ABSTRACT
Multidrug resistance mediated by ß-lactamase in Gram-negative bacilli is a serious public health problem. Sewers are considered reservoirs of multiresistant bacteria due to presence of antibiotics that select them and favor their dissemination. The present study evaluated the antibiotic resistance profile and ß-lactamases production in Gram-negative bacilli isolates from hospital sewage and urban wastewater treatment plants (UWWTP) in Brazil. Bacteria were isolated and identified with biochemical tests. Antibiotic susceptibility testing was performed by the disk-diffusion method and detection of extended-spectrum ß-lactamase and carbapenemases by enzymatic inhibitor and conventional PCR. Differences in resistance to amoxicillin clavulanic, aztreonam, cefepime, and cefotaxime were observed in hospital sewage compared with urban sewage (p < 0.05). The multidrug-resistant phenotype was observed in 33.3% of hospital sewage isolates (p = 0.0025). ß-lactamases genes were found in 35.6% of isolates, with the most frequent being blaKPC and blaTEM (17.8%), and blaSHV and blaCTX-M (13.3% and 8.9%, respectively). The data obtained are relevant, since the bacteria detected are on the priority pathogens list from the World Health Organization and hospital sewage could be released untreated into the municipal collection system, which may favor the spread of resistance. Changes in hospital sewage discharge practices, as well as additional technologies regarding effluent disinfection in the UWWTP, can prevent the spread of these bacteria into the environment and negative impact on water resources.
Subject(s)
Environmental Monitoring , Gram-Negative Bacteria , Medical Waste Disposal , Wastewater , beta-Lactamases , Anti-Bacterial Agents , Brazil , Cities , Gram-Negative Bacteria/enzymology , Gram-Negative Bacteria/genetics , Hospitals , Microbial Sensitivity TestsABSTRACT
The dissemination of multiresistant Klebsiella pneumoniae carbapenemase (KPC)-2-producing Klebsiella pneumoniae isolates belonging to international high-risk clones poses a major health care threat. In this study, 48 nonduplicated, carbapenem-resistant K. pneumoniae isolated from 2011 to 2014 in a tertiary hospital were investigated. The blaKPC-2 gene was the only determinant for carbapenem resistance. The blaCTX-M-15 gene was the main determinant for the production of extended-spectrum beta-lactamase (ESBL), whereas aph(3')-Ia and qnrB were the most common genes associated with resistance to aminoglycosides and quinolones, respectively. Nine different sequence types (STs) were identified. The most common was ST340. Molecular typing by enterobacterial repetitive intergenic consensus-PCR placed 48 strains among 10 different clusters. In the studied hospital, the high-risk clone of KPC-2-producing K. pneumoniae ST340, harboring genes that codify aminoglycoside modifying enzymes, QnrB and CTX-M-15 plus CTXM-2-type ESBLs, is disseminated and acts as a major agent of infections in critically ill patients.
Subject(s)
Bacterial Proteins/genetics , Klebsiella pneumoniae/genetics , beta-Lactamases/genetics , Aminoglycosides/genetics , Anti-Bacterial Agents/pharmacology , Brazil , Carbapenems/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Humans , Klebsiella Infections/drug therapy , Klebsiella Infections/microbiology , Klebsiella pneumoniae/drug effects , Microbial Sensitivity Tests/methods , Molecular Epidemiology/methods , Multilocus Sequence Typing/methods , Quinolones/pharmacology , Tertiary Care CentersABSTRACT
OBJECTIVES: Klebsiella pneumoniae is considered an opportunistic pathogen and an important agent of nosocomial and community infections. It presents the ability to capture and harbour several antimicrobial resistance genes and, in this context, the extensive use of carbapenems to treat serious infections has been responsible for the selection of several resistance genes. This study reports the draft genome sequence of a KPC-2-producing K. pneumoniae strain (Kp10) simultaneously harbouring blaCTX-M-15 and blaCTX-M-59 genes isolated from urine culture of a patient with Parkinson's disease. METHODS: Classical microbiological methods were applied to isolate and identify the strain, and PCR and sequencing were used to identify and characterise the genes and the genetic environment. Whole-genome sequencing (WGS) was performed using a Nextera XT DNA library and a NextSeq platform. RESULTS: WGS analysis revealed the presence of 5915 coding genes, 46 RNA-encoding genes and 255 pseudogenes. Kp10 belonged to sequence type 340 (ST340) of clonal complex 258 (CC258) and carried 20 transferable genes associated with antimicrobial resistance, comprising seven drug classes. Although the simultaneous presence of different blaCTX-M genes in the same strain is rarely reported, the blaKPC-2, blaCTX-M-15 and blaCTX-M-59 genes were not associated with the same genetic mobile structure in Kp10. CONCLUSIONS: These results confirm the capacity of K. pneumoniae to harbour several antimicrobial resistance genes. Thus, this draft genome could help in future epidemiological studies regarding the dissemination of clinically relevant resistance genes.
Subject(s)
Drug Resistance, Bacterial , Genome, Bacterial , Interspersed Repetitive Sequences , Klebsiella pneumoniae/genetics , Sequence Analysis, DNA , beta-Lactamases/genetics , Aged , Bacteriological Techniques , Female , Genes, Bacterial , Humans , Klebsiella Infections/microbiology , Klebsiella pneumoniae/isolation & purification , Molecular Sequence Annotation , Parkinson Disease/complications , Polymerase Chain Reaction , Urine/microbiology , Whole Genome SequencingABSTRACT
The horizontal transfer of a plasmid bearing the blaKPC-2 gene from K. pneumoniae to E. cloacae infecting the respiratory tract of a patient during meropenem therapy was elucidated. This finding is particularly worrisome, since these drugs are of last resort for multidrug-resistant Gram-negative pathogens.
