جستجوی مقالات مرتبط با کلیدواژه "پپتید های ضد میکروبی" در نشریات گروه "پزشکی"

Multi-drug resistant (MDR) Acinetobacter baumannii is a prevalent hospital pathogen. Antimicrobial peptides (AMPs), such as Oncorhyncin II, have been proposed for treating MDR pathogens. This study aimed to assess the antibacterial activity of recombinant protein Oncorhyncin II against Acinetobacter baumannii (ATCC19606) under in vitro conditions.

In this experimental study, the gene construct pET32a-oncorhyncin II was transferred to Escherichia coli BL21 (DE3) for expressing the recombinant Oncorhyncin II protein. Purification was optimized using nickel affinity chromatography (Ni-NTA), and the peptide's efficacy was evaluated by determining the minimum inhibitory concentration (MIC), bactericidal kinetics, and growth kinetics against Acinetobacter baumannii (ATCC19606).

The recombinant Oncorhyncin II protein was successfully expressed in E. coli BL21 (DE3) and purified with over 70% purity. The MIC assay confirmed effective antibacterial activity of Oncorhyncin II against Acinetobacter baumannii at a concentration of 95.87 μg/ml. At 2x MIC, Oncorhyncin II led to a rapid reduction in viable cell count and decreased turbidity of the bacterial inoculum in bactericidal and growth kinetics assessments.

The produced recombinant Oncorhyncin II exhibited potent antibacterial activity against Acinetobacter baumannii. These findings can contribute to the development and production of novel antimicrobial drugs for treating infections caused by Acinetobacter baumannii.

Vitamin D is known for its roles in calcium metabolism and bone health. With the spread of COVID-19 epidemic, roles of this vitamin in strengthening host immune system has received more attention. Nearly 900 genes have been identified, whose expression is controlled by vitamin D. Most of these genes are involved in innate and adaptive immune systems. Vitamin D prohibits the penetration of viruses deep into tissues by maintaining intercellular connections. This characteristic of vitamin D prevents rapid spread of the coronavirus in the lungs. Stimulating immune cell differentiation, increasing killing capacity of macrophages and increasing production of antimicrobial peptides such as cathelicidin and β-defensin by vitamin D increase the immune system ability to fight coronavirus. Moreover, vitamin D decreases over secretion of inflammatory cytokines; thus, prohibiting cytokine storm and uncontrolled inflammation in the lungs. Modulating activity of the renin-angiotensin system and preventing over accumulation of angiotensin 2 are other functions of vitamin D in protecting tissues, especially lungs, against the coronavirus.