Ribeirão Preto, São Paulo, Brazil, were tested for the presence or absence of Listeria spp. by the immunoassay Listeria Rapid Test, Oxoid. Two L. monocytogenes positive and six artificially contaminated samples of minimally processed leafy vegetables were evaluated by the Most Probable Number (MPN) with detection by classical culture method and also culture method combined with real-time PCR (RTi-PCR) for 16S rRNA genes of L. monocytogenes. Positive MPN enrichment tubes were analyzed by RTi-PCR with primers specific for L. monocytogenes using the commercial preparation ABSOLUTE QPCR SYBR Green Mix (ABgene, UK). Real-time PCR assay presented good exclusivity and inclusivity results and no statistical significant difference was found in comparison with the conventional culture method (p < 0.05). Moreover, RTi-PCR was fast and easy to perform, with MPN results obtained in ca. 48 h for RTi-PCR in comparison to 7 days for conventional method.

Fiscalização de verduras comercializadas no município de Ribeirão Preto, SP

Resumo O consumo de verduras cruas constitui importante meio de transmissao de varias doencasinfecciosas. Este estudo tem como objetivo a avaliacao microbiologica e parasitologica de verdurascomercializadas no municipio de Ribeirao Preto, SP, abrangendo todos os pontos de venda ao consumidor.Do total de 172 estabelecimentos fixos ou ambulantes analisados, 115 (67%) apresentaram hortalicas comirregularidades: elevada concentracao de coliformes fecais em 63%, presenca de Salmonella em 9% e deenteroparasitas em 33%. Os pontos de venda com maior frequencia de hortalicas com resultados inadequadosforam: mercearias (92%), CEAGESP (75%), quitandas (71%), vendedores ambulantes (71%), feiras-livres(69%), supermercados (52%) e hortas (18%). O tipo de contaminacao apresentou distribuicao uniforme emrelacao aos locais de venda e a variedade da hortalica. A maioria (61%) das verduras contaminadas eraprocedente de hortas localizadas no municipio de Ribeirao Preto. Considerando a elevada frequencia decontaminacao fecal e o potencial risco de doencas veiculadas pelas hortalicas, sugerimos uma vigilânciasanitaria mais atuante na fiscalizacao de alimentos oferecidos a populacao.Palavras-chaves: Verduras. Coliformes fecais. Salmonella. Cisticercose.Abstract The ingestion of raw vegetables represents an important means of transmission of several infectiousdiseases. The objective of the present study was to perform a microbiological and parasitological evaluationof the vegetables commercially sold in the municipality of Ribeirao Preto, SP, Brazil. Of a total of 172 commercialconcerns analyzed, 115 (67%) presented irregularities in the vegetables they sold, such as elevatedconcentration of fecal coliforms in 63%, presence of Salmonella in 9%, and presence of enteroparasites in33%. The commercial concerns with the highest frequencies of vegetables showing inadequate results were:grocery stores (92%), CEAGESP (75%), fruit and vegetables stores (71%), traveling vendors (71%), fairs(69%), supermarkets (52%), and vegetable gardens (18%). The type of contamination was uniformly distributedamong these commercial concerns. Most of the contaminated vegetables (61%) were from gardens located inthe municipality of Ribeirao Preto. Considering the high frequency of fecal contamination and the potential riskof disease transmitted by vegetables, we suggest greater enforcement in the sanitary surveillance of the foodoffered to the population.Key-words: Lettuce. Vegetable. Fecal coliforms. Salmonella. Cysticercosis.The ingestion of raw vegetables represents an important means of transmission of several infectious diseases. The objective of the present study was to perform a microbiological and parasitological evaluation of the vegetables commercially sold in the municipality of Ribeirão Preto, SP, Brazil. Of a total of 172 commercial concerns analyzed, 115 (67%) presented irregularities in the vegetables they sold, such as elevated concentration of fecal coliforms in 63%, presence of Salmonella in 9%, and presence of enteroparasites in 33%. The commercial concerns with the highest frequencies of vegetables showing inadequate results were: grocery stores (92%), CEAGESP (75%), fruit and vegetables stores (71%), traveling vendors (71%), fairs (69%), supermarkets (52%), and vegetable gardens (18%). The type of contamination was uniformly distributed among these commercial concerns. Most of the contaminated vegetables (61%) were from gardens located in the municipality of Ribeirão Preto. Considering the high frequency of fecal contamination and the potential risk of disease transmitted by vegetables, we suggest greater enforcement in the sanitary surveillance of the food offered to the population.

Avaliação da contaminação de hortas produtoras de verduras após a implantação do sistema de fiscalização em Ribeirão Preto, SP

This study evaluated the microbiological and parasitological contamination of 88 market gardens producing green vegetables, of which 47 had been investigated previously. The contamination rate was 38.3% in the market gardens previously evaluated and 43.9% in the new market gardens. Food safety requires a continuous and efficient sanitary surveillance system for market gardens.

Análise da cadeia de produção de verduras em Ribeirão Preto, SP

With the aim of assessing the cumulative risk of lettuce contamination, 45 production chains were investigated. The presence of thermotolerant coliforms, Salmonella and/or parasites was detected in 69% of these, in all steps of the production chain. Quality control in all steps of the lettuce production process should be intensified.