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.

Emergence of Imipenem Resistance in a CpxA-H208P-Variant-Producing Clinical Isolate.

The PmirS clinical isolate, which was susceptible to imipenem (0.5 μg/mL) and amikacin (1 μg/mL), was recovered from a bronchial aspirate of a patient who recently underwent lung transplantation. The PmirR clinical isolate, which exhibited resistance to imipenem (16 μg/mL) and amikacin (24 μg/mL), was isolated 3 weeks later from the same patient and the same specimen type.

Success of Escherichia coli O25b:H4 Sequence Type 131 Clade C Associated with a Decrease in Virulence.

O25b:H4 sequence type 131 (ST131), which is resistant to fluoroquinolones and which is a producer of CTX-M-15, is globally one of the major extraintestinal pathogenic (ExPEC) lineages. Phylogenetic analyses showed that multidrug-resistant ST131 strains belong to clade C, which recently emerged from clade B by stepwise evolution. It has been hypothesized that features other than multidrug resistance could contribute to this dissemination since other major global ExPEC lineages (ST73 and ST95) are mostly antibiotic susceptible.

High Prevalence of ST131 Subclades C2-30Rx and C1-M27 Among Extended-Spectrum β-Lactamase-Producing Causing Human Extraintestinal Infections in Patients From Two Hospitals of Spain and France During 2015.

The present study was carried out to evaluate the prevalence of sequence type 131 (ST131) among 188 extended-spectrum β-lactamase-producing (ESBL-EC) collected in 2015 in Lucus Augusti University hospital (Lugo, Spain) and AP-HP Beaujon hospital (Clichy, France) with regard to other STs and to characterize, the types of ESBL produced, serotypes, virulence factor (VF)-encoding genes and the ST131 clades and subclades. ST131 was detected in 33 (39.1%) and 46 (47.

Clonal Structure, Virulence Factor-encoding Genes and Antibiotic Resistance of , Causing Urinary Tract Infections and Other Extraintestinal Infections in Humans in Spain and France during 2016.

is the main pathogen responsible for extraintestinal infections. A total of 196 clinical consecutively isolated during 2016 in Spain (100 from Lucus Augusti hospital in Lugo) and France (96 from Beaujon hospital in Clichy) were characterized. Phylogroups, clonotypes, sequence types (STs), O:H serotypes, virulence factor (VF)-encoding genes and antibiotic resistance were determined.

Risk factors for carbapenem-resistant Enterobacteriaceae infections: a French case-control-control study.

This study aimed to assess characteristics associated with infections due to carbapenem-resistant Enterobacteriaceae (CRE), producing (CPE) or not producing (non-CPE) carbapenemase, among hospitalised patients in 2014-2016 in France. Case-patients with CRE were compared to two control populations. In multivariate analysis comparing 160 CRE cases to 160 controls C1 (patients with a clinical sample positive for carbapenem-susceptible Enterobacteriaceae), five characteristics were linked to CRE: male gender (OR = 1.

Interplay Between Membrane Permeability and Enzymatic Barrier Leads to Antibiotic-Dependent Resistance in .

The interplay between membrane permeability alterations and the enzymatic barrier contributes to multidrug resistance. We assessed the specific effect of the efflux levels of the main efflux pumps (AcrAB and OqxAB), alone and associated with the loss of the main porins (OmpK35 and OMPK36), on the activity of various antibiotics by constructing a set of isogenic strains, including strains with plasmid-mediated β-lactamases (DHA-1, CTX-M-15, and OXA-48). The two pumps contributed to intrinsic chloramphenicol resistance and AcrAB to that of nalidixic acid and cefoxitin, whereas they had no impact on the activity of the other 11 antibiotics tested.

Emergence of plasmid-mediated colistin resistance (mcr-1) among Enterobacteriaceae strains: Laboratory detection of resistance and measures to control its dissemination.

The increasing use of colistin has contributed to the emergence of resistant bacteria and to an increase in the frequency of infections caused by naturally resistant Enterobacteriaceae strains such as Proteus, Providencia, Morganella, and Serratia. In August 2016, the French High Council for Public Health (French acronym HCSP) received a request from the Ministry of Health on the advice of the French National Public Health agency (Santé publique France) with regard to measures that should be taken to tackle the emergence of plasmid-mediated colistin resistance among Enterobacteriaceae strains. French healthcare facilities were asked to take the necessary measures as soon as possible, such as updating the definition of emerging highly resistant bacteria and defining the identification methods so as to take account of the evolving epidemiology of this type of resistance.

In-vivo loss of carbapenem resistance by extensively drug-resistant Klebsiella pneumoniae during treatment via porin expression modification.

Klebsiella pneumoniae, an Enterobacteriaceae that mostly causes hospital-acquired infections, belongs to the recently published WHO's list of antibiotic-resistant pathogens that pose the greatest threat to human health. Indeed, K. pneumoniae is the enterobacterial species most concerned by both resistance to extended-spectrum cephalosporins, due to extended-spectrum β-lactamase (ESBL) production, and resistance to carbapenems, i.

Development of an algorithm for phenotypic screening of carbapenemase-producing Enterobacteriaceae in the routine laboratory.

Background: Carbapenemase-producing Enterobacteriaceae (CPE) are difficult to identify among carbapenem non-susceptible Enterobacteriaceae (NSE). We designed phenotypic strategies giving priority to high sensitivity for screening putative CPE before further testing.

Methods: Presence of carbapenemase-encoding genes in ertapenem NSE (MIC > 0.

Trends of extended-spectrum β-lactamase-producing Escherichia coli sequence type 131 and its H30 subclone in a French hospital over a 15-year period.

Sequence type 131 (ST131) is a predominant lineage among extraintestinal pathogenic Escherichia coli. It plays a major role in the worldwide dissemination of E. coli producing extended-spectrum β-lactamases (ESBLs).

The challenges of multi-drug-resistance in hepatology.

Antimicrobial resistance has become a major global public health security problem that needs coordinated approaches at regional, national and international levels. Antibiotic overuse and the failure of control measures to prevent the spread of resistant bacteria in the healthcare environment have led to an alarming increase in the number of infections caused by resistant bacteria, organisms that resist many (multi-drug and extensively drug-resistant strains), if not all (pan-drug-resistant bacteria) currently available antibiotics. While Gram-positive cocci resistance (methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci) shows a heterogeneous geographical distribution, extended-spectrum β-lactamase-producing Enterobacteriaceae and carbapenem-resistant Enterobacteriaceae have become pandemic worldwide and endemic in some parts of the world, respectively.

Modulation of Membrane Influx and Efflux in Escherichia coli Sequence Type 131 Has an Impact on Bacterial Motility, Biofilm Formation, and Virulence in a Caenorhabditis elegans Model.

Energy-dependent efflux overexpression and altered outer membrane permeability (influx) can promote multidrug resistance (MDR). The present study clarifies the regulatory pathways that control membrane permeability in the pandemic clone Escherichia coli sequence type 131 (ST131) and evaluates the impact of efflux and influx modulations on biofilm formation, motility, and virulence in the Caenorhabditis elegans model. Mutants of two uropathogenic E.

Costs associated with implementation of a strict policy for controlling spread of highly resistant microorganisms in France.

Objective: To assess costs associated with implementation of a strict 'search and isolate' strategy for controlling highly drug-resistant organisms (HDRO).

Design: Review of data from 2-year prospective surveillance (01/2012 to 12/2013) of HDRO.

Setting: Three university hospitals located in northern Paris.

A new mechanism to render clinical isolates of Escherichia coli non-susceptible to imipenem: substitutions in the PBP2 penicillin-binding domain.

Objectives: So far, two types of mechanism are known to be involved in carbapenem non-susceptibility of Escherichia coli clinical isolates: reduced outer membrane permeability associated with production of ESBLs and/or overproduction of class C β-lactamases; and production of carbapenemases. Non-susceptibility to only imipenem observed in two clinical isolates suggested a new mechanism, described in the present study.

Methods: The ST was determined for the two isolates of E.

Genetic, biochemical characterization and mutagenesis of the chromosomal class A β-lactamase of Raoultella (formerly Klebsiella) terrigena.

Background: Chromosomal class A β-lactamases have been characterized in Raoultella ornithinolytica and Raoultella planticola. The purpose of this study was to characterize that of Raoultella terrigena.

Materials And Methods: The blaTER-1 gene of R.