Heterogeneity among Virulence and Antimicrobial Resistance Gene Profiles of Extraintestinal Escherichia coli Isolates of Animal and Human Origin

Abstract

Extraintestinal pathogenic Escherichia coli (ExPEC) isolates collected from different infected animals and from human patients with extraintestinal infections in 2001 were characterized for their phenotypic and genotypic antimicrobial resistance profiles, genotypes, and key virulence factors. Among the 10 antimicrobial agents tested, resistance to ampicillin, tetracycline, and sulfonamides was most frequent. Multiresistant strains were found in both the animal and the human groups of isolates. Resistance gene distribution was assessed by colony hybridization. Similar antibiotic resistance patterns could be observed in the animal and the human isolates. Although some resistance genes, such as bla TEM , sulI, and sulII, were equally represented in the animal and human ExPEC isolates, differences in the distributions of tetracycline [tet(D)], chloramphenicol (catI, catIII, and floR), and trimethoprim (dhfrI, dhfrV, dhfrVII, and dhfrXIII) resistance genes were observed between the animal and the human isolates. Approximately one-third of the ExPEC isolates possessed a class 1 integron. The four major different variable regions of the class 1 integron contained aminoglycoside (aadA1, aadA2, aadA5, and aadA6) and/or trimethoprim (dhfrIb, dhfrXII, and dhfrXVII) resistance genes. The ExPEC strains belonged to different phylogenetic groups, depending on their host origin. Strains isolated from animal tissues belonged to either a commensal group (group A or B1) or a virulent group (group B2 or D), while the majority of the human isolates belonged to a virulent group (group B2 or D). Although the limited number of isolates evaluated in the present study prevents firm epidemiological conclusions from being made, on a more global scale, these data demonstrate that extraintestinal isolates of E. coli can possess relatively distinct intra-and intergroup resistance gene profiles, with animal isolates presenting a more heterogeneous group than human isolates.

Commonality among Fluoroquinolone-Resistant Sequence Type ST131 Extraintestinal Escherichia coli Isolates from Humans and Companion Animals in Australia

“…This supports previous evidence that extraintestinal pathogenic E. coli (ExPEC) from humans and companion animals, particularly strains belonging to group B2, share similar virulence genotypes and phylogenetic origins (25,31).…”

Prevalence of integrons and Antimicrobial Resistance Genes Among Clinical Isolates of Enterobacter spp. From Hospitals of Tehran

“…The ability of integrons to integrate resistance gene cassettes makes them prime pools for the further dissemination of antibiotic resistance among clinical isolates of gram-negative bacteria, including Enterobacter isolates (13). Our findings indicated that the 41 % of isolated Enterobacter were integron positive, this rate of integron positive in our isolates are similar with published reports that Enterobacter harbors high prevalence of integron class 1, lower class 2 and no class 3 (14)(15)(16).…”

Perfil de sensibilidade e multirresistência em linhagens de Escherichia coli isoladas de infecção do trato urinário, de piometra e de fezes de cães

“…Maynard et al (2004), ao investigarem ExPEC isoladas de diferentes espécies animais e do homem, encontraram 60% de resistência às sulfonamidas e acima de 50% para tetraciclinas e ampicilina. A multirresistência a três ou mais drogas foi encontrada em mais de 50% dos isolados, mostrando a similaridade de resistência entre linhagens isoladas de homens e outros animais.…”