Microbial contamination of disinfectants and antiseptics in four major hospitals in Trinidad

ABSTRACT

OBJECTIVE: To assess the microbial contamination of disinfectants and antiseptics in major hospitals on the Caribbean island of Trinidad. METHODS: For this cross-sectional study, disinfectants and antiseptics were sampled from the pharmacy departments, the pediatric/neonatal wards, and the surgical wards of four hospitals. The samples were cultured for aerobic bacteria on nutrient agar using the surface plating method. The antibiotic sensitivity of bacterial isolates was determined by the disk diffusion method, using 14 antimicrobial agents. We studied a total of 180 disinfectant/antiseptic samples 60 of chlorhexidine gluconate (Hibitane), 60 of chlorhexidine gluconate and cetrimonium bromide (Savlon), and 60 of methylated spirit. RESULTS: Of the 180 samples studied, 11 of them (6.1 percent) were contaminated by aerobic bacteria. All bacteria isolated were Pseudomonas spp. Of the 11 contaminated samples, 6 of them (54.5 percent) occurred at the pharmacy level while 5 (45.5 percent) were from diluted pre-use or in-use samples in the pediatric/neonatal wards or the surgical wards. Chlorhexidine gluconate and cetrimonium bromide accounted for 9 of the 11 contaminated disinfectants/antiseptics (81.8 percent), and chlorhexidine gluconate accounted for the remaining 2 (18.2 percent). Only two of the four hospitals had contaminated disinfectant/antiseptic samples. All 24 isolates of Pseudomonas spp. tested were resistant to one or more of the 14 antimicrobial agents tested, with the prevalence of resistance to ciprofloxacin, norfloxacin, tobramycin, and gentamicin being 58.3 percent, 50.0 percent, 45.8 percent, and 41.7 percent, respectively. CONCLUSIONS: Our results show that contaminated disinfectants/antiseptics pose a health risk to patients, particularly in the pediatric and surgical wards. The high prevalence of resistance to antimicrobial agents exhibited by the Pseudomonas spp. that were isolated is of special therapeutic concern