Molecular Characterization of Enterococcus faecium Clinical Isolates Harbouring erm (T) from an Italian Hospital.

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.

poxtA amplification and mutations in 23S rRNA confer enhanced linezolid resistance in Enterococcus faecalis.

Objectives: This study aimed to explore the evolutionary patterns and resistance mechanisms of an Enterococcus faecalis strain harbouring poxtA under linezolid exposure.

Methods: A poxtA-carrying E. faecalis electrotransformant DJH702 with a linezolid minimum inhibitory concentration of 4 mg/L was exposed to increasing concentrations of linezolid (8-64 mg/L).

Persistence and evolution of linezolid- and methicillin-resistant Staphylococcus epidermidis ST2 and ST5 clones in an Italian hospital.

Objectives: Staphylococcus epidermidis is a member of the human skin microbiome. However, in recent decades, multidrug-resistant and hospital-adapted S. epidermidis clones are increasingly involved in severe human infections associated with medical devices and in immunocompromised patients.

Genetic analysis of vancomycin-variable Enterococcus faecium clinical isolates in Italy.

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.

An Isolated from Bovine Feces in Italy Shares - and -Carrying Plasmids with Enterococci from Switzerland.

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.

Characterization of a prophage and a defective integrative conjugative element carrying the optrA gene in linezolid-resistant Streptococcus dysgalactiae subsp. equisimilis isolates from pigs, Italy.

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.

Genomic Analysis of a Linezolid-Resistant Causing Bacteremia: Report from a University Hospital in Central Italy.

Although coagulase negative staphylococci are rarely associated with complicated diseases, in some cases they cause life-threatening infections. Here we described a clinical case of a bacteremia due to a methicillin- and linezolid-resistant in a patient previously treated with linezolid. Whole genome sequencing revealed the common mutation G2576T in all rDNA 23S alleles and several acquired resistance genes.

Identification of plasmids co-carrying cfr(D)/optrA and cfr(D2)/poxtA linezolid resistance genes in two Enterococcus avium isolates from swine brain.

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.

The Emerging Nosocomial Pathogen Klebsiella michiganensis Genetic Analysis of a KPC-3 Producing Strain Isolated from Venus Clam.

The 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.

Oxazolidinones: mechanisms of resistance and mobile genetic elements involved.

The oxazolidinones (linezolid and tedizolid) are last-resort antimicrobial agents used for the treatment of severe infections in humans caused by MDR Gram-positive bacteria. They bind to the peptidyl transferase centre of the bacterial ribosome inhibiting protein synthesis. Even if the majority of Gram-positive bacteria remain susceptible to oxazolidinones, resistant isolates have been reported worldwide.

Clinical and microbiological features of ceftolozane/tazobactam-resistant Pseudomonas aeruginosa isolates in a university hospital in central Italy.

Objectives: Ceftolozane/tazobactam (C/T) is a novel cephalosporin and β-lactamase inhibitor combination with great activity against Pseudomonas aeruginosa. To assess P. aeruginosa susceptibility to C/T, a surveillance study was conducted from October 2018 to March 2019 at the University Hospital 'Ospedali Riuniti' in Ancona, Italy.

Linezolid-resistant Enterococcus gallinarum isolate of swine origin carrying cfr, optrA and poxtA genes.

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.