Virulence genes in Escherichia coli isolates from commercialized saltwater mussels Mytella guyanensis (Lamarck, 1819)

Abstract

The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumer’s health.

Carbapenem-resistant Escherichia coli from shrimp and salmon available for purchase by consumers in Canada: a risk profile using the Codex framework

“…for spectinomycin-streptomycin, sulphonamide and tetracycline resistance) [24,[26][27][28]. Pathogenic, and particularly Shiga-toxigenic E. coli strains have been identified in seafood products and their production environment including shellfish, raw and ready-to-eat fish and retail shrimp [29][30][31][32][33][34][35][36][37]. The coexistence of virulence/pathogenicity genes and ARGs has been demonstrated in several studies of E. coli isolated from the aquatic environment and seafood [38][39][40][41][42][43][44][45].…”

“…Enteropathogenic E. coli have been found to contain a diversity of mobile plasmids encoding virulence factors such as secretion systems mediating bacterial adherence to the host epithelial cells and heat-labile/heat-stable toxin production in addition to ARGs (e.g., for spectinomycinstreptomycin, sulfonamide and tetracycline resistance) [24,[26][27][28]. Pathogenic, and particularly shiga-toxigenic E. coli strains have been identified in seafood products and their production environment including shellfish, raw and ready-to-eat fish and retail shrimp [29][30][31][32][33][34][35][36][37]. The coexistence of virulence/pathogenicity genes and ARGs has been demonstrated in several studies of E. coli isolated from the aquatic environment and seafood [38][39][40][41][42][43][44][45].…”

Mapping of the world scientific production on bacterial and fungal microbiota in mollusks

“…Although developing countries present few studies on this topic, Brazil has advanced in investigations on bacterial infections (Pereira et al 2007, Ramos et al 2014, Silva et al 2018) due to the increase in aquaculture production in recent years, which in 2018 was 445,000 t, with seafood production corresponding to 4.7% (FAO 2018). Consequently, there has been an increase in diseases caused by consuming contaminated seafood, especially in developing countries (Barbosa et al 2019, Silva et al 2020. Due to the damage caused by pathogenic Escherichia coli strains in these countries, there has been great concern regarding microorganisms in mollusks, mainly due to a lack of basic sanitation and high consumption (Barbosa et al 2019).…”

Genotypical characterization of thermotolerant coliforms isolated from food produced by a Solidarity Economic Venture of Bahia (Brazil)

“…Therefore, the investigation of virulence genes in Escherichia coli isolates is necessary to identify pathogenic strains, as was done by Barbosa et al (2019) in a research carried out with mussel (Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil, and the elt gene, typical from enterotoxigenic infection, was detected in 75% of the 24 isolates.…”