Identification of airborne dissemination of epidemic multiresistant strains of Pseudomonas aeruginosa at a CF centre during a cross infection outbreak

BACKGROUND

Chronic Pseudomonas aeruginosa infection is a major cause of morbidity and mortality for individuals with cystic fibrosis (CF). P aeruginosa cross infection outbreaks have recently been reported at CF holiday camps and specialist centres. The mechanism of cross infection is unknown. A study was performed to look for the presence of epidemic strains of P aeruginosa in the environment of a CF centre during a cross infection outbreak and to examine their potential modes of spread between patients.

METHODS

Microbiological sampling of the environment of the CF facility was performed, including room air sampling. Individual P aeruginosa strains were identified by bacterial fingerprinting. The typing patterns were compared with those of epidemic strains responsible for cross infection among the patients.

RESULTS

Epidemic P aeruginosa strains were isolated from room air when patients performed spirometric tests, nebulisation, and airway clearance, but were not present in other areas of the inanimate environment of the CF centre.

CONCLUSIONS

Aerosol dissemination may be the most important factor in patient-to-patient spread of epidemic strains of P aeruginosa during recent cross infection outbreaks at adult CF centres.

Spread of a multiresistant strain of Pseudomonas aeruginosa in an adult cystic fibrosis clinic

We initiated a prospective surveillance study to investigate possible Pseudomonas aeruginosa cross-infection in our cystic fibrosis centre. We characterised isolates by pyocin typing and pulsed-field gel electrophoresis. 22 (14%) of 154 patients with chronic P aeruginosa had isolates with similar and new pyocin and pulsed-field gel electrophoresis types. The shared isolates showed unusual phenotypic features: they were non-pigmented, non-motile, and resistant to a number of antipseudomonal antibiotics. Cross-infection by a multiresistant P aeruginosa strain has therefore occurred in patients attending our cystic fibrosis centre. We recommend microbiological surveillance in other cystic fibrosis centres.

Burkholderia gladioli: recurrent abscesses in a patient with cystic fibrosis

We describe a case of an adult patient with cystic fibrosis who developed chronic pulmonary infection and multiple episodes of soft tissue abscesses with Burkholderia gladioli; this organism should be added to the list of potential pathogens for individuals with cystic fibrosis.

Electron microscopy and serological features of a patient with Q fever prosthetic valve endocarditis

The clinical, serological and electron microscopic findings in a 47 year old woman with bioprosthetic valve coxiella endocarditis occurring 15 years after streptococcal endocarditis are described. The patient underwent valvular surgery a total of four times to control symptoms and remains well on medical therapy more than two years after her last operation.