Antibiotic resistance of Staphylococcus aureus from ICUs in the Netherlands 1996 to 2006
© Rijnders et al; licensee BioMed Central Ltd. 2009
Published: 13 March 2009
Staphylococcus aureus is a potential pathogenic microorganism and a causative agent of ~25% of infections in intensive care patients. Optimal empiric therapy may reduce morbidity and mortality. Therefore, it is essential to provide the clinician with resistance data of the local circulating strains and patients pathogens. A national surveillance program of the Dutch Antibiotic Resistance Surveillance Group was started in the Netherlands in 1996 to gain insight into the emergence of microbial resistance at local, regional and national levels. This study describes the findings of resistance development of S. aureus from ICUs of 14 large referral hospitals all over the Netherlands over a 10-year period from 1996 to 2006.
In the first 6 months of each year, the participating hospitals collected clinical isolates from, among others, blood and respiratory samples. In total 943 isolates were collected: 250 from three hospitals in the north, 187 from two in the east, 229 from five in the west and 280 from four in the south. The susceptibility to relevant antibiotics was determined by micro broth dilution according to the Clinical and Laboratory Standards Institute guidelines.
Resistance to penicillin fluctuated over time at ~75%; seven methicillin-resistant S. aureus were isolated (0.7%). Resistance to clarithromycin increased to 10% in 2003, but decreased in 2006 to 6%, the level before 2003. Resistance to clindamycin fluctuated over time from 4 to 8%. Doxycyclin resistance varied between 2 and 10%. No resistance to vancomycin, teicoplanin and linezolid was demonstrated. Resistance to gentamicin and rifampicin was sporadically found. The prevalence of fluoroquinolone resistance was between 0 and 4% until 2002. In 2003, a peak in the prevalence of fluoroquinolone resistance (ciprofloxacin 14% and moxifloxacin 8%) was observed. Resistance to ciprofloxacin remained at this high level until 2005 and decreased in 2006. Resistance to moxifloxacin decreased immediately. Regional differences were observed for ciprofloxacin, with the highest resistance in the western and southern parts and with doxycyclin with the lowest resistance rate in the northern part.
During the 10-year study period only an increase in resistance to ciprofloxacin was observed. The data presented still justify the empiric choice of flucloxacillin (with rifampicin or gentamicin depending on the indication) in case of an infection probably caused by S. aureus in ICU patients.
This article is published under license to BioMed Central Ltd.