Multidrug efflux systems in Escherichia coli and Enterobacter cloacae obtained from wholesome broiler carcasses

Brazilian Journal of Microbiology

Maria Aparecida S. Moreira²  Patrícia P.c.f. Rodrigues¹  Rafael S. Tomaz¹  Célia A. De Moraes¹ 

[1] ,Universidade Federal de Viçosa Departamento de Veterinária Setor de Medicina Veterinária Preventiva e Saúde PúblicaViçosa MG ,Brasil

关键词: multiresistance;    antimicrobials;    Enterobacteriaceae;    proton-motive force;    diversity;    multirresistência;    antimicrobianos;    Enterobacteriaceae;    força próton motora;    diversidade;   

DOI  :  10.1590/S1517-83822009000200007

来源: SciELO

【 摘 要 】

Members of the Enterobacteriaceae family are present in the intestines of man and animals as commensals or are important disease causing agents. Bacteria bearing multidrug efflux systems (MDR) are able to survive adverse ecological niches. Multiresistant Escherichia coli and Enterobacter cloacae isolates from wholesome broiler carcasses were investigated for the presence of MDR. Lowering of Minimal Inhibitory Concentration for antimicrobials in the presence of a proton-motive force (PMF) uncoupler was tested as a potential display of the MDR phenotype. PCR amplification of the genes encoding AcrA and AcrB, components of a MDR system was performed. Diversity of each species was ascertained by Pulsed-Field Gel Electrophoresis (PFGE) of DNA digested with endonuclease XbaI. For all the isolates, except E. coli 1 and E. cloacae 9, lowering of MIC or of the growth rate in the presence of antimicrobials was observed, indicating a PMF dependent resistance mechanism. Expected products of DNA amplification with acrAB derived primers was obtained with all E. coli strains and with two of the five E. cloacae strains. Dendrogram generated shows diverse pulsetypes, confirming the genetic diversity among the strains. An important issue and related public health is the fact that different models and mechanisms of antimicrobial resistance are present in a small number of non-pathogenic strains and isolated from the same origin. These may be sources of resistance genes to others microorganisms, among them, pathogenic strains.

【 授权许可】

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