The use of loop AMP in detection of Shiga-toxin (stx) gene among escherichia coli from aquaculture and other environments

Considerable amount of cases of Shiga-toxin producing Escherichia coli (STEC) has been reported which result in the need to detect the presence of this harmful E. coli in food and environmental sources. Diseases caused by STEC are Hemolytic Uremic Syndrome (HUS) and Hemorrhagic Colitis (HC). A lot of samples being used in researches are mostly from retailed chain store or farms. The need to look into aquaculture and other environmental water is very crucial since there are very few researches done on aquaculture and other environmental water. In this study, samples were taken from Asajaya Empurau fish farm, Damai river stream, Permai beach and Permai rainforest resort. Enterobacteriaceae were successfully isolated using Eosin Methylene Blue agar and E. coli were successfully identified through a series of biochemical test. DNA was isolated using boiling method and Loop-AMP was conducted to detect toxigenic genes carried by E. coli. It was found that none of the isolates were carried stx 1 or stx 2 gene. However, multiplex-PCR detected three isolates which carried stx 1 and stx 2 gene. (GTG)s-PCR was carried out to detect the diversity among the isolates and was found that the genetic diversity among E. coli isolates were not high. Two major clusters with one of the cluster having 2 sub clusters were detected. Water quality for Damai downstream, Damai middle stream, Permai beach, Permai rainforest resort were classed at class lIB which is safe for water recreational activities with body contact