High prevalence of carriage of mcr-1-positive enteric bacteria among healthy children from rural communities in the Chaco region, Bolivia, September to October 2016

Abstract

BackgroundThe mcr-1 gene is a transferable resistance determinant against colistin, a last-resort antimicrobial for infections caused by multi-resistant Gram-negatives.AimTo study carriage of antibiotic-resistant bacteria in healthy school children as part of a helminth control and antimicrobial resistance survey in the Bolivian Chaco region.MethodsFrom September to October 2016 we collected faecal samples from healthy children in eight rural villages. Samples were screened for mcr-1- and mcr-2 genes. Antimicrobial susceptibility testing was performed, and a subset of 18 isolates representative of individuals from different villages was analysed by whole genome sequencing (WGS).ResultsWe included 337 children (mean age: 9.2 years, range: 7–11; 53% females). The proportion of mcr-1 carriers was high (38.3%) and present in all villages; only four children had previous antibiotic exposure. One or more mcr-1-positive isolates were recovered from 129 positive samples, yielding a total of 173 isolates (171 Escherichia coli, 1 Citrobacter europaeus, 1 Enterobacter hormaechei). No mcr-2 was detected. Co-resistance to other antimicrobials varied in mcr-positive E. coli. All 171 isolates were susceptible to carbapenems and tigecycline; 41 (24.0%) were extended-spectrum β-lactamase producers and most of them (37/41) carried bla CTX-M-type genes. WGS revealed heterogeneity of clonal lineages and mcr-genetic supports.ConclusionThis high prevalence of mcr-1-like carriage, in absence of professional exposure, is unexpected. Its extent at the national level should be investigated with priority. Possible causes should be studied; they may include unrestricted use of colistin in veterinary medicine and animal breeding, and importation of mcr-1-positive bacteria via food and animals.

Prevalence and Epidemiology of Multidrug-Resistant Pathogens in the Food Chain and the Urban Environment in Northwestern Germany

“…In other European countries, the prevalence of mcr - 1 in the community or among patients in hospitals was also low (0–0.4%) [ 22 , 23 , 24 ]. The travel-associated acquisition of mcr - E. coli is in agreement with findings of mcr - 1 carriage rates of 5–88% in China, Bolivia, and Vietnam [ 25 , 26 ]. In these countries, reports indicate a livestock- or food-associated exchange of mcr - E. coli .…”

Characterization of Antimicrobial Resistance in Serratia spp. and Citrobacter spp. Isolates from Companion Animals in Japan: Nosocomial Dissemination of Extended-Spectrum Cephalosporin-Resistant Citrobacter freundii

“…portucalensis ( n = 6), and C. europaeus ( n = 2) (Figure 1). To the best of our knowledge, this is the first report on the isolation of C. portucalensis and C. europaeus strains from animals, although these species have been rarely reported in humans [26,27]. These findings imply the prevalence of several Citrobacter species in companion animals, in addition to C. freundii .…”

Plasmidic resistance to colistin mediated by mcr-1 gene in Escherichia coli clinical isolates in Argentina: A retrospective study, 2012–2018

“…The mcr-1.5 variant was previously described only in three countries: Japan, Bolivia, and Argentina ( 13 , 28 , 29 ). In the present collection, 13.5% of the isolates were positive for this variant.…”