Bactérias zoonóticas isoladas de Passeriformes silvestres recuperados do tráfico de animais no estado do Ceará/Brasil / Zoonotic bacteria isolated from wild Passeriformes recovered from animal trafficking in the State of Ceará/Brazil

A ordem dos Passeriformes é uma das mais pressionadas pelas ações antrópicas, especialmente as relativas ao tráfico de animais, que, devido às más condições de manejo e higiênico-sanitárias, favorecem a infecção dos espécimes por patógenos virulentos e zoonóticos, como cepas de Escherichia coli e Salmonella spp., cujo isolamento em suabes cloacais, bem como a análise dos genes de virulência das cepas de E. coli foram objetivos do estudo. Para isso, 120 Passeriformes silvestres nativos, recebidos pelo Cetas/CE, foram avaliados individualmente. As cepas isoladas foram submetidas a teste de disco difusão para determinação da sensibilidade aos antimicrobianos. Em etapa posterior, foi realizada PCR para a detecção de oito genes de virulência dos principais patotipos diarreiogênicos de E. coli. Quanto aos resultados, nenhuma cepa de Salmonella spp. foi isolada, no entanto a ocorrência de E. coli foi de 40,8%. Foi observada elevada resistência, principalmente aos antimicrobianos tetraciclina, ampicilina e sulfazotrim, ocorrendo multirresistência em 42,8% das cepas. Pela análise molecular, foram diagnosticados quatro entre os nove genes pesquisados, com a identificação de EPEC típicas, EPEC atípicas, ETEC, EHEC e EAEC. Os resultados apontam para a importância de Passeriformes como possíveis disseminadores de zoonoses.(AU)

The order Passeriformes is one of the most pressured by anthropic actions, especially those related to animal trafficking. Due to poor sanitary and hygienic conditions, the infection of the specimens is favored by virulent and zoonotic pathogens such as strains of Escherichia coli and Salmonella spp., whose isolation in cloacal swabs as well as the analysis of the virulence genes of E. coli strains were the objectives of the study. For this, 120 native wild Passeriformes, received by CETAS/CE were individually evaluated. The isolated strains were submitted to diffusion disc test to determine sensitivity to antimicrobials. In a later stage, PCR was performed for the detection of eight virulence genes from the main E. coli diarrhoeagenic pathogens. Regarding the results, no strain of Salmonella spp. was isolated; however, the occurrence of E. coli was 40.8%. High resistance was observed, mainly to the antimicrobials Tetracycline, Ampicillin and Sulfazotrim, with multi-resistance in 42.8% of the strains. By molecular analysis, four of the nine genes were diagnosed, identifying typical EPEC, atypical EPEC, ETEC, EHEC and EAEC. The results point to the importance of Passeriformes as possible disseminators of zoonoses.(AU)

Intestinal cell migration damage induced by enteropathogenic Escherichia coli strains

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.