Escherichia Coli; Diarrhea, Enteroaggregative, Escherichia Coli Infections, Escherichia Coli Pneumonia, Mechanical Ventilation Complication, Nosocomial Pneumonia, Ventilator Associated Pneumonia
Conditions
Keywords
virulence factor genes;, phenotyping, genotyping, antimicrobial susceptibility
Brief summary
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
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.
Interventions
None listed
Sponsors
Hôpital Louis Mourier
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* adult, admitted to the intensive care unit * under invasive mechanical ventilation * presence of Escherichia coli in lower respiratory tract specimen
Exclusion criteria
\-
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| phylogenetic group determination | 50 minutes | 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| O-type determination | 50 minutes | 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 |
| virulence factor (VF) gene content determination | 90 minutes | 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) |
| antimicrobial susceptibility determination | 24 hours | 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 |
| presence of betalactamase | 90 minutes | Detection of gene sequences coding for the CTX-M and TEM enzymes was performed by PCR with genomic DNA |
Other
| Measure | Time frame | Description |
|---|---|---|
| phylogenetic group belonging in other existing Escherichia coli collections | 24 hours | comparison of phylogenetic group belonging of the present isolates to those of two previously published collections, originating from the Paris area, France; one that comprises 280 E. coli strains isolated from the stools of community adult subjects in 2010 (COLIVILLE) and that can be considered as commensal strains and the other that comprises 373 E. coli strains isolated from the blood of 373 patients hospitalized in seven different hospitals, during the course of bacteraemia in 2005 (COLIBAFI study) |
| virulence factor (VF) gene content in E. coli isolates responsible for pneumonia and in those responsible for simple colonization | median time frame is 11.5 days with a maximum of 35 days | comparison of virulence factor (VF) gene content between isolates responsible for pneumonia and those for simple colonization |
| O-type distribution in other existing Escherichia coli collections | 24 hours | comparison of O-type distribution of the present isolates to those of two previously published collections, originating from the Paris area, France; one that comprises 280 E. coli strains isolated from the stools of community adult subjects in 2010 (COLIVILLE) and that can be considered as commensal strains and the other that comprises 373 E. coli strains isolated from the blood of 373 patients hospitalized in seven different hospitals, during the course of bacteraemia in 2005 (COLIBAFI study) |
| virulence factor (VF) gene content in other existing Escherichia coli collections | 24 hours | comparison of virulence factor (VF) gene content of the present isolates to those of two previously published collections, originating from the Paris area, France; one that comprises 280 E. coli strains isolated from the stools of community adult subjects in 2010 (COLIVILLE) and that can be considered as commensal strains and the other that comprises 373 E. coli strains isolated from the blood of 373 patients hospitalized in seven different hospitals, during the course of bacteraemia in 2005 (COLIBAFI study) |
| phylogenetic group belonging in E. coli isolates responsible for pneumonia and in those responsible for simple colonization | median time frame is 11.5 days with a maximum of 35 days | comparison of phylogenetic group belonging between isolates responsible for pneumonia and those for simple colonization |
| O-type distribution in E. coli isolates responsible for pneumonia and in those responsible for simple colonization | median time frame is 11.5 days with a maximum of 35 days | comparison of O-type distribution between isolates responsible for pneumonia and those for simple colonization |
Outcome results
None listed