Gut Bacteria of Water Monitor Lizard (Varanus salvator) Are a Potential Source of Antibacterial Compound(s)

Abstract

For the past few decades, there has been limited progress in the development of novel antibacterials. Previously, we postulated that the gut microbiota of animals residing in polluted environments are a forthcoming supply of antibacterials. Among various species, the water monitor lizard is an interesting species that feeds on organic waste and the carcass of wild animals. Gut microbiota of the water monitor lizard were sequestered, identified and cultivated in RPMI-1640 to produce conditioned medium (CM). Next, the antimicrobial properties of CM were evaluated versus a selection of Gram-negative (Escherichia coli K1, Serratia marcescens, Pseudomonas aeruginosa, Salmonella enterica and Klebsiella pneumoniae) and Gram-positive bacteria (Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus, and Bacillus cereus). CM were partially characterized by heat inactivation at 95°C for 10 min and tested against P. aeruginosa and S. pyogenes. CM were also tested against immortalized human keratinocytes (HaCaT) cells lines. The results demonstrated that gut microbiota isolated from water monitor lizard produced molecules with remarkable bactericidal activities. To determine the identity of the active molecules, CM were subjected to Liquid Chromatography-Mass Spectrometry. Several molecules were identified belonging to the classes of flavonoids, terpenoids, alkaloids, polyhydroxy alkaloids, polyacetylenes, bisphenols, amides, oxylipin and pyrazine derivatives with known broad-spectrum antimicrobial, anti-tumour, anti-oxidant, anti-inflammatory, and analgesic attributes. Furthermore, the detailed analysis of these molecules could lead us to develop effective therapeutic antibacterials.

Crocodylus porosus Sera a Potential Source to Identify Novel Epigenetic Targets: In Silico Analysis

“…Epigenetic treatment holds great potential in the treatment of several diseases such as metabolic disorders, cancer, and cardiovascular and neurological diseases [ 4 ]. Furthermore, the ability of the epigenome to be flexible, has enabled scientists to investigate its reversal through designing epigenetic drugs as an approach to ameliorate disease phenotypes.…”

“…Furthermore, crocodiles have also been reported to possess bioactive peptides that revealed anti-oxidative, anti-inflammatory, anti-microbial, and anti-cancer attributes [ 1 , 2 ]. In this regard, we have recently postulated and shown that the sera and gut bacteria of animals such as crocodiles ( Crocodylus palustris and Crocodylus porosus) and water monitor lizard ( Varanus salvator ), tortoise ( Cuora amboinensis kamaroma ) as well as other species that reside in polluted environments depict anti-tumour and antibacterial activities and may contribute to the longevity and hardiness of these species [ 3 , 4 ].…”

Antibacterial Activities of Selected Pure Compounds Isolated from Gut Bacteria of Animals Living in Polluted Environments

“…In our previous studies, we have isolated gut bacteria from animals/pests and tested their conditioned media (extracts) against multi-drug resistant Gram-negative and Gram-positive bacteria [9,15]. Bioactive molecules were identified (see Supplementary Figures S1-S5) [9,23] and out of which a few selected compounds were obtained from Sigma Aldrich and tested for their antibacterial properties. The results revealed that all three compounds exhibited significant bactericidal activities (Figure 1a,b) (P < 0.05, using student's t-test, two-tailed distribution).…”

“…Bacterial species used in this study include multi-drug resistant Pseudomonas aeruginosa (ATCC 10145) and Streptococcus pyogenes (ATCC 49399) and grown overnight at 37 • C and maintained aerobically prior to experimentations as previously described [23].…”

Gut microbiome–immune system interaction in reptiles

“…Reptiles also possess greater longevity than similar‐sized land mammals, for example crocodiles are long‐lived reptiles sometimes living up to 100 years, advocating that we ought to learn from these species. Given that most of the immune system is thought to reside in the gut, accordingly, we speculated that the gut microbiome of reptiles most likely contributes to their robust immune system, their ability to thwart infectious diseases, cancer, and in some cases display limited or negligible senescence (Akbar, Siddiqui, Sagathevan, Iqbal, et al, 2019; Akbar, Siddiqui, Sagathevan, et al, 2020; Jeyamogan et al, 2019, 2020; Siddiqui et al, 2021; Wiertsema et al, 2021). Currently, the gut microbiome is accepted to play a crucial role on the health of the host, and a surfeit of studies have depicted that the gut microbiome may provide protection against neurodevelopment disorders, as well as cancer, among other diseases (Lee et al, 2021; Mohajeri et al, 2018; Siddiqui et al, 2021).…”