No genetic link between E. coli isolates carrying mcr-1 in bovines and humans in France.

Background: Colistin is a last-line antibiotic used to treat severe human infections caused by carbapenemase-producing Gram-negative bacteria. In parallel, colistin has massively been used in the veterinary field so that mcr-1-positive E. coli have spread worldwide in livestock, potentially constituting a reservoir of colistin-resistant isolates that can be further transmitted to humans.

Decoding Pseudomonas aeruginosa: Genomic insights into adaptation, antibiotic resistance, and the enigmatic role of T6SS in interbacterial dynamics.

Pseudomonas aeruginosa demonstrates a remarkable capacity for adaptation and survival in diverse environments. Furthermore, its clinical importance is underscored by its intrinsic and acquired resistance to a wide range of antimicrobial agents, posing a substantial challenge in healthcare settings. Amidst this complex landscape of resistance, the Type VI Secretion System (T6SS) in P.

MAST® D72C test: a novel option for ESBL, AmpC and carbapenemase detection.

Purpose: The MAST® D72C test is a phenotypical test which can detect ESBL and AmpC production in Enterobacterales. It can also identify the suspected presence of carbapenemase. The aim of the present study was to assess the sensitivity and specificity of this test and to discuss its usefulness in laboratories, especially those that use only an automated AST system.

Cytotoxic necrotizing factor 1 hinders colon tumorigenesis induced by colibactin-producing in mice.

Colorectal cancer (CRC) patients are frequently colonized by colibactin-producing (CoPEC) (>40%), which enhances tumorigenesis in mouse models of CRC. We observed that 50% of CoPEC also contains the gene, which encodes cytotoxic necrotizing factor-1 (CNF1), an enhancer of the eukaryotic cell cycle. The impact of its co-occurrence with colibactin (Clb) has not yet been investigated.

Genes mcr improve the intestinal fitness of pathogenic E. coli and balance their lifestyle to commensalism.

Background: The plasmid-mediated resistance gene mcr-1 confers colistin resistance in Escherichia coli and paves the way for the evolution to pan-drug resistance. We investigated the impact of mcr-1 in gut colonization in the absence of antibiotics using isogenic E. coli strains transformed with a plasmid encoding or devoid of mcr-1.

Dynamics of extended-spectrum cephalosporin resistance genes in Escherichia coli from Europe and North America.

Extended-spectrum cephalosporins (ESCs) are critically important antimicrobial agents for human and veterinary medicine. ESC resistance (ESC-R) genes have spread worldwide through plasmids and clonal expansion, yet the distribution and dynamics of ESC-R genes in different ecological compartments are poorly understood. Here we use whole genome sequence data of Enterobacterales isolates of human and animal origin from Europe and North America and identify contrasting temporal dynamics.

Host Colonization as a Major Evolutionary Force Favoring the Diversity and the Emergence of the Worldwide Multidrug-Resistant ST131.

The emergence of multidrug-resistant Escherichia coli ST131 is a major worldwide public health problem in humans. According to the "one health" approach, this study investigated animal reservoirs of ST131, their relationships with human strains, and the genetic features associated with host colonization. High-quality genomes originating from human, avian, and canine hosts were classified on the basis of their accessory gene content using pangenomic.

Successful Dissemination of Plasmid-Mediated Extended-Spectrum β-Lactamases in Enterobacterales over Humans to Wild Fauna.

Background: The emergence of multidrug-resistant bacteria remains poorly understood in the wild ecosystem and at the interface of habitats. Here, we explored the spread of containing IncI1-ST3 plasmid encoding resistance gene () in human-influenced habitats and wild fauna using a genomic approach.

Methods: Multilocus sequence typing (MLST), single-nucleotide polymorphism comparison, synteny-based analysis and data mining approaches were used to analyse a dataset of genomes and circularised plasmids.

Pathogenicity Factors of Genomic Islands in Intestinal and Extraintestinal .

is a versatile bacterial species that includes both harmless commensal strains and pathogenic strains found in the gastrointestinal tract in humans and warm-blooded animals. The growing amount of DNA sequence information generated in the era of "genomics" has helped to increase our understanding of the factors and mechanisms involved in the diversification of this bacterial species. The pathogenic side of that is afforded through horizontal transfers of genes encoding virulence factors enables this bacterium to become a highly diverse and adapted pathogen that is responsible for intestinal or extraintestinal diseases in humans and animals.

Avrilella dinanensis gen. nov., sp. nov., a novel bacterium of the family Flavobacteriaceae isolated from human blood.

Polyphasic taxonomic analysis was performed on a novel bacterium, designated UR159, isolated in 2016 from human blood of a septic patient hospitalized in France. Preliminary 16S rRNA gene sequence-based phylogenetic analysis indicated that strain UR159 belonged to the family Flavobacteriaceae, forming a distinct phyletic line distantly related (<94% sequence similarity) to known species of the family. Further phenotypic, chemotaxonomic and genomic analyses were performed.

Deletion in an Enterobacter hormaechei Isolate as a Consequence of Therapeutic Failure of Key Antibiotics in a Long-Term Hospitalized Patient.

Genome changes are central to the adaptation of bacteria, especially under antibiotic pressure. The aim of this study was to report phenotypic and genomic adaptations undergone by an clinical strain that became highly resistant to key antimicrobials during a 4-month period in a patient hospitalized in an intensive care unit (ICU). All six clinical strains isolated in one ICU-hospitalized patient have been studied.

Carbapenem Resistance Conferred by OXA-48 in K2-ST86 Hypervirulent Klebsiella pneumoniae, France.

We recovered 2 carbapenem-resistant K2-ST86 hypermucoviscous Klebsiella pneumoniae isolates from patients in France. The isolates had genetic attributes of hypervirulent K. pneumoniae but differed in ability to cause mouse lethality.

Next-Generation Sequencing and MALDI Mass Spectrometry in the Study of Multiresistant Processed Meat Vancomycin-Resistant Enterococci (VRE).

Vancomycin-resistant enterococci (VRE), due to their intrinsic resistance to various commonly used antibiotics and their malleable genome, make the treatment of infections caused by these bacteria less effective. The aims of this work were to characterize isolates of spp. that originated from processed meat, through phenotypic and genotypic techniques, as well as to detect putative antibiotic resistance biomarkers.

The Transcriptional Repressor SmvR Is Important for Decreased Chlorhexidine Susceptibility in Enterobacter cloacae Complex.

Major facilitator superfamily (MFS) efflux pumps have been shown to be important for bacterial cells to cope with biocides such as chlorhexidine (CHX), a widely used molecule in hospital settings. In this work, we evaluated the role of two genes, and , in CHX resistance in complex (ECC). encodes an MFS pump whereas , located upstream of codes for a TetR-type transcriptional repressor.

Emergence of optrA-mediated linezolid resistance in enterococci from France, 2006-16.

Objectives: To describe the epidemiological trend of linezolid-resistant enterococci (LRE) collected in France from 2006 to 2016 and to extensively characterize LRE isolates.

Methods: The National Reference Center for Enterococci (NRC-Enc) received enterococcal isolates suspected to be VRE and/or LRE from all French hospitals between 2006 and 2016. LRE isolates were phenotypically characterized and their genomes were entirely sequenced by Miseq (Illumina).

Development and Multicentric Validation of a Lateral Flow Immunoassay for Rapid Detection of MCR-1-Producing .

Colistin has become a last-resort antibiotic for the treatment of infections caused by highly drug-resistant Gram-negative bacteria. Moreover, it has been widely used in the livestock sector. As a consequence, colistin resistance is emerging worldwide.

Rapid detection and discrimination of chromosome- and MCR-plasmid-mediated resistance to polymyxins by MALDI-TOF MS in Escherichia coli: the MALDIxin test.

Background: Polymyxins are currently considered a last-resort treatment for infections caused by MDR Gram-negative bacteria. Recently, the emergence of carbapenemase-producing Enterobacteriaceae has accelerated the use of polymyxins in the clinic, resulting in an increase in polymyxin-resistant bacteria. Polymyxin resistance arises through modification of lipid A, such as the addition of phosphoethanolamine (pETN).

Diversity of DHA-1-encoding plasmids in Klebsiella pneumoniae isolates from 16 French hospitals.

Objectives: To provide new insights into the spread of plasmidic cephalosporinase DHA-1, 16 strains of Klebsiella pneumoniae and a strain of Klebsiella variicola producing DHA-1 were isolated between January 2012 and December 2013 in six regions of France and two French overseas departments and territories.

Methods: Disc diffusion assays, isoelectric focusing and PCRs were used to characterize the plasmidic DHA-1 β-lactamase. Plasmid analysis was performed by the method of Kado and Liu and WGS.

Novel Enterobacter Lineage as Leading Cause of Nosocomial Outbreak Involving Carbapenemase-Producing Strains.

We investigated unusual carbapenemase-producing Enterobacter cloacae complex isolates (n = 8) in the novel sequence type (ST) 873, which caused nosocomial infections in 2 hospitals in France. Whole-genome sequence typing showed the 1-year persistence of the epidemic strain, which harbored a bla ST1-IncHI2 plasmid, in 1 health institution and 2 closely related strains harboring bla in the other. These isolates formed a new subgroup in the E.