High prevalence of qnr genes in commensal enterobacteria from healthy children in Peru and Bolivia.

A remarkable prevalence of qnrB (54%) and, at a lower level, of qnrS (14%) was discovered in pools of commensal enterobacteria from 310 healthy children living in Peru and Bolivia, using a metagenomic approach. Analysis of randomly selected enterobacterial pools revealed that qnrB was mainly carried by Escherichia coli and qnrS by Klebsiella pneumoniae. Investigation of 11 qnrB-positive isolates and 9 qnrS-positive isolates revealed the presence of plasmid-borne qnrB19 (n = 8), qnrB2 (n = 2), qnrB10 (n = 1), and qnrS1 (n = 9) genes.