Genomic investigation unveils high-risk ESBL producing Enterobacteriaceae within a rural environmental water body.

Antimicrobial resistance is regarded as a global threat to public health, animals, and the environment, emerging in response to extensive utilization of antimicrobials. The determinants of antimicrobial resistance are transported to susceptible bacterial populations through genetic recombination or through gene transfer, mediated by bacteriophages, plasmids, transposons, and insertion sequences. To determine the penetration of antimicrobial resistance into the bacterial population of the Thiruvandarkoil Lake, a water body located in the rural settings of Puducherry, India, culture-based microbiological and genomic approaches were used. Resistant bacterial isolates obtained from microbiological screening were subjected to whole genome sequencing and the genetic determinants of antimicrobial resistance were identified using in silico genomic tools. Cephalosporin-resistant isolates were found to produce extended spectrum beta lactamases, encoded by blaVEB-6 (in Proteus mirabilis PS01), blaSHV-12 and ompK36 mutation (in Klebsiella quasipneumoniae PS02) and blaSHV-12, blaACT-16, blaCTX-M and blaNDM-1 in (Enterobacter hormaechei PS03). Genes encoding heavy metal resistance, virulence and resistance to detergents were also detected in these resistant isolates. Among ESBL-producing organisms, one mcr-9-positive Enterobacter hormaechei was also identified in this study. To our knowledge, this is the first report of mcr-9 carrying bacterium in the environment in India. This study seeks the immediate attention of policy makers, researchers, government officials and environmental activists in India, to develop surveillance programs to monitor the dissemination of antimicrobial resistance in the environment.

Genomic insights into plasmid-mediated antimicrobial resistance in the bacterium Bhargavaea beijingensis strain PS04.

The dissemination of antimicrobial-resistant bacteria through environment is a major health concern for public health. Pathogenic bacteria in natural environment can mediate the transfer of antimicrobial-resistant genes via horizontal gene transfer to naturally occurring bacteria in the soil. Bhargavaea beijingensis is a Gram-negative bacterium that is commonly found in soil and water. In recent years, there has been an emergence of antibiotic-resistant strains of environmental bacteria, which pose a significant threat to human health. One mechanism of antibiotic resistance in bacteria is through the acquisition of plasmids, which can carry genes that confer resistance to various antibiotics. In this study, a novel plasmid of repUS12 replicon type was identified in the strain PS04 of B. beijingensis, which carried the ermT and tet(L) genes, encoding resistance to macrolides, lincosamides, and tetracycline. The plasmid was found to be the first of its kind in B. beijingensis and was thought to have been acquired through horizontal gene transfer. The emergence of plasmid-mediated resistance in B. beijingensis highlights the need for continued surveillance and monitoring of antibiotic resistance in environmental bacteria.

The menace of colistin resistance across globe: Obstacles and opportunities in curbing its spread.

Colistin-resistance in bacteria is a big concern for public health, since it is a last resort antibiotic to treat infectious diseases of multidrug resistant and carbapenem resistant Gram-negative pathogens in clinical settings. The emergence of colistin resistance in aquaculture and poultry settings has escalated the risks associated with colistin resistance in environment as well. The staggering number of reports pertaining to the rise of colistin resistance in bacteria from clinical and non-clinical settings is disconcerting. The co-existence of colistin resistant genes with other antibiotic resistant genes introduces new challenges in combatting antimicrobial resistance. Some countries have banned the manufacture, sale and distribution of colistin and its formulations for food producing animals. However, to tackle the issue of antimicrobial resistance, a one health approach initiative, inclusive of human, animal, and environmental health needs to be developed. Herein, we review the recent reports in colistin resistance in bacteria of clinical and non-clinical settings, deliberating on the new findings obtained regarding the development of colistin resistance. This review also discusses the initiatives implemented globally in mitigating colistin resistance, their strength and weakness.