Occurrence of Leptospira Species from Rodents, Soil and Water from an Oil Palm Plantation in Northern Sarawak

Abstract

Leptospirosis is a death-causing disease caused by corkscrew-shaped bacteria, Leptospira especially in tropical countries. Current study was aimed to detect pathogenic, intermediate and saprophytic Leptospira species using polymerase chain reaction (PCR) assay from an oil palm plantation in Borneo, specifically in Miri, Malaysia. Materials and Methods: A total of 63 samples from rodents (n = 3), water (n = 30) and soil (n = 30) were isolated from an oil palm estate in Northern Sarawak, Borneo. All samples were inoculated into modified semisolid Ellinghausen-McCullough-Johnson-Harris (EMJH) broth with 5-fluorouracil and incubated for a month. Polymerase chain reaction (PCR) was performed using primer targeting lipL32 (423 bp) for pathogenic, 16S rRNA (331 bp) for intermediate and rrs (240 bp) for saprophytic species. Results: pathogenic Leptospira was found in 33.3% rodents (1/3) Rattus tiomanicus, 23.3% soil samples (7/30) and 16.7% water samples (5/30). Intermediate species were demonstrated in the other 66.7% rodents (2/3), Sundamys muelleri and Rattus exulans and 10% soil samples (3/30). Saprophytic species was found in only 3.3% soil sample (1/30). Results from DNA sequencing analysis indicated that the most dominant pathogenic Leptospira species discovered in the study was Leptospira interrogans, followed by Leptospira noguchii and Leptospira weilii. Conclusion: These preliminary findings provide baseline data on the occurrence of Leptospira species in captured rodents and the environment. These findings could assist in control and prevention of leptospirosis among oil palm estate workers in Sarawak. Awareness and knowledge on leptospirosis should be promoted among oil palm workers for prevention and mitigation