Survival Capabilities of Giardia lamblia Trophozoites in Supplemented Stool Cultures at Different Incubation Temperatures.

Abstract

A stool sample from a 24 years old HIV positive female patient at Lahor Public Health and Research Centre containing trophozoites of Giardia lamblia was prepared in duplicate. One set was supplemented with 0.5% dextrose saline and subjected to different temperatures i.e. 4°C, ambient temperature i.e. 27°C, and 37°C while the other was not reinforced with glucose but kept under the same conditions. The aim of this study was to test the survival capabilities of the trophozoites under these conditions. On a two hourly microscopical examination of the samples, it was found that the trophozoites could not survive for two hours at 4°C in feacal samples not containing and in the one containing 0.5% dextrose saline. At room temperature, the trophozoites survived for 24 hours in feacal sample supplemented with 0.5% dextrose saline. Encystment occurred in both after 18 and 16 hours respectively. At 37°C, no motile trophozoites were seen at 4 hours in the feacal sample containing 0.5% dextrose saline, while the sample not containing the sugar could support the motile trophozoites for more than 16 hours: In ensuring quality and accurate diagnosis of Gardiasis, prompt analysis of stool specimens is required, however, situations may arise that there is need to delay processing of samples especially in an environment like ours where power supply is very erratic, patient's own stool, therefore, supplemented with 0.5% dextrose saline and incubated at room temperature could serve as G. lamblia trophozoites extender.

Keywords: Giardia lamblia, survival, temperature, 0.5% dextrose saline.