ABSTRACT
The present study was aimed to detect the carbapenemase, extended-spectrum ß-lactamase (ESBL), and intI1 gene of class 1 integron among fermenting (n = 61) and nonfermenting (n = 10) bacterial isolates recovered from water samples (n = 128). Isolates were identified by 16S rRNA sequencing. These isolates showed reduced-susceptibility to third-generation cephalosporins and carbapenems. The isolates varied in number and size of plasmids (2 kb to >20 kb). Plasmid DNA screening showed 5·6, 7, 11·2 and 26·7% prevalence of blaKPC , blaNDM , blaSHV and blaTEM genes respectively. Diverse blaNDM (blaNDM-1 and blaNDM-4 ) and blaSHV subtypes (blaSHV-2 and blaSHV-11 ) were recorded, unlike the single allelic blaKPC (blaKPC-2 ) and blaTEM (blaTEM-1 ) gene. Of the total 27 bla-gene-producing bacterial isolates, seven isolates co-harboured the carbapenemase genes (blaNDM or blaKPC or the both) along with the ESBL genes (blaSHV or blaTEM ). The intI1 gene of class 1 integron was detected among 12 (44·4%) of ESBL- and/or carbapenemase-harbouring isolates. Gene transferability was seen among four of the 10 Enterobacteriaceae donors. Carbapenemases and ESBLs with class 1 integron among aquatic environmental isolates raise the serious issue of the biosecurity and health of the ecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: Anthropologically affected and polluted environment harbours the resistance threats, where a diverse bacterial species maintain, develop and exchange genetic determinants that constitute a risk to human and ecological health. The antimicrobial resistance (AMR) in Enterobacteriaceae and non-Enterobacteriaceae bacteria caused the failure of the therapy of last resort (carbapenems) and thus lead to life-threatening infections affecting public health. Surveillance and monitoring of AMR could be important for epidemiological, diagnostic testing and control of pathogens. This is a point-prevalence study reporting the comparative occurrence and co-occurrence of carbapenemase and extended-spectrum ß-lactamase genes among fermenting and nonfermenting bacteria isolated from the aquatic environment in India.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Carbapenems/pharmacology , Drug Resistance, Bacterial/genetics , Enterobacteriaceae/genetics , beta-Lactamases/genetics , Cross-Sectional Studies , Ecosystem , Enterobacteriaceae/drug effects , Enterobacteriaceae/isolation & purification , Humans , India , Integrons , Microbial Sensitivity Tests , Plasmids/genetics , RNA, Ribosomal, 16S , WaterABSTRACT
Emission rates and emission factors of particulate matter and polycyclic aromatic hydrocarbons (PAHs) were determined in the emissions of three prevalent mosquito coil brands available in the market in India, under controlled conditions in an environmental chamber. The emission rates varied between the brands and ranged between 2.0 ± 1.9 to 27.1 ± 1.5 µg h(-1) for brand A, 3.4 ± 1.1 to 32.3 ± 1.2 µg h(-1) for brand B and 3.1 ± 1.0 to 72.2 ± 1.1 µg h(-1) for brand C for different compounds. Five and six ring PAHs were not detected, however four and three ring PAHs dominated. Three ring PAHs contributed 24 %, 42 % and 29 %, while four ring compounds contributed 53 %, 35 % and 61 % to total PAHs in the three brands. Carcinogenic PAH compounds were also present in the emissions, indicating the potential risks associated with the inhalation of coil smoke.
