Highly Variable Patterns of Antimicrobial Resistance in CommensalEscherichia coliIsolates from Pigs, Sympatric Rodents, and Flies

Abstract

Antimicrobial-resistant Escherichia coli strains from pigs, sympatric rodents, and flies from two large farms in the Czech Republic with different antibiotic exposure histories were characterized based on antimicrobial resistance genes, integrons, and macrorestriction DNA profiles. Isolates of E. coli were tested for susceptibility to 12 antimicrobial agents according to the standard disk diffusion method. In resistant isolates, polymerase chain reaction was used to detect antibiotic resistance genes, integrase genes, and gene cassettes. Pulsed-field gel electrophoresis (PFGE) was used for molecular subtyping of E. coli. In farm A (long-term use of amoxicillin only), 75% (n = 198), 65% (n = 49), 11% (n = 139), and 82% (n = 177) of E. coli isolates from piglets, sows, sympatric rodents, and flies, respectively, were antibiotic resistant. In farm B (various antibiotics commonly used), 53% (n = 154), 69% (n = 98), and 54% (n = 74) of E. coli isolates from piglets, sows, and sympatric rodents, respectively, were antibiotic resistant. In both farms, the highest resistance prevalence was to tetracycline, and resistance patterns of isolates were greatly variable. Isolates with the same resistance phenotype, genes, and PFGE profile were found in pigs and flies. Isolates from rodents showed unique PFGE profiles. Close contact of sympatric rodents and flies with pigs or their products was associated with colonization of rodents and flies with resistant bacteria or transfer of resistance genes found in pig intestinal flora.

Multidrug resistance in <i>Escherichia coli</i> carrying integrons isolated from a pig farm with moderate antibiotic use

“…E. coli strains resistant to four and five antibiotics simultaneously were the most prevalent (27.3% and 28.4%, respectively) (Table 2). Values obtained in this work agree with other authors whose studies were performed with isolates from countries where the surveillance programs have not been settled and antibiotic use is not properly regulated (Literak et al, 2009;Marchant and Moreno, 2013). The most frequent multiresistance profiles observed were TET-ENR-AMX-FLOR-FOSF (22.7%), TET-TIA-ENR (13.6%) and TET-ENR-AMX-FLOR (12.5%) ( Table 2).…”

“…These results are in agreement with Literak et al (2009) (Lanz et al, 2003;Phongpaichit et al, 2007) and a high prevalence of E. coli carried class 1 integrons (Phongpaichit et al, 2007).…”

High Levels of Antimicrobial Resistance among Escherichia coli Isolates from Livestock Farms and Synanthropic Rats and Shrews in the Mekong Delta of Vietnam

“…Humans may become infected with AMR bacteria through occupational exposure and ingestion of contaminated food and water (11). In addition, antimicrobials used on farms have been reported to increase AMR in organisms isolated from areas exposed to farm waste (12), as well as in the flora of wildlife trapped in their proximity (13,14).…”

Antimicrobial Resistance in Indicator Escherichia coli Isolates from Free-Ranging Livestock and Sympatric Wild Ungulates in a Natural Environment (Northeastern Spain)

“…Moreover, many studies have found similarities in the patterns of resistance in bacterial isolates from livestock and small fauna, e.g., rodents (7,8), insects (7,9), or birds (9), from the farm settings. Thus, we were interested in determining whether wild ungulates in close contact with free-ranging livestock carry indicator bacteria with similar resistance profiles.…”