ABSTRACT
Introduction: The antimicrobial resistance (AMR) mobilome plays a key role in the dissemination of resistance genes encoded by mobile genetics elements (MGEs) including plasmids, transposons (Tns), and insertion sequences (ISs). These MGEs contribute to the dissemination of multidrug resistance (MDR) in enteric bacterial pathogens which have been considered as a global public health risk. Methods: To further understand the diversity and distribution of AMR genes and MGEs across different plasmid types, we utilized multiple sequence-based computational approaches to evaluate AMR-associated plasmid genetics. A collection of 1,309 complete plasmid sequences from Gammaproteobacterial species, including 100 plasmids from each of the following 14 incompatibility (Inc) types: A/C, BO, FIA, FIB, FIC, FIIA, HI1, HI2, I1, K, M, N, P except W, where only 9 sequences were available, was extracted from the National Center for Biotechnology Information (NCBI) GenBank database using BLAST tools. The extracted FASTA files were analyzed using the AMRFinderPlus web-based tools to detect antimicrobial, disinfectant, biocide, and heavy metal resistance genes and ISFinder to identify IS/Tn MGEs within the plasmid sequences. Results and Discussion: In silico prediction based on plasmid replicon types showed that the resistance genes were diverse among plasmids, yet multiple genes were widely distributed across the plasmids from enteric bacterial species. These findings provide insights into the diversity of resistance genes and that MGEs mediate potential transmission of these genes across multiple plasmid replicon types. This notion was supported by the observation that many IS/Tn MGEs and resistance genes known to be associated with them were common across multiple different plasmid types. Our results provide critical insights about how the diverse population of resistance genes that are carried by the different plasmid types can allow for the dissemination of AMR across enteric bacteria. The results also highlight the value of computational-based approaches and in silico analyses for the assessment of AMR and MGEs, which are important elements of molecular epidemiology and public health outcomes.
ABSTRACT
The widespread escalation of bacterial resistance threatens the safety of the food chain. To investigate the resistance characteristics of E. coli strains isolated from disinfected tableware against both disinfectants and antibiotics, 311 disinfected tableware samples, including 54 chopsticks, 32 dinner plates, 61 bowls, 11 cups, and three spoons were collected in Chengdu, Sichuan Province, China to screen for disinfectant- (benzalkonium chloride and cetylpyridinium chloride) and tigecycline-resistant isolates, which were then subjected to antimicrobial susceptibility testing and whole genome sequencing (WGS). The coliform-positive detection rate was 51.8% (161/311) and among 161 coliform-positive samples, eight E. coli strains were multidrug-resistant to benzalkonium chloride, cetylpyridinium chloride, ampicillin, and tigecycline. Notably, a recently described mobile colistin resistance gene mcr-10 present on the novel IncFIB-type plasmid of E. coli EC2641 screened was able to successfully transform the resistance. Global phylogenetic analysis revealed E. coli EC2641 clustered together with two clinically disinfectant- and colistin-multidrug-resistant E. coli strains from the US. This is the first report of mcr-10-bearing E. coli detected in disinfected tableware, suggesting that continuous monitoring of resistance genes in the catering industry is essential to understand and respond to the transmission of antibiotic resistance genes from the environment and food to humans and clinics.
ABSTRACT
Opportunistic premise plumbing pathogens (OPPP) are microorganisms that are native to the plumbing environment and that present an emerging infectious disease problem. They share characteristics, such as disinfectant resistance, thermal tolerance, and biofilm formation. The colonisation of domestic water systems presents an elevated health risk for immune-compromised individuals who receive healthcare at home. The literature that has identified the previously described OPPPs (Aeromonas spp., Acinetobacter spp., Helicobacter spp., Legionella spp., Methylobacterium spp., Mycobacteria spp., Pseudomonas spp., and Stenotrophomonas spp.) in residential drinking water systems were systematically reviewed. By applying the Preferred reporting items for systematic reviews and meta-analyses guidelines, 214 studies were identified from the Scopus and Web of Science databases, which included 30 clinical case investigations. Tap components and showerheads were the most frequently identified sources of OPPPs. Sixty-four of these studies detected additional clinically relevant pathogens that are not classified as OPPPs in these reservoirs. There was considerable variation in the detection methods, which included traditional culturing and molecular approaches. These identified studies demonstrate that the current drinking water treatment methods are ineffective against many waterborne pathogens. It is critical that, as at-home healthcare services continue to be promoted, we understand the emergent risks that are posed by OPPPs in residential drinking water. Future research is needed in order to provide consistent data on the prevalence of OPPPs in residential water, and on the incidence of waterborne homecare-associated infections. This will enable the identification of the contributing risk factors, and the development of effective controls.
ABSTRACT
Disinfectants can effectively inhibit or kill microorganisms on the surface of objects and transmission media, which are widely used in food, hygiene, health, pandemic prevention and other fields. During the COVID-19 pandemic, the global use of disinfectants increased sharply, which played an important role in effectively preventing and controlling the spread of the virus and preventing the spread of the pandemic. However, improper use of disinfectants will reduce its effectiveness and even induce microbial resistance, which may increase the risk of infectious disease transmission. The disinfectant resistance gene of microorganism will also aggravate its pollution and transmission risk through vertical reproduction or horizontal transfer between the same or different species, which seriously threatens public health safety. At present, the wide emergence of antibiotic resistance gene (ARG) has attracted global attention to public health, but the understanding of disinfectant resistance is very limited. This paper reviews the research on microbial resistance to disinfectants in recent years, focusing on the mechanism of microbial resistance by forming biofilm, reducing cell membrane permeability, over expressing efflux pump, producing specific enzymes to eliminate or attenuate disinfectants, and changing action targets. The formation of strong biofilm can effectively prevent disinfectants from approaching microorganisms, reduce microbial sensitivity and improve resistance;the reduction of cell membrane permeability depends on the changes of membrane protein, phospholipid and lipopolysaccharide, which can reduce the entry of disinfectants into microbial cells;the overexpression of efflux pump system is conducive to microorganisms to discharge harmful substances in cells;the action of specific enzymes can degrade the effective components of disinfectants or improve microbial immunity;the change of target can reduce the combination of disinfectant and action site, so as to reduce the disinfection effect. In addition, aiming at the acquisition and transmission of microbial disinfectant resistance, the chromosome and plasmid mediated resistance genes as well as the relationship between microbial disinfectant resistance and antibiotic resistance in the environment were discussed. Disinfectant resistance genes can be transferred and transmitted by transformation, transduction or conjugation through mobile genetic elements such as plasmids and phages, which puts forward new requirements for scientific disinfection.