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 blaAmpC 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.