Eradication of respiratory tract MRSA at a large adult cystic fibrosis centre.

INTRODUCTION: The prevalence of MRSA in patients with CF is increasing. There is no consensus as to the optimum treatment. METHOD: An observational cohort study of all patients with MRSA positive sputum, 2007-2012. All eradication attempts with subsequent culture results were reviewed. Single vs dual antibiotic regimens were compared for both new and chronic infections. RESULTS: 37 patients (median FEV1 58.7 (27.6-111.5)% predicted) were identified, of which 67.6% (n = 25) had newly acquired MRSA. Compared with single regimens, a high proportion of dual regimens achieved MRSA eradication (84.6% vs 50%; p = 0.1) for new infections. Rifampicin/Fusidic acid was associated with high success rates (100% vs 60% for other dual regimens (p = 0.13)). Compared with new infections, chronic MRSA was much less likely to be eradicated (18.2%, p = 0.01). CONCLUSION: Combined antibiotic therapy, particularly Rifampicin/Fusidic acid, is a well-tolerated and effective means of eradicating MRSA in patients with cystic fibrosis.

Service evaluation to establish the sensitivity, specificity and additional value of broad-range 16S rDNA PCR for the diagnosis of infective endocarditis from resected endocardial material in patients from eight UK and Ireland hospitals.

Infective endocarditis (IE) can be diagnosed in the clinical microbiology laboratory by culturing explanted heart valve material. We present a service evaluation that examines the sensitivity and specificity of a broad-range 16S rDNA polymerase chain reaction (PCR) assay for the detection of the causative microbe in culture-proven and culture-negative cases of IE. A clinical case-note review was performed for 151 patients, from eight UK and Ireland hospitals, whose endocardial specimens were referred to the Microbiology Laboratory at Great Ormond Street Hospital (GOSH) for broad-range 16S rDNA PCR over a 12-year period. PCR detects the causative microbe in 35/47 cases of culture-proven IE and provides an aetiological agent in 43/69 cases of culture-negative IE. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the 16S rDNA PCR assay were calculated for this series of selected samples using the clinical diagnosis of IE as the reference standard. The values obtained are as follows: sensitivity = 67 %, specificity = 91 %, PPV = 96 % and NPV = 46 %. A wide range of organisms are detected by PCR, with Streptococcus spp. detected most frequently and a relatively large number of cases of Bartonella spp. and Tropheryma whipplei IE. PCR testing of explanted heart valves is recommended in addition to culture techniques to increase diagnostic yield. The data describing the aetiological agents in a large UK and Ireland series of culture-negative IE will allow future development of the diagnostic algorithm to include real-time PCR assays targeted at specific organisms.

Needle-stick injuries in the National Health Service: a culture of silence.

Injury by contaminated sharp instruments and needles constitutes a major occupational hazard for healthcare workers. In a confidential survey at a district general hospital, 300 healthcare professionals were asked about their personal experience of needle-stick injury and their attitudes to reporting. 279 individuals responded, of whom 38% had experienced at least one needle-stick (mean 1.8) in the past year and 74% had sustained such an injury during their careers (mean 3.0). Although 80% of respondents were aware that such incidents should be notified, only 51% of those affected had reported all needle-stick injuries. Doctors were less likely to report than nurses, despite a higher liability to injury. This survey adds to evidence of a culture of silence pertaining to needle-stick injuries. The consequent risks to health, and the ethical and financial implications, remain uncertain.

Environmental contamination by organisms causing urinary tract infection.

We have examined the bedsheets, floor and bedside chairs of 33 patients with urinary tract infections for organisms causing urinary infection. In ten patients the causative organism was recovered from the undersheet, and in two of these it was also recovered from the floor and bedside chair. Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae and Enterococcus faecalis were recovered from sheets, while Group B beta-haemolytic streptococci and Candida tropicalis were also found on floors and chairs.