Characterization of CTX-M enzymes, quinolone resistance determinants, and antimicrobial residues from hospital sewage, wastewater treatment plant, and river water.
Multidrug-resistant (MDR) bacteria are widespread in hospitals and have been increasingly isolated from aquatic environments. The aim of the present study was to characterize extended-spectrum β-lactamase (ESBL) and quinolone-resistant Enterobacteriaceae from a hospital effluent, sanitary effluent, inflow sewage, aeration tank, and outflow sewage within a wastewater treatment plant (WWTP), as well as river water upstream and downstream (URW and DRW, respectively), of the point where the WWTP treated effluent was discharged. β-lactamase (bla) genes, plasmid-mediated quinolone resistance (PMQR), and quinolone resistance-determining regions (QRDRs) were assessed by amplification and sequencing in 55 ESBL-positive and/or quinolone-resistant isolates. Ciprofloxacin residue was evaluated by high performance liquid chromatography. ESBL-producing isolates were identified in both raw (n=29) and treated (n=26) water; they included Escherichia coli (32), Klebsiella pneumoniae (22) and Klebsiella oxytoca (1). Resistance to both cephalosporins and quinolone was observed in 34.4% of E. coli and 27.3% of K. pneumoniae. Resistance to carbapenems was found in 5.4% of K. pneumoniae and in K. oxytoca. Results indicate the presence of blaCTX-M(51/55, 92.7%) and blaSHV(8/55, 14.5%) ESBLs, and blaGES(2/55, 3.6%) carbapenemase-encoding resistance determinants. Genes conferring quinolone resistance were detected at all sites, except in the inflow sewage and aeration tanks. Quinolone resistance was primarily attributed to amino acid substitutions in the QRDR of GyrA (47%) or to the presence of PMQR (aac-(6')-Ib-cr, oqxAB, qnrS, and/or qnrB; 52.9%) determinants. Ciprofloxacin residue was absent only from URW. Our results have shown strains carrying ESBL genes, PMQR determinants, and mutations in the gyrA QRDR genes mainly in hospital effluent, URW, and DRW samples. Antimicrobial use, and the inefficient removal of MDR bacteria and antibiotic residue during sewage treatment, may contribute to the emergence and spreading of resistance in the environment, making this a natural reservoir.
Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe (FPP/IPPPP), Curitiba, Paraná, Brazil. Electronic address: conte.danieli@gmail.com.
Danieli
D
Conte
Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe (FPP/IPPPP), Curitiba, Paraná, Brazil; Hospital de Clínicas, Universidade Federal do Paraná (HC-UFPR), Curitiba, Paraná, Brazil. Electronic address: jukasuko@gmail.com.
Jussara Kasuko
JK
Palmeiro
Departamento de Patologia Básica, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, Paraná, Brazil. Electronic address: keitenogueira@gmail.com.
Keite
K
da Silva Nogueira
Sewage service unit, Companhia de Saneamento do Paraná (SANEPAR), Curitiba, Paraná, Brazil. Electronic address: thiagomrl@sanepar.com.br.
Thiago Marenda Rosa
TM
de Lima
Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe (FPP/IPPPP), Curitiba, Paraná, Brazil; Pharmacy Department, Health Sciences Sector, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, Brazil. Electronic address: marcoacardoso@yahoo.com.br.
Marco André
MA
Cardoso
Pharmacy Department, Health Sciences Sector, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, Brazil. Electronic address: pontarolo@ufpr.br.
Roberto
R
Pontarolo
Pharmacy Department, Health Sciences Sector, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, Brazil. Electronic address: flaviadegaut@yahoo.com.br.
Flávia Lada
FL
Degaut Pontes
Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe (FPP/IPPPP), Curitiba, Paraná, Brazil; Hospital de Clínicas, Universidade Federal do Paraná (HC-UFPR), Curitiba, Paraná, Brazil. Electronic address: lmdallacosta@gmail.com.
Libera Maria
LM
Dalla-Costa
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000032:analysis* / Q000633:toxicity; D001426:Bacterial Proteins / Q000378:metabolism; D002939:Ciprofloxacin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D004755:Enterobacteriaceae / Q000302:isolation & purification; D004926:Escherichia coli / Q000187:drug effects; D007711:Klebsiella pneumoniae / Q000187:drug effects; D010957:Plasmids / Q000187:drug effects; D015363:Quinolones / Q000633:toxicity*; D045483:Rivers; D012722:Sewage / Q000032:analysis*; D062065:Wastewater / Q000032:analysis*; D001618:beta-Lactamases / Q000378:metabolism
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D002939:Ciprofloxacin; D015363:Quinolones; D012722:Sewage; D062065:Wastewater; D001618:beta-Lactamases; C063912:carbapenemase
Drug resistance; Enterobacteriaceae; Wastewater