Efficacy and contamination of in-use disinfectants in Rajavithi General Hospital.

Quality testing of disinfectant in-use in Rajavithi General Hospital was conducted to evaluate the germicidal activity and contamination. Two hundred and thirty-four samples of 4 commonly used disinfectants in operating rooms, labour rooms and the surgical intensive care unit were studied. Results showed that 2 of 126 samples of chlorhexidine/cetrimide 1:100 dilution were contaminated by P.maltophilia and A.xylosoxidans and failed the in-use test. One of 34 samples of phenolics yielded A.lowffii. Two of 16 hypochlorite 0.05% grew E.cloacae, Enterobacter spp., A.calcoaceticus and Pseudomonas spp. Forty-six samples of 1:500 and 1:100 of quaternary ammonium compound, and 12 samples of 1% hypochlorite were not contaminated. Bacterial contamination and failure to kill bacteria by disinfectants reflected improper preparation and use of these solutions. Periodic quality testing is clearly indicated.

Cross-infection of gentamicin-methicillin-resistant Staphylococcus aureus in a male surgical ward at Rajavithi General Hospital.

Between January and December 1987, gentamicin-methicillin-resistant strains of Staphylococcus aureus (GMRSA) were isolated from 7 patients in a male surgical ward at Rajavithi General Hospital. Six patients developed significant infection which included sepsis (2), pneumonia (1), infection in the eye, ear and wound (1), wound infection (2), and one patient had GMRSA isolated from his sputum. The strains were untypable with standard phage type and were resistant to methicillin, gentamicin, amikacin, kanamycin, streptomycin, tetracycline, erythromycin and chloramphenicol, but susceptible o vancomycin and cotrimoxazole. GMRSA were also isolated from bed-rail and the used rubber gloves left in the affected room. The GMRSA strains contained 5 plasmids of molecular weight of 18, 11, 2, 1.8 and 1.7 Md. The 2Md plasmid coded for chloramphenicol resistance and the 1.8 Md plasmid for erythromycin resistance.

Microbial contamination of enteral feeds.

The microbiological quality of 4 feed ingredients and 29 hospital-prepared non-sterile enteral feeds were determined. All 4 feed ingredients yielded no growth of micro-organisms, but all 29 enteral feeds had aerobic viable counts exceeding 10(5) organisms g-1 with a high coliform count in each feed. Both the aerobic palte count and the coliform count exceeded numerical limits for micro-organisms in enteral feeds. Sources of contamination were the feed containers and the liquidizer which were inadequately disinfected.