OBJECTIVES: To identify the species distribution, antibiotic susceptibility patterns and clinical profiles of CoNS isolated from blood cultures among paediatric patients in Hospital Kuala Lumpur (HKL).
METHODS: This study involved CoNS isolation from blood cultures of paediatric in-patients of the Paediatric Institute HKL. Isolates were identified to species level using Analytical Profile Index Staph identification strips and antimicrobial susceptibility pattern following Kirby-Bauer Disc Diffusion method. The clinical profiles of patients were obtained from their medical records.
RESULTS: Eleven CoNS species were identified from 148 isolates. Staphylococcus epidermidis was the most frequent species isolated (67.6%). The majority of the isolates showed resistance to penicillin (85.8%); while 70.3% were methicillin-resistant (MR) CoNS, which demonstrated a significant association with true infection (p=0.021). Predictors for significant CoNS infection included thrombocytopaenia, presence of predisposing factors, nosocomial infection, blood collected from peripheral vein, and CoNS isolated from two consecutive blood cultures. The most common predisposing factors for the isolation of CoNS were the presence of peripheral (54.1%) and central venous catheters (35.1%).
CONCLUSION: CoNS can cause significant bloodstream infections. The isolation of CoNS from blood cultures should be carefully interpreted by considering the predictive factors. Local data regarding predictive factors of patients with culture-positive CoNS, species distribution and antimicrobial susceptibility pattern are useful to determine the significance of blood culture results and care management of patients.
MATERIALS AND METHODS: The detection of inducible clindamycin resistance was performed by D-test using erythromycin and clindamycin discs as per CDC guidelines.
RESULTS: Among the 244 clinical isolates of staphylococci studied, 32 (13.1%) showed inducible clindamycin resistance and belonged to the MLSBi phenotype. Among the MLS B i phenotypes, 10 isolates were methicillin-resistant Staphylococcus aureus (38.4% of the total MRSA), 16 were methicillin-sensitive Staphylococcus aureus (12.9% of the total MSSA) and 6 were coagulase-negative staphylococci (6.3% of the total CONS).
CONCLUSION: The test for inducible resistance to clindamycin should be included in the routine antibiotic susceptibility testing, as it will help in guiding therapy.