Objectives: To clarify the genetic basis of high-level linezolid resistance in three Clostridioides difficile strains from calves.
Methods: A WGS approach was used to comprehensively characterize C. difficile A501, A505 and A516 strains exhibiting high linezolid MICs, and to clarify their phylogenetic relationships.
Objectives: To characterize the optrA-, cfr(D)- and vanA-carrying linear plasmids detected in three MDR enterococcal clinical isolates.
Methods: Enterococcus faecium (868), E. faecium (1001) and Enterococcus faecalis (2048), which were linezolid- and vancomycin-resistant due to the presence of optrA, cfr(D) and vanA genes, were tested for their susceptibility to several antibiotics.
The presence of erm(T) gene conferring resistance to macrolides, lincosamides and streptogramin B (MLS), was screened in 296 enterococci collected from clinical samples in a central Italy hospital and seven Enterococcus faecium isolates resulted positive to erm(T) by PCR. All isolates were resistant to erythromycin, tetracycline, ciprofloxacin and ampicillin but susceptible to vancomycin and chloramphenicol. Whole Genome Sequencing analysis revealed that in five E.
View Article and Find Full Text PDFAfter harvesting of cones used for beer production, the remaining hop vegetative biomass requires disposal. The hop plant contains bioactive compounds in all its parts-cones, leaves, and roots-exhibiting interesting antioxidant, antiviral, and antibacterial properties. In this work, extracts obtained from hop leaves, a plant material often neglected in the hop cultivation, have been investigated; the qualitative UHPLC-MS/MS and GC-TOF-MS characterization revealed the presence of bioactive compounds such as polyphenols, α- and β-acids and terpenes are present.
View Article and Find Full Text PDFEur J Clin Microbiol Infect Dis
April 2024
Purpose: To investigate the occurrence of vancomycin-variable enterococci (VVE) in a hospital in central Italy.
Methods: vanA positive but vancomycin-susceptible Enterococcus faecium isolates (VVE-S) were characterized by antibiotic susceptibility tests, molecular typing (PFGE and MLST), and WGS approach. The reversion of VVE-S to a resistant phenotype was assessed by exposure to increasing vancomycin concentrations, and the revertant isolates were used in filter mating experiments.
The MexXY-OprM multidrug efflux pump (EP) in aminoglycosides resistant Pseudomonas aeruginosa is one of the major resistance mechanisms, which is often overexpressed in strains isolated from pulmonary chronic disease such as cystic fibrosis. In this research, we focused on the design of potential efflux pumps inhibitors, targeting MexY, the inner membrane component, in an allosteric site. Berberine has been considered as lead molecule since we previously demonstrated its effectiveness in targeting MexY in laboratory reference strains.
View Article and Find Full Text PDFJ Antimicrob Chemother
December 2023
Microb Drug Resist
September 2023
To investigate the occurrence of oxazolidinone resistance genes, 18 florfenicol-resistant enterococci were isolated from 66 fecal samples collected from several cattle farms in central Italy. The PCR screening indicated that only a bovine florfenicol-resistant isolate, 249031-C, was positive for the presence of and genes. The strain was tested for its susceptibility to florfenicol, chloramphenicol, linezolid, tedizolid, tetracycline, erythromycin, and vancomycin.
View Article and Find Full Text PDFJ Antimicrob Chemother
July 2023
Objectives: To investigate the optrA-carrying genetic elements and their transferability in two linezolid-resistant Streptococcus dysgalactiae subsp. equisimilis (SDSE) strains of swine origin.
Methods: SDSE strains (V220 and V1524) were phenotypically and genotypically characterized.
Oxazolidinones are critically important antibiotics to treat human infections caused by multidrug-resistant bacteria, therefore the occurrence of linezolid-resistant enterococci from food-producing animals poses a serious risk to human health. In this study, Enterococcus avium 38157 and 44917 strains, isolated from the brain of two unrelated piglets, were found to carry the linezolid resistance genes cfr(D)-optrA, and cfr(D2)-poxtA, respectively. Whole genome sequencing analysis of E.
View Article and Find Full Text PDFAntibiotics (Basel)
November 2022
Background: The presence of carbapenemase-producing bacteria (CPB) in animal hosts and along the food chain may result in the development of reservoirs for human infections. Several CPB strains isolated from animals have been reported, suggesting that transmission and dissemination of the corresponding genes between humans and animals may occur. Animal and food samples have complex backgrounds that hinder the detection of CPB present in low concentrations by standard detection procedures.
View Article and Find Full Text PDFThe recovery and characterization of a multidrug-resistant, KPC-3-producing Klebsiella michiganensis that was obtained from Venus clam samples is reported in this study. A whole-genome sequencing (WGS) analysis using Illumina and Nanopore technologies of the 23999A2 isolate revealed that the strain belonged to the new sequence type 382 (ST382) and carried seven plasmid replicon sequences, including four IncF type plasmids (FII, FIIY, FIIk, and FIB), one IncHI1 plasmid, and two Col plasmids. The FIB and FII plasmids showed high homology to each other and to multireplicon pKpQIL-like plasmids that are found in epidemic KPC-K.
View Article and Find Full Text PDFJ Antimicrob Chemother
February 2022
Objectives: To characterize a linezolid-resistant Enterococcus gallinarum isolate of porcine origin co-carrying cfr, optrA and poxtA genes.
Methods: The genome was sequenced using the Illumina and Nanopore platforms. The presence of circular intermediates was examined by inverse PCR.
Objectives: To investigate the genetic elements and the transferability of linezolid resistance genes in three enterococci co-carrying cfr(D) and poxtA2 isolates from manure of a swine farm in central Italy.
Methods: Two Enterococcus faecalis isolates and one Enterococcus casseliflavus isolate carrying both cfr(D) and poxtA genes were tested for their susceptibility to florfenicol, chloramphenicol, linezolid, tedizolid, tetracycline and vancomycin. Linezolid resistance genes transfer (filter mating), localization (S1-PFGE/hybridization), genetic elements and relatedness between isolates (WGS) were analysed.
We report a novel IncHI2 plasmid coharboring , two copies of , and resistance genes in a human Escherichia coli isolate of the new serogroup O188. The gene was included in a class 1 integron, in a cassette bracketed by IS and ΔIS1R, and in two copies within a new composite Tn-like transposon. The emergence of carbapenem and colistin resistance genes in a single plasmid is of great concern for upcoming clinical therapies.
View Article and Find Full Text PDFAppl Environ Microbiol
April 2021
Linezolid is a last-resort antibiotic for the treatment of severe infections caused by multidrug-resistant Gram-positive organisms; although linezolid resistance remains uncommon, the number of linezolid-resistant enterococci has increased in recent years due to worldwide spread of acquired resistance genes (, , and ) in clinical, animal, and environmental settings. In this study, we investigated the occurrence of linezolid-resistant enterococci in marine samples from two coastal areas in Italy. Isolates grown on florfenicol-supplemented Slanetz-Bartley agar plates were investigated for their carriage of , , and genes; was found in one isolate, was found in three isolates and two isolates, and was not found.
View Article and Find Full Text PDFInt J Environ Res Public Health
February 2021
The first wave of the COVID-19 pandemic brought about a broader use of masks by both professionals and the general population. This resulted in a severe worldwide shortage of devices and the need to increase import and activate production of safe and effective surgical masks at the national level. In order to support the demand for testing surgical masks in the Italian context, Universities provided their contribution by setting up laboratories for testing mask performance before releasing products into the national market.
View Article and Find Full Text PDFBraz J Microbiol
December 2020
A retrospective study of the epidemiology of vancomycin-resistant enterococci (VRE) in a regional hospital of central Italy in 2001-2018 demonstrated an increased VRE prevalence since 2016. A total of 113 VRE isolates, 89 E. faecium (VREfm) and 24 E.
View Article and Find Full Text PDFAims: Extensively-drug-resistant Pseudomonas aeruginosa constitutes a serious threat to patients suffering from Cystic Fibrosis (CF). In these patients, P. aeruginosa lung infection is commonly treated with aminoglycosides, but treatments are largely unsuccessful due a variety of resistance mechanisms.
View Article and Find Full Text PDFUnlike human isolates, environmental isolates have not been thoroughly investigated for the diversity and transferability of antibiotic-resistant plasmids. In this study, antibiotic-resistant strains from marine sediment ( = 50) and clams ( = 53) were analyzed (i) for their plasmid content using a PCR-based plasmid replicon typing (PBRT) kit and (ii) for the transferability of plasmid-associated antibiotic resistance (AR) traits by mating experiments. Fifteen of the thirty replicons targeted by the PBRT kit were detected in the isolates; 8/15 were identified in both sediment and clam isolates, although at different frequencies.
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