Apport de la PCR en temps réel pour le diagnostic précoce de faibles colonisations à P. aeruginosa chez les enfants atteints de mucoviscidose

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Using SNOMED-CT to Help the Transition from Microbiological Data to ICD-10 Sepsis Codes.

International audienceAssigning ICD-10 code of sepsis in regard of a pathogenic bacterium found in an haemoculture requires knowledge of microbiology because of the difference of granularity. The aim of this paper is to automate this coding thanks to the use of SNOMED-CT. A dichotomous classification of bacteria causing sepsis has been generated in respect of ICD-10. Our algorithm follows this and explores SNOMED-CT to assign the right ICD-10 code of the sepsis. Applied to a list of 164 bacteria, the system has an error rate of 1.22 %

Use of Whole-Genome Sequencing to Explore Mycobacterium tuberculosis Complex Circulating in a Hotspot Department in France

The Seine-Saint-Denis is the French metropolitan department with the highest incidence of tuberculosis (TB). Our aim was to explore epidemiological and phylogenetic characteristics of TB strains in this hotspot department. We performed WGS on 227 strains of Mycobacterium tuberculosis complex isolated from patients at the Avicenne Hospital from 2016 to 2021 and randomly selected to represent the clinical diversity of French TB localization. Clinical and demographic data were recorded for each TB patient. The mean age of patients was 36 years old. They came from Africa (44%), Asia (27%), Europe (26%) and America (3%). Strains isolated from extrapulmonary samples were associated with Asian patients, whereas strains isolated from pulmonary samples were associated with European patients. We observed a high level of lineage diversity in line with the known worldwide diversity. Interestingly, lineage 3 was associated with lymph node TB. Additionally, the sensitivity of WGS for predicting resistance was 100% for rifampicin, isoniazid and ethambutol and 66.7% for pyrazinamide. The global concordance with drug-susceptibility testing using the phenotypic approach was 97%. In microbiology laboratories, WGS turns out to be an essential tool for better understanding local TB epidemiology, with direct access to circulating lineage identification and to drug susceptibilities to first- and second-line anti-TB drugs

Specialization of small non-conjugative plasmids in Escherichia coli according to their family types

International audienceWe undertook a comprehensive comparative analysis of a collection of 30 small (<25 kb) non-conjugative Escherichia coli plasmids previously classified by the gene sharing approach into 10 families, as well as plasmids found in the National Center for Biotechnology Information (NCBI) nucleotide database sharing similar genomic sequences. In total, 302 mobilizable (belonging to 2 MOB rep and 5 MOB RNA families) and 106 non-transferable/relaxase-negative (belonging to three ReL RNA families) plasmids were explored. The most striking feature was the specialization of the plasmid family types that was not related to their transmission mode and replication system. We observed a range of host strain specificity, from narrow E. coli host specificity to broad host range specificity, including a wide spectrum of Enterobacteriaceae. We found a wide variety of toxin/antitoxin systems and colicin operons in the plasmids, whose numbers and types varied according to the plasmid family type. The plasmids carried genes conferring resistance spanning almost all of the antibiotic classes, from those to which resistance developed early, such as sulphonamides, to those for which resistance has only developed recently, such as colistin. However, the prevalence of the resistance genes varied greatly according to the family type, ranging from 0 to 100 %. The evolutionary history of the plasmids based on the family type core genes showed variability within family nucleotide divergences in the range of E. coli chromosomal housekeeping genes, indicating long-term co-evolution between plasmids and host strains. In rare cases, a low evolutionary divergence suggested the massive spread of an epidemic plasmid. Overall, the importance of these small non-conjugative plasmids in bacterial adaptation varied greatly according to the type of family they belonged to, with each plasmid family having specific hosts and genetic traits

Complete Nucleotide Sequence of Plasmid pTN48, Encoding the CTX-M-14 Extended-Spectrum β-Lactamase from an Escherichia coli O102-ST405 Strain▿

The sequence of pTN48, a plasmid of the FII-FIB replicon type that encodes a CTX-M-14 enzyme in an Escherichia coli strain of the phylogenetic group D2 O102-ST405 clone, was determined. pTN48 is, for the most part, a mosaic of virulence, antibiotic resistance, and addiction system modules found in various other plasmids. The presence of multiple addiction systems indicates that the plasmid should be stably maintained in the E. coli clone, favoring dissemination of the CTX-M-14 enzyme

Molecular Detection of Isoniazid Monoresistance Improves Tuberculosis Treatment: A Retrospective Cohort in France.

International audienceOBJECTIVES: Isoniazid-monoresistant tuberculosis (HR-TB) requires early diagnosis and adapted treatment to achieve optimal outcomes. The primary aim of the study was to assess the impact of the implementation of rapid diagnostic tests on HR-TB treatment in France. METHODS: We designed a retrospective multicentre study including consecutive HR-TB patients diagnosed in 2016 and 2017. Implementation of a molecular assay detecting isoniazid resistance directly on a clinical sample was recorded. The association between early implementation of such assays and adequate treatment was assessed by a multivariable Cox proportional hazards model. RESULTS: Overall, 99 HR-TB patients were included from 20 University Hospitals. Among all smear-positive HR-TB patients, only 26% beneficiated from early molecular HR detection. This detection was independently associated with shorter time to adequate treatment (HR~=~2.0 [1.1-3.8], p~=~0.03). CONCLUSION: In our study, molecular detection of HR on an initial sample was independently associated with earlier treatment adaptation

Isoniazid-monoresistant tuberculosis in France: risk factors, treatment outcomes and adverse events

International audienceObjectives: Isoniazid-monoresistant tuberculosis (HR-TB) is the most prevalent form of drug-resistant TB worldwide and in France and is associated with poorer treatment outcomes compared to drug-susceptible TB (DS-TB). The objective of this study was to determine the characteristics of HR-TB patients in France and to compare outcomes and safety of treatment for HR-TB and DS-TB.Methods: A case-control multicentre study was performed to identify risk factors associated with HR-TB and to compare treatment outcomes and safety among HR-TB patients and DS-TB patients.Results: Characteristics of 99 HR-TB diagnosed and treated in university hospitals of Paris, Lille, Caen and Strasbourg were compared to 99 DS-TB's. Female sex (OR = 2.2; 1.0-4.7), birth in the West-Pacific WHO region (OR = 4.6; 1.1-18.7) and resistance to streptomycin (OR = 77.5; 10.1-594.4) were found to be independently associated with HR-TB. Rates of treatment success did not differ significantly between HR-TB and DS-TB.Conclusions: Factors associated with HR-TB are not relevant enough to efficiently screen TB patients at risk of HR-TB. The systematic implementation of rapid molecular testing on clinical samples remains the only effective way to make the early diagnosis of HR-TB and adapt the treatment

Characterization of a P1-Like Bacteriophage Carrying an SHV-2 Extended-Spectrum β-Lactamase from an Escherichia coli Strain

P1 bacteriophages lysogenize bacteria as independent plasmid-like elements. We describe here a P1-like bacteriophage, RCS47, carrying a bla(SHV-2) gene, isolated from a clinical strain of Escherichia coli from phylogroup B1, and we report the prevalence of P1-like prophages in natural E. coli isolates. We found that 70% of the sequence of RCS47, a 115-kb circular molecule, was common to the reference P1 bacteriophage under GenBank accession no. AF234172.1, with the shared sequences being 99% identical. RCS47 had acquired two main foreign DNA fragments: a 9,636-bp fragment mobilized by two IS26 elements containing a bla(SHV-2) gene, and an 8,544-bp fragment mobilized by two IS5 elements containing an operon encoding a dimethyl sulfoxide reductase. The reference P1 prophage plasmid replication gene belonged to the IncY incompatibility group, whereas that of RCS47 was from an unknown group. The lytic capacity of RCS47 and bla(SHV-2) gene transduction, through the lysogenization of RCS47 in the recipient E. coli strains, were not demonstrated. The prevalence of P1-like prophages in various animal and human E. coli strain collections, as determined by the PCR detection of repL, the lytic replication gene, was 12.6%. No differences in the prevalences of these prophages were found between extended-spectrum β-lactamase (ESBL)-producing and non-ESBL-producing strains (P = 0.69), but this prevalence was lower in phylogroup B2 than in the other phylogroups (P = 0.008), suggesting epistatic interactions between P1 family phages and the genetic background of E. coli strains. P1-like phages are part of the mobile elements that carry antibiotic resistance. The high prevalence of P1-like prophages suggests their role may be underestimated

Extended-spectrum b-lactamase-encoding genes are spreading on a wide range of Escherichia coli plasmids existing prior to the use of third-generation cephalosporins

All supporting data, code and protocols have been provided within the article or through supplementary data files. Three supplementary tables are available with the online version of this article.International audienceTo understand the evolutionary dynamics of extended-spectrum b-lactamase (ESBL)-encoding genes in Escherichia coli, we undertook a comparative genomic analysis of 116 whole plasmid sequences of human or animal origin isolated over a period spanning before and after the use of third-generation cephalosporins (3GCs) using a gene-sharing network approach. The plasmids included 82 conjugative, 22 mobilizable and 9 non-transferable plasmids and 3 P-like bacteriophages. ESBL-encoding genes were found on 64 conjugative, 6 mobilizable, 2 non-transferable plasmids and 2 P1-like bacteriophages, indicating that these last three types of mobile elements also play a role, albeit modest, in the diffusion of the ESBLs. The network analysis showed that the plasmids clustered according to their genome backbone type, but not by origin or period of isolation or by antibiotic-resistance type, including type of ESBL-encoding gene. There was no association between the type of plasmid and the phylogenetic history of the parental strains. Finer scale analysis of the more abundant clusters IncF and IncI1 showed that ESBL-encoding plasmids and plasmids isolated before the use of 3GCs had the same diversity and phylogenetic history, and that acquisition of ESBL-encoding genes had occurred during multiple independent events. Moreover, the bla CTX-M-15 gene, unlike other CTX-M genes, was inserted at a hot spot in a bla TEM-1-Tn2 transposon. These findings showed that ESBL-encoding genes have arrived on wide range of pre-existing plasmids and that the successful spread of bla CTX-M-15 seems to be favoured by the presence of well-adapted IncF plasmids that carry a Tn2-bla TEM-1 transposon