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.
OBJECTIVES: The study was undertaken to evaluate the possibility to isolate bacteriolytic bacteriophages against S.aureus from raw sewage water and examine their efficacy as antimicrobial agents in vitro.
METHODS: Bacteriophages were isolated from the raw sewage using the agar overlay method. Isolated bacteriophages were plaque purified to obtain homogenous bacteriophage isolates. The host range of the bacteriophages was determined using the spot test assay against the 25 MRSA and 36 MSSA isolates obtained from the Sarawak General Hospital. Staphylococcus saprophyticus, Staphylococcus sciuri and Staphylococcus xylosus were included as non-SA controls. The identity of the bacteriophages was identified via Transmission Electron Microscopy and genomic size analysis. Their stability at different pH and temperature were elucidated.
RESULTS: A total of 10 lytic bacteriophages infecting S.aureus were isolated and two of them namely ΦNUSA-1 and ΦNUSA-10 from the family of Myoviridae and Siphoviridae respectively exhibited exceptionally broad host range against >80% of MRSA and MSSA tested. Both bacteriophages were specific to S.aureus and stable at both physiologic pH and temperature.
CONCLUSION: This study demonstrated the abundance of S.aureus specific bacteriophages in raw sewage. Their high virulence against both MSSA and MRSA is an excellent antimicrobial characteristic which can be exploited for bacteriophage therapy against MRSA.
METHODS: A total of 370 agricultural biotechnology students from Universiti Sultan Zainal Abidin in Besut, Terengganu, were enrolled in this study. Antimicrobial susceptibility profiles were evaluated by standard methods. PCR detection of resistance and virulence genes was performed on S. aureus that were methicillin-resistant, macrolide-lincosamide-streptogramin B (MLSB )-positive phenotype and/or positive for the leukocidin (pvl) gene followed by staphylococcal cassette chromosome mec (SCCmec), staphylococcal protein A (spa) and accessory gene regulator (agr) typing.
RESULTS: One hundred and nineteen of 370 students carried S. aureus (32%); 18 of the isolates were MRSA (15%). Erythromycin resistance was detected in 20% (24/119) of which 15% (18/119) were MRSA and 5% (6/119) MSSA. Among the 24 erythromycin-resistant isolates, D-test was positive in 29% (7/24) displaying inducible MLSB , whereas the remaining 71% (17/24) showed constitutive MLSB phenotypes. Nine (7.6%) of 119 isolates were pvl positive: 44% MRSA (4/9) and 56% MSSA (5/9). Staphylococcal surface protein sasX gene was present in 92% of MRSA and 8% of MSSA isolates. The majority of MRSA isolates were agr type I (15/18; 83%). Five spa types identified with spa t037 were predominant, followed by spa types (t304 and t8696) as newly reported Malaysian MRSA in a community setting.
CONCLUSION: The presence of MRSA with SCCmec of hospital-associated features and globally recognised spa types in community setting is worrisome. Furthermore, the presence of MLSB strains among multidrug-resistant (MDR) S. aureus with sasX as well as pvl-positive isolates highlights the potential risk of a community setting in facilitating the dissemination of both virulence and resistance determinants.
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.