Related Experiment Videos
Acquisition of endemic Pseudomonas aeruginosa on an intensive therapy unit
K D Allen1, C A Bartzokas, R Graham
1Department of Medical Microbiology, Royal Liverpool Hospital.
Abstract:
During a 9-month period, patients, staff and environment were monitored in order to trace the source of endemic Pseudomonas aeruginosa on our intensive therapy unit (ITU). Of 81 patients studied, 14 (17%) acquired 15 different pyocin types while on the ITU. The most frequent site of colonization was the rectum (11 patients). Rectal strains subsequently appeared in urine (two patients), wound (one) and sputum (four) of six patients. Three episodes of cross-infection (wound (two), urine (one] occurred without development of rectal colonization. Strains isolated from the environment and staff were not implicated. While gastrointestinal carriage of P. aeruginosa may not be detected on admission to the ITU, excessive use of antibiotics may be responsible for apparent acquisition of the organism followed by endogenous transfer of the rectal strains to other sites of the body.
Insights
Pseudomonas aeruginosa colonization in intensive therapy units (ITUs) often originates from the patient
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Critical Care Medicine
Background:
- Endemic Pseudomonas aeruginosa poses a significant threat in intensive therapy units (ITUs).
- Understanding the transmission dynamics is crucial for infection control.
Purpose of the Study:
- To investigate the source and transmission of endemic Pseudomonas aeruginosa within an ITU.
- To identify common colonization sites and potential cross-infection pathways.
Main Methods:
- A 9-month prospective study monitoring patients, staff, and the environment.
- Isolation and characterization of Pseudomonas aeruginosa strains using pyocin typing.
- Tracking patient colonization sites, including rectum, urine, wound, and sputum.
Main Results:
- 17% of patients acquired Pseudomonas aeruginosa during their ITU stay.
- The rectum was the most frequent colonization site (11 patients).
- Endogenous transfer from the rectum to other sites (urine, wound, sputum) was observed in six patients; three cross-infections occurred without rectal colonization.
Conclusions:
- Environmental and staff contamination were not implicated as sources.
- Gastrointestinal carriage may not be apparent on admission.
- Excessive antibiotic use may promote P. aeruginosa acquisition and endogenous transfer.