scholarly journals Phenotypic and genotypic characterization of linezolid-resistant Enterococcus faecium from the USA and Pakistan

2019 ◽  
Vol 74 (12) ◽  
pp. 3445-3452 ◽  
Author(s):  
Kate E Wardenburg ◽  
Robert F Potter ◽  
Alaric W D’Souza ◽  
Tahir Hussain ◽  
Meghan A Wallace ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Enterococcus Faecium ◽  
Antibiotic Resistance Genes ◽  
23S Rrna ◽  
Linezolid Resistance ◽  
Geographical Regions ◽  
The Us ◽  
The Usa ◽  
Acquired Antibiotic Resistance

Abstract Objectives Linezolid is an important therapeutic option for the treatment of infections caused by VRE. Linezolid is a synthetic antimicrobial and resistance to this antimicrobial agent remains relatively rare. As a result, data on the comparative genomics of linezolid resistance determinants in Enterococcus faecium are relatively sparse. Methods To address this knowledge gap in E. faecium, we deployed phenotypic antibiotic susceptibility testing and Illumina WGS on hospital surface (environmental) and clinical isolates from the USA and Pakistan. Results We found complete concordance between isolate source country and mechanism of linezolid resistance, with all the US isolates possessing a 23S rRNA gene mutation and the Pakistan isolates harbouring two to three acquired antibiotic resistance genes. These resistance genes include the recently elucidated efflux-pump genes optrA and poxtA and a novel cfr-like variant. Although there was no difference in the linezolid MIC between the US and Pakistan isolates, there was a significant difference in the geometric mean of the MIC between the Pakistan isolates that had two versus three of the acquired antibiotic resistance genes. In five of the Pakistan E. faecium that possessed all three of the resistance genes, we found no difference in the local genetic context of poxtA and the cfr-like gene, but we identified different genetic contexts surrounding optrA. Conclusions These results demonstrate that E. faecium from different geographical regions employ alternative strategies to counter selective pressure of increasing clinical linezolid use.

scholarly journals Acquired Antibiotic Resistance Genes: An Overview

2011 ◽  
Vol 2 ◽  
Author(s):  
Angela H. A. M. van Hoek ◽  
Dik Mevius ◽  
Beatriz Guerra ◽  
Peter Mullany ◽  
Adam Paul Roberts ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Acquired Antibiotic Resistance

scholarly journals Cotransfer of Antibiotic Resistance Genes and a hylEfm-Containing Virulence Plasmid in Enterococcus faecium

2009 ◽  
Vol 53 (10) ◽  
pp. 4240-4246 ◽  
Author(s):  
Cesar A. Arias ◽  
Diana Panesso ◽  
Kavindra V. Singh ◽  
Louis B. Rice ◽  
Barbara E. Murray
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Enterococcus Faecium ◽  
Antibiotic Resistance Genes ◽  
The United States ◽  
Virulence Plasmid ◽  
Gene Encoding ◽  
Healthy Human ◽  
Gentamicin Resistance ◽  
High Level

ABSTRACT The hylEfm gene (encoding a putative hyaluronidase) has been found almost exclusively in Enterococcus faecium clinical isolates, and recently, it was shown to be on a plasmid which increased the ability of E. faecium strains to colonize the gastrointestinal tract. In this work, the results of mating experiments between hylEfm -containing strains of E. faecium belonging to clonal cluster 17 and isolated in the United States and Colombia indicated that the hylEfm gene of these strains is also carried on large plasmids (>145 kb) which we showed transfer readily from clinical strains to E. faecium hosts. Cotransfer of resistance to vancomycin and high-level resistance (HLR) to aminoglycosides (gentamicin and streptomycin) and erythromycin was also observed. The vanA gene cluster and gentamicin resistance determinants were genetically linked to hylEfm , whereas erm(B) and ant(6)-I, conferring macrolide-lincosamide-streptogramin B resistance and HLR to streptomycin, respectively, were not. A hylEfm -positive transconjugant resulting from a mating between a well-characterized endocarditis strain [TX0016 (DO)] and a derivative of a fecal strain of E. faecium from a healthy human volunteer (TX1330RF) exhibited increased virulence in a mouse peritonitis model. These results indicate that E. faecium strains use a strategy which involves the recruitment into the same genetic unit of antibiotic resistance genes and determinants that increase the ability to produce disease. Our findings indicate that the acquisition of the hylEfm plasmids may explain, at least in part, the recent successful emergence of some E. faecium strains as nosocomial pathogens.

Characterization of multiresistance gene cfr(C) variants in Campylobacter from China

2019 ◽  
Vol 74 (8) ◽  
pp. 2166-2170 ◽  
Author(s):  
Dejun Liu ◽  
Xing Li ◽  
Weiwen Liu ◽  
Hong Yao ◽  
Zhihai Liu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Genomic Islands ◽  
Campylobacter Coli ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Novel Variants ◽  
The Usa ◽  
Variant Genes

Abstract Objectives To investigate the occurrence, the genetic environment and the functionality of novel variants of the MDR gene cfr(C) in Campylobacter from China. Methods A total of 370 Campylobacter isolates of porcine and chicken origin collected from three regions of China in 2015 were screened for cfr(C) by PCR. The phenotypes and genotypes of cfr(C)-positive isolates were investigated by antimicrobial susceptibility testing, PFGE, MLST, S1-PFGE, Southern blotting and WGS. Quantitative RT–PCR was used to compare the expression levels of the cfr(C) variants in their original isolate and clone constructs in Campylobacter jejuni NCTC 11168. Results Four (1.1%) porcine Campylobacter coli isolates were positive for cfr(C). They failed to show elevated MICs of phenicols. The deduced Cfr(C) sequences identified exhibited 2–6 amino acid changes compared with the original Cfr(C) reported in the USA. Cloning of the cfr(C) variant genes into C. jejuni NCTC 11168 resulted in ≥32-fold increases in the MICs of phenicols, indicating that the cfr(C) variant genes are functional. The cfr(C)-carrying isolates belonged to three genotypes and WGS analysis revealed the cfr(C) genes were chromosomally located in MDR genomic islands, which contained multiple antibiotic resistance genes of Gram-positive origin. Conclusions This study identified chromosomal cfr(C) genes in C. coli isolates from China. They appeared functionally dormant in the original isolates but were fully functional when cloned and expressed in C. jejuni. The cfr(C) genes were co-transferred with other antibiotic resistance genes, possibly from Gram-positive bacteria. These findings reveal new insights into the function and transmission of cfr(C) in Campylobacter.

scholarly journals The distribution of antibiotic resistance genes in chicken gut microbiota commensals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helena Juricova ◽  
Jitka Matiasovicova ◽  
Tereza Kubasova ◽  
Darina Cejkova ◽  
Ivan Rychlik
Keyword(s):  
Antibiotic Resistance ◽  
Gut Microbiota ◽  
Resistance Genes ◽  
Intestinal Tract ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Tetracycline Resistance Genes ◽  
Gene Coding ◽  
Chicken Gut Microbiota ◽  
Acquired Antibiotic Resistance

AbstractAntibiotic resistance in bacterial pathogens or several indicator bacteria is commonly studied but the extent of antibiotic resistance in bacterial commensals colonising the intestinal tract is essentially unknown. In this study, we aimed to investigate the presence of horizontally acquired antibiotic resistance genes among chicken gut microbiota members in 259 isolates with known whole genomic sequences. Altogether 124 isolates contained at least one gene coding for antibiotic resistance. Genes coding for the resistance to tetracyclines (detected in 101 isolates), macrolide-lincosamide-streptogramin B antibiotics (28 isolates) and aminoglycosides (25 isolates) were the most common. The most frequent tetracycline resistance genes were tet(W), tet(32), tet(O) and tet(Q). Lachnospiraceae and Ruminococcaceae frequently encoded tet(W). Lachnospiraceae commonly coded also for tet(32) and tet(O). The tet(44) gene was associated with Erysipelotrichaceae and tet(Q) was detected in the genomes of Bacteroidaceae and Porphyromonadaceae. Without any bias we have shown that antibiotic resistance is quite common in gut commensals. However, a comparison of codon usage showed that the above-mentioned families represent the most common current reservoirs but probably not the original host of the detected resistances.

scholarly journals Genetics of Acquired Antibiotic Resistance Genes in Proteus spp.

2020 ◽  
Vol 11 ◽  
Author(s):  
Delphine Girlich ◽  
Rémy A. Bonnin ◽  
Laurent Dortet ◽  
Thierry Naas
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Acquired Antibiotic Resistance
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