Emergence of a multidrug-resistant ST 27 Escherichia coli co-harboring blaNDM-1, mcr-1, and fosA3 from a patient in China

Carbapenem-resistant Escherichia coli exhibit diverse spatiotemporal epidemiological characteristics across the globe

Carbapenem-resistant Escherichia coli (CREC) poses a severe global public health risk. This study reveals the worldwide geographic spreading patterns and spatiotemporal distribution characteristics of resistance genes in 7918 CREC isolates belonging to 497 sequence types (ST) and originating from 75 countries. In the last decade, there has been a transition in the prevailing STs from highly virulent ST131 and ST38 to higher antibiotic-resistant ST410 and ST167. The rise of multi-drug resistant strains of CREC carrying plasmids with extended-spectrum beta-lactamase (ESBL) resistance genes could be attributed to three important instances of host-switching events. The spread of CREC was associated with the changing trends in blaNDM-5, blaKPC-2, and blaOXA-48, as well as the plasmids IncFI, IncFII, and IncI. There were intercontinental geographic transfers of major CREC strains. Various crucial transmission hubs and patterns have been identified for ST131 in the United Kingdom, Italy, the United States, and China, ST167 in India, France, Egypt, and the United States, and ST410 in Thailand, Israel, the United Kingdom, France, and the United States. This work is valuable in managing CREC infections and preventing CREC occurrence and transmission inside healthcare settings and among diverse hosts.

Situation Report on mcr-Carrying Colistin-Resistant Clones of Enterobacterales: A Global Update Through Human-Animal-Environment Interfaces

In the twenty-first century, antibiotic resistance (ABR) is one of the acute medical emergencies around the globe, overwhelming human-animal-environmental interfaces. Hit-or-mis use of antibiotics exacerbates the crisis of ABR, dispersing transferable resistance traits and challenging treatment regimens based on life-saving drugs such as colistin. Colistin is the highest priority critically important antimicrobials for human medicine, but its long use as a growth promoter in animal husbandry reduces clinical efficacy. Since 2015, the emergence and spread of mobile colistin resistance (mcr)-carrying colistin-resistant clones of Enterobacterales have been markedly sustained in both humans and animals, especially in developing countries. Hospital and community transmissions of mcr clones pose a high risk for infection prevention and outbreaks at the national and international levels. Several public health and limited one health studies have highlighted the genomic insights of mcr clones, clarifying the chromosomal sequence types (STs) and plasmid incompatibility (Inc) types. But this information is segregated into humans and animals, and rarely are environmental sectors complicating the understanding of possibly intercontinental and sectoral transmission of these clones. India is the hotspot for superbugs, including mcr-carrying colistin-resistant isolates that threaten cross-border transmission. The current review provided an up-to-date worldwide scenario of mcr-carrying STs and plasmid Inc types among the Gram-negative bacilli of Enterobacterales across human-animal-environmental interfaces and correlated with the available information from India.

Multi-drug Resistance, β-Lactamases Production, and Coexistence of bla NDM-1 and mcr-1 in Escherichia coli Clinical Isolates From a Referral Hospital in Kathmandu, Nepal

The ability of pathogenic Escherichia coli to produce carbapenemase enzymes is a characteristic that allows them to resist various antibiotics, including last-resort antibiotics like colistin and carbapenem. Our objectives were to identify rapidly developing antibiotic resistance (AR), assess β-lactamases production, and detect mcr-1 and bla _NDM-1 genes in the isolates. A prospective cross-sectional study was carried out in a referral hospital located in Kathmandu from November 2019 to December 2020 using standard laboratory and molecular protocols. Among 77 total E. coli isolates, 64 (83.1%) of them were categorized as MDR. Phenotypically 13 (20.3%) colistin-resistant, 30 (46.9%) ESBL and 8 (12.5%) AmpC producers, and 5 (7.8%) ESBL/AmpC co-producers were distributed among MDR-E. coli. Minimum inhibitory concentrations (MIC) against the majority of MDR isolates were exhibited at 1 g/L. Of these 77 E. coli isolates, 24 (31.2%) were carbapenem-resistant. Among these carbapenem-resistant bacteria, 11 (45.9%) isolates were reported to be colistin-resistant, while 15 (62.5%) and 2 (8.3%) were MBL and KPC producers, respectively. Out of 15 MBL producers, 6 (40%) harbored bla _NDM-1, and 8 (61.5%) out of 13 colistin-resistant pathogens possessed mcr-1. The resistance by colistin- and carbapenem were statistically associated (P < .001). However, only 2 (18.2%) of the co-resistant bacteria were found to have both genes. Our study revealed the highly prevalent MDR and the carbapenem-resistant E. coli and emphasized that the pathogens possess a wide range of capabilities to synthesize β-lactamases. These findings could assist to expand the understanding of AR in terms of enzyme production.

Hybrid IncFIA/FIB/FIC(FII) plasmid co-carrying blaNDM-5 and fosA3 from an Escherichia coli ST117 strain of retail chicken

Carbapenems and fosfomycin are important antibiotics used to treat Enterobacteriaceae-associated infections. This study aimed to characterize the co-resistance and co-dissemination mechanism of carbapenem and fosfomycin resistance in an Escherichia coli ST117 strain isolated from retail chicken meat. Antimicrobial susceptibility testing showed that an E. coli CS18F strain had a multidrug resistance profile, including carbapenem and fosfomycin resistance. The presence of bla_NDM-5 and fosA3 genes was confirmed by PCR and Sanger sequencing. The bla_NDM-5 and fosA3 genes were successfully transferred to the recipient strain E. coli J53 via conjugation, and the transconjugants had elevated minimum inhibitory concentrations (MICs) for meropenem and fosfomycin. Whole genome sequencing (WGS) of E. coli CS18F revealed that bla_NDM-5 and fosA3 were colocalized on an IncFIA/FIB/FIC(FII) type plasmid of 189,141 bp, which was designated as pCS18F-NDM-Fos. A novel structure with five IS26 sequences flanking the multiple drug resistance region (MDRR) was identified, and three copies of IS26 were found to be flanked bla_NDM-5, fosA3, dfrA12, aadA2, and sul1. Three types of translocation units (TUs) were identified by PCR, containing either the resistance gene bla_NDM-5 and an IS26 sequence, fosA3, and an IS26 sequence, or both, indicating their potential co-transfer via TUs. Thus, this is an unprecedented report of the presence of a plasmid co-carrying bla_NDM-5 and fosA3 and TUs potentially mediating their simultaneous transfer.

Molecular Characteristics of Antimicrobial Resistance and Virulence in Klebsiella pneumoniae Strains Isolated from Goose Farms in Hainan, China

We retrospectively investigated 326 samples that were collected from goose farms in Hainan Province, China, in 2017. A total of 33 carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates were identified from 326 samples, and the 33 CRKP isolates were characterized based on whole-genome sequencing (WGS) data from the Illumina and Oxford Nanopore Technologies (ONT) platforms. All of these 33 CRKP isolates possessed bla_NDM-5, and a single isolate coharbored mcr-1 and bla_NDM-5, while 4 isolates carried multiple virulence and metal tolerance gene clusters. One CRKP strain (CMG-35-2) was selected for long sequence reading. A hybrid plasmid carrying the virulence, resistance, and metal resistance gene in the strain was found. It possessed 2 backbones [IncFIB(K)-IncFII(K)] within a single plasmid that were closely related to K. pneumoniae plasmids from a human-associated habitat in the United States and from a human isolate in Hong Kong. A mouse abdominal infection model indicated that that strain was of the moderate virulence phenotype. This study revealed that K. pneumoniae on goose farms is an important reservoir for bla_NDM-5 and these bacteria are represented by a diversity of sequence types. The heterozygous multiple drug resistance genes carried on plasmids highlighted the genetic complexity of CRKP and the urgent need for continued active surveillance. IMPORTANCE CRKP is one of the most important pathogens, which can cause infection not only in humans but also in waterfowl. The discovery of bla_NDM-5-producing K. pneumoniae in waterfowl farms in recent years suggests that waterfowl are an important reservoir for bla_NDM-5-producing Enterobacteriaceae. However, there are few studies on the spread of bla_NDM-5-producing bacteria in waterfowl farms. Our study showed that the IncX3 plasmid carrying bla_NDM-5 in goose farms is widely present in K. pneumoniae isolates and a large number of resistance genes are accumulated in it. We found a transferable IncFIB-FII hybrid plasmid that combines virulence, resistance, and metal resistance genes, which allow transfer of these traits between bacteria in different regions. The results of this study contribute to a better understanding of the prevalence and transmission of carbapenem-resistant K. pneumoniae in goose farms.

Global Prevalence and Molecular Epidemiology of mcr-Mediated Colistin Resistance in Escherichia coli Clinical Isolates: A Systematic Review

BACKGROUND AND AIM

The continuing rise in infections caused by multi-drug resistant (MDR) bacteria is one of the most serious public health issues in today's societies. Colistin is a last-resort antimicrobial medication used to treat infections caused by MDR gram-negative bacteria; therefore resistance to this antibiotic is extremely hazardous. The current study aimed to evaluate the global prevalence and distribution of colistin resistance genes among human clinical isolates of Escherichia coli (E. coli) as a systematic review.

METHODS

PubMed, Embase, and Web of Science databases were systematically searched. For further evaluation, all original English-language articles that demonstrated colistin resistance in E. coli clinical isolates published between 2000 and 2020 were examined.

RESULTS

Out of 4857 initial articles, after various stages of review and evaluation, 190 related articles were selected. More than 79 % of the publications selected in this research were published from 2014 to 2020. In Asia, Europe, America, Africa, and Oceania, the prevalence of mobilized colistin resistance (mcr) producing colistin-resistant E. coli was 66.72%, 25.48%, 5.19%, 2.27%, and 0.32 %, respectively.

CONCLUSION

The recent widespread spreading of E. coli strains harboring mcr conferring colistin resistance, especially in Asia and Europe, is concerning and needs more attention.

Development and comparison of two nanomaterial label-based lateral flow immunoassays for the detection of five antibacterial synergists

Label is a significant factor when analyzing the performance of lateral flow immunoassays (LFIAs). Thus, this study developed two nanomaterial label-based LFIA and compared their analytical performance in practical applications.