Related Experiment Video
Updated: Mar 29, 2026
Author Spotlight: Leptospira DNA Detection in Water for Environmental Analysis and Disease Surveillance
Published on: June 14, 2024
Molecular detection of pathogenic leptospiral protein encoding gene (lipL32) in environmental aquatic biofilms
K Vinod Kumar1, C Lall1, R Vimal Raj1
1Regional Medical Research Centre (ICMR), WHO Collaborating Centre for Diagnosis, Reference, Research and Training in Leptospirosis, Port Blair, Andaman and Nicobar Islands, India.
Unlabelled:
Leptospirosis is a zoonotic disease often encountered during post-monsoon season due to exposure with contaminated water. Leptospires have long been regarded as solitary organisms that persist in soil and aquatic environments. Here, the presence of leptospires in the aquatic biofilm exposed in the paddy field, sewers and stagnant rain water was demonstrated. Biofilm samples from paddy field water, submerged paddy leaves, sewers and stagnant rain waters from urban and rural areas were collected. Total genomic DNA was extracted and pathogenic leptospiral specific gene amplification was carried out to determine the spatial distribution of the bacteria. The degree of pathogenic Leptospira in biofilms from paddy field surface water, submerged leaf, were 33·3% and 27·2% respectively, whereas in rural and urban area, the sampling sites such as stagnant rain water, domestic sewer and collective sewers showed 11·1%, 13% and 16·6% with leptospires respectively. Higher proportion of pathogenic Leptospira in aquatic ecosystems, such as paddy field, could be one of the main factors for the occurrence of disease, more among the agricultural workers. This study would help to identify various survival strategies of leptospires in the environment and thus disease transmission.
Significance And Impact Of The Study:
Little is known regarding the mechanisms by which pathogenic leptospires persist in aqueous environment, outside the mammalian host. In this view this is the first report of the distribution of Leptospira in environmental biofilm such as sewers and paddy leaf surfaces. This ability of pathogenic Leptospira to survive in aquatic ecosystems especially in biofilms could be one of the main factors which facilitate its survival in the environment, and thus disease transmission among the risk groups, such as sewage and agriculture worker. This study will encourage researchers in the field to consider biofilm as an important factor, when detecting leptospires in environment.
Insights
Pathogenic Leptospira bacteria were found in aquatic biofilms in paddy fields and sewers, indicating these environments are key to disease transmission, especially for agricultural workers. This highlights the importance of biofilms in understanding leptospirosis spread.
Area of Science:
- Environmental microbiology
- Zoonotic disease research
- Bacterial ecology
Background:
- Leptospirosis is a significant zoonotic disease transmitted through contaminated water.
- Leptospires are typically found in soil and water but their environmental persistence mechanisms are poorly understood.
- Aquatic biofilms are potential reservoirs for microbial pathogens.
Purpose of the Study:
- To investigate the presence and distribution of pathogenic Leptospira in aquatic biofilms.
- To determine the role of biofilms in the environmental survival and transmission of Leptospira.
- To identify high-risk environments for Leptospira exposure.
Main Methods:
- Collection of biofilm samples from paddy fields, sewers, and stagnant rainwater in urban and rural areas.
- Extraction of total genomic DNA from biofilm samples.
- Pathogen-specific gene amplification to detect and quantify Leptospira.
Main Results:
- Pathogenic Leptospira were detected in biofilms from paddy field surface water (33.3%) and submerged leaves (27.2%).
- Leptospira were also found in urban and rural biofilms from stagnant rainwater (11.1%), domestic sewers (13%), and collective sewers (16.6%).
- Higher prevalence in paddy field biofilms suggests a significant role in disease transmission to agricultural workers.
Conclusions:
- This is the first report demonstrating Leptospira distribution in environmental biofilms, including sewers and paddy leaves.
- The ability of pathogenic Leptospira to survive in aquatic biofilms is a key factor in environmental persistence and disease transmission.
- Biofilms should be considered crucial in environmental surveillance and risk assessment for leptospirosis.
