ABSTRACT
INTRODUCTION: Resistance of Candida species to fluconazole has been increasingly reported worldwide. To date, the prevalence of resistance to fluconazole in Singapore is unknown. The aim of this study was to use a newly described agar disc diffusion method to study levels of susceptibility of Candida species to fluconazole in several hospitals in Singapore. MATERIALS AND METHODS: Three hundred and ninety Candida isolates from clinical specimens collected from different sites were tested, of which 191 isolates (49.0%) were C. albicans, 69 (17.7%) were C. parapsilosis, 59 (15.1%) were C. glabrata, 51 (13.1%) were C. tropicalis and 4 (1.0%) were C. krusei. Susceptibility testing was performed using 25 micrograms fluconazole discs and standard Mueller-Hinton agar supplemented with 2% glucose and 0.5 microgram/mL of methylene blue. RESULTS: Overall, 381 (97.7%) isolates were susceptible, 6 (1.5%) were susceptible dose-dependent, and 3 (0.8%) were resistant to fluconazole. Of the individual species, 99.5% of C. albicans, 93.2% of C. glabrata, 0% of C. krusei, and 100% of C. parapsilosis, C. tropicalis and other Candida species were susceptible. CONCLUSION: The resistance of Candida species to fluconazole, as measured using a new disc diffusion method, is low in Singapore, with the exception of C. krusei. Fluconazole remains a useful agent for the treatment of candidiasis in this country.
Subject(s)
Antifungal Agents/pharmacology , Candida/drug effects , Candida/immunology , Candidiasis/immunology , Drug Resistance, Fungal/immunology , Fluconazole/pharmacology , Immunodiffusion/methods , Antifungal Agents/administration & dosage , Antifungal Agents/therapeutic use , Candida/isolation & purification , Candidiasis/drug therapy , Candidiasis/microbiology , Colony Count, Microbial , Dose-Response Relationship, Drug , Fluconazole/administration & dosage , Fluconazole/therapeutic use , Humans , In Vitro Techniques , Reproducibility of Results , Sensitivity and Specificity , SingaporeABSTRACT
OBJECTIVES: To study the minimum inhibitory concentrations (MICs) of Propionibacterium acnes (P. acnes) isolates to selected antibiotics from patients with acne vulgaris in Singapore and determine if resistance increases with prolonged use of antibiotics. DESIGN: A single-centre prospective study. SETTING: Tertiary dermatological referral centre in Singapore. PATIENTS: One hundred and fifty patients with acne vulgaris seen at the National Skin Centre. RESULTS: In patients who had never been on antibiotics, there were no resistant isolates of P. acnes. In patients who had been on short-term antibiotics (between 6 to 18 weeks), there were 2 resistant strains among the 34 isolates (6.25%); in patients who had been on antibiotics for longer periods, there were 11 resistant strains among the 51 isolates (21.6%). The differences in the rates of isolation of resistant strains between patients who had not been on antibiotics to those that had been on long-term antibiotics were statistically significant (P = 0.015). There was also a significant difference in isolation of resistant strains from those on short-term antibiotics compared to those who had been on long-term antibiotics (P = 0.036). Resistance to erythromycin was most commonly encountered. Most of the erythromycin-resistant strains also showed cross-resistance to clindamycin. The average MICs to antibiotics such as minocycline, erythromycin and clindamycin in those on long-term antibiotics were significantly higher when compared to patients who had not been on antibiotics. CONCLUSIONS: Antibiotic resistance in P. acnes isolates in Singapore follows similar patterns to studies conducted in Europe. Resistance to erythromycin was most commonly seen, and this is associated with cross-resistance to clindamycin. Among the tetracycline group of drugs, the average MICs to tetracycline was higher than that for doxycycline, which in turn was higher than that for minocycline. Antibiotic resistance can occur with short-term antibiotic courses, and the rate of resistance increases as the duration of antibiotic consumption increases.
Subject(s)
Acne Vulgaris/microbiology , Anti-Bacterial Agents/pharmacology , Drug Resistance, Microbial , Propionibacterium acnes/drug effects , Acne Vulgaris/drug therapy , Adult , Ambulatory Care Facilities , Anti-Bacterial Agents/administration & dosage , Female , Gram-Positive Bacterial Infections/drug therapy , Humans , Male , Microbial Sensitivity Tests , Probability , Propionibacterium acnes/isolation & purification , Referral and Consultation , Sensitivity and Specificity , SingaporeABSTRACT
A large outbreak of food poisoning occurred in Singapore in March 1995 when a total of 188 inmates in an institution was taken ill. Salmonella enteritidis was isolated from the stool cultures of 35 inmates (16 symptomatic and 19 asymptomatic). All the isolates were of the serotype profile 0:1, 9, 12 and H:g, m (antigen phase I); all were sensitive to ampicillin, ceftriaxone, chloramphenicol, co-trimoxazole and ciprofloxacin. Plasmid profile analysis and restriction enzyme fragmentation patterns (REFPs), as generated with EcoRI and HindIII, of a 60 kb plasmid obtained from these isolates were all identical, confirming that the outbreak resulted from a single source of infection. Stratified statistical analysis of food-specific attack rates strongly implicated imported canned luncheon pork consumed by the inmates on 26 March 95 as the single most probable cause of the food poisoning [p < 10(6), Mantel-Haenszel weighted odds ratio (OR) = 14.33; 95% confidence interval (CI) = 6.20-33.15]. The median incubation period of this outbreak was 19.3 hours and the median duration of illness was three days. The outbreak was rapidly brought under control through prompt implementation of epidemic control measures which comprised active search for diarrheal cases, rectal swabbing of asymptomatic inmates, isolation of those found to be infected, and maintenance of a high standard of personal, food and environmental hygiene.
