Factors associated with emergence of pristinamycin-resistant Staphylococcus aureus in a dermatology department: a case-control study.

BACKGROUND: Pristinamycin is used for the treatment of Staphylococcus aureus skin infection. Staphylococcus aureus pristinamycin resistance is usually low. The frequency of pristinamycin-resistant S. aureus (PRSA) increased in the Caen University Hospital dermatology department from 1% in 1998 to >11% in 1999-2002. OBJECTIVES: This study aimed to identify the factors associated with PRSA acquisition. METHODS: Incidences of PRSA and pristinamycin consumption were calculated for the dermatology department and for the rest of the hospital from 1997 to 2007. Individual factors of PRSA acquisition in the dermatology department from 2000 to 2001 were analysed in a retrospective case-control study including 23 cases of PRSA skin colonization or infection and 46 controls with pristinamycin-susceptible S. aureus. Clonal relatedness of isolates was analysed by pulsed-field gel electrophoresis and pristinamycin resistance genes were detected by polymerase chain reaction. Conditional logistic regression was performed to analyse the relationship between pristinamycin resistance and epidemiological and microbiological data. RESULTS: PRSA frequency and pristinamycin consumption were significantly higher in the dermatology department than in other hospital departments. Two epidemic clones of two and six isolates were found for periods of 1 and 2 months, respectively. Thirteen of the 23 PRSA isolates (57%), including all isolates of the two epidemic clones, were found 48 h after the hospitalization or later. PRSA was associated with pristinamycin use during the previous year [odds ratio (OR) 5.60, 95% confidence interval (CI) 1.41-22.22], cumulative use of antibiotics exceeding 1 week during the previous year (OR 4.63, 95% CI 1.47-14.54) and methicillin resistance (OR 6.35, 95% CI 1.38-29.15). CONCLUSIONS: Results suggest that antimicrobial selective pressure and microbial cross-transmission are involved in PRSA acquisition.

Hospital-wide modification of fluoroquinolone policy and meticillin-resistant Staphylococcus aureus rates: a 10-year interrupted time-series analysis.

In our tertiary university hospital, fluoroquinolones were prohibited during 2001 leading to a 90% reduction in their use. Our objective was to examine the trends in meticillin-resistant Staphylococcus aureus (MRSA) following the reintroduction of fluoroquinolones. We conducted a 10-year time-series analysis of monthly MRSA according to: (i) period of fluoroquinolone restriction (January 2001 to January 2002); (ii) period of fluoroquinolone increase up to pre-restriction levels (January 2002 to December 2004); and (iii) an observational period including the implementation of a hand hygiene campaign with alcohol-based hand rub (January 2005 to June 2009). We used segmented linear autoregression analysis to assess trends between adjacent periods. Fluoroquinolone use increased from 5.2 defined daily doses (DDD) per 1000 patient-days in 2001 to 56.6 DDD per 1000 patient-days in 2005 reaching pre-restriction fluoroquinolone levels (P<0.001) and remained stable during 2005-2010 (P=0.65). The monthly proportion of MRSA decreased during the period of FQ restriction (-0.49 per month, P<0.05). The reintroduction of fluoroquinolones was associated with a significant increase in MRSA (+0.68 per month, P<0.02) compared to the previous period. During period 3, we observed a significant change in MRSA (-5.9, P<0.002) compared to the previous period (-0.32 per month, P<0.001). During the latter period, hand hygiene was promoted and alcohol-based hand-rub consumption increased from 3411 L in 2005 to 14,599 L in 2009. This study reinforces the rationale for a hospital-wide fluoroquinolone formulary policy to control MRSA and suggests that it has an additive effect with a hand hygiene promotion.

[Restropective investigation about the treatment of candidaemia in a French university hospital in 2004]. / Etude rétrospective de la prise en charge des candidémies en 2004 dans un centre hospitalier universitaire français.

This study aimed to retrospectively evaluate the adequate use of antifungal drugs in the treatment of the candidaemia. A collection of clinical, biological and therapeutic data was carried out for the patients who had a positive blood culture for Candida species during the year 2004. The antifungal therapy was compared to the guidelines of the French Conference of consensus named "Prise en charge des candidoses et aspergilloses invasives de l'adulte". The degree of conformity was classified as follows: complying, partly complying (molecule in conformity but delay of treatment or unsuited dosing) and not complying with the guidelines. The analysis was performed, according to the guidelines, before and after knowledge of Candida species growing from the blood culture. On 29 candidaemia, the found species were: Candida albicans 55%, Candida glabrata 14%, Candida krusei 10%, Candida parapsilosis and Candida lusitaniae 7%, Candida pelliculosa and Candida tropicalis 3.5%. Only 19 candidaemia were included in this study because blood cultures were known positive for Candida on the day of death (N=7) or medical charts were not available (N=3). For treatment before identification of Candida species, 37% were complying, 37% in partly complying and 26% not complying with the guidelines. For the treatment after identification of the species, 26% were complying, 63% partly complying and 11% not complying with the guidelines. As a whole, antifungal therapy was totally or partly complying in 74 to 89% of candidaemia in adult patients. Lower dosages of fluconazole explained most of the treatments that partly complied with guidelines.