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.

MATERIALS & METHODS: This study was conducted in Hospital Kuala Lumpur, Malaysia from January 2016 to December 2017. A total of 303 isolates were included in this study which was obtained from 238 patients. The patients' microbiological worksheets and medical notes were reviewed to determine the antimicrobial susceptibility patterns, demographic data, classification of infection, and outcome (survival versus death).

RESULTS: Most of the patients were in the age group of one to less than five years old (41%) with 58% male and 85% Malay patients. Common causes of BSI were Staphylococcus aureus (17%), followed by Klebsiella pneumoniae (15%), Acinetobacter baumanii (10%), Pseudomonas aeruginosa (10%), and Escherichia coli (6%). Sixty percent of BSI episodes were caused by gram-negative bacteria, 34% by gram-positive bacteria, and 6% by fungi. Most of the infections were classified as hospital-acquired infections (72%), followed by healthcareassociated (20%) and community-acquired infections (8%). There were 33% of methicillin-resistant Staphylococcus aureus, 53% of extended-spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae, and 33% ESBL producing Escherichia coli. The overall case fatality rate (CFR) was 27% with the highest CFR caused by Serratia marcescens (53.3%).

METHODS: Swabs from four body sites of 129 HIV-infected patients were cultured for S. aureus and identified by standard microbiological procedures. The isolates were subjected to antimicrobial susceptibility testing by disk diffusion against penicillin, erythromycin, clindamycin, and cotrimoxazole. PCR was used to detect the PVL gene and genetic relationship between the isolates was determined by using pulse field gel electrophoresis.

RESULTS: A total of 51 isolates of S. aureus were obtained from 40 (31%) of the patients. The majority (43.1%) of the isolates were obtained from the anterior nares. Thirteen (25.5%) of all the isolates were resistant to more than one category of antibiotics, with one isolate identified as MRSA. Thirty-eight (74.5%) isolates (including the MRSA isolate) carried PVL gene where the majority (44.7%) of these isolates were from the anterior nares. A dendogram revealed that the isolates were genetically diverse with 37 distinct pulsotypes clustered in 11 groups.

Methods: A cross-sectional study was conducted from March to July 2019 on 126 students and 37 laboratory staff/clinical instructors' MPs from the Faculty of Health Sciences, Universiti Teknologi MARA, Malaysia by a simple random sampling technique. Along with the questionnaire, a swab sample from each participant's MPs was collected and transported to the microbiology laboratory for bacterial culture as per standard microbiological procedures and antimicrobial susceptibility test by the disc diffusion technique. Data were analysed by the Statistical Package for Social Sciences Programme version 24.

Results: All of the tested MPs were contaminated with either single or mix bacterial agents. Bacillus spp. (74.8%), coagulase-negative staphylococci (CoNS; 47.9%) and S. aureus (20.9%) were the most predominant bacterial isolates, whilst the least isolate was Proteus vulgaris (P. vulgaris) (2.5%). Oxacillin resistance was seen in 5.9% of S. aureus isolate. A comparison of bacteria type and frequency among gender showed a significant difference with P. vulgaris (P = 0.003) and among profession showed a significant difference with S. aureus (P = 0.004).

PURPOSE: The purpose of this in vitro study was to assess the antimicrobial effect of sub 10-nm AgNPs in maxillofacial silicone against Staphylococcus aureus, Candida albicans, and mixed species biofilms containing both and to test the effectiveness of different AgNP concentrations against all 3 biofilms in vitro.

MATERIAL AND METHODS: Silicone disks (M511; Technovent Ltd) containing 0.0% (control), 0.1%, and 0.5% AgNPs were fabricated and treated with S. aureus, C. albicans, and mixed species strains of both in 24-well culture plates containing appropriate media. Each well received a 0.1-mL aliquot of the standardized suspension of microorganisms. The plates were incubated for 21 consecutive days, and colony-forming units per milliliter (CFU/mL) were measured on the first, third, fifth, seventh, fifteenth, and twenty-first day with the Miles and Misra method. Data were analyzed by 2-way ANOVA and the paired t test to evaluate the relationship between AgNP concentration, microbial strain, and time (α=.05). Mean CFU/mL differences for each time and for each biofilm category were assessed by repeated measure ANOVA.