IISc-study develops 'venom maps' of deadly snake in India, could help predict nature of snake bite

New Delhi: Researchers have developed "venom maps" using local climate conditions that could help predict the venom characteristics of Russell's viper, a deadly snake found widely in India.

A team of researchers from the Indian Institute of Science (IISc), Bengaluru said the venom maps could help clinicians select the most appropriate treatment for patients with snake bites. The findings of the research have been published in the journal "PLOS Neglected Tropical Diseases".

Author Kartik Sunagar from the Centre for Ecological Sciences, IISc said, "Russell's viper is arguably the clinically most important snake species in the world. It kills and maims more people than any other snake species." "As a result, it is important to precisely unravel the composition, activity and potency of Russell's viper venoms and understand the role of biotic and abiotic factors in shaping them," he added.

The researchers explained that the toxic effects of a snake's venom are caused by concentrations of enzymes, which are influenced by factors, such as climate and availability of prey.

"Recent studies from our laboratory have shed light on the influence of biotic factors, such as developmental shifts in diet, on Russell's viper venom composition and toxicity," Sunagar said.

However, the factors driving changes in the venom of Russell's viper are unknown, the researchers said.

"Here, we highlight, for the first time, the role of climatic conditions, such as temperature, humidity and rainfall, in driving the biochemical functions of Russell's viper venoms," Sunagar said.

For the study, the researchers analysed venom samples from 115 snakes collected from 34 locations across India. The activity of venom toxins, including enzymes that break down proteins, phospholipids and amino acids, was tested.

Climate data gathered over the time was then used to understand the link between the venom composition and the local climate where the snakes were caught, the researchers said.

Temperature and rainfall were found to partly explain the region-to-region variation in snake-venom composition.

"Our findings reveal a collective influence of various temperature and precipitation parameters that partly explain the variability in enzymatic activities of D. russelii venom," the authors wrote.

The breakdown of proteins, or "protease activity", was found to be higher among snakes in drier regions of India, they said.

Using this data, the team created a map of expected venom types of Russell's vipers across its range in India.

The maps could help predict the clinical symptoms of snake bites in different regions and thus, develop targeted therapies, such as toxin-specific antibodies, the researchers said.