Characteristics of Lower Respiratory Tract Escherichia Coli Isolates in Mechanically Ventilated Intensive Care Patients

Study Overview
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Brief Summary
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Prospective, multicenter observational study to collect Escherichia coli (E. coli) isolates originating from mechanically ventilated intensive care unit (ICU) patients; in order to characterize phenotype and genotype of E. coli strains retrieved from the lower respiratory tract of ventilated patients.

Detailed Description
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Prospective, observational, multiple center study performed in 14 ICUs in France to collect Escherichia coli (E. coli) isolates originating from mechanically ventilated intensive care unit (ICU) patients; in order to characterize phenotype and genotype of E. coli strains retrieved from the lower respiratory tract of ventilated patients. All E. coli isolates identified in the microbiology lab and retrieved from a lung specimen (either tracheal aspirate, bronchoalveolar lavage, or telescopic plugged catheter) originating from an ICU patient will be kept, and stored at -80°C in brain-heart infusion broth containing glycerol 20 %. They will be then centralized in the investigators' research unit for further analysis that includes determination of Antimicrobial susceptibility, E. coli phylotype , O-type, and virulence factor gene content. These isolates will be compared to those of two previously published collections, one from the stools of community subjects, considered as commensal strains, the other from the blood of bacteraemia patients.

Official Title
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Characteristics of Lower Respiratory Tract Escherichia Coli Isolates Colonizing and Infecting Mechanically Ventilated Intensive Care Patients: a French Multicenter Prospective Collection

Conditions
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Nosocomial Pneumonia, Ventilator Associated Pneumonia, Escherichia Coli Infections, Escherichia Coli Pneumonia, Escherichia Coli; Diarrhea, Enteroaggregative, Mechanical Ventilation Complication

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult, admitted to the intensive care unit under invasive mechanical ventilation presence of Escherichia coli in lower respiratory tract specimen Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| phylogenetic group determination | Quadruplex polymerase chain reaction (PCR) method was used to determine the E. coli phylogenetic group (A, B1, B2, C, D, E, F), or Escherichia clade I belonging | 50 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| O-type determination | polymerase chain reaction (PCR) method was used to search for the most anticipated serotypes in extra-intestinal infections : O1, O2a, O2b, O4, O6, O7, O12, O15, O16, O17, O18, O22, O25a, O25b, O45a, O75, O78 | 50 minutes | 
| virulence factor (VF) gene content determination | Multiplex PCR was used to detect genes encoding for eleven frequently encountered extraintestinal VFs (S and F fimbriae (sfa/foc), pili associated with pyelonephritis (papC), P adhesin (papGII, papGIII), the ferric yersiniabactin uptake receptor (fyuA), iron transport (iroN), aerobactin (aer), conjugal transfer protein (traT), N-acetylglucosamine 2-epimerase protein (neuC), hemolysin (hlyC), and the cytotoxic necrotizing factor 1(cnf1) | 90 minutes | 
| antimicrobial susceptibility determination | Antimicrobial susceptibility of each isolate was determined by disk-diffusion method according to the French Society of Microbiology. Resistance score was defined as the sum of inactive in vitro antimicrobial agents for each isolate | 24 hours | 
| presence of betalactamase | Detection of gene sequences coding for the CTX-M and TEM enzymes was performed by PCR with genomic DNA | 90 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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virulence factor genes;, phenotyping, genotyping, antimicrobial susceptibility