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Droplet Digital PCR and PCR-free BIOSensors for the Detection of Resistance-associated SNPs in Pneumocystis Jirovecii

Active, not recruiting
Conditions
Pneumocystis Pneumonia
Registration Number
NCT06431958
Lead Sponsor
University Hospital, Brest
Brief Summary

The main objective of the proposed research is to identify Pneumocystis jirovecii mutant strains on 4 genes encoding therapeutic targets such as dihydropteroate synthase (DHPS), dihydrofolate reductase (DHFR), cytochrome b (CYB), inosine-5'-monophosphate dehydrogenase (IMPDH) and therefore to assess the prevalence of potentially resistant strains in patients infected with P. jirovecii.

Detailed Description

Pneumocystis jirovecii (P. jirovecii) is an opportunistic pathogenic fungus responsible for pulmonary infection or Pneumocystis pneumonia (PCP) in immunocompromised patients. There is currently no system for its in vitro culture. The diagnostic methods used are mainly based on molecular biology techniques which also allow the detection and analysis of single nucleotide polymorphisms (SNPs), particularly at the level of genes coding for the targets of molecules widely used in the prevention and treatment of PCP. These SNPs may represent missense mutations potentially associated with treatment resistance. They may result from exposure of patients to these treatments before the development of P. jirovecii infection. However, data concerning the prevalence of these mutations remains scarce, particularly in France. Methods for detecting these mutations based on PCR followed by DNA sequencing have limitations in terms of sensitivity. The evaluation of new, more sensitive and rapid tools for the detection and characterization of pathogens in this context is necessary.

The main objective of the proposed research is to identify P. jirovecii mutant strains on 4 genes encoding therapeutic targets such as dihydropteroate synthase (DHPS), dihydrofolate reductase (DHFR), cytochrome b (CYB), inosine-5'-monophosphate dehydrogenase (IMPDH) and therefore to assess the prevalence of potentially resistant strains in patients infected with P. jirovecii.

The secondary objectives are:

* to determine the factors associated (e.g. exposure to treatments) with mutant P. jirovecii strains

* to determine the impact of mutations on the effectiveness of anti-Pneumocystis treatment (e.g. favorable vs. unfavorable evolution of the infection)

* to evaluate two methods - digital droplet PCR and biosensors without PCR - for the detection and characterization of mutations associated with resistance in Pneumocystis jirovecii

Recruitment & Eligibility

Status
ACTIVE_NOT_RECRUITING
Sex
All
Target Recruitment
300
Inclusion Criteria
  • Patients in whom P. jirovecii was detected in a pulmonary sample (bronchoalveolar lavage, sputum, bronchial aspiration, oropharyngeal rinse, nasopharyngeal sample)
  • No opposition
  • Patient affiliated to a social security system
Exclusion Criteria
  • Patients under legal protection (guardianship, curatorship)
  • Refusal to participate

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Presence of specific strains of Pneumocystis jirovecii potentially resistant to treatments in patients infected with this fungusat inclusion

Four genes encoding therapeutic targets such as dihydropteroate synthase (DHPS), dihydrofolate reductase (DHFR), cytochrome b (CYB), inosine-5'-monophosphate dehydrogenase (IMPDH) will be amplified and sequenced to detect single nucleotide polymorphisms (Single Nucleotide Polymorphism, SNP), in particular those potentially linked to resistance to anti-Pneumocystis treatments.

Secondary Outcome Measures
NameTimeMethod
to determine the factors associated (e.g. exposure to treatments) with P. jirovecii mutant strainsat inclusion

Trial Locations

Locations (1)

Chu Brest

🇫🇷

Brest, France

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