مقالات پذیرفته شده در هفتمین کنگره بین المللی زیست پزشکی
Design and Production of an Engineered Endolysin with Lytic Activity against Methicillin-Resistant Staphylococcus Aureus
Design and Production of an Engineered Endolysin with Lytic Activity against Methicillin-Resistant Staphylococcus Aureus
Sarvenaz Janbaz,1Amir Maleksabet,2,*Negar Meschi,3
1. Department of Medical Biotechnology, Faculty of Advanced Technologies in Medicine, Mazandaran University of Medical Sciences, Sari, Iran 2. Department of Medical Biotechnology, Faculty of Advanced Technologies in Medicine, Mazandaran University of Medical Sciences, Sari, Iran 3. Department of Medical Biotechnology, Faculty of Advanced Technologies in Medicine, Mazandaran University of Medical Sciences, Sari, Iran
Introduction: Improper use of antibiotics has alarmingly led to the emergence of antibiotic resistance. Hence, we urgently needed to find a suitable alternative to traditional antibiotics. Endolysins are enzymes produced at the end of the phage replication cycle and destroy the peptidoglycan of the bacterial cell wall leading to the lysis of the host bacterial cell. These enzymes are species-specific, exhibit high lytic activity, and it is almost impossible for bacteria to develop resistance against them. Lysozyme subfamily 2 (LYZ2) is a modular region of the gene 61 (gp61) of phage φMR11 with lytic activity against S. aureus. However, it does not possess a cell wall recognition domain, usually found in lysins acting against gram-positive bacteria. Therefore, we aimed to design a chimeric endolysin capable of specifically targeting and eliminating methicillin-resistant Staphylococcus aureus (MRSA) bacteria.
Methods: In this study, we engineered the LYZ2 by fusing a Staphylococcus aureus cell wall-binding domain (CBD) to its C-terminus and cloned the chimeric protein (named chimeric staphylococcus aureus–targeting enzybiotic (CSTEnz)) into the pET28a vector, and expressed the enzyme in E. coli BL21 (DE3) cell. The antibacterial property of the enzyme was further evaluated by turbidity reduction assay, disk diffusion assay, and antimicrobial susceptibility testing.
Results: The engineered lysin displayed a rapid and specific lytic activity against susceptible and Methicillin-resistant staphylococcus aureus and inhibited the growth of the bacteria at concentrations higher than 0.5 µg/ml. Besides, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of CSTEnz were 128 and 64 times lower than those of LYZ2, indicating the increased bacteriolytic activity of the engineered version of the enzyme.
Conclusion: In conclusion, the chimeric enzybiotic can be used as a potential antibacterial agent to limit infections caused by methicillin-resistant Staphylococcus aureus.