Impact of infection control interventions on rates of Staphylococcus aureus bacteraemia in National Health Service acute hospitals, East Midlands, UK, using interrupted time-series analysis.

BACKGROUND: Reducing healthcare-associated infection (HCAI) is a UK national priority. Multiple national and regional interventions aimed at reduction have been implemented in National Health Service acute hospitals, but assessment of their effectiveness is methodologically challenging. AIM: To assess the effectiveness of national and regional interventions undertaken between 2004 and 2008 on rates of meticillin-resistant Staphylococcus aureus (MRSA) and meticillin-sensitive Staphylococcus aureus (MSSA) bacteraemia within acute hospitals in the East Midlands, using interrupted time-series analysis. METHODS: We used segmented regression to compare rates of MRSA and MSSA bacteraemia in the pre-intervention, implementation, and post-intervention phases for combined intervention packages in eight acute hospitals. FINDINGS: Most of the change in MSSA and MRSA rates occurred during the implementation phase. During this phase, there were significant downward trends in MRSA rates for seven of eight acute hospital groups; in four, this was a steeper quarter-on-quarter decline compared with the pre-intervention phase, and, in one, an upward trend in the pre-intervention phase was reversed. Regarding MSSA, there was a significant positive effect in four hospital groups: one upward trend during the pre-intervention phase was reversed, two upward trends plateaued, and in one hospital group an indeterminate trend decreased significantly. However, there were significant increasing trends in quarterly MSSA rates in four hospital groups during the implementation or post-intervention periods. CONCLUSION: The impact of interventions varied by hospital group but the overall results suggest that national and regional campaigns had a beneficial impact on MRSA and MSSA bacteraemia within the East Midlands.

The effect of PUVA therapy on glycoprotein biosynthesis in uninvolved psoriatic epidermis.

Protein and N-linked glycoprotein biosynthesis was studied in the uninvolved epidermis of patients with psoriasis by the incorporation of radiolabelled leucine and mannose prior to and during PUVA treatment. Analysis of the polyacrylamide gel electrophoresis (PAGE) patterns of the 3[H]-labelled proteins and glycoproteins showed that the major changes in untreated uninvolved psoriatic epidermis compared to normal epidermis were: (a) a shift towards the synthesis of low-molecular-weight glycoproteins; (b) the absence of a 48-kDa peak labelled with mannose; (c) the appearance of 3[H]-mannose-labelled peaks at 40-36 kDa. PUVA treatment gradually changed the PAGE profile back more towards that expected for normal epidermis, with the reintroduction of a 52-48-kDa glycoprotein and reduction of the peaks in the 40-34-kDa region. This effect was dependent on uninterrupted treatment. The PUVA-treated PAGE profiles were compared to those expected in skin tumours (i.e. increased 3[H]-mannose-labelled peaks at 95 and 40-34 kDa with an absence of 62-kDa peaks). It appeared that these criteria were not seen generally as a result of PUVA treatment. However, the results indicate that tumour development may be possible if a patient responds to PUVA treatment by showing an increased peak at 95 and 40-34 kDa in association with a loss of an 3[H]-mannose-labelled peak at 62 kDa.

A comparison of glycoprotein biosynthesis in benign and malignant squamous epithelioma and normal epidermis.

Protein and N-linked glycoprotein biosynthesis was studied in histologically verified normal epidermis, actinic keratoses, keratoacanthoma, intra-epidermal carcinoma and squamous-cell carcinoma using polyacrylamide gel electrophoresis (PAGE). The PAGE profiles of 3[H]-leucine-labelled proteins and 3[H]-mannose-labelled glycoprotein from all disease states studied differed from each other and from normal epidermis. A large 3[H]-mannose-labelled glycoprotein region (band A) with a peak at 97-92 kDa appeared to indicate the presence of a relatively large proportion of basaloid cells in the tissue. An associated peak in the region of 78-74 kDa also appeared in normal epidermis and what appeared to be non-invasive lesions. The main region of change in all lesions corresponded to the 66-34-kDa region (bands B and C). The absence of a group of glycoproteins and proteins in the 62-58-kDa region appeared to be specific for invasive squamous-cell carcinoma. All tumours showed a peak at 38-34 kDa which was not present in normal epidermis. Actinic keratosis had a pattern similar to normal epidermis except that the peaks of band B tended towards the higher-molecular-weight end of the band than those in normal epidermis and peaks at 28-22 kDa were seen. The latter seemed to correspond to the presence of a high proportion of spinous cells in the tissue sample.