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1.
Front Microbiol ; 15: 1370553, 2024.
Article in English | MEDLINE | ID: mdl-38680922

ABSTRACT

Introduction: The colonization of patients by carbapenemase-producing Enterobacterales (CPE) has been associated with heightened mortality, especially in vulnerable individuals within intensive care units (ICUs). Our study aimed to comprehensively assess CPE prevalence among ICU patients across the Mediterranean region pre-COVID-19, conducting a multicenter prevalence study in the first quarter of 2019. Methods: We collected clinical data and rectal or fecal samples from 256 ICU patients for CPE testing. Additionally, we performed whole-genome sequencing on 40 representative CPE strains to document their molecular characteristics. Results: Among the 256 patients, CPE was detected in 73 samples (28.5%), with prevalence varying from 3.3 to 69.0% across participating centers. We observed 13 colistin-resistant CPE strains, affecting three ICUs. Genetic analysis revealed highly diverse E. coli and K. pneumoniae strains, predominantly from international high-risk clones. Notably, blaOXA-48 and blaNDM-1 were the most prevalent carbapenemase genes. Molecular typing uncovered potential patient clusters in six centers. Significantly, longer hospital stays were associated with increased CPE carriage (p < 0.001). Nine centers across Morocco, Tunisia, Egypt, and Lebanon voluntarily participated. Discussion: Our study provides CPE prevalence in Mediterranean ICUs and reaffirms established CPE presence in this setting but also provides updates on the molecular diversity of CPE strains. These findings highlight the imperative of reinforcing infection control measures in the participating ICUs to curtail escalated mortality rates, and of strictly applying isolation measures around patients originating from the Mediterranean region when transferred to other healthcare institutions.

2.
J Fish Biol ; 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38634148

ABSTRACT

The current study investigated the structure and function of the olfactory system of the Lusitanian toadfish, Halobatrachus didactylus, using histology and electrophysiology (electro-olfactogram [EOG]), respectively. The olfactory system consists of a digitated anterior peduncle, of unknown function, containing the inhalant nostril. This then leads to a U-shaped olfactory chamber with the olfactory epithelium-identified by Gαolf-immunoreactivity-on the ventral surface. A large lacrimal sac is connected to this tube and is likely involved in generating water movement through the olfactory chamber (this species is largely sedentary). The exhalent nostril lies by the eye and is preceded by a bicuspid valve to ensure one-way flow of water. As do other teleosts, H. didactylus had olfactory sensitivity to amino acids and bile acids. Large-amplitude EOG responses were evoked by fluid from the anterior and posterior testicular accessory glands, and bile and intestinal fluids. Anterior gland and intestinal fluids from reproductive males were significantly more potent than those from non-reproductive males. Male urine and skin mucus proved to be the least potent body fluids tested. These results suggest that chemical communication-as well as acoustic communication-may be important in the reproduction of this species and that this may be mediated by the accessory glands and intestinal fluid.

3.
Front Cell Infect Microbiol ; 14: 1341161, 2024.
Article in English | MEDLINE | ID: mdl-38390622

ABSTRACT

Introduction: Infections caused by carbapenemase-producing Enterobacteriaceae (CPE) pose a significant threat, leading to severe morbidity and mortality among newborns. Methods: This study, conducted at Franceville hospital's maternity and neonatology wards from February 22nd to June 20th, 2022, investigated the prevalence of CPE in 197 parturients and 203 newborns. Rectal swabs were taken from parturients before delivery and from newborns 30 minutes after birth. Blood culture samples were collected if signs of infection were observed in newborns during a 28-day follow-up. A total of 152 environmental samples were obtained, comprising 18 from sinks, 14 from incubators, 27 from cradles, 39 from maternal beds, 14 from tables and desks, four from the two baby scales and 36 from bedside furniture. Results: None of the 203 newborns were found to be CPE carriers 30 minutes after delivery. CPE carriage was found in 4.6% of mothers. When comparing colonized and uncolonized parturients, well-established risk factors for CPE carriage, such as recent hospitalization and antibiotic therapy, were more frequently observed among CPE carriers (33.3 vs 10.6% for hospitalization in the past 15 days; 55.5 vs 30.3% for hospitalization during pregnancy, and 55.5 vs 35.1% for antibiotic therapy during pregnancy). Notably, the prevalence of treatment with amoxicillin and clavulanic acid was 44.4% in CPE carriers compared to 17.0% in non-carriers. The incidence density of CPE-associated bloodstream infection was 0.49 per 100 newborns, accounting for a fatal case of CPE-associated bacteremia identified in one of the 203 newborns. Seven environmental samples returned positive for CPE (5 sinks and two pieces of furniture). Whole genome sequencing, performed on the 25 CPE isolates, revealed isolates carrying blaNDM-7 (n=10), blaNDM-5 (n=3), blaOXA181 (n=10), blaOXA48 (n=2) or blaOXA244 (n=1), along with genetic traits associated with the ability to cause severe and difficult-to-treat infections in newborns. Core genome comparison revealed nine CPE belonging to three international high-risk clones: E. coli ST410 (four mothers and a sink), two E. coli ST167 (a mother and a piece of furniture), and K. pneumoniae ST307 (a sink and a piece of furniture), with highly similar genetic backgrounds shared by maternal and environmental isolates, suggesting maternal contamination originating from the environment. Discussion: Our study reveals key findings may guide the implementation of infection control measures to prevent nosocomial infections in newborns: the prevalence of CPE carriage in one out of 20 parturients, an infection occurring in one out of 400 newborns, substantial contamination of the care environment, clinical and environmental CPE isolates possessing genetic traits associated with the ability to cause severe and challenging infections, and clonal relationships between clinical and environmental isolates suggesting CPE spread within the wards, likely contributing to the acquisition and colonization of CPE by parturients during pregnancy.


Subject(s)
Carbapenem-Resistant Enterobacteriaceae , Enterobacteriaceae Infections , Female , Humans , Infant , Infant, Newborn , Pregnancy , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins/genetics , beta-Lactamases/genetics , beta-Lactamases/therapeutic use , Carbapenem-Resistant Enterobacteriaceae/genetics , Carbapenems/therapeutic use , Enterobacteriaceae/genetics , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/drug therapy , Escherichia coli/genetics , Gabon , Klebsiella pneumoniae , Mothers
4.
Eur J Med Res ; 28(1): 528, 2023 Nov 16.
Article in English | MEDLINE | ID: mdl-37974277

ABSTRACT

BACKGROUND: Central catheters expose ICU patients at risk of catheter-related bloodstream infections. A mechanism by which these infections occur is the contamination of the catheter during its insertion if aseptic techniques are not strictly applied. Recent studies suggest that the use of ultrasound guidance (USG) may increase the risk of catheter contamination during insertion. We assessed current practices regarding the use of USG during catheter insertion, with a focus on identifying breaches of the surgical asepsis required for this invasive procedure. METHODS: In 26 intensive care units, we evaluated the use of USG during catheter insertion, using a questionnaire addressed to intensivists and direct observation of their practices. RESULTS: We analyzed 111 questionnaires and 36 observations of intensivists placing catheters. The questionnaires revealed that 88% of intensivists used USG for catheter insertion. Among those using USG, 56% had received specific training, 17% benefited from specific recommendations, 76% marked the insertion site before skin antisepsis, and during catheter insertion, 96% used sterile gel and 100% used a sterile sheath and sterile gloves. We identified potential deviations from strict aseptic technique, including contact between the sheath and the needle (19.4%), handling of the US system during catheter insertion (2.8%), and use of sterile devices, where they were not yet necessary (during the marking site or skin antisepsis), resulting in their contamination at the time of catheter insertion. CONCLUSIONS: Interventions aimed at ensuring compliance with measures to prevent CRBs should be organized to prevent an increase in infections associated with US-guided catheter insertion.


Subject(s)
Catheterization, Central Venous , Catheterization, Peripheral , Humans , Catheterization, Central Venous/adverse effects , Catheterization, Central Venous/methods , Intensive Care Units , Skin , Catheterization, Peripheral/adverse effects
5.
BMC Med Educ ; 23(1): 731, 2023 Oct 06.
Article in English | MEDLINE | ID: mdl-37803431

ABSTRACT

BACKGROUND: Patients who have short peripheral venous catheters (PVC) face an elevated risk of developing bloodstream infections. Preventing catheter-related infections relies on implementing multiple measures, including practicing proper hand hygiene (HH) during catheter placement. METHODS: We conducted a four-part study: (1) an evaluation of HH practices through direct observation of PVC placements, coupled with the study of the microbial flora of the HCWs fingers just before the placement; (2) the development of an educational tool based on the collected observational and microbiological data; (3) the training to the HCWs observed during the first part, using this tool; and (4) the subsequent observation of the trained HCWs to measure the impact of the training on practice improvement. RESULTS: Compliant HH was observed in 23.5% of the 647 HCWs observed during PVC placement before training. The microbiological study revealed fewer pathogens on the fingertips of the HCWs practicing compliant HH compared other HCWs (2.6 vs 11,7%; p = 0.003). The comparison of practices before and after training, assessed among 180 HCWs, showed an increase in the proportion of HCWs performing compliant HH (25.0 vs 63.2%; p < 0.001). CONCLUSIONS: Training HCWs using our educational tool, which combines reminders of best practices and risk factors associated with PVC-related infections, engaging HCWs (presentation of practice evaluation), identifying professionals deviating from best practices (simulation videos), and objectively assessing fingertip contamination (microbiological study), significantly improved compliance with HH gestures and glove usage. We encourage infection control teams to utilize this tool to raise awareness among HCWs responsible for PVC placement about the risk of infection associated inadequate hand hygiene.


Subject(s)
Cross Infection , Hand Hygiene , Humans , Cross Infection/prevention & control , Infection Control , Hygiene , Guideline Adherence , Catheters , Health Personnel/education
6.
Microorganisms ; 10(9)2022 Sep 16.
Article in English | MEDLINE | ID: mdl-36144459

ABSTRACT

A prospective 3-month study carried out in 267 ICUs revealed an S. aureus nosocomial bacteremia in one admitted patient out of 110 in adult and pediatric sectors, and in one out of 230 newborns; 242 S. aureus bacteremias occurred during the study, including 7.9% MRSA-bacteremias. In one ICU out of ten, the molecular characteristics, antimicrobial susceptibility profiles and biofilm production of the strains responsible for S. aureus bacteremia were studied. Of the 53 strains studied, 9.4% were MRSA and 52.8% were resistant to erythromycin. MLST showed the predominance of CC398 (37.7% of the strains) followed by CC8 (17.0%), CC45 (13.2%) and CC30 (9.4%). The lukF/S genes were absent from our isolates and tst-1 was found in 9.4% of the strains. Under static conditions and without exposure to glucose, biofilm production was rare (9.4% of the strains, without any CC398). The percentage increased to 62.3% for strains grown in broth supplemented with 1% glucose (including 7 out of 9 CC8 and 17 out of the 20 CC398). Further study of the CC398, including whole genome sequencing, revealed (1) highly frequent patient death within seven days after CC398 bacteremia diagnosis (47.4%), (2) 95.0% of the strains producing biofilm when exposed to sub-inhibitory concentrations of cloxacillin, (3) a stronger biofilm production following exposure to cloxacillin than that observed in broth supplemented with glucose only (p < 0.001), (4) a high minimum biofilm eradication concentration of cloxacillin (128 mg/L) indicating a low cloxacillin susceptibility of biofilm-growing CC398, (5) 95.0% of the strains carrying a ϕSa-3 like prophage and its particular evasion cluster (i.e., yielding chp and scin genes), and (6) 30.0% of the strains carrying a ϕMR11-like prophage and yielding a higher ability to produce biofilm. Our results provide evidence that active surveillance is required to avoid spreading of this virulent staphylococcal clone.

7.
Genes (Basel) ; 12(11)2021 10 30.
Article in English | MEDLINE | ID: mdl-34828356

ABSTRACT

Among clinically relevant lineages of Staphylococcus aureus, the lineage or clonal complex 398 (CC398) is of particular interest. Strains from this lineage were only described as livestock colonizers until 2007. Progressively, cases of infection were reported in humans in contact with farm animals, and now, CC398 isolates are increasingly identified as the cause of severe infections even in patients without any contact with animals. These observations suggest that CC398 isolates have spread not only in the community but also in the hospital setting. In addition, several recent studies have reported that CC398 strains are evolving towards increased virulence and antibiotic resistance. Identification of the origin and emergence of this clonal complex could probably benefit future large-scale studies that aim to detect sources of contamination and infection. Current evidence indicates that the evolution of CC398 strains towards these phenotypes has been driven by the acquisition of prophages and other mobile genetic elements. In this short review, we summarize the main knowledge of this major lineage of S. aureus that has become predominant in the human clinic worldwide within a single decade.


Subject(s)
DNA, Bacterial/genetics , Staphylococcal Infections/microbiology , Staphylococcus aureus/classification , Animals , Animals, Domestic/microbiology , Evolution, Molecular , Humans , Interspersed Repetitive Sequences , Population Surveillance , Prophages/genetics , Staphylococcal Infections/veterinary , Staphylococcus aureus/genetics , Staphylococcus aureus/virology
8.
Mol Ecol ; 30(24): 6642-6658, 2021 12.
Article in English | MEDLINE | ID: mdl-34601781

ABSTRACT

Chemosensation is a critical signalling process in animals and especially important in sea cucumbers, a group of ecologically and economically important marine echinoderms (class Holothuroidea), which lack audio and visual organs and rely on chemical sensing for survival, feeding and reproduction. The ionotropic receptors are a recently identified family of chemosensory receptors in insects and other protostomes, related to the ionotropic glutamate receptor family (iGluR), a large family of membrane receptors in metazoan. Here we characterize the echinoderm iGluR subunits and consider their possible role in chemical communication in sea cucumbers. Sequence similarity searches revealed that sea cucumbers have in general a higher number of iGluR subunits when compared to other echinoderms. Phylogenetic analysis and sequence comparisons revealed GluH as a specific iGluR subfamily present in all echinoderms. Homologues of the vertebrate GluA (aka α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, AMPA), GluK (aka kainate) and GluD (aka delta) were also identified. The GluN (aka N-methyl-d-aspartate, NMDA) as well as the invertebrate deuterostome subfamily GluF (aka phi) are absent in echinoderms. The echinoderm GluH subfamily shares conserved structural protein organization with vertebrate iGluRs and the ligand binding domain (LBD) is the most conserved region; genome analysis indicates evolution via lineage and species-specific tandem gene duplications. GluH genes (named Grih) are the most highly expressed iGluRs subunit genes in tissues in the sea cucumber Holothuria arguinesis, with Griha1, Griha2 and Griha5 exclusively expressed in tentacles, making them candidates to have a chemosensory role in this species. The multiple GluH subunits may provide alternative receptor assembly combinations, thus expanding the functional possibilities and widening the range of compounds detected during aggregation and spawning in echinoderms.


Subject(s)
Receptors, Ionotropic Glutamate , Sea Cucumbers , Animals , Echinodermata/genetics , Invertebrates , Phylogeny , Receptors, Ionotropic Glutamate/genetics
9.
Microorganisms ; 9(6)2021 May 21.
Article in English | MEDLINE | ID: mdl-34063935

ABSTRACT

CC17 Streptococcus agalactiae carrying group-A prophages is increasingly responsible for neonatal infections. To investigate the impact of the genetic features of a group-A prophage, we first conducted an in silico analysis of the genome of 12/111phiA, a group-A prophage carried by a strain responsible for a bloodstream infection in a parturient. This revealed a Restriction Modification system, suggesting a prophage maintenance strategy and five ORFs of interest for the host and encoding a type II toxin antitoxin system RelB/YafQ, an endonuclease, an S-adenosylmethionine synthetase MetK, and an StrP-like adhesin. Using the WT strain cured from 12/111phiA and constructing deleted mutants for the ORFs of interest, and their complemented mutants, we demonstrated an impact of prophage features on growth characteristics, cell morphology and biofilm formation. Our findings argue in favor of 12/111phiA domestication by the host and a role of prophage features in cell autoaggregation, glycocalyx and biofilm formation. We suggest that lysogeny may promote GBS adaptation to the acid environment of the vagina, consequently colonizing and infecting neonates.

11.
Clin Microbiol Infect ; 27(9): 1347.e9-1347.e14, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33640576

ABSTRACT

OBJECTIVES: The aim was to assess the incidence of sink contamination by multidrug-resistant (MDR) Pseudomonas aeruginosa and Enterobacteriaceae, risk factors for sink contamination and splashing, and their association with clinical infections in the intensive care setting. METHODS: A prospective French multicentre study (1 January to 30 May 2020) including in each intensive care unit (ICU) a point-prevalence study of sink contamination, a questionnaire of risk factors for sink contamination (sink use, disinfection procedure) and splashing (visible plashes, distance and barrier between sink and bed), and a 3-month prospective infection survey. RESULTS: Seventy-three ICUs participated in the study. In total, 50.9% (606/1191) of the sinks were contaminated by MDR bacteria: 41.0% (110/268) of the sinks used only for handwashing, 55.3% (510/923) of those used for waste disposal, 23.0% (62/269) of sinks daily bleached, 59.1% (126/213) of those daily exposed to quaternary ammonium compounds (QACs) and 62.0% (285/460) of those untreated; 459 sinks (38.5%) showed visible splashes and 30.5% (363/1191) were close to the bed (<2 m) with no barrier around the sink. MDR-associated bloodstream infection incidence rates ≥0.70/1000 patient days were associated with ICUs meeting three or four of these conditions, i.e. a sink contamination rate ≥51%, prevalence of sinks with visible splashes ≥14%, prevalence of sinks close to the patient's bed ≥21% and no daily bleach disinfection (6/30 (20.0%) of the ICUs with none, one or two factors vs. 14/28 (50.0%) of the ICUs with three or four factors; p 0.016). DISCUSSION: Our data showed frequent and multifactorial infectious risks associated with contaminated sinks in ICUs.


Subject(s)
Cross Infection , Equipment Contamination , Intensive Care Units , Water Supply , Cross Infection/epidemiology , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae , Humans , Prospective Studies , Pseudomonas aeruginosa , Risk Factors
12.
Clin Infect Dis ; 73(9): e2781-e2788, 2021 11 02.
Article in English | MEDLINE | ID: mdl-33137174

ABSTRACT

BACKGROUND: The issue of contact precautions as contributory factors for reducing Pseudomonas aeruginosa (Pa) infections in intensive care units (ICUs) remains questioned. We evaluated the impact of the addition of contact precautions to standard precautions for Pa-positive patients on incidence of ICU-acquired Pa infections. METHODS: In this multicenter, cluster-randomized crossover trial, 10 French ICUs were randomly assigned (1:1) to sequence 0-1 (6-month control period [CP]/3-month washout period/6-month intervention period [IP]) or sequence 1-0 (6-month IP/3-month washout period/6-month CP). A surveillance screening program for Pa was implemented. Competing-risks regression models were built with death and discharge without the occurrence of ICU-acquired Pa infection (the primary outcome) as competing events. Models were adjusted for within-ICU correlation and patient- and ICU-level covariates. The Simpson diversity index (SDI) and transmission index (TI) of Pa isolates were derived from pulsed-field gel electrophoresis typing. RESULTS: Within recruited ICUs, the cumulative incidence and incidence rate of ICU-acquired Pa infections were 3.38% (55/1625) versus 3.44% (57/1658) and 3.31 versus 3.52 per 1000 patient-days at risk during the CP and IP, respectively. Multivariable models indicated that the intervention did not significantly change the cumulative incidence (subdistribution hazard ratio, .91; 95% confidence interval [CI], .49-1.67; P = .76) or rate (cause-specific hazard ratio, 1.36; 95% CI, .71-2.63; P = .36) of the primary outcome. SDI and TI did not significantly differ between CP and IP. CONCLUSIONS: The addition of contact precautions to standard precautions for Pa-positive patients with a surveillance screening program does not significantly reduce ICU-acquired Pa infections in non-outbreak situations. Clinical Trials Registration. ISRCTN92710225.


Subject(s)
Cross Infection , Pseudomonas Infections , Cross Infection/epidemiology , Cross Infection/prevention & control , Cross-Over Studies , Humans , Incidence , Intensive Care Units , Pseudomonas Infections/epidemiology , Pseudomonas Infections/prevention & control , Pseudomonas aeruginosa
13.
Sci Rep ; 10(1): 3348, 2020 02 25.
Article in English | MEDLINE | ID: mdl-32098989

ABSTRACT

Sea cucumbers lack vision and rely on chemical sensing to reproduce and survive. However, how they recognize and respond to environmental cues remains unknown. Possible candidates are the odorant receptors (ORs), a diverse family of G protein-coupled receptors (GPCRs) involved in olfaction. The present study aimed at characterizing the chemosensory GPCRs in sea cucumbers. At least 246 distinct GPCRs, of which ca. 20% putative ORs, were found in a transcriptome assembly of putative chemosensory (tentacles, oral cavity, calcareous ring, and papillae/tegument) and reproductive (ovary and testis) tissues from Holothuria arguinensis (57 ORs) and in the Apostichopus japonicus genome (79 ORs). The sea cucumber ORs clustered with those of sea urchin and starfish into four main clades of gene expansions sharing a common ancestor and evolving under purifying selection. However, the sea cucumber ORs repertoire was the smallest among the echinoderms and the olfactory receptor signature motif LxxPxYxxxxxLxxxDxxxxxxxxP was better conserved in cluster OR-l1 which also had more members. ORs were expressed in tentacles, oral cavity, calcareous ring, and papillae/tegument, supporting their potential role in chemosensing. This study is the first comprehensive survey of chemosensory GPCRs in sea cucumbers, and provides the molecular basis to understand how they communicate.


Subject(s)
Phylogeny , Receptors, G-Protein-Coupled/genetics , Receptors, Odorant/genetics , Sea Cucumbers/physiology , Animals , Echinodermata/genetics , Echinodermata/physiology , Genome/genetics , Olfactory Receptor Neurons/metabolism , Sea Cucumbers/genetics , Sequence Alignment , Stichopus/genetics , Transcriptome/genetics
14.
Front Med (Lausanne) ; 6: 243, 2019.
Article in English | MEDLINE | ID: mdl-31788475

ABSTRACT

We report a post-facelift infection due to Mycobacterium chelonae. An environmental strain recovered from the water supply network of the surgical clinic and the clinical strains were considered non-differentiable using whole genome sequencing. After the unhealed wound's exposure to M. chelonae while showering early at the clinic after surgery, a lasting exposure of the colonized wound to the warm and moist working conditions of a bakery may have been favorable to the infection's development.

15.
Article in English | MEDLINE | ID: mdl-31192160

ABSTRACT

Group B Streptococcus (GBS) is a major cause of invasive disease in neonates worldwide. Monitoring data have revealed a continuing trend toward an increase in neonatal GBS infections, despite the introduction of preventive measures. We investigated this trend, by performing the first ever characterization of the prophage content for 106 GBS strains causing neonatal infections between 2002 and 2018. We determined whether the genome of each strain harbored prophages, and identified the insertion site of each of the prophages identified. We found that 71.7% of the strains carried at least one prophage, and that prophages genetically similar to livestock-associated phiD12, carrying genes potentially involved in GBS pathogenesis (e.g., genes encoding putative virulence factors and factors involved in biofilm formation, bacterial persistence, or adaptation to challenging environments) predominated. The phiD12-like prophages were (1) associated with CC17 and 1 strains (p = 0.002), (2) more frequent among strains recovered during the 2011-2018 period than among those from 2002-2010 (p < 0.001), and (3) located at two major insertion sites close to bacterial genes involved in host adaptation and colonization. Our data provide evidence for a recent increase in lysogeny in GBS, characterized by the acquisition, within the genome, of genetic features typical of animal-associated mobile genetic elements by GBS strains causing neonatal infection. We suggest that lysogeny and phiD12-like prophage genetic elements may have conferred an advantage on GBS strains for adaptation to or colonization of the maternal vaginal tract, or for pathogenicity, and that these factors are currently playing a key role in the increasing ability of GBS strains to infect neonates.


Subject(s)
Livestock/virology , Prophages/genetics , Streptococcal Infections/microbiology , Streptococcus agalactiae/genetics , Streptococcus agalactiae/virology , Adaptation, Physiological , Animals , Female , Genome, Bacterial , Humans , Infant, Newborn , Lysogeny , Mutagenesis, Insertional , Streptococcus agalactiae/physiology , Virulence/genetics , Virulence/physiology , Virulence Factors/genetics , Virulence Factors/physiology
16.
Front Microbiol ; 10: 742, 2019.
Article in English | MEDLINE | ID: mdl-31105650

ABSTRACT

Until 2007, Staphylococcus aureus from clonal complex 398 (CC398) was exclusively associated with livestock species and companion animals. Recently, several studies described the emergence of S. aureus CC398 as etiologies of severe infections in humans living in an animal-free environment. Recent sequencing efforts showed that the mobile genetic elements found in CC398 isolates were specific for each population and enabled differentiation of strains responsible for asymptomatic colonization from strains involved in bloodstream infections. We mobilized prophages from a human CC398 isolate and introduced them into two naïve ancestral isolates devoid of prophages that exclusively colonize animals. These lysogenized ancestral CC398 isolates acquired features related to virulence, such as an increased capacity to adhere to human extracellular matrix proteins and the ability to invade and survive within non-phagocytic cells. Pathogenicity of several clinical isolates from the CC398 lineage as well as ancestral and in vitro lysogenized ancestral counterparts was assessed in a model of infectious endocarditis in rats. Natural and artificial lysogens were not only more invasive than their prophage-free parent but also showed an increased capacity to multiply within aortic vegetations. This study identified prophages as mediators of bacterial virulence in a model of infectious endocarditis, probably through promotion of interaction with extracellular matrix components. Further studies are needed to identify mechanisms leading to promotion of intrinsic virulence.

17.
Eur J Clin Microbiol Infect Dis ; 38(5): 921-926, 2019 May.
Article in English | MEDLINE | ID: mdl-30826996

ABSTRACT

Although Pseudomonas aeruginosa has a non-clonal epidemic population structure, recent studies have provided evidence of the existence of epidemic high-risk clones. The aim of this study was to assess the molecular epidemiology of P. aeruginosa isolates responsible for infections in French ICUs, regardless of resistance patterns. For a 1-year period, all non-duplicate P. aeruginosa isolated from bacteremia and pulmonary infections in ten adult ICUs of six French university hospitals were characterized by antimicrobial susceptibility testing and genotyping (MLST and PFGE). We identified ß-lactamases with an extended spectrum phenotypically and by sequencing. The 104 isolates tested were distributed in 46 STs, of which 7 epidemic high-risk (EHR) clones over-represented: ST111, ST175, ST235, ST244, ST253, ST308, and ST395. Multidrug-resistant (MDR) isolates mostly clustered in these EHR clones, which frequently spread within hospitals. Only one ST233 isolate produced the carbapenemase VIM-2. PFGE analysis suggests frequent intra-hospital cross-transmission involving EHR clones. For ST395 and ST308, we also observed the progression from wild-type to MDR resistance pattern within the same PFGE pattern. Molecular epidemiology of P. aeruginosa in French ICUs is characterized by high clonal diversity notably among antimicrobial susceptible isolates and the over-representation of EHR clones, particularly within MDR isolates, even though multidrug resistance is not a constant inherent trait of EHR clones.


Subject(s)
Intensive Care Units/statistics & numerical data , Molecular Epidemiology , Pseudomonas Infections/epidemiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/isolation & purification , Anti-Bacterial Agents , Bacteremia/epidemiology , Bacteremia/microbiology , Cross Infection/epidemiology , Cross Infection/microbiology , DNA, Bacterial/genetics , Drug Resistance, Multiple, Bacterial , Electrophoresis, Gel, Pulsed-Field , France/epidemiology , Genotype , Hospitals, University , Humans , Microbial Sensitivity Tests , Multilocus Sequence Typing , Pneumonia, Bacterial/epidemiology , Pneumonia, Bacterial/microbiology , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/drug effects , Sequence Analysis, DNA , beta-Lactamases/genetics
18.
Sci Rep ; 8(1): 239, 2018 01 10.
Article in English | MEDLINE | ID: mdl-29321586

ABSTRACT

The importance of chemical communication in reproduction has been demonstrated in many marine broadcast spawners. However, little is known about the use of chemical communication by echinoderms, the nature of the compounds involved and their mechanism(s) of action. Here, the hypothesis that the sea cucumber Holothuria arguinensis uses chemical communication for aggregation and spawning was tested. Water conditioned by males, but not females, attracted both males and females; gonad homogenates and coelomic fluid had no effect on attraction. Male spawning water, but not female spawning water, stimulated males and females to release their gametes; the spermatozoa alone did not induce spawning. H. arguinensis male spawning water also induced spawning in the phylogenetically related H. mammata. This indicates that males release pheromones together with their gametes that induce spawning in conspecifics and possibly sympatric species. Finally, the male pheromone seems to be a mixture with at least one labile compound (biological activity is lost after four hours at ambient temperature) possibly including phosphatidylcholines. The identification of pheromones in sea cucumbers offers a new ecological perspective and may have practical applications for their aquaculture.


Subject(s)
Behavior, Animal , Biomarkers , Sea Cucumbers/physiology , Animals , Chromatography, Liquid , Female , Gonads/metabolism , Male , Mass Spectrometry , Maze Learning
19.
Front Microbiol ; 8: 1858, 2017.
Article in English | MEDLINE | ID: mdl-29033915

ABSTRACT

We compared the performance of incontinence product (IP) and rectal swabbing for the detection of multidrug-resistant Enterobacteriaceae (MDRE) carriage in a large multicenter study conducted in February 2017 among the residents of 23 French nursing homes. The study included 547 residents who habitually wore IP, 88 of whom were MDRE carriers (16.1%). Positive results were obtained for both rectal and IP swabs for 64 of these residents, for rectal swabs only for 22 and for IP swabs only for two of these patients. The estimated prevalence of MDRE carriage depended on the type of sample: 15.7% for rectal swabs and 12.1% for IP swabs (p < 0.001). The positive percent agreement was 84.2% and the negative percent agreement was 97.4%. Rectal swabbing remains the best method for detecting MDRE carriage in elderly residents, but our findings provide support for the use of swabs from IP used overnight to increase response rates in MDRE surveys in elderly residents that habitually wear IP, when rectal swabbing is not feasible.

20.
BMC Genomics ; 18(1): 133, 2017 02 06.
Article in English | MEDLINE | ID: mdl-28166723

ABSTRACT

BACKGROUND: It has been suggested that prophages in the ST398 S. aureus clone are responsible for expanding ST398's spectrum of action and increasing its ability to cause human infections. We carried out the first characterization of the various prophages carried by 76 ST398 bloodstream infection (BSI) isolates obtained over 9 years of observation. RESULTS: Whole-genome sequencing of 22 representative isolates showed (1) the presence of the φ3-prophage and diverse genetic features typical of animal-associated isolates (i.e., SCCmec XI element, Tn916 transposon and non φ3-prophages) in a majority of BSI isolates, (2) one BSI isolate devoid of the φ3-prophage but otherwise similar to an animal-infecting isolate, (3) 35 prophages carrying numerous genes previously associated with virulence or immune evasion in animal models of staphylococcal infections. The analysis of prophage content in all 76 BSI isolates showed an increasing prevalence of polylysogeny over time. Overall, over the course of the last 10 years, the BSI isolates appear to have acquired increasing numbers of genetic features previously shown to contribute to bacterial adaptation and virulence in animal models of staphylococcal infections. CONCLUSIONS: We hypothesize that lysogeny has played a significant role in increasing the ability of the ST398 clone to cause infections in humans. Our findings highlight the risk that the ST398 lineage will increase its threat to public health by continuing to acquire virulence and/or multiple antibiotic-resistance genes from hospital-associated clones of Staphylococcus aureus.


Subject(s)
Adaptation, Physiological , Prophages/physiology , Staphylococcus aureus/physiology , Staphylococcus aureus/virology , Animals , Evolution, Molecular , Humans , Phylogeny , Polymorphism, Single Nucleotide , Staphylococcal Infections/blood , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Whole Genome Sequencing
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