Escherichia coli
Mechanisms of ResistanceSpread of NDM-5 and OXA-181 Carbapenemase-Producing Escherichia coli in ChadWe detected for the first time blaNDM-5 and blaOXA-181 in Escherichia coli isolates from hospitalized patients and healthy volunteers in Chad. These resistance genes were located on IncX3 and IncF plasmids. Despite the large diversity of E. coli clones, the...
Mechanisms of ResistanceComplete Nucleotide Sequence of a Novel Plasmid Bearing the High-Level Tigecycline Resistance Gene tet(X4)We reported the complete nucleotide sequence of a tet(X4)-carrying plasmid, pSTB20-1T, from a tigecycline-resistant Escherichia coli isolate in China. Sequence analysis indicated that pSTB20-1T contains a hybrid plasmid backbone and a tet(X4)-containing multidrug resistance region, likely originated through recombination of multiple plasmids. tet...
Mechanisms of ResistanceNovel 5-Nitrofuran-Activating Reductase in Escherichia coliThe global spread of multidrug-resistant enterobacteria warrants new strategies to combat these pathogens. One possible approach is the reconsideration of “old” antimicrobials, which remain effective after decades of use. Synthetic 5-nitrofurans such as furazolidone, nitrofurantoin, and nitrofurazone are such a class of antimicrobial drugs.
Mechanisms of ResistanceIdentification of FosA8, a Plasmid-Encoded Fosfomycin Resistance Determinant from Escherichia coli, and Its Origin in Leclercia adecarboxylataA plasmid-located fosfomycin resistance gene, fosA8, was identified from a CTX-M-15-producing Escherichia coli isolate recovered from urine. Identification of this gene was obtained by whole-genome sequencing. It encoded FosA8, which shares 79% and 78% amino acid identity with the most closely related FosA2 and FosA1 enzymes, respectively. The fosA8...
Mechanisms of ResistanceUpregulation of PBP1B and LpoB in cysB Mutants Confers Mecillinam (Amdinocillin) Resistance in Escherichia coliMecillinam (amdinocillin) is a β-lactam antibiotic that inhibits the essential penicillin-binding protein 2 (PBP2). In clinical isolates of Escherichia coli from urinary tract infections, inactivation of the cysB gene (which encodes the main regulator of cysteine biosynthesis, CysB) is the major cause of resistance. How a nonfunctional CysB protein confers...
Mechanisms of ResistancePlasmid-Mediated mcr-1 Colistin Resistance in Escherichia coli from a Black Kite in RussiaThe gene mcr-1 conferring resistance to last-line antibiotic colistin has been reported globally. Here, we describe the first detection of plasmid-mediated colistin resistance in Russian wildlife, an isolate of Escherichia coli sequence type 2280 from a black kite (Milvus migrans) scavenging raptor. Whole-genome sequencing and plasmid transferability...
Mechanisms of Resistancemcr-9, an Inducible Gene Encoding an Acquired Phosphoethanolamine Transferase in Escherichia coli, and Its OriginThe plasmid-located mcr-9 gene, encoding a putative phosphoethanolamine transferase, was identified in a colistin-resistant human fecal Escherichia coli strain belonging to a very rare phylogroup, the D-ST69-O15:H6 clone. This MCR-9 protein shares 33% to 65% identity with the other plasmid-encoded MCR-type enzymes identified (MCR-1 to -8) that have been found...
Mechanisms of ResistanceMultiple Copies of qnrA1 on an IncA/C2 Plasmid Explain Enhanced Quinolone Resistance in an Escherichia coli MutantIn a previous study, mutants with enhanced ciprofloxacin resistance (Cipr) were selected from Escherichia coli J53/pMG252 carrying qnrA1. Strain J53 Cipr 8-2 showed an increase in the copy number and transcription level of qnrA1. We sequenced the plasmids on Illumina and MinION platforms.
Mechanisms of ResistanceRapid Increase in Carbapenemase-Producing Enterobacteriaceae in Retail Meat Driven by the Spread of the blaNDM-5-Carrying IncX3 Plasmid in China from 2016 to 2018The presence and molecular characteristics of carbapenemase-producing Enterobacteriaceae (CPE) among meat products in China were investigated. A total of 110 carbapenem-resistant Enterobacteriaceae (CRE) isolates, including 94 ...
Experimental TherapeuticsUnexpected Activity of Oral Fosfomycin against Resistant Strains of Escherichia coli in Murine PyelonephritisFosfomycin tromethamine activity is well established for oral treatment of uncomplicated lower urinary tract infections, but little is known about its potential efficacy in pyelonephritis. Ascending pyelonephritis was induced in mice infected with 6 strains of Escherichia coli (fosfomycin MICs, 1 μg/ml to 256 μg/ml). The urine pH was 4.5 before infection and 5.5 to 6....