Antibacterial activities of serum from the Komodo Dragon (Varanus komodoensis)

Rodolfo Falconi,Bekky Muscher,Danyell Henry,Judith Bryja,Mark Merchant

doi:10.4081/mr.2013.e4

Rodolfo Falconi, Bekky Muscher + Show 3 more

Open Access

https://doi.org/10.4081/mr.2013.e4

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Journal: Microbiology Research	Publication Date: Jul 15, 2013
Citations: 9	License type: cc-by

Affiliation: McNeese State University

Abstract

Komodo dragons (Varanus komodoensis) are able to feed on large prey items by injecting a dose of toxic bacteria with their bite that, over time, kills the prey by systemic infection. Dragons also suffer bites from other members of their own species during territorial disputes and feeding frenzies. However, they do not suffer the same fate as their prey, suggesting that they have developed a strong immunity to bacterial infections. This study was undertaken to determine the antibacterial activities of serum from the Komodo dragon. Bacterial cultures were treated with different volumes serum from Varanus komodoensis and the growth was monitored by optical density at 430 nm. In addition, the serum was treated with protease, chelators of divalent metal ions, or with mild heat to determine the mechanism of antibacterial activities. Treatment of bacterial cultures with serum from Komodo dragons (Varanus komodoensis) resulted in a volume-dependent decrease in bacterial growth. Cultures of Escherichia coli, Staphylococcus aureus, and Klebsiella oxytoca exhibited moderate-strong growth inhibition by V. komodoensis serum, while cultures of Streptococcus epidermitis, Salmonella typhimurium, Providencia stuartii, and Shigella flexneri were nearly completely obliterated for 24 h by only 10% (v/v) serum. The antibacterial activity of V. komodensis serum occurred very rapidly, as 18% of E. coli growth was inhibited by a five min exposure to serum. Furthermore, 10- and 20-min incubations of E. coli with serum from V. komodoensis resulted in 43 and 68% inhibition of bacterial growth, respectively. The bactericidal capacity of the serum against E. coli was 2,075,000 bacteria/μL serum, and was inhibited by mild heat treatment, pronase, EDTA, and phosphate, indicating that the anti-bacterial action is most probably due to the presence of a potent serum complement protein system.

Highlights

The Komodo dragon (Varanus komodoensis) is an endangered species of monitor lizardMark Merchant,[1] Danyell Henry,[1] Rodolfo Falconi,[1] Becky Muscher,[2] Judith Bryja[3] indigenous to only five islands in the Lesser Sunda region of southeast Indonesia.[1]
At 24 hrs, 10% V. komodoensis serum (v/v) produced a 44% decrease in E. coli growth, while 25, 50, 75, and 100% serum caused 58, 75, 93, and 98% decreases in the Komodo dragon results in 96.4% of the bacteria killed
Four aliquots of serum were incubated at 56oC for o 30 min. These serum samples (500 μL) were N all incubated with 20 μL of an E. coli culture in oensis (10% volume) inhibited Shigella flexnerii growth by 95% at 24 hrs (Figure 1D), and exhibited similar results for cultures of Salmonella typhimurium (Figure 1E)

Summary

Introduction

The Komodo dragon (Varanus komodoensis) is an endangered species of monitor lizard. Mark Merchant,[1] Danyell Henry,[1] Rodolfo Falconi,[1] Becky Muscher,[2] Judith Bryja[3] indigenous to only five islands in the Lesser Sunda region of southeast Indonesia.[1]. It is the largest lizard in the world, reaching lengths of.

Komodo dragons kill prey items with a lethal

Findings

Komodo dragon serum