Characterization of multidrug-resistant Gram-negative bacilli isolated from hospitals effluents: first report of a bla OXA-48 -like in Klebsiella oxytoca, Algeria

Abstract

The antibiotic susceptibility profile and antimicrobial resistance determinants were characterized on Gram-negative bacilli (GNB) isolated from Algerian hospital effluents. Among the 94 isolates, Enterobacteriaceae was the predominant family, with Escherichia coli and Klebsiella pneumoniae being the most isolated species. In non-Enterobacteriaceae, Acinetobacter and Aeromonas were the predominant species followed by Pseudomonas, Comamonas, Pasteurella, and Shewanella spp. The majority of the isolates were multidrug-resistant (MDR) and carried different antimicrobial resistance genes including bla CTX-M , bla TEM , bla SHV , bla OXA-48 -like, bla OXA-23 , bla OXA-51 , qnrB, qnrS, tet(A), tet(B), tet(C), dfrA1, aac(3)-IIc (aacC2), aac(6′)-1b, sul1, and sul2. The qacEΔ1-sul1 and intI2 signatures of class 1 and class 2 integrons, respectively, were also detected. Microarray hybridization on MDR E. coli revealed additional resistance genes (aadA1 and aph3strA, tet30, mphA, dfrA12, bla cmy2 , bla ROB1 , and cmlA1) and classified the tested strains as commensals, thus highlighting the potential role of humans in antibiotic resistance dissemination. This study is the first report of bla OXA-48 -like in Klebsiella oxytoca in Algeria and bla OXA-23 in A. baumannii in Algerian hospital effluents. The presence of these bacteria and resistance genes in hospital effluents represents a serious public health concern since they can be disseminated in the environment and can colonize other hosts.