Expression du deuxième gène cassette dans un intégron de classe 1

PARIS-BIUP (751062107) / SudocSudocFranceF

Infections génitales à Neisseria gonorrhoeae (intérêt de la technique de typage moléculaire NG-MAST pour différencier rechute et réinfection)

PARIS7-Xavier Bichat (751182101) / SudocSudocFranceF

related to travel in south-eastern Asia, France, June 2019.

International audienceWe report two cases of multidrug-resistant Neisseria gonorrhoeae urogenital infection with ceftriaxone resistance in a heterosexual couple in south-western France who were successfully treated with a single, high dose of intramuscular ceftriaxone (1 g). Whole genome sequencing of isolate F91 identified MLST13871, NG-MAST1086, NG-STAR233. Patient history revealed the isolate F91 was most likely acquired during a trip to Cambodia and belongs to the successful multidrug-resistant FC428 Asian clone

Klebsiella pneumoniae Carbapenemase Variants Resistant to Ceftazidime-Avibactam: an Evolutionary Overview

International audienceFirst variants of the Klebsiella pneumoniae carbapenemase (KPC), KPC-2 and KPC-3, have encountered a worldwide success, particularly in K. pneumoniae isolates. These beta-lactamases conferred resistance to most beta-lactams including carbapenems but remained susceptible to new beta-lactam/beta-lactamase inhibitors, such as ceftazidime-avibactam

First Description of NOD2 Variant Associated with Defective Neutrophil Responses in a Woman with Granulomatous Mastitis Related to Corynebacteria ▿

We report the first case of granulomatous mastitis due to Corynebacterium kroppenstedtii linked to strongly impaired neutrophil responses to Nod2 agonist and a single nucleotide polymorphism within the NOD2 gene (SNP13 [Leu1007fsinsC]) in a heterozygous state. These findings provided the first demonstration of impaired Nod2 function associated with corynebacterial infection

Genetic and Phenotypic Study of the \emphPectobacterium\emph Versatile Beta-Lactamase, the Enzyme Most Similar to the Plasmid-Encoded TEM-1

International audienceThis study aimed to compare the chromosomal beta-lactamase from Pectobacterium versatile , PEC-1, with the well-known and globally distributed TEM-1 in terms of genetic and functional properties. Despite the similarities between the enzymes, we obtained no definitive proof of gene transfer for the emergence of bla PEC-1 from bla TEM-1 . , ABSTRACT Genus Pectobacterium bacteria include important agricultural pathogens. Pectobacterium versatile isolates contain a chromosome-borne beta-lactamase, PEC-1. This enzyme is the closest relative of TEM-1, a plasmid-borne beta-lactamase widespread in the Enterobacterales . We performed bioinformatics and phenotypic analyses to investigate the genetic and phenotypic features of PEC-1 and its frequency and ability to spread within genus Pectobacterium . We also compared the characteristics of PEC-1 and TEM-1 and evaluated the likelihood of transfer. We found that bla PEC-1 was present principally in a small number of genetic environments in P. versatile . Identical bla PEC-1 genetic environments were present in closely related species, consistent with the high frequency of genetic exchange within the genus Pectobacterium . Despite the similarities between PEC-1 and TEM-1, their genetic environments displayed no significant identity, suggesting an absence of recent transfer. Phenotypic analyses on clonal constructs revealed similar hydrolysis spectra. Our results suggest that P. versatile is the main reservoir of PEC-1, which seems to transfer to closely related species. The genetic distance between PEC-1 and TEM-1, and the lack of conserved elements in their genetic environments, suggest that any transfer that may have occurred must have taken place well before the antibiotic era. IMPORTANCE This study aimed to compare the chromosomal beta-lactamase from Pectobacterium versatile , PEC-1, with the well-known and globally distributed TEM-1 in terms of genetic and functional properties. Despite the similarities between the enzymes, we obtained no definitive proof of gene transfer for the emergence of bla PEC-1 from bla TEM-1 . Indeed, given the limited degree of sequence identity and the absence of a common genetic environment, it seems unlikely that any transfer of this gene has occurred recently. However, although bla PEC-1 was found mostly in one specific clade of the P. versatile species, certain isolates from other closely related species, such as Pectobacterium brasiliense and Pectobacterium polaris , may also carry this gene inserted into common genetic environments. This observation suggests that genetic exchanges are frequent, accounting for the diffusion of bla PEC-1 between isolates from different Pectobacterium species and, potentially, to exogenous mobile genetic elements

Genetic and Phenotypic Study of the \emphPectobacterium\emph Versatile Beta-Lactamase, the Enzyme Most Similar to the Plasmid-Encoded TEM-1

International audienceThis study aimed to compare the chromosomal beta-lactamase from Pectobacterium versatile , PEC-1, with the well-known and globally distributed TEM-1 in terms of genetic and functional properties. Despite the similarities between the enzymes, we obtained no definitive proof of gene transfer for the emergence of bla PEC-1 from bla TEM-1 . , ABSTRACT Genus Pectobacterium bacteria include important agricultural pathogens. Pectobacterium versatile isolates contain a chromosome-borne beta-lactamase, PEC-1. This enzyme is the closest relative of TEM-1, a plasmid-borne beta-lactamase widespread in the Enterobacterales . We performed bioinformatics and phenotypic analyses to investigate the genetic and phenotypic features of PEC-1 and its frequency and ability to spread within genus Pectobacterium . We also compared the characteristics of PEC-1 and TEM-1 and evaluated the likelihood of transfer. We found that bla PEC-1 was present principally in a small number of genetic environments in P. versatile . Identical bla PEC-1 genetic environments were present in closely related species, consistent with the high frequency of genetic exchange within the genus Pectobacterium . Despite the similarities between PEC-1 and TEM-1, their genetic environments displayed no significant identity, suggesting an absence of recent transfer. Phenotypic analyses on clonal constructs revealed similar hydrolysis spectra. Our results suggest that P. versatile is the main reservoir of PEC-1, which seems to transfer to closely related species. The genetic distance between PEC-1 and TEM-1, and the lack of conserved elements in their genetic environments, suggest that any transfer that may have occurred must have taken place well before the antibiotic era. IMPORTANCE This study aimed to compare the chromosomal beta-lactamase from Pectobacterium versatile , PEC-1, with the well-known and globally distributed TEM-1 in terms of genetic and functional properties. Despite the similarities between the enzymes, we obtained no definitive proof of gene transfer for the emergence of bla PEC-1 from bla TEM-1 . Indeed, given the limited degree of sequence identity and the absence of a common genetic environment, it seems unlikely that any transfer of this gene has occurred recently. However, although bla PEC-1 was found mostly in one specific clade of the P. versatile species, certain isolates from other closely related species, such as Pectobacterium brasiliense and Pectobacterium polaris , may also carry this gene inserted into common genetic environments. This observation suggests that genetic exchanges are frequent, accounting for the diffusion of bla PEC-1 between isolates from different Pectobacterium species and, potentially, to exogenous mobile genetic elements

Fosfomycin-trometamol (FT) or fluoroquinolone (FQ) as single-dose prophylaxis for transrectal ultrasound-guided prostate biopsy (TRUS-PB): A prospective cohort study

International audienceObjectives: The increasing incidence of fluoroquinolones (FQ) resistance may lower its efficacy in preventing UTI following transrectal ultrasound-guided prostate biopsy (TRUS-PB). We assessed the efficacy and safety of FQ and fosfomycin-trometamol (FT) in patients undergoing TRUS-PB.Methods: A prospective observational study was conducted between April 2017 and June 2019 and enrolled men undergoing TRUS-PB and receiving a single-dose of FQ (FQ-arm) or FT (FT-arm) for UTI prophylaxis per physician's choice. The primary efficacy endpoint was self-reported TRUS-PB UTI. We assessed baseline factors associated with UTI with logistic regression.Results: A total of 222 men were enrolled, 141/222 (64%) received FQ, and 81/222 (36%) FT. The median age was 67.6 years [IQR, 61.4-72.1] and the Charlson score was 3 [IQR, 3-5]. The overall incidence of self-reported TRUS-PB UTI was 12% (24/197, (95%CI, 8%-17%)): 15% (17/116, (95% CI, 10%-17%)) in FQ-arm, versus 9% (7/81, 95% CI (5%-13%)) in FT-arm (RR = 0.55 (95% CI, 0.22-1.40), p-value = 0.209). No baseline characteristic was significantly associated with TRUS-PB UTI. Safety was similar between the arms: the rate of the reported adverse event was 31% (36/116, (95% CI, 25%-37%) in the FQ-arm versus 36% (28/81, (95% CI, 28%-41%)) in the FT-arm (RR = 1.17 (95% CI, 0.64-2.15), p = 0.602).Conclusions: TRUS-PB UTI prophylaxis with FT and FQ has similar efficacy and safety. A randomized comparison of these two antibiotics is warranted

Utility of anaerobic bottles for the diagnosis of bloodstream infections

International audienceBACKGROUND:Obligate anaerobes usually account for less than 10% of bacteria recovered from blood cultures (BC). The relevance of routine use of the anaerobic bottle is under debate. The aim of this study was to evaluate the utility of anaerobic bottles for the diagnosis of bloodstream infections (BSI).METHODS:We conducted a 6-month, retrospective, monocentric study in a tertiary hospital. All positive BC were grouped into a single episode of bacteremia when drawn within 7 consecutive days. Bacteremia were classified into contaminants and BSI. Charts of patients with BSI due to obligate anaerobes were studied.RESULTS:A total of 19,739 blood cultures were collected, 2341 of which (11.9%) were positive. Anaerobic bottles were positive in 1528 (65.3%) of all positive BC but were positive alone (aerobic bottles negative) in 369 (15.8%). Overall 1081 episodes of bacteremia were identified, of which 209 (19.3%) had positive anaerobic bottles alone. The majority 126/209 (60.3%) were contaminants and 83 (39.7%) were BSI. BSI due to facultative anaerobes, obligate aerobes and obligate anaerobes were identified in 67 (80.7%), 3 (3.6%) and 13 (15.7%) of these 83 episodes, respectively. BSI due to obligate anaerobic bacteria were reported in 9 patients with gastro-intestinal disease, in 3 with febrile neutropenia and in 1 burned patient.CONCLUSIONS:Anaerobic bottles contributed to the diagnosis of a significant number of episodes of bacteremia. Isolated bacteria were mostly contaminants and non-obligate anaerobic pathogens. Rare BSI due to obligate anaerobes were reported mainly in patients with gastro-intestinal disorders and during febrile neutropenia

Capturing the mutational landscape of the beta-lactamase TEM-1

International audienceAdaptation proceeds through the selection of mutations. The distribution of mutant fitness effect and the forces shaping this distribution are therefore keys to predict the evolutionary fate of organisms and their constituents such as enzymes. Here, by producing and sequencing a comprehensive collection of 10,000 mutants, we explore the mutational landscape of one enzyme involved in the spread of antibiotic resistance, the beta-lactamase TEM-1. We measured mutation impact on the enzyme activity through the estimation of amoxicillin minimum inhibitory concentration on a subset of 990 mutants carrying a unique missense mutation, representing 64% of possible amino acid changes in that protein reachable by point mutation. We established that mutation type, solvent accessibility of residues, and the predicted effect of mutations on protein stability primarily determined alone or in combination changes in minimum inhibitory concentration of mutants. Moreover, we were able to capture the drastic modification of the mutational landscape induced by a single stabilizing point mutation (M182T) by a simple model of protein stability. This work thereby provides an integrated framework to study mutation effects and a tool to understand/define better the epistatic interactions