GENES DE VIRULENCIA E RESISTí­Å NCIA ANTIMICROBIANA DE Vibrio parahaemolyticus EM ÁREAS DE OSTREICULTURA

Abstract

This study aimed to quantify Vibrio spp. and evaluate the profile of antimicrobial susceptibility and virulence factors in Vibrio parahaemolyticus strains in the samples of oysters collected from two estuaries of the Baixo Sul, Bahia. The samples were collected between June 2015 and January 2016 from natural banks (E1) (oyster) and from cultivation areas (E2) (water and oyster). For the quantification of Vibrio spp., the most probable number (MPN) was determined and the characterization of V. parahaemolyticus marker (species-specific) gene tl was performed. Pathogenicity was observed with the Kanagawa test, and the presence of the tdh, trh and ure genes were tested. The antimicrobial sensitivity test included disc diffusion method with 15 antimicrobial discs, β-lactamase enzyme production, and the presence of blaTEM, blaSHV, and blaCTX-M. The maximum density of Vibrio spp. in the samples from cultivation was 4.70 log MPN g-1 and extractivism was 6.10 log MPN g-1, with the temperature being the most influencing variable on the presence of microorganisms in the cultivation area (E2). The tl gene was detected in 71% of the isolates, without the presence of tdh, trh and ure genes. All strains of V. parahaemolyticus were Kanagawa negative. High antimicrobial resistance was observed in the β-lactam antibiotics (cephalothin - 72%, ampicillin - 60%) and aminoglycosides (amikacin - 64%), with multi-resistance in 88% of the strains of V. parahaemolyticus, of which 68% of the resistance was mediated by plasmids. Phenotypically, no production of β-lactamase enzymes was observed, but the presence of blaTEM genes was observed. The multiresistant character of plasmids reported in V. parahaemolyticus strains increases the concern about native bacteria in the marine environment since it can potentially compromise the control of this bacterium infection in bivalve mollusks.

O gênero Vibrio: conceitos atuais e novas perspectivas

“…No que se refere ao tratamento de infecções causadas por Vibrio spp., antimicrobianos como ciprofloxacina, doxiciclina, azitromicina, tetraciclina, cefotaxima e a combinação de amoxicilina e ácido clavulânico são frequentemente utilizados (Jang et al, 2014;Baker-Austin et al, 2018). Contudo, estudos mais recentes vêm relatando um aumento nas taxas de resistência a antimicrobianos frequentemente empregados no setor clínico como, por exemplo, aminoglicosídeos, cefalosporinas de terceira geração, carbapenemas e quinolonas (Cardoso et al, 2018;Lee et al, 2018;Ashrafudoulla et al, 2019, Zago et al, 2020a, 2020b. Relatos de resistência a esses antimicrobianos serão abordados a seguir.…”

“…(Baker-Austin et al, 2018). Contudo, estudos já demonstraram significativas taxas de resistência à amicacina em estirpes de V. parahaemolyticus isolados de animais marinhos destinados ao consumo humano, como por exemplo camarões (60% de estirpes resistentes) e ostras (64% de estirpes resistentes), indicando uma possível rota de transmissão de bactérias resistentes aos seres humanos (Melo et al, 2011;Cardoso et al, 2018). Estirpes de V. parahaemolyticus isoladas de amostras de água e sedimentos também já foram descritas na literatura apresentando taxas de resistência variando de 29,1 a 55,2% a outros antimicrobianos da classe dos aminoglicosídeos, como canamicina, gentamicina e neomicina (Devi et al, 2009).…”

Aquatic environments: A potential source of antimicrobial-resistant Vibrio spp.

“…isolated from tropical estuary were resistant to carbapenems, cephalosporins, fluoroquinolones, sulphonamides and tetracyclines whilst confirming the presence of extended‐spectrum beta‐lactamase (ESBL)‐resistant genes ( bla TEM , bla SHV , bla GES , bla CTX‐M‐1,2 and bla TEM ) in V. parahaemolyticus and V. harveyi (Canellas et al, 2021). Similarly, V. parahaemolyticus isolates were positive for the bla TEM ARG whilst showing the highest resistance to beta‐lactams (Cardoso et al, 2018). In another study, V. alginolyticus isolated from seawater in Norway harboured bla CARB and bla ampC genes (Håkonsholm et al, 2020).…”

Perfil fenotípico e genotípico de resistência e virulência de Vibrio parahaemolyticus isolados de água e ostras / Phenotypic and genotypic profile of resistance and virulence of Vibrio parahaemolyticus isolated from water and oysters

“…Resistência em cepas de V. parahaemolyticus aos β-lactâmicos também foi verificada em isolados provenientes da Baia de Todos os Santos, em São Francisco do Conde, Bahia, Brasil (SILVA et al, 2018). No Baixo Sul da Bahia, além da elevada resistência aos β-lactâmicos e aminoglicosídeos, também foi observada multirresistência em 88% das cepas de V. parahaemolyticus estudadas (CARDOSO et al, 2018).…”