Genomic and Phenotypic Diversity of Carbapenemase-producing Escherichia Coli Strains Circulating in Southern France

NCT07676513 — Not yet recruiting, 163 participants, Centre Hospitalier Universitaire de Nīmes

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Genomic and Phenotypic Diversity of Carbapenemase-producing Escherichia Coli Strains Circulating in Southern France. The "CARBA-COLI" Study

RegistryNCT07676513, acronym CARBACOLI
StatusNot yet recruiting
Study typeObservational
Enrollment163 (Estimated)
SponsorCentre Hospitalier Universitaire de Nīmes (Other)
ConditionsAntibiotic Resistance, Enterobacteriaceae Infections, Carbapenem-Resistant Enterobacteriaceae Infection, Colonization
InterventionsMultiLocus Sequence Typing (Genetic)
Datesstart 2026-08-01 (estimated), primary completion 2027-10-01 (estimated), completion 2028-08-01 (estimated), first posted 2026-06-30, last updated 2026-07-08
Locations1 site in France

Related Papers Related Patents Related Grants Related Experts
All trials for Antibiotic Resistance All trials for Enterobacteriaceae Infections All trials of MultiLocus Sequence Typing

-Summary

Carbapenemase-producing Enterobacteriaceae (CPE) are classified as emerging Highly Resistant Bacteria (eHRB) because they expose infected patients to the risk of treatment failure due to the strains' resistance to last-line β-lactams, carbapenems, and frequent co-resistance to other classes of antibiotics, leading to increased morbidity and mortality. Their high epidemiogenic potential has enabled their global spread. In France, the incidence of Carbapenemase-producing Enterobacteriaceae is rising sharply, both in colonization and in infections. Parallel to this increase, Escherichia coli has become the most common Carbapenemase-producing Enterobacteriaceae (35% of strains in 2024, National Research Committee data), surpassing Klebsiella pneumoniae (24%).

The investigators hypothesize that the increase in the prevalence of carbapenemase-producing Echerichia coli is associated with a diversification of clones, enzymes, and their variants, and may pose a threefold threat: i) the spread of genes encoding carbapenemases within pathogenic extraintestinal Echerichia coli (ExPEC) pathogroups responsible for urinary tract infections and bacteremias, with a high risk of resistance spreading in the community, ii) the silent spread of Echerichia coli strains producing OXA-48 variants with reduced carbapenem hydrolytic activity, OXA-244 and OXA-484, which are not detected or poorly detected by conventionally used screening media and iii) the emergence of New Dehli Metallo-beta-lactamase (NDM) variants with high hydrolytic activity, such as NDM-5, within Echerichia coli clones possessing Penicillin-Binding Proteins (PLPs) with low affinity for antibiotics, leading to very high-level resistance and a therapeutic dead end in infected patients.

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+Detailed description

Predicted to become the leading cause of death worldwide by 2050, antibiotic resistance poses a major global challenge. In France, the "2022-2025 National Strategy" led by the Ministry of Solidarity and Health combines the promotion of appropriate antibiotic use with preventive measures to control infections involving multi- and highly resistant bacteria, both in the community and in healthcare facilities.

Carbapenemase-producing Enterobacteriaceae (CPE) are classified as emerging Highly Resistant Bacteria (eHRB) because they expose infected patients to the risk of treatment failure due to the strains' resistance to last-line β-lactams, carbapenems, and frequent co-resistance to other classes of antibiotics, leading to increased morbidity and mortality. Their high epidemiogenic potential has enabled their global spread. In France, the incidence of Carbapenemase-producing Enterobacteriaceae is rising sharply, both in colonization and in infections. Parallel to this increase, Escherichia coli has become the most common Carbapenemase-producing Enterobacteriaceae species (35% of strains in 2024 National Research Committee data), surpassing Klebsiella pneumoniae (24%).

In 2011, the Microbiology and Hospital Hygiene Laboratory at Nîmes University Hospital was designated an expert center for emerging Highly Resistant Bacteria, and then, in 2021, a Reference Medical Biology Laboratory for emerging Highly Resistant Bacteria. Between 2023 and 2024, a total of 479 CPE strains were isolated or sent to the laboratory for analysis, representing a 45% increase compared to the 2021-2022 period. Of these strains, 163 were Echerichia coli (vs. 71 between 2021 and 2022, +130%). Furthermore, the number of carbapenemase-producing Echerichia coli strains from diagnostic samples increased very sharply (+231%) during the 2023-2024 period (n=86), compared to 2021-2022 (n=26). These samples came from hospital laboratories and private clinics, as well as community laboratories. The potential for community spread of highly antibiotic-resistant and virulent strains raises concerns about an epidemic outbreak following the same pattern as that of CTX-M extended-spectrum beta-lactamase (ESBL)-producing Echerichia coli in the 2000s. Screening for CPE colonization and adherence to strict additional hygiene precautions in cases of carriage are the means of combating cross-transmission of these strains in healthcare facilities. These preventive measures are not applicable in the community setting.

The investigators hypothesize that the increase in the prevalence of carbapenemase-producing Echerichia coli is associated with a diversification of clones, enzymes, and their variants, and may pose a threefold threat: i) the spread of genes encoding carbapenemases within pathogenic extraintestinal Echerichia coli (ExPEC) pathogroups responsible for urinary tract infections and bacteremias, with a high risk of resistance spreading in the community, ii) the silent spread of Echerichia coli strains producing OXA-48 variants with reduced carbapenem hydrolytic activity, OXA-244 and OXA-484, which are not detected or poorly detected by conventionally used screening media and iii) the emergence of New Dehli Metallo-beta-lactamase (NDM) variants with high hydrolytic activity, such as NDM-5, within Echerichia coli clones possessing Penicillin-Binding Proteins (PLPs) with low affinity for antibiotics, leading to very high-level resistance and a therapeutic dead end in infected patients.

+Arms and interventions

  • MultiLocus Sequence Typing (Genetic): Study of the genetic diversity of carbapenemase-producing E. coli strains from the Reference Laboratory for Medical Biology (LBMR) for Emerging Highly Resistant Bacteria (eHRB) via whole-genome sequencing of bacterial genomes and analysis using whole-genome MultiLocus Sequence Typing (wgMLST) to characterize the molecular epidemiology and identify high-risk clones circulating in southern France and assessment of the content of antibiotic resistance genes (resistome), virulence genes (virulome), and plasmids (percentage of presence).

+Outcome measures

Primary outcomes

  • Genetic diversity of carbapenemase-producing E. coli strains from the Reference Laboratory for Medical Biology for Emerging Highly Resistant Bacteria [2 years]: Typing via whole-genome sequencing of bacterial genomes and analysis using whole-genome MultiLocus Sequence Typing (wgMLST) to characterize the molecular epidemiology and identify high-risk clones circulating in southern France
  • Assessment of the content of antibiotic resistance genes (resistome), virulence genes (virulome), and plasmids (percentage of presence). [2 years]: Resistome, virulome and plasmids will be measured as percentages in each strain identified.

Secondary outcomes

  • Antibiotic resistance phenotype: [2 years]: Antibiotic susceptibility testing on Mueller-Hinton agar plates with determination of Minimum Inhibitory Concentrations (MICs) of last-line antibiotics in liquid Mueller-Hinton medium
  • Study of bacterial growth curves for the main identified clones [2 years]: Growth curves will be compared using the Gompertz nonlinear regression model with GraphPad Prism 9.2 software (San Diego, CA, USA).
  • Study of biofilm formation (Bioflux 200TM system) for the main identified clones, [2 years]: The Bioflux 200TM system will be used to study biofilm formation
  • Study of bacterial motility (swimming, swarming) for the main identified clones [2 years]: The motility of the different bacterial strains will be assessed by comparing the average migration diameters for swimming and swarming. The experiments will be conducted independently three times.
  • Performance of eHRB screening media on carbapenemase-producing E. coli strains [2 years]: Performance of the chromID® CARBA-SMART (bioMérieux), the BrillianceTM CRE (Thermo Fisher), and mSuperCARBATM (CHROMagar) will be evaluated and compared following inoculation with a bacterial suspension of various E. coli strains.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Age [2 years]: Age will be recorded in years with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Sex [2 years]: The patient's sex will be recorded as M/F/non-binary with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Department of residence [2 years]: The patient's department of residence will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Medical history [2 years]: The patient's medical history will be examined with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Type of infection [2 years]: The type of infection will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Comorbidities [2 years]: Comorbidities will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Length of hospital stay [2 years]: The length of hospital stay will be recorded in days with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Invasive devices [2 years]: The presence of invasive devices will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Surgery [2 years]: The need for surgery will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Antibiotic exposure [2 years]: Antibiotic exposure will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Repeat hospitalizations [2 years]: Repeat hospitalizations will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Recent travel [2 years]: Recent travel will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Inter-hospital transfers [2 years]: Inter-hospital transfers will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.
  • Risk factors for infections caused by carbapenemase-producing E. coli. : Cross-transmission [2 years]: Cross-transmission (patient contact) between asymptomatic carriers and individuals with an infection will be recorded with the aim of identifying possible risk factors for infections caused by carbapenemase-producing E. coli.

+Eligibility

Sex: All

Inclusion Criteria:

* Not applicable to this study of an existing collection of Carbapenemase-producing Enterobacteriaceae strains.

Exclusion Criteria:

* Not applicable to this study of an existing collection of Carbapenemase-producing Enterobacteriaceae strains.

+Locations (1)

FacilityCityCountryStatus
Nîmes University HospitalNîmes, GardFrance