1 Key Laboratory of Subtropical Medicinal Edible Resources Development and Utilization in Yunnan Province, Department of Biology andChemistry, Puer University, Puer Yunnan 665000, China2 Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms of ChineseAcademy of Sciences, Kunming Institute of Zoology, Kunming Yunnan 650223, China3 Department of Clinical Laboratories, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, China4 Institute of Comparative Study of Traditional Materia Medica, Institute of Integrative Medicine of Fudan University, Shanghai 200433, China
This work was supported by grants from the National Natural Sciences Foundation of China(31572268, 31560596), the Key Research Program of the Chinese Academy of Sciences (KJZD-EW-L03), "Yunnan Scholar" Program, the Yunnan Applied Basic Research Projects (2016FD076), the National Training Program of Innovation and Entrepreneurship for Undergraduates (201510685001, 201610685001), and Puer University (RCXM003 & CXTD011)
Cationic antimicrobial peptides (AMPs) are considered as important candidate therapeutic agents, which exert potent microbicidal properties against bacteria, fungi and some viruses. Based on our previous findings king cobra cathelicidin (OH-CATH) is a 34-amino acid peptide that exerts strong antibacterial and weak hemolytic activity. The aim of this research is to evaluate the efficacy of both OH-CATH30 and its analog D-OH-CATH30 against clinical isolates comparing with routinely utilized antibiotics in vitro. In this study, 584 clinical isolates were tested (spanning 2013–2016) and the efficacy of the candidate peptides and antibiotics were determined by a broth microdilution method according to the CLSI guidelines. Among the 584 clinical isolates, 85% were susceptible to OH-CATH30 and its analogs. Both L- and D-OH-CATH30 showed higher efficacy against (toward) Gram-positive bacteria and stronger antibacterial activity against nearly all Gram-negative bacteria tested compare with antibiotics. The highest bactericidal activity was detected against Acinetobacter spp., including multi-drug-resistant Acinetobacter baumannii (MRAB) and methicillin-resistant Staphylococcus aureus (MRSA). The overall efficacy of OH-CATH30 and its analogs was higher than that of the 9 routinely used antibiotics. OH-CATH30 is a promising candidate drug for the treatment of a wide variety of bacterial infections which are resistant to many routinely used antimicrobial agents.