INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES vol:16 pages:E437-E437
ICID edition:15 location:Bangkok, Thailand date:13-16 June 2012
Background: Staphylococcus aureus is a common cause of blood stream infection (BSI); treatment options are jeopardized by quickly emerging resistance. Epidemiological and resistance data on invasive S. aureus infections in Cambodia are scarce.
Methods: Isolates and epidemiological data were recovered from patients with BSI presenting at Sihanouk Hospital Centre of HOPE between July 2007 and December 2010. Identification of S. aureus isolates was performed by conventional methods. Antibiotic susceptibilities were assessed using disk diffusion and MicroScan® (Siemens Healthcare) according to CLSI guidelines. Molecular characterization included spa typing, Staphylococcal Chromosomal Cassette (SCC) mec typing, Multi Locus Sequence Typing (MLST) and screening for presence of Panton Valentin Leukocidin (PVL) and toxic shock syndrome toxin (TSST) encoding genes by PCR.
Results: We observed 51 S.aureus blood stream infections in 46 patients (65.2% male, mean age 42 years (range 16-67 y), representing 12.0% of all clinically significant blood stream isolates. Comorbidity included diabetes (11.0%) and HIV-infection (23.9%); 7.8% of the S. aureus BSI were hospital-associated. In 21(41.2%) episodes, skin and soft tissue infections (SSTI) were the presumed focus of infection with 8 (38.1%) PVL-associated.Twelve isolates (23.5%) were methicillin resistant (MRSA); 5 of those were from HIV+ patients. Resistance rates for clindamycin, sulfamethoxazole-trimethoprim (SMX-TMP), fluoroquinolones and azithromycin were high, especially among MRSA (Table 1). Five MRSA isolates displayed combined resistance to clindamycin, SMX-TMP, tetracyclin, erythromycin and moxifloxacin. No resistance for vancomycin was noted.The spa typing revealed 4 different types among MRSA and 21 in MSSA. Predominant types were t189-ST188 (n = 10; 6 were MRSA SCCmec IV), t1379-ST834 (n = 4; all MRSA SCCmec IV and TSST-positive), t159-ST121 (n = 9; 8/9 PVL-positive) and t034-ST1232 (n = 6; all MSSA and PVL-positive). Five patients had one or more recurrent BSI episodes; spa typing revealed that 3 were relapses and 2 reinfections.
Conclusion: S. aureus causing BSI in Cambodia are highly diverse. MRSA and multi drug resistance are common, especially in patients with HIV. Treatment options are very limited; the availability of effective antibiotics in Cambodia is urgently needed. Local microbiological surveillance data are essential to improve awareness and implement infection control measures.