Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
64
result(s) for
"Barbut, Frédéric"
Sort by:
Clostridioides difficile: diagnosis and treatments
2019
AbstractClostridioides difficile (formerly Clostridium) is a major cause of healthcare associated diarrhea, and is increasingly present in the community. Historically, C difficile infection was considered easy to diagnose and treat. Over the past two decades, however, diagnostic techniques have changed in line with a greater understanding of the physiopathology of C difficile infection and the use of new therapeutic molecules. The evolution of diagnosis showed there was an important under- and misdiagnosis of C difficile infection, emphasizing the importance of algorithms recommended by European and North American infectious diseases societies to obtain a reliable diagnosis. Previously, metronidazole was considered the reference drug to treat C difficile infection, but more recently vancomycin and other newer drugs are shown to have higher cure rates. Recurrence of infection represents a key parameter in the evaluation of new drugs, and the challenge is to target the right population with the adapted therapeutic molecule. In multiple recurrences, fecal microbiota transplantation is recommended. New approaches, including antibodies, vaccines, and new molecules are already available or in the pipeline, but more data are needed to support the inclusion of these in practice guidelines. This review aims to provide a baseline for clinicians to understand and stratify their choice in the diagnosis and treatment of C difficile infection based on the most recent data available.
Journal Article
Evidence for contamination as the origin for bacteria found in human placenta rather than a microbiota
2020
Until recently the in utero environment of pregnant women was considered sterile. Recent high-sensitivity molecular techniques and high-throughput sequencing lead to some evidence for a low-biomass microbiome associated with the healthy placenta. Other studies failed to reveal evidence for a consistent presence of bacteria using either culture or molecular based techniques. Comparing conflicting \"placental microbiome\" studies is complicated by the use of varied and inconsistent protocols. Given this situation, we undertook an evaluation of the in utero environment sterility using several controlled methods, in the same study, to evaluate the presence or absence of bacteria and to explain contradictions present in the literature. Healthy pregnant women (n = 38) were recruited in three maternity wards. Placenta were collected after cesarean section with or without Alexis.sup.® and vaginal delivery births. For this study we sampled fetal membranes, umbilical cord and chorionic villi. Bacterial presence was analyzed using bacterial culture and qPCR on 34 fetal membranes, umbilical cord and chorionic villi samples. Shotgun metagenomics was performed on seven chorionic villi samples. We showed that the isolation of meaningful quantities of viable bacteria or bacterial DNA was possible only outside the placenta (fetal membranes and umbilical cords) highlighting the importance of sampling methods in studying the in utero environment. Bacterial communities described by metagenomics analysis were similar in chorionic villi samples and in negative controls and were dependent on the database chosen for the analysis. We conclude that the placenta does not harbor a specific, consistent and functional microbiota.
Journal Article
Carriage and colonization of C. difficile in preterm neonates: A longitudinal prospective study
by
Aires, Julio
,
Butel, Marie-José
,
Barbut, Frédéric
in
Antibiotics
,
Biology and Life Sciences
,
Birth weight
2019
Premature neonates (PN) present multiple risk factors for high frequencies and high levels of colonization by C. difficile, yet data is missing about this specific pediatric population. Here, we investigated PN C. difficile carriage and colonization dynamics, analyzed the impact of perinatal determinants on colonization, and characterized the isolates.
A one year longitudinal monocentric prospective cohort study was performed on 121 PN. C. difficile strains isolated from fecal samples on selective medium were identified and characterized by PCR (tpi housekeeping gene; tcdA and tcdB, and binary toxin genes), capillary gel-based electrophoresis PCR-ribotyping, and Multi-Locus Variable-number tandem-repeat Analysis (MLVA).
Of the 379 samples analyzed, 199 (52%) were C. difficile culture positive with the mean levels of C. difficile colonization decreasing significantly (P = .027) over time. During hospitalization, C. difficile colonization frequency increased up to 61% with 95% of the strains belonging to both non-toxigenic PCR-ribotypes (RTs) FR082 (35%) and 032 (60%). After hospital discharge, if a higher diversity in RTs was observed, RTs FR082 and 032 remained predominant (respectively 40% and 28%). MLVA showed clonal relationship within each FR082 and 032 RTs. Ten toxigenic strains (5%) were isolated, all tcdA+/tcdB+ except for one tcdA-/tcdB+, and all being acquired after hospitalization. At 1 week, the only factors found to be linked with a higher frequency of C. difficile colonization were a higher gestational age (P = 0.006) and a higher birth weight (P = 0.016).
The dynamics of C. difficile colonization in PN followed a specific pattern. C. difficile colonization rapidly occurred after birth with a low diversity of non-toxigenic RTs. After hospitalization, non-toxigenic RTs diversity increased. Sporadic carriage of toxigenic strains was observed after hospitalization.
Journal Article
Editorial: Clostridioides difficile infection
2024
Even after adequate antibiotic therapy against CD, CDI recurrences are observed due to the germination of remaining CD spores, favored by the relative increase in primary bile acids (5,6). [...]recent studies suggest that Enterococci and CD may interact through metabolic cross-talk during CDI, enhancing mutual colonization, persistence, and pathogenesis in the gut (7). [...]the long-term impact of SARS-CoV-2 and CD coinfection remains unknown. The gastrointestinal tract expresses SARS-CoV-2 receptors such as the angiotensin-converting enzyme 2 and transmembrane serine protease 2 (10). [...]COVID-19 can directly damage the gastrointestinal tract. [...]COVID-19 patients with hospital-acquired CDI had a significantly higher in-hospital mortality rate (23.1%) compared to patients with hospital-acquired CDI but without COVID-19 (14.3%) (p: 0.006).
Journal Article
Heterogeneity in practices to reduce the risk of transmission of Clostridioides difficile in healthcare settings: a survey of ESCMID Study Group for Clostridioides difficile (ESGCD) members
by
Khanafer, Nagham Léa
,
Barbut, Frédéric
,
Fitzpatrick, Fidelma
in
Clostridioides difficile
,
Compliance
,
Diarrhea
2024
Clostridioides difficile is a leading cause of healthcare-associated infections. The main objective was to assess the current landscape of CDI infection prevention and control (IPC) practices. An anonymous survey of IPC practices for CDI was conducted between July 25 and October 31, 2022. Precautions for symptomatic patients were applicable for 75.9% and were discontinued 48 h minimum after the resolution of diarrhea for 40.7% of respondents. Daily cleaning of CDI patients’ rooms was reported by 23 (42.6%). There was unexpected heterogeneity in IPC practices regarding the hospital management of CDI.
Journal Article
Transmission of Legionnaires’ Disease through Toilet Flushing
2020
We describe 2 cases of healthcare-associated Legionnaires' disease in patients in France hospitalized 5 months apart in the same room. Whole-genome sequencing analyses showed that clinical isolates from the patients and isolates from the room's toilet clustered together. Toilet contamination by Legionella pneumophila could lead to a risk for exposure through flushing.
Journal Article
Clostridium difficile: New Insights into the Evolution of the Pathogenicity Locus
2015
The major virulence factors of
Clostridium difficile
are toxins A and B. These toxins are encoded by
tcdA
and
tcdB
genes, which form a pathogenicity locus (PaLoc) together with three additional genes that have been implicated in regulation (
tcdR
and
tcdC
) and secretion (
tcdE
). To date, the PaLoc has always been found in the same location and is replaced in non-toxigenic strains by a highly conserved 75/115 bp non-coding region. Here, we show new types of
C. difficile
pathogenicity loci through the genome analysis of three atypical clinical strains and describe for the first time a variant strain producing only toxin A (A
+
B
−
). Importantly, we found that the PaLoc integration sites of these three strains are located in the genome far from the usual single known PaLoc integration site. These findings allowed us to propose a new model of PaLoc evolution in which two “Mono-Toxin PaLoc” sites are merged to generate a single “Bi-Toxin PaLoc”.
Journal Article
Contribution of MALDI‐TOF mass spectrometry and machine learning including deep learning techniques for the detection of virulence factors of Clostridioides difficile strains
by
Giai Gianetto, Quentin
,
Godmer, Alexandre
,
Barbut, Frédéric
in
Acids
,
Algorithms
,
Artificial intelligence
2024
Clostridioides difficile (CD) infections are defined by toxins A (TcdA) and B (TcdB) along with the binary toxin (CDT). The emergence of the ‘hypervirulent’ (Hv) strain PR 027, along with PR 176 and 181, two decades ago, reshaped CD infection epidemiology in Europe. This study assessed MALDI‐TOF mass spectrometry (MALDI‐TOF MS) combined with machine learning (ML) and Deep Learning (DL) to identify toxigenic strains (producing TcdA, TcdB with or without CDT) and Hv strains. In total, 201 CD strains were analysed, comprising 151 toxigenic (24 ToxA+B+CDT+, 22 ToxA+B+CDT+ Hv+ and 105 ToxA+B+CDT−) and 50 non‐toxigenic (ToxA−B−) strains. The DL‐based classifier exhibited a 0.95 negative predictive value for excluding ToxA−B− strains, showcasing accuracy in identifying this strain category. Sensitivity in correctly identifying ToxA+B+CDT− strains ranged from 0.68 to 0.91. Additionally, all classifiers consistently demonstrated high specificity (>0.96) in detecting ToxA+B+CDT+ strains. The classifiers' performances for Hv strain detection were linked to high specificity (≥0.96). This study highlights MALDI‐TOF MS enhanced by ML techniques as a rapid and cost‐effective tool for identifying CD strain virulence factors. Our results brought a proof‐of‐concept concerning the ability of MALDI‐TOF MS coupled with ML techniques to detect virulence factor and potentially improve the outbreak's management. This study assessed the use of MALDI‐TOF Mass Spectrometry combined with Machine Learning including Deep Learning techniques to identify toxigenic and hypervirulent strains of Clostridioides difficile. The method demonstrated high accuracy, particularly in excluding non‐toxigenic strains with a negative predictive value of 0.95 and consistently high specificity (>0.96) for detecting binary producing strains. The findings suggest that MALDI‐TOF MS enhanced by ML techniques is a rapid, cost‐effective tool for detecting virulence factors in CD strains, potentially improving outbreak management.
Journal Article
A Randomised, Controlled Trial: Effect of a Multi-Strain Fermented Milk on the Gut Microbiota Recovery after Helicobacter pylori Therapy
2021
Helicobacter pylori (Hp) eradication therapy alters gut microbiota, provoking gastrointestinal (GI) symptoms that could be improved by probiotics. The study aim was to assess the effect in Hp patients of a Test fermented milk containing yogurt and Lacticaseibacillus (L. paracasei CNCM I-1518 and I-3689, L. rhamnosus CNCM I-3690) strains on antibiotic associated diarrhea (AAD) (primary aim), GI-symptoms, gut microbiota, and metabolites. A randomised, double-blind, controlled trial was performed on 136 adults under 14-day Hp treatment, receiving the Test or Control product for 28 days. AAD and GI-symptoms were reported and feces analysed for relative and quantitative gut microbiome composition, short chain fatty acids (SCFA), and calprotectin concentrations, and viability of ingested strains. No effect of Test product was observed on AAD or GI-symptoms. Hp treatment induced a significant alteration in bacterial and fungal composition, a decrease of bacterial count and alpha-diversity, an increase of Candida and calprotectin, and a decrease of SCFA concentrations. Following Hp treatment, in the Test as compared to Control group, intra-subject beta-diversity distance from baseline was lower (padj = 0.02), some Enterobacteriaceae, including Escherichia-Shigella (padj = 0.0082) and Klebsiella (padj = 0.013), were less abundant, and concentrations of major SCFA (p = 0.035) and valerate (p = 0.045) were higher. Viable Lacticaseibacillus strains were detected during product consumption in feces. Results suggest that, in patients under Hp treatment, the consumption of a multi-strain fermented milk can induce a modest but significant faster recovery of the microbiota composition (beta-diversity) and of SCFA production and limit the increase of potentially pathogenic bacteria.
Journal Article
Nosocomial transmission of Clostridium difficile ribotype 027 in a Chinese hospital, 2012–2014, traced by whole genome sequencing
2016
Background
The rapid spread of
Clostridium difficile
NAP1/BI/027 (
C. difficile
027) has become one of the leading threats of healthcare-associated infections worldwide. However,
C. difficile
027 infections have been rarely reported in Asia, particularly in China.
Results
In this study, we identified a rare
C. difficile
bloodstream infection (BSI) from three isolates of a patient during repeated hospital admission. This finding triggered a retrospective epidemiological study to scan all cases and strains emerged from this ward during the past three years. Using medical personnel interviews, medical record reviews and the genomic epidemiology, two outbreaks in 2012 and 2013–2014 were identified. Through using whole genome sequencing, we succeeded to trace the origin of the BSI strain. Surprisingly, we found the genome sequences were similar to
C. difficile
027 strain R20291, indicating the occurrence of a rare
C. difficile
027 strain in China. Integrated epidemiological investigation and whole genome sequencing of all strains, we constructed a nosocomial transmission map of these two
C. difficile
027 outbreaks and traced the origin of the infection.
Conclusions
By genome sequencing, spatio-temporal analysis and field epidemiology investigation, we can estimate their complex transform network and reveal the possible modes of transmission in this ward. Based on their genetic diversity, we can assume that the toilets, bathroom, and janitor’s equipment room may be contaminated area, which may be suggested to improve infection control measures in the following health care.
Journal Article