Household cockroaches carry CTX-M-15-, OXA-48- and NDM-1-producing enterobacteria, and share beta-lactam resistance determinants with humans

Background This study was designed to investigate whether household cockroaches harbor cephalosporin-resistant enterobacteria that share resistance determinants with human inhabitants. From February through July 2016, whole cockroach homogenates and human fecal samples from 100 households were cultured for cephalosporin-resistant enterobacteria (CRe). The CRe were examined for plasmid-mediated AmpC, ESBL, and carbapenemase genes; antibiotic susceptibility patterns; and conjugative transfer of antibiotic resistance mechanisms. Clonal associations between CRe were determined by multi-locus sequence typing (MLST). Results Twenty CRe were recovered from whole cockroach homogenates from 15 households. The prevalence of households with cockroaches that harbored CRe, AmpC- (based on phenotype, with no identifiable bla AmpC genes), ESBL-, and carbapenemase-producers were 15, 4, 5%(2 bla CTX-M-15/TEM-1 ; 1 bla CTX-M-15/TEM-4 ; 1 bla TEM-24 ; 1 bla SHV-4 ) and 3%(2 bla NDM-1 genes and 1 bla OXA-48 gene), respectively. Overall, 20 CRe were recovered from 61 fecal samples of inhabitants from all 15 households that had cockroach samples positive for CRe. Of these, 5CRe (1 per household) were positive for ESBLs ( bla TEM-24 , bla TEM-14 , bla CTX-M-15/TEM-4 , bla SHV-3 , bla CTX-M-15/TEM-1 ) and none carried AmpCs or carbapenemases. From 4% of households, the pair of cockroach and human CRe shared the same sequence type (ST), clonal complex (CC), antibiogram, and conjugable bla gene sequence (house 34, E. coli ST9/CC20- bla TEM-4 ; house 37, E. coli ST44/CC10- bla CTX-15/TEM-4 ; house 41, E. coli ST443/CC205- bla CTX-15/TEM-1 ; house 49, K. pneumoniae ST231/CC131- bla SHV-13 ). Conclusion The findings provide evidence that household cockroaches may carry CTX-M-15-, OXA-48- and NDM-1-producers, and share clonal relationship and beta-lactam resistance determinants with humans.