subsp. and as emerging human uropathogens in elderly patients.

has been considered a very rare cause of human urinary tract infections (UTIs). However, little is known about its clinical significance and antimicrobial susceptibility, and genomic data from clinical isolates are lacking. This study aimed at analyzing clinical, microbiological, and genomic data of urinary isolates.

Misidentification of Raoultella spp. (R. terrigena, R. planticola) and Klebsiella spp. (K. variicola, K. grimontii) as Klebsiella pneumoniae: Retrospective study of a necropsy-associated bacterial collection from horses.

Misidentifications as Klebsiella pneumoniae were observed during a French retrospective study of a necropsy-associated K. pneumoniae bacterial collection from horses. Accordingly, the present study aimed to further characterise the 12 Raoultella spp.

[How to promote medical biology to medical students: interest of interactive clinical cases in biological laboratory].

Despite its central role in modern medicine, medical biology tends to attract fewer future physicians. The reasons for this disinterest are varied: a lack of awareness about the specialty among students, the medico-technical nature of the field, the financialization of private healthcare structures, and regulatory requirements, such as the implementation of demanding quality systems that distance students from medical issues. Since the 2018-2019 academic year, a medical biology workshop has been integrated into the problem-based learning sessions of semiology for second-year medical students (DFGSM2) at the Health Faculty of Caen.

Are causing recurrent cystitis just ordinary uropathogenic (UPEC) strains?

Specific determinants associated with Uropathogenic (UPEC) causing recurrent cystitis are still poorly characterized. Using strains from a previous clinical study (Vitale study, clinicaltrials.gov, identifier NCT02292160) the aims of this study were (i) to describe genomic and phenotypic traits associated with recurrence using a large collection of recurrent and paired sporadic UPEC isolates and (ii) to explore within-host genomic adaptation associated with recurrence using series of 2 to 5 sequential UPEC isolates.

Central role of the locus in the multidrug resistance in ESBL.

The aim of this study was to evaluate the proportion of resistance to a temocillin, tigecycline, ciprofloxacin, and chloramphenicol phenotype called t2c2 that resulted from mutations within the locus among extended-spectrum β-lactamases (ESBL-E) isolated in three intensive care units for 3 years in a French university hospital. Two parallel approaches were performed on all 443 ESBL-E included: (i) the minimal inhibitory concentrations of temocillin, tigecycline, ciprofloxacin, and chloramphenicol were determined and (ii) the genomes obtained from the Illumina sequencing platform were analyzed to determine multilocus sequence types, resistomes, and diversity of several -associated genes including operon. Among the 443 ESBL-E strains included, isolates of ( = 194), ( = 122), and complex () ( = 127) were found.

Antimicrobial resistance and genetic diversity of strains from different clinical sources in horses.

Introduction: is a major cause of infections and reproductive disorders among horses, ranked in recent French studies as the sixth most frequently isolated bacterial pathogen in equine clinical samples. The proportion of multidrug-resistant (MDR) is therefore significant in a context where MDR strains are considered a major global concern by the World Health Organization.

Methods: In this study, we used a genomic approach to characterize a population of 119 equine strains collected by two laboratories specialized in animal health in Normandy (France).

Proteomic characterization of persisters in Enterococcus faecium.

Background: Enterococcus faecium is a Gram-positive bacterium, naturally present in the human intestinal microbiota, but is also an opportunistic pathogen responsible for healthcare-associated infections. Persisters are individuals of a subpopulation able to survive by arrest of growth coping with conditions that are lethal for the rest of the population. These persistent cells can grow again when the stress disappears from their environment and can cause relapses.

Are causing recurrent cystitis just ordinary Uropathogenic (UPEC) strains?

Specific determinants associated with Uropathogenic (UPEC) causing recurrent cystitis are still poorly characterized. The aims of this study were (i) to describe genomic and phenotypic traits associated with recurrence using a large collection of recurrent and paired sporadic UPEC isolates, and (ii) to explore within-host genomic adaptation associated with recurrence using series of 2 to 5 sequential UPEC isolates. Whole genome comparative analyses between 24 recurrent cystitis isolates (RCIs) and 24 phylogenetically paired sporadic cystitis isolates (SCIs) suggested a lower prevalence of putative mobile genetic elements (MGE) in RCIs, such as plasmids and prophages.

Unique Changes in the Incidence of Acute Chest Syndrome in Children With Sickle Cell Disease Unravel the Role of Respiratory Pathogens: A Time Series Analysis.

Background: Acute chest syndrome (ACS) is a life-threatening complication of sickle cell disease (SCD). Although respiratory pathogens are frequently detected in children with ACS, their respective role in triggering the disease is still unclear. We hypothesized that the incidence of ACS followed the unprecedented population-level changes in respiratory pathogen dynamics after COVID-19-related nonpharmaceutical interventions (NPIs).

Temocillin Resistance in the Enterobacter cloacae Complex Is Conferred by a Single Point Mutation in BaeS, Leading to Overexpression of the AcrD Efflux Pump.

The Enterobacter cloacae complex (ECC) has become a major opportunistic pathogen with antimicrobial resistance issues. Temocillin, an "old" carboxypenicillin that is remarkably stable toward β-lactamases, has been used as an alternative for the treatment of multidrug-resistant ECC infections. Here, we aimed at deciphering the never-investigated mechanisms of temocillin resistance acquisition in .

A 10-year microbiological study of Pseudomonas aeruginosa strains revealed the circulation of populations resistant to both carbapenems and quaternary ammonium compounds.

Pseudomonas aeruginosa is one of the leading causes of healthcare-associated infections. For this study, the susceptibility profiles to antipseudomonal antibiotics and a quaternary ammonium compound, didecyldimethylammonium chloride (DDAC), widely used as a disinfectant, were established for 180 selected human and environmental hospital strains isolated between 2011 and 2020. Furthermore, a genomic study determined resistome and clonal putative relatedness for 77 of them.

Antimicrobial Resistance and Genetic Diversity of Strains Isolated from Equine and Other Veterinary Samples.

is one of the leading causes of healthcare-associated infections in humans. This bacterium is less represented in veterinary medicine, despite causing difficult-to-treat infections due to its capacity to acquire antimicrobial resistance, produce biofilms, and persist in the environment, along with its limited number of veterinary antibiotic therapies. Here, we explored susceptibility profiles to antibiotics and to didecyldimethylammonium chloride (DDAC), a quaternary ammonium widely used as a disinfectant, in 168 strains isolated from animals, mainly Equidae.

Exploring Cluster-Dependent Antibacterial Activities and Resistance Pathways of NOSO-502 and Colistin against Enterobacter cloacae Complex Species.

The Enterobacter cloacae complex (ECC) is a group of diverse environmental and clinically relevant bacterial species associated with a variety of infections in humans. ECC have emerged as one of the leading causes of nosocomial infections worldwide. The purpose of this paper is to evaluate the activity of NOSO-502 and colistin (CST) against a panel of ECC clinical isolates, including different Hoffmann's clusters strains, and to investigate the associated resistance mechanisms.

Machine learning-based typing of Salmonella enterica O-serogroups by the Fourier-Transform Infrared (FTIR) Spectroscopy-based IR Biotyper system.

Background: Salmonella enterica is among the major burdens for public health at global level. Typing of salmonellae below the species level is fundamental for different purposes, but traditional methods are expensive, technically demanding, and time-consuming, and therefore limited to reference centers. Fourier transform infrared (FTIR) spectroscopy is an alternative method for bacterial typing, successfully applied for classification at different infra-species levels.

Hairy cell leukemia: a specific 17-gene expression signature points to new targets for therapy.

Background: Hairy cell leukemia (HCL) is a rare chronic B cell malignancy, characterized by infiltration of bone marrow, blood and spleen by typical "hairy cells" that bear the BRAFV600E mutation. However, in addition to the intrinsic activation of the MAP kinase pathway as a consequence of the BRAFV600E mutation, the potential participation of other signaling pathways to the pathophysiology of the disease remains unclear as the precise origin of the malignant hairy B cells.

Materials And Methods: Using mRNA gene expression profiling based on the Nanostring technology and the analysis of 290 genes with crucial roles in B cell lymphomas, we defined a 17 gene expression signature specific for HCL.

Inactivation of the Response Regulator AgrA Has a Pleiotropic Effect on Biofilm Formation, Pathogenesis and Stress Response in Staphylococcus lugdunensis.

Staphylococcus lugdunensis is a coagulase-negative Staphylococcus that emerges as an important opportunistic pathogen. However, little is known about the regulation underlying the transition from commensal to virulent state. Based on knowledge of S.

Wide Distribution and Specific Resistance Pattern to Third-Generation Cephalosporins of Complex Members in Humans and in the Environment in Guadeloupe (French West Indies).

Species belonging to complex have been isolated in numerous environments and samples of various origins. They are also involved in opportunistic infections in plants, animals, and humans. Previous prospection in Guadeloupe (French West Indies) indicated a high frequency of complex strains resistant to third-generation cephalosporins (3GCs) in a local lizard population (), but knowledge of the distribution and resistance of these strains in humans and the environment is limited.

Identification of the iron-limitation stimulon in Staphylococcus lugdunensis.

During the infectious process, pathogens such as Staphylococcus lugdunensis have to cope with the condition of host-induced iron-limitation. Using the RNAseq approach, we performed the first global transcriptomic analysis of S. lugdunensis cells incubated in the absence and presence of iron chelator.

Within-Host Microevolution of Urinary Isolates: A Seven-Patient Longitudinal Genomic and Phenotypic Study.

Background: is responsible for up to 10% of healthcare associated urinary tract infections (UTI), which can be difficult to treat and can lead to bacterial persistence. While numerous whole genome sequencing (WGS) analyses have explored within-host genomic adaptation and microevolution of during cystic fibrosis (CF) infections, little is known about adaptation to the urinary tract.

Results: Whole genome sequencing was performed on 108 urinary isolates, representing up to five isolates collected from 2 to 5 successive urine samples from seven patients hospitalized in a French hospital over 48-488 days.

Phenotypic and proteomic approaches of the response to iron-limited condition in Staphylococcus lugdunensis.

Background: Staphylococcus lugdunensis is a coagulase-negative Staphylococcus part of the commensal skin flora but emerge as an important opportunistic pathogen. Because iron limitation is a crucial stress during infectious process, we performed phenotypic study and compared proteomic profiles of this species incubated in absence and in presence of the iron chelator 2,2'-dipyridyl (DIP).

Results: No modification of cell morphology nor cell wall thickness were observed in presence of DIP.

Unexpected Cell Wall Alteration-Mediated Bactericidal Activity of the Antifungal Caspofungin against Vancomycin-Resistant Enterococcus faecium.

has become a major opportunistic pathogen with the emergence of vancomycin-resistant enterococci (VRE). As part of the gut microbiota, they have to cope with numerous stresses, including effects of antibiotics and other xenobiotics, especially in patients hospitalized in intensive care units (ICUs) who receive many medications. The aim of this study was to investigate the impact of the most frequently prescribed xenobiotics for ICU patients on fitness, pathogenicity, and antimicrobial resistance of the -positive Aus0004 reference strain.