Dept. of Mathematics, BITS-PILANI, Hyderabad Campus, Hyderabad, India.
Laboratory of Medical Microbiology, School of Life Sciences, Sambalpur University, Sambalpur, India.
Appl Biochem Biotechnol. 2021 Jun;193(6):1639-1653. doi: 10.1007/s12010-021-03510-2. Epub 2021 Feb 9.
In time, diagnosis and detection of virulence factor and its pathogenomics study continues to grow and this leads to novel treatments for infectious diseases. The objective of this study was to detect and characterise virulence genes in a haemolytic strain of Staphylococcus aureus in vitro and molecular interaction studies with herbal essential oil components in silico. A hospital biosample-isolated strain of Staphylococcus aureus (BMS-2) was resistant towards Cephalosporin. The PCR-amplified FASTA nucleotide sequence was identical with S. aureus strains absolutely. The calculated GC value was 34.05%. The translated protein sequence was identified with a conserved domain of hlyII β-channel forming cytolysin belonging to leukocidin superfamily and was predicted as a stable, non-transmembrane protein comprising B cell epitopes. Structurally, the protein was found to be composed of α helix, π-helix, extended strands, β-sheet, turn and bends with atomic composition as CHNOS. The molecular docking studies made between the HlyII cytolysin (receptor) and wet lab studied essential oil components (citral a, citronellol, eucalyptol, eugenol, geraniol, linalool, menthol, piperine and thymol) as ligands using Autodock 1.5.6 tool had inferred about prevalence of hydrogen bonds as well as covalent bonds in the intermolecular interactions. Amino acids like Tyr68, Tyr 69, Asn106, Asp67 and Asn106 were observed to be the most active residues for H-bond and hydrophobic bonds respectively. Only geraniol had interaction with glycine residue of the toxin molecule. In conclusion, geraniol with the highest ligand efficiency was observed to be the most potent phyto-constituent interacting with the in vitro detected hlyII cytotoxin.
随着时间的推移，对毒力因子及其病原体组学的诊断和检测不断发展，这为传染病的治疗提供了新的方法。本研究的目的是在体外检测和表征一株溶血葡萄球菌的毒力基因，并通过计算机模拟研究草药精油成分与该基因的分子相互作用。一株从医院生物样本中分离出来的金黄色葡萄球菌（BMS-2）对头孢菌素具有耐药性。通过 PCR 扩增的 FASTA 核苷酸序列与金黄色葡萄球菌株完全相同。计算的 GC 值为 34.05%。翻译后的蛋白序列与 hlyII β-通道形成细胞毒素的保守结构域相匹配，属于白细胞毒素超家族，被预测为一种稳定的、非跨膜蛋白，包含 B 细胞表位。结构上，该蛋白由 α 螺旋、π 螺旋、伸展链、β 折叠、转角和弯曲组成，原子组成是 CHNOS。通过 Autodock 1.5.6 工具，对 HlyII 细胞毒素（受体）与经过湿实验室研究的精油成分（柠檬醛 a、香茅醇、桉叶油醇、丁香酚、香叶醇、芳樟醇、薄荷醇、胡椒碱和百里酚）之间的分子对接研究表明，在分子间相互作用中存在氢键和共价键。观察到 Tyr68、Tyr69、Asn106、Asp67 和 Asn106 等氨基酸是与 H 键和疏水键最活跃的残基。只有香叶醇与毒素分子中的甘氨酸残基相互作用。总之，具有最高配体效率的香叶醇被观察到是与体外检测到的 hlyII 细胞毒素相互作用的最有效的植物成分。
