Periódicos Brasileiros em Medicina Veterinária e Zootecnia

Antibacterial potential of a basic phospholipase A sub>2 /sub>(VRV-PL-VIIIa) from Daboia russelii pulchella (Russell's viper) venom

Sudharshan, ShivalingaiahLakkappa Dhananjaya, Bhadrapura

title>Abstract /title> sec> title>Background: /title> p>Microbial/bacterial resistance against antibiotics poses a serious threat to public health. Furthermore, the side effects of these antibiotics have stimulated tremendous interest in developing new molecules from diverse organisms as therapeutic agents. This study evaluates the antibacterial potential of a basic protein, italic>Vipera russellii /italic> venom phospholipase A sub>2 /sub> fraction VIIIa (VRV-PL-VIIIa), from Daboia italic>russelii pulchella /italic> venom against gram-positive and gram-negative bacteria. /p> /sec> sec> title>Methods: /title> p>The antibacterial potential of VRV-PL-VIIIa in the presence and absence of an inhibitor (p-bromophenacyl bromide) was tested against gram-positive and gram-negative bacteria and the minimum inhibitory concentration was determined by microdilution tests. /p> /sec> sec> title>Results: /title> p>VRV-PL-VIIIa demonstrated potent antibacterial activities against all the human pathogenic strains tested. It more effectively inhibited such gram-positive bacteria as italic>Staphylococcus aureus /italic> and italic>Bacillus subtilis /italic>, when compared to the gram-negative bacteria italic>Escherichia coli, Vibrio cholerae, Klebsiella pneumoniae /italic> and italic>Salmonella paratyphi /italic>. It inhibited bacterial growth at minimum inhibitory concentration values ranging from 11.1 to 19.2 g/mL. The anti-bacterial potential of VRV-PL-VIIIa was comparable to the standards gentamycin, chlorophenicol and streptomycin. The PLA sub>2 /sub>'s hemolytic and antibacterial activities were strongly correlated. Furthermore, even in the presence of p-bromophenacyl bromide, intense antibacterial activity was observed, suggesting a dissociation or partial overlapping of the bactericidal/antimicrobial domains. /p> /sec> sec> title>Conclusion: /title> p>VRV-PL-VIIIa demonstrated potent antibacterial activities against all the human pathogenic strains tested. The study shows that despite a strong correlation between enzymatic and antimicrobial activities of VRV-PL-VIIIa, it may possess additional properties that mimic the bactericidal/membrane permeability-increasing protein. This study encourages further in-depth studies on the molecular mechanisms of antibacterial properties of VRV-PL-VIIIa, which would thereby facilitate development of this protein into a possible therapeutic lead molecule for treating bacterial infections. /p> /sec>

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