Characterization of the variable region in the class 1 integron of antimicrobial-resistant Escherichia coli isolated from surface water

Abstract

Fecal bacteria are considered to be a potential reservoir of antimicrobial resistance genes in the aquatic environment and could horizontally transfer these genes to autochthonous bacteria when carried on transferable and/or mobile genetic elements. Such circulation of resistance genes constitutes a latent public health hazard. The aim of this study was to characterize the variable region of the class 1 integron and relate its genetic content to resistance patterns observed in antimicrobial-resistant Escherichia coli isolated from the surface waters of Patos Lagoon, Southern Brazil. Genetic diversity of the isolates and presence of the qacEΔ1 gene, which confers resistance to quaternary ammonium compounds, were also investigated. A total of 27 isolates were analyzed. The variable region harbored dfrA17, dfrA1 and dfrA12 genes, which confer resistance to trimethoprim, and aadA1, aadA5 and aadA22 genes that encode resistance to streptomycin/spectinomycin. Most of the isolates were considered resistant to quaternary ammonium compounds and all of them carried the qacEΔ1 gene at the 3′ conserved segment of the integron. ERIC-PCR analyses of E. coli isolates that presented the integrons showed great genetic diversity, indicating diverse sources of contamination in this environment. These results suggest that fecal bacteria with class 1 integrons in aquatic environments are potentially important reservoirs of antibiotic-resistance genes and may transfer these elements to other bacteria that are capable of infecting humans.

Genetic Environment of blaTEM-1, blaCTX-M-15, blaCMY-42 and Characterization of Integrons of Escherichia coli Isolated From an Indian Urban Aquatic Environment

“…It has been reported that integrons carrying antimicrobial resistance gene cassettes were highly prevalent in aquatic environment ( Guo et al, 2011 ; Canal et al, 2016 ). Moreover, Class 1 integrons have been reported widely in Gram-negative bacteria which were responsible for both the spread and increase of antimicrobial resistance throughout the world ( Koczura et al, 2013 ; Canal et al, 2016 ).…”

“…It has been reported that integrons carrying antimicrobial resistance gene cassettes were highly prevalent in aquatic environment ( Guo et al, 2011 ; Canal et al, 2016 ). Moreover, Class 1 integrons have been reported widely in Gram-negative bacteria which were responsible for both the spread and increase of antimicrobial resistance throughout the world ( Koczura et al, 2013 ; Canal et al, 2016 ). Our analysis also revealed that Class 1 integrons were common in E. coli isolates of river Yamuna (50%), more than those reported from strains isolated from Malaysia (21%) ( Ghaderpour et al, 2015 ), France and Portugal (11%) ( Laroche et al, 2009 ; Pereira et al, 2013 ), and Czechia (15%) ( Dolejská et al, 2009 ).…”

High abundances of class 1 integrase and sulfonamide resistance genes, and characterisation of class 1 integron gene cassettes in four urban wetlands in Nigeria

“…All the array types reported in this study have been previously reported in the literature. Array types 1 and 3 in particular have been reported widely in bacteria from human clinical sources, aquaculture, farm animals, rivers and hospital wastewater in Nigeria and Ghana [29,72,73], Central African Republic [74], Egypt [75], Europe [76][77][78][79][80][81][82][83], China [84][85][86], Brazil [87], Canada [54] and US [88]. The Type 1 cassette (dfrA7) was found associated with a widely disseminated Tn21-type transposon in Nigeria and Ghana [72].…”

Serotyping, antibiotic susceptibility, and virulence genes screening of Escherichia coli isolates obtained from diarrheic buffalo calves in Egyptian farms

“…The main factor in the emergence of multidrug-resistance (MDR) strains is the ability of bacteria to gain and disseminate exogenous genes through mobile genetic elements [ 4 ]. The upgrowth of E. coli isolates with MDR phenotypes has been formerly reported and may extend from one ecosystem to another by lateral gene transfer; integrons [ 5 ].…”