β-Lactam Inoculum Effect in Methicillin-Susceptible Staphylococcus aureus Infective Endocarditis.

Importance: Infective endocarditis (IE) caused by Staphylococcus aureus is associated with high mortality, approximately 20% to 30%, mostly in the first month, with no improvement in recent decades. Current opinion is that antistaphylococcal penicillin and cefazolin are equally effective in treating methicillin-susceptible S aureus (MSSA) IE, and both are recommended as possible first-line treatments. Most MSSA strains carry the β-lactamase blaZ gene, and some blaZ-positive strains exhibit an inoculum effect, meaning increased minimum inhibitory concentrations at high inoculum.

Evaluation of several routine methods for fosfomycin and mecillinam susceptibility testing of Enterobacterales urine isolates.

Objectives: Performance evaluation of routine laboratory methods to determine the susceptibility of Enterobacterales urinary isolates to fosfomycin (oral administration) and mecillinam.

Methods: We collected 347 Enterobacterales isolates from monomicrobial midstream urine samples from women with significant bacteriuria and leukocyturia. Mostly non-Escherichia coli isolates (i.

Enterobacterales carrying chromosomal AmpC β-lactamases in Europe (EuESCPM): Epidemiology and antimicrobial resistance burden from a cohort of 27 hospitals, 2020-2022.

Introduction: The ESCPM group (Enterobacter species including Klebsiella aerogenes - formerly Enterobacter aerogenes, Serratia species, Citrobacter freundii complex, Providencia species and Morganella morganii) has not yet been incorporated into systematic surveillance programs.

Methods: We conducted a multicentre retrospective observational study analysing all ESCPM strains isolated from blood cultures in 27 European hospitals over a 3-year period (2020-2022). Diagnostic approach, epidemiology, and antimicrobial susceptibility were investigated.

HlyF, an underestimated virulence factor of uropathogenic Escherichia coli.

Objectives: Urinary tract infections (UTIs) are primarily caused by uropathogenic Escherichia coli (UPEC). This study aims to elucidate the role of the virulence factor HlyF in the epidemiology and pathophysiology of UTIs and investigate the dissemination of plasmids carrying the hlyF gene.

Methods: An epidemiological analysis was conducted on a representative collection of 225 UPEC strains isolated from community-acquired infections.

Screening for β-lactam resistance by penicillin G in the Streptococcus anginosus group challenged by rare strains with altered PBPs.

Background: Streptococcus anginosus group (SAG) strains are common pathogens causing abscesses and bacteraemia. They are generally susceptible to β-lactams, which constitute first-line treatment. EUCAST recommends testing penicillin G susceptibility to screen for β-lactam resistance.

Insights into the acquisition of the island and production of colibactin in the population.

The island codes for the enzymes necessary for synthesis of the genotoxin colibactin, which contributes to the virulence of strains and is suspected of promoting colorectal cancer. From a collection of 785 human and bovine isolates, we identified 109 strains carrying a highly conserved island, mostly from phylogroup B2, but also from phylogroups A, B1 and D. Different scenarios of acquisition were deduced from whole genome sequence and phylogenetic analysis.

Uropathogenic E. coli induces DNA damage in the bladder.

Urinary tract infections (UTIs) are among the most common outpatient infections, with a lifetime incidence of around 60% in women. We analysed urine samples from 223 patients with community-acquired UTIs and report the presence of the cleavage product released during the synthesis of colibactin, a bacterial genotoxin, in 55 of the samples examined. Uropathogenic Escherichia coli strains isolated from these patients, as well as the archetypal E.

Siderophore-Microcins in : Determinants of Digestive Colonization, the First Step Toward Virulence.

Siderophore-microcins are antimicrobial peptides produced by enterobacteria, especially and strains. The antibiotic peptide is post-translationally modified by the linkage of a siderophore moiety. Therefore, it can enter and kill phylogenetically related bacteria by a "Trojan Horse" stratagem, by mimicking the iron-siderophore complexes.

The synergistic triad between microcin, colibactin, and salmochelin gene clusters in uropathogenic Escherichia coli.

A functional synergy was previously demonstrated between microcin, salmochelin and colibactin islands in Escherichia coli strains from B2 phylogroup. We aimed to determine this association prevalence in uropathogenic E. coli, and whether it was predictive of the infection severity in a collection of 225 E.

Deciphering the interplay between the genotoxic and probiotic activities of Escherichia coli Nissle 1917.

Although Escherichia coli Nissle 1917 (EcN) has been used therapeutically for over a century, the determinants of its probiotic properties remain elusive. EcN produces two siderophore-microcins (Mcc) responsible for an antagonistic activity against other Enterobacteriaceae. EcN also synthesizes the genotoxin colibactin encoded by the pks island.

Enhanced culture recovery of Campylobacter with modified Cary-Blair medium: A practical field experience.

Modified Cary-Blair medium derived devices have been implemented in many laboratories to optimize culture recovery of common bacterial enteric pathogens. Our analysis constitutes the first report of routine laboratory experience supporting the idea that the use of such devices enhances Campylobacter recovery from stools.

Minimum inhibitory concentration (MIC) distribution among wild-type strains of Legionella pneumophila identifies a subpopulation with reduced susceptibility to macrolides owing to efflux pump genes.

Legionnaires' disease is a severe pneumonia mainly caused by Legionella pneumophila that is treated by antibiotics. The purpose of this study was to describe the susceptibility of clinical strains of L. pneumophila to eight antibiotics used for treatment of legionellosis.

Macrolide resistance in Legionella pneumophila: the role of LpeAB efflux pump.

Objectives: A previous study on 12 in vitro -selected azithromycin-resistant Legionella pneumophila lineages showed that ribosomal mutations were major macrolide resistance determinants. In addition to these mechanisms that have been well described in many species, mutations upstream of lpeAB operon, homologous to acrAB in Escherichia coli , were identified in two lineages. In this study, we investigated the role of LpeAB and of these mutations in macrolide resistance of L.

Depressed patients' preferences for type of psychotherapy: a preliminary study.

Background: The treatment recommendations for depressed patients by the American Psychiatric Association encourage a focus on the patient's preferences. The focus of this study was the preference of depressed inpatients for the type of psychotherapy.

Methods: Twenty-nine subjects of both sexes who were hospitalized with a major depressive episode were interviewed at 5-day intervals with the same questions after the depressive episode resolved, as indicated by a score less than 7 on the Hamilton Depression Rating Scale (HDRS).

Detection of Achromobacter xylosoxidans in hospital, domestic, and outdoor environmental samples and comparison with human clinical isolates.

Achromobacter xylosoxidans is an aerobic nonfermentative Gram-negative rod considered an important emerging pathogen among cystic fibrosis (CF) patients worldwide and among immunocompromised patients. This increased prevalence remains unexplained, and to date no environmental reservoir has been identified. The aim of this study was to identify potential reservoirs of A.

Choice of different dyes to label tyrosine and nitrotyrosine.

In this work, we will present some attempts to analyze tyrosine and nitrotyrosine using capillary electrophoresis and either UV-Visible detection or laser-induced fluorescence (LIF) detection. An argon ion (488 nm) laser is used for fluorescein isothiocyanate (FITC) and 7-fluoro-4-nitro-2,1,3-benzoxadiazole (NBD-F). A near infrared (780 nm) laser is used for NIR 780 derivatives.