The High-Efficiency Degradation of Multiple Mycotoxins by Lac-W Laccase in the Presence of Mediators.

Mycotoxin cocontamination is a severe threat to health and economic security worldwide. The mycotoxins aflatoxin B (AFB), zearalenone (ZEN), deoxynivalenol, T-2 toxin, fumonisin B, and ochratoxin A are of particular concern due to their substantial toxicity. Lac-W is a laccase with the unique property of degrading these six mycotoxins in the absence of redox mediators.

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).

Research note: characteristics of bla and mcr-1 co-producing Escherichia coli from retail chicken meat.

Carbapenems and colistin are vital antimicrobials used to treat Enterobacteriaceae-caused infections. The present study aimed to characterize the coexistence mechanism of carbapenem and colistin resistance in an Escherichia coli isolated from retail chicken meat. A total of 4 E.

Prevalence and characterization of aminoglycoside resistance gene aph(2")-If-carrying Campylobacter jejuni.

Campylobacter jejuni is recognized as a significant foodborne pathogen, and recent studies have indicated a rising trend of aminoglycosides resistance gene aph(2″)-If among C. jejuni isolates from food-producing animals in China. However, systematic information about aph(2″)-If-positive C.

Tandem amplification of a plasmid-borne tet(A) variant gene confers tigecycline resistance in Escherichia coli.

Objectives: To elucidate the mechanism of tigecycline resistance in Escherichia coli that is mediated by the tet(A) variant gene.

Methods: E. coli strain 573 carried a plasmid-borne tet(A) variant gene, tentatively designated tet(A)TIG, that conferred decreased tigecycline susceptibility (MIC 0.

Laccase Lac-W detoxifies aflatoxin B and degrades five other major mycotoxins in the absence of redox mediators.

A multicopper oxidase Lac-W from Weizmannia coagulans 36D1 was identified and characterized as a laccase (Lac-W) with a robust enzymatic activity, which was used in various mycotoxins degradation. We demonstrated that Lac-W could directly degrade six major mycotoxins in the absence of redox mediators in pH 9.0, 24h static incubation at room temperature, including aflatoxin B (AFB 88%), zearalenone (60%), deoxynivalenol (34%), T-2 toxin (19%), fumonisin B (18%), and ochratoxin A (12%).

IS257-mediated amplification of tet(L) variant as a novel mechanism of enhanced tigecycline resistance in Staphylococcus cohnii.

The mechanism of enhanced tigecycline MIC in Staphylococcus cohnii after in vitro tigecycline exposure was investigated. S. cohnii 11-B-312 was exposed to incremental concentrations of tigecycline (2-32 mg/L) and the mutants growing at 8, 16 and 32 mg/L were determined by AST and WGS.

Emergence of high-level tigecycline resistance due to the amplification of a tet(A) gene variant in clinical carbapenem-resistant Klebsiella pneumoniae.

Objective: To investigate the prevalence of a tet(A) gene variant and its role in developing high-level tigecycline resistance among carbapenem-resistant Klebsiella pneumoniae (CRKP) clinical isolates.

Methods: The mechanism of high-level tigecycline resistance in CRKP mediated by a tet(A) variant was explored by induction experiments, antimicrobial susceptibility testing, whole-genome sequencing and bioinformatics analysis. The amplification and overexpression of the tet(A) variant were measured by the determination of sequencing depth, gene copy numbers, and qRT-PCR.

Genomic insights into linezolid-resistant Enterococci revealed its evolutionary diversity and poxtA copy number heterogeneity.

Objectives: This study aimed to determine the molecular mechanisms of linezolid-resistant enterococci (LRE) in swine slaughterhouses in China and apply the "One Health" perspective to analyse the evolutionary dynamics of poxtA-positive E. faecium in clinical and non-clinical settings worldwide.

Methods: The phenotypic and genomic characteristics of multiple LRE isolates were systematically investigated using antimicrobial susceptibility testing, transfer assays, evolutionary experiments, quantitative RT-PCR assays, whole-genome sequencing, and bioinformatics analyses.

Pathogen-Targeting Bimetallic Nanozymes as Ultrasonic-Augmented ROS Generator against Multidrug Resistant Bacterial Infection.

Clinical treatment of multidrug resistant (MDR) pathogens-induced infection is emerging as a growing challenge in global public health due to the limited selection of clinically available antibiotics. Nanozymes as artificial enzymes that mimicked natural enzyme-like activities, are received great attention for combating MDR pathogens. However, the relatively deficient catalytic activity in the infectious microenvironment and inability to precisely targeting pathogen restrains their clinical anti-MDR applications.

Linezolid-Resistant Enterococcus faecalis of Chicken Origin Harbored Chromosome-Borne and Plasmid-Borne , (D), and Genes.

The aim of this study was to investigate the transferability of acquired linezolid resistance genes and associated mobile genetic elements in an Enterococcus faecalis isolate QZ076, cocarrying , , (D), and genes. MICs were determined by broth microdilution. Whole-genome sequencing (WGS) was performed using the Illumina and Nanopore platforms.

Emergence of lnu(C) variant conferring lincomycin resistance in Campylobacter coli of chicken origin.

Lincomycin is widely used in respiratory and gastrointestinal infection in veterinary medicine and food animal production. Campylobacter members are vital foodborne pathogens causing campylobacteriosis, and the resistance to lincosamides is seldom reported. To date, only the rRNA methyltransferase Erm(B) has been confirmed to be associated with lincosamides resistance in Campylobacter.

Characterization of a genomic Island carrying the (X4) gene in porcine co-harboring plasmid-borne and genes.

Tigecycline and carbapenems are last-resort antimicrobial agents to treat serious infections caused by multi-drug resistant bacterial pathogens. However, the co-occurrence of tigecycline and carbapenem resistance determinants challenges the clinical efficacy of these antimicrobial agents. In this study, we report the co-existence of (X4), and genes in the porcine isolate 19110F47.

Hybrid IncFIA/FIB/FIC(FII) plasmid co-carrying bla 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.

Excision and integration of unconventional circularizable structures involving the erm(B) gene in enterococci.

Traditionally, insertion sequences (ISs) play a major role in disseminating antimicrobial resistance genes (ARGs) in bacteria through transposition and translocation, forming regions that contain multiple ARGs flanked by single or multiple copies of IS. In addition, unconventional circularizable structures (UCSs), lacking recombinase genes but being surrounded by directly repeated sequences (DRs) of various sizes which do not contain transposase genes, were reported to be involved in the dissemination of ARGs. In this study, a novel UCS was identified on plasmid pE508-2 in E.

Plasmid-Assisted Horizontal Transfer of a Large (E)-Carrying Genomic Island in Enterococcus faecalis.

The horizontal transfer of genomic islands is essential for the adaptation and evolution of Enterococcus faecalis. In this study, three porcine E. faecalis strains, each harboring a large (E)-carrying genomic island, were identified.

A Small Multihost Plasmid Carrying (T) Identified in .

The aim of this study was to determine the mobile genetic elements involved in the horizontal transfer of (T) in , and its transmission ability in heterologous hosts. A total of 159 erythromycin-resistant enterococci isolates were screened for the presence of macrolide resistance genes by PCR. Whole genome sequencing for (T)-carrying E165 was performed.

Studies on the Transmission of a Tigecycline Resistance-Mediating (A) Gene Variant from Enterobacter hormaechei via a Two-Step Recombination Process.

To investigate the contribution of a (A) variant to tigecycline resistance in Enterobacter hormaechei and the recombination events that occurred during transmission of this variant. MICs were determined by broth microdilution. G17 was characterized by PCR, transfer assay, S1-PFGE, Southern blot hybridization, and WGS analysis.

A novel lysin Ply1228 provides efficient protection against Streptococcus suis type 2 infection in a murine bacteremia model.

Streptococcus suis is an important zoonotic pathogen that is difficult to control with antibiotics due to the widespread development of multidrug-resistant strains. Phage lysin is considered a potential therapeutic agent to combat S. suis.

Recombination events that occur in a poxtA-carrying Enterococcus faecium during the conjugation process.

Objectives: To investigate transferability of the poxtA-carrying plasmids in Enterococcus faecium and the mechanism of recombination that occurs during the conjugation process.

Methods: MICs were determined by broth microdilution. Transferability of the poxtA-carrying plasmids in E.

Plasmid Fusion and Recombination Events That Occurred during Conjugation of -Carrying Plasmids in Enterococci.

Linezolid plays a crucial role in the treatment of infections caused by multiresistant Gram-positive bacteria. The gene not only confers oxazolidinone and phenicol resistance but also decreases susceptibility to tetracycline. In this study, we investigated structural changes in mobilizable -carrying plasmids in enterococci which occurred during conjugation experiments using S1-PFGE (pulsed-field gel electrophoresis), Southern blot hybridization, and whole-genome sequencing (WGS) analysis.

(T)-Mediated Macrolide-Lincosamide Resistance in Streptococcus suis.

To investigate the presence and location of (T) in clinical Streptococcus suis isolates and explore the transmission ability and fitness cost of (T)-carrying mobile genetic elements among S. suis isolates, MICs were determined by broth microdilution. The presence of (T) in S.

Novel Tet(L) Efflux Pump Variants Conferring Resistance to Tigecycline and Eravacycline in Staphylococcus Spp.

Tigecycline is regarded as one of the few important last-resort antibiotics to treat complicated skin and intra-abdominal infections. Members of the genus Staphylococcus are zoonotic pathogens and pose a serious threat to public health. Tigecycline resistance in this species appears to be a rare phenomenon, and the mechanisms underlying tigecycline resistance have not been fully elucidated.