Lack of dissemination of acquired resistance to β‐lactams in small wild mammals around an isolated village in the Amazonian forest

Abstract

In this study, we quantitatively evaluated the spread of resistance to β-lactams and of integrons in small rodents and marsupials living at various distances from a point of antibiotic's use. Rectal swabs from 114 animals were collected in Trois-Sauts, an isolated village in French Guiana, and along a 3 km transect heading through the non-anthropized primary forest. Prevalence of ticarcillin-resistant enterobacteria was 36% (41/114). Klebsiella spp., naturally resistant to ticarcillin, were found in 31.1% (23/73) of animals from the village and in an equal ratio of 31.7% (13/41) of animals trapped along the transect. By contrast Escherichia coli with acquired resistance to ticarcillin were found in 13.7% (10/73) of animals from the village and in only 2.4% (1/41) of those from the transect (600 m from the village). There was a huge diversity of E. coli and Klebsiella pneumoniae strains with very unique and infrequent sequence types. The overall prevalence of class 1 integrons carriage was 19.3% (22/114) homogenously distributed between animals from the village and the transect, which suggests a co-selection by a non-antibiotic environmental factor. Our results indicate that the anthropogenic acquired antibiotic resistance did not disseminate in the wild far from the point of selective pressure.

Day-to-Day Dynamics of Commensal Escherichia coli in Zimbabwean Cows Evidence Temporal Fluctuations within a Host-Specific Population Structure

“…Antibiotic resistance was studied both phenotypically and genotypically. First, global antibiotic resistance was analyzed by plating fecal samples on Drigalski agar plates containing 32 mg/liter ticarcillin, which was selective for penicillin-resistant isolates (57), and Drigalski agar plates containing 20 mg/liter tetracycline, which was selective for tetracycline-resistant isolates (58). The lower limit of detection was 10 2 CFU/g of feces.…”

Escherichia coli Population Structure and Antibiotic Resistance at a Buffalo/Cattle Interface in Southern Africa

“…In these subdominant resistant strains, multiple resistance was observed (Table 2), which is mainly conferred by mobile genetic elements. Such a mechanism of selfish gene spread rather than strain or plasmid spread has recently been proposed to explain the dissemination of acquired resistance to ␤-lactams in small wild mammals in French Guiana pristine forest from an Amerindian village (48).…”

“…These behaviors can explain the presence of phylogroups of potential human origin (i.e., phylogroup A) and ABR against human antibiotics. It has been recently shown in the Amazonian forest that acquired ABR did not disseminate in the wild far (600 m) from the point of selective pressure represented by the village (48).…”

Genetic characterization of commensal Escherichia coli isolated from laboratory rodents

“…As E. coli is widely used as an indicator of antimicrobial selection pressure (Grønvold et al 2010 ) and newly introduced bacteria species may transfer antimicrobial resistant determinants to commensal species (Schmidt et al 2015 ), assessment of the genetic characteristics of commensal E. coli would provide information on the virulence status in the animals housed in the animal experimental facility. The occurrence of horizontal gene transfer of beta-lactamases among E. coli (Jaureguy et al 2008 ; Koga et al 2015 ) and the reverse transfer of antimicrobial resistance from humans to animals (Grall et al 2015 ) could transpire as a result of the close interaction between scientists (humans) and laboratory rodents (animals). Hence, determination of antimicrobial resistance at the genetic level is important for understanding and limit antimicrobial resistance.…”