Genetic variations in Aeromonas hydrophila isolates from clinical and environmental sources in Thailand.

Aeromonas hydrophila, a widely distributed human pathogen causing a variety of diseases, can be isolated from clinical and environmental sources. Analysis in Thailand of 110 isolates of Aeromonas hydrophila by randomly amplified polymorphic DNA-PCR (RAPD-PCR) revealed one specific RAPD pattern group (G) that was associated only with strains from environmental sources. Cytotoxic activity, adhesion to epithelial cells and exoenzyme secretions of A. hydrophila were also investigated. A comparison of isolates with pattern group G with a set of isolates derived from human blood showed low induction of cytotoxicity from those with RAPD pattern group G suggesting low virulence of these strains.

Bacterial contamination of re-usable and disposable syringes and needles.

Re-usable glass and disposable plastic syringes and needles were tested for their sterility. Ninety-one re-usable glass, 111 disposable plastic syringes, 105 re-usable and 91 disposable needles were determined for microbial contamination by direct method using soy-bean-casein digest and fluid thioglycolate media. The positive results were 2.2 per cent (2/91), 0.9 per cent (1/111), 2.9 per cent (3/105) and 3.3 per cent (3/91) for re-usable and disposable syringes and needles, respectively. It is concluded that there is no difference in the rates of contamination of re-usable and disposable items.