Detection of Carbapenem resistance genes and Cephalosporin, and Quinolone Resistance genes along with oqxAB gene in E. coli in hospital waste water: a matter of concern

Authors : Chandran SP, Diwan V, Tamhankar AJ, Joseph BV, Rosales-Klintz S, Mundayoor S, Lundborg CS, Macaden R

Publication Year : 2014

Abstract :

This study was done to detect the presence of Escherichia coli resistant to cephalosporins, carbapenems and quinolones in hospital waste-water.
Waste-waters from a rural (H1) and an urban (H2) hospital were tested for E. coli resistant to cephalosporins, carbapenem and quinolones. Genes coding for chromosomal and plasmid- mediated resistance and phylogenetic grouping was detected by Multiplex Polymerase chain reaction (PCR) and for genetic relatedness by rep-PCR. Out of 190 (H1=94; H2=96) E. coli examined, 44% were resistant to both cephalosporins and quinolones and 3% to imipenem. ESBLs were detected phenotypically in 96% of the isolates, the gene blaCTX-M coding for 87% and blaTEM for 63%. Quinolone-resistance was due to mutations in gyrA and parC genes in 97% and plasmid- coded aac-(6')-Ib-cr in 89% of isolates. Only in one carbapenem resistant E. coli, NDM-1 was detected. Nearly 67% of the isolates belonged to phylogenetic group B2. There was no genetic relatedness among the isolates.
Hospital wastewater contains genetically diverse multidrugresistant E. coli.
This study stresses the need for efficient water-treatment plants in health-care settings as a public-health measure to minimize spread of multidrug-resistant bacteria into the environment.