The Prevalence and Characterization of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Bacteria from Hospital Sewage, Treated Effluents and Receiving Rivers

Abstract

Hospital sewage plays a key role in the dissemination of antibiotic-resistant genes (ARGs) by serving as an environmental antimicrobial resistance reservoir. In this study, we aimed to characterize the cephalosporin- and carbapenem-resistant isolates from hospital sewage and receiving rivers. The results showed that ESBL (blaCTX-M) and carbapenemase genes (blaNDM and blaKPC) were widely detected in a number of different bacterial species. These resistance genes were mainly harbored in Enterobacteriaceae, followed by Acinetobacter and Aeromonas isolates. More attention should be given to these bacteria as important vectors of ARGs in the environment. Furthermore, we showed that the multidrug resistance phenotype was highly prevalent, which was found in 85.5% Enterobacteriaceae and 75% Acinetobacter strains. Notably, the presence of carbapenemase genes in isolates from treated effluents and receiving rivers indicates that the discharges of wastewater treatment plants could be an important source for high-risk resistance genes propagation to the environment. In conclusion, this study shows a high prevalence of ESBL- and carbapenemase-producing bacteria in hospital sewage and receiving rivers in China. These findings have serious implications for human health, and also suggest the need for more efforts to control the dissemination of resistant bacteria from hospital sewage into the environment.

Diversity of Antimicrobial-Resistant Aeromonas Species Isolated from Aquatic Environments in Brazil

“…As that effluent does not receive any disinfecting pretreatment, this may contribute to the dissemination of MDR bacteria that were also found in the sanitary effluent located near the Complexo Hospital de Clínicas (Universidade Federal do Paraná) (CHC-UFPR). Our results are consistent with previous studies, showing that MDR Aeromonas strains are spreading rapidly in different environmental compartments and may be involved in the maintenance and dissemination of carbapenemase genes (14,18,(29)(30)(31).…”

“…Growing levels of drug resistance, especially to β-lactam, have been reported in Aeromonas spp. not only in clinical isolates, but also in isolates from water ecosystems and aquatic organisms (13,29,31). In our study, CTX-M β-lactamase harboring strains were the prevalent group in WWTP that receives high amounts of microbial contaminants from hospitals effluents and other sources as well as in DRW.…”

“…Despite several studies reporting the emergence of MDR and/or β-lactamase-producing Aeromonas isolates (30,31) and rare reports of bla KPC-2 (17,29,32,33), rare β-lactamase-encoding genes identified in our study deserve further attention. In particular, bla GES-1 and bla GES-7 encode ESBLs, whereas bla GES-5 and bla GES-16 encode enzymes able to hydrolyze carbapenems (34).…”

Antimicrobial resistance in Aeromonas species isolated from aquatic environments in Brazil

“…2019; Zhang et al . 2020), rare β‐lactamase‐encoding genes identified in our study deserve further attention. In particular, bla GES‐1 and bla GES‐7 encode ESBLs, whereas bla GES‐5 and bla GES‐16 encode enzymes able to hydrolyse carbapenems (Cuzon et al .…”

Trends, new insights and perspectives in the treatment of hospital effluents

“…Some of the selected ARB are Acinetobacter baumannii , carbapenem-resistant; Pseudomonas aeruginosa , carbapenem-resistant; Enterobacteriaceae , carbapenem-resistant, 3 rd generation cephalosporin-resistant (with priority 1) and Enterococcus faecium , vancomycin-resistant (with priority 2). Many investigations have been carried out in recent years (( 43 ), ( 44 ), ( 45 ), ( 18 ), ( 46 )) demonstrating the increasing efforts made by research groups in this field and the increasing amount of data collected on their occurrence. The cited investigations concluded that the resistance to antibiotics is generally higher in HWW rather than in domestic wastewater, and if hospital effluent is not properly disinfected it may strongly contribute to the spread of ARB in the environment.…”