Publications by authors named "Luce Landraud"

We report 72 metagenome-assembled genomes (MAGs) of recovered from the vaginal microbiomes of pregnant women. The MAGs have an estimated median genome size of 5.1 Mb (IQR 4.

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Article Synopsis
  • The study investigates the impact of vaginal microbiota (VM) on asymptomatic bacteriuria (ASB) in 1,553 pregnant women, highlighting the dominance of E. coli as a common cause of bacteriuria and newborn infections.
  • Results indicate that a healthy VM, usually rich in Lactobacillus species, is disturbed during bacteriuria, leading to an increase in harmful gut-associated bacteria, particularly E. coli.
  • Molecular analysis of E. coli genomes reveals the presence of extraintestinal pathogenic strains, suggesting that reduced Lactobacillus abundance may enable opportunistic pathogens to thrive, thereby compromising women's health during pregnancy.
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It has been shown that an evolutionary tradeoff between vertical (host growth rate) and horizontal (plasmid conjugation) transmissions contributes to global plasmid fitness. As conjugative IncC plasmids are important for the spread of multidrug resistance (MDR), in a broad range of bacterial hosts, we investigated vertical and horizontal transmissions of two multidrug-resistant IncC plasmids according to their backbones and MDR-region rearrangements, upon plasmid entry into a new host. We observed plasmid genome deletions after conjugation in three diverse natural clinical strains, varying from null to high number depending on the plasmid, all occurring in the MDR region.

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Toxoplasmosis is a ubiquitous parasitic infection caused by Toxoplasma gondii (Tg). In immunocompetent people, the infection may be asymptomatic with the induction of an immune response that may prevent reinfection or transmission to the fetus in immune pregnant woman. In immunocompromised persons or seronegative pregnant woman with a primary infection during pregnancy, the infection may result in the loss of life, sight, cognition, and motor function in the immune-compromised person or immunologically immature fetus.

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Multiresistance plasmids belonging to the IncI incompatibility group have become one of the most pervasive plasmid types in extended-spectrum beta-lactamase-producing of animal origin. The extent of the burden imposed on the bacterial cell by these plasmids seems to modulate the emergence of "epidemic" plasmids. However, data in the natural environment of the strains are scarce.

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Background And Aims: A highly sensitive and specific point-of-care method for diagnosing spontaneous bacterial peritonitis (SBP) is currently lacking. The objective of the present study is to evaluate the diagnostic value of a rapid, easy-to-use, mid-infrared fiber evanescent wave spectroscopy (MIR-FEWS) method for ruling out SBP.

Patients And Methods: Cirrhotic patients ( = 256) at five centers in France were included for suspected SBP or for the scheduled evacuation of ascites fluid.

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Background: The occurrence of COVID-19 during the pregnancy can cause several negative maternal and neonatal outcomes. Nasopharyngeal viral load is associated with inflammatory markers and might influence the disease severity in non-pregnant patients, but there are no data about the relationship between viral load and perinatal outcomes in pregnant patients.

Objective: To investigate the hypothesis that nasopharyngeal SARS-CoV-2 load (estimated with real-time polymerase chain reaction delta cycle (ΔCt), measured in hospital clinical laboratories) is associated with perinatal outcomes, when COVID-19 is diagnosed in the third trimester of pregnancy.

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Epidemiological projections point to acquisition of ever-expanding multidrug resistance (MDR) by , a commensal of the digestive tract and a source of urinary tract pathogens. Bioinformatics analyses of a large collection of genomes from EnteroBase, enriched in clinical isolates of worldwide origins, suggest the Cytotoxic Necrotizing Factor 1 (CNF1)-toxin encoding gene, , is preferentially distributed in four common sequence types (ST) encompassing the pandemic MDR lineage ST131. This lineage is responsible for a majority of extraintestinal infections that escape first-line antibiotic treatment, with known enhanced capacities to colonize the gastrointestinal tract.

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Article Synopsis
  • The study focused on the SARS-CoV-2 variant α, which became a concern in 2021, examining its genetic diversity and connection to severe COVID-19 outcomes.
  • Conducted in 11 ICUs in Greater Paris, it analyzed 413 patients and found that variant α was prevalent but did not lead to higher mortality compared to pre-existing variants or other variants.
  • Despite differences in age and underlying health conditions among patients with different variants, the research concluded that there was no significant link between specific viral mutations and day-28 mortality rates.
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Background: Infants with COVID-19 can often present with fever without source, which is a challenging situation in infants <90 days old. The "step-by-step" algorithm has been proposed to identify children at high risk of bacterial infection. In the context of the COVID-19 pandemic, we aimed to reassess the diagnostic performance of this algorithm.

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  • The study investigates the vaginal germ profile in cases of preterm prelabor rupture of membranes (PPROM) and its link to early-onset neonatal infection (EONI).
  • Among the 268 PPROM cases analyzed, 14.55% of neonates developed EONI, with dysbiosis (imbalance in the vaginal microbiome) at the time of rupture being significantly associated with EONI risk.
  • The findings suggest that while the presence of specific pathogens in vaginal cultures was not linked to EONI, dysbiosis at rupture and delivery heightened the risk of clinical intra-uterine infections.
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Despite a fitness cost imposed on bacterial hosts, large conjugative plasmids play a key role in the diffusion of resistance determinants, such as CTX-M extended-spectrum β-lactamases. Among the large conjugative plasmids, IncF plasmids are the most predominant group, and an F2:A1:B- IncF-type plasmid encoding a CTX-M-15 variant was recently described as being strongly associated with the emerging worldwide sequence type 131 (ST131)-O25b:H4 30Rx/C2 sublineage. In this context, we investigated the fitness cost of narrow-range F-type plasmids, including the F2:A1:B- IncF-type CTX-M-15 plasmid, and of broad-range C-type plasmids in the K-12-like J53-2 strain.

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What We Already Know About This Topic: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Oropharyngeal care with chlorhexidine to prevent ventilator-associated pneumonia is currently questioned, and exhaustive microbiologic data assessing its efficacy are lacking. The authors therefore aimed to study the effect of chlorhexidine mouthwash on oropharyngeal bacterial growth, to determine chlorhexidine susceptibility of these bacteria, and to measure chlorhexidine salivary concentration after an oropharyngeal care.

Methods: This observational, prospective, single-center study enrolled 30 critically ill patients under mechanical ventilation for over 48 h.

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The increasing incidence of ESBL-producing Enterobacteriaceae (ESBL-E) in France prompted the publication of national recommendations in 2010. Based on these, we developed a toolkit and a warning system to optimise management of ESBL-E infected or colonised patients in both community and hospital settings. The impact of this initiative on quality of care was assessed in a teaching hospital.

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Extra-corporeal membrane oxygenation (ECMO) is a promising life-saving technique for critically ill patients. Bacterial infection is a frequent complication, and Escherichia coli the predominant causative pathogen, but little is known about the characteristics of E. coli strains in these infections.

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After the deaths of 2 preterm neonates with Bacillus cereus systemic infection in the same intensive care unit, we investigated the pathogenic potential of this bacterium. Genetic and virulence analysis indicated the neonates were infected with 2 different strains with a virulence potential similar to environmental strains, indicating likely patient immune response failure.

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The detection of the activities of pathogen-encoded virulence factors by the innate immune system has emerged as a new paradigm of pathogen recognition. Much remains to be determined with regard to the molecular and cellular components contributing to this defense mechanism in mammals and importance during infection. Here, we reveal the central role of the IL-1β signaling axis and Gr1+ cells in controlling the Escherichia coli burden in the blood in response to the sensing of the Rho GTPase-activating toxin CNF1.

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ARG-ANNOT (Antibiotic Resistance Gene-ANNOTation) is a new bioinformatic tool that was created to detect existing and putative new antibiotic resistance (AR) genes in bacterial genomes. ARG-ANNOT uses a local BLAST program in Bio-Edit software that allows the user to analyze sequences without a Web interface. All AR genetic determinants were collected from published works and online resources; nucleotide and protein sequences were retrieved from the NCBI GenBank database.

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Background: Klebsiella pneumoniae is one of the most important pathogens responsible for nosocomial outbreaks worldwide. Epidemiological analyses are useful in determining the extent of an outbreak and in elucidating the sources and the spread of infections. The aim of this study was to investigate the epidemiological spread of K.

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Objective: To extend our previous work on evaluating the use of oligonucleotide arrays to discriminate colonization from infection owing to Staphylococcus aureus in diabetic foot ulcers (DFUs).

Research Design And Methods: Patients admitted to 14 French diabetic foot departments for a DFU were screened for entry into the study. At admission, ulcers were classified based on clinical examination according to the Infectious Diseases Society of America system.

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Inactivation of the host GTPase RhoA by staphylococcal epidermal cell differentiation inhibitor (EDIN) exotoxins triggers the formation of large transcellular tunnels, named macroapertures, in endothelial cells. We used bioluminescent strains of Staphylococcus aureus to monitor the formation of infection foci during the first 24 h of hematogenous bacterial dissemination. Clinically derived EDIN-expressing S.

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Article Synopsis
  • Extraintestinal pathogenic Escherichia coli (ExPEC) strains pose a significant public health threat, and understanding their diversity and genomic features is vital for identifying highly invasive strains.
  • A study analyzed 161 E. coli isolates from patients with bacteremia, revealing a high diversity of strains divided into five major phylogenetic lineages, with specific clonal complexes associated with urinary infections.
  • The research highlighted that different clonal complexes have unique genomic characteristics, contributing to our understanding of E. coli strains' pathogenesis and the variability in clinical outcomes.
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Studies on the interactions of bacterial pathogens with their host have provided an invaluable source of information on the major functions of eukaryotic and prokaryotic cell biology. In addition, this expanding field of research, known as cellular microbiology, has revealed fascinating examples of trans-kingdom functional interplay. Bacterial factors actually exploit eukaryotic cell machineries using refined molecular strategies to promote invasion and proliferation within their host.

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