Caerin 1.1 and 1.9 Peptides from Australian Tree Frog Inhibit Antibiotic-Resistant Bacteria Growth in a Murine Skin Infection Model.

Shu Chen,Pingping Zhang,Xiaosong Liu,Liyin Xiao,Kuihai Wu,Ying Liu,Guoying Ni,Guoqiang Chen,Tianfang Wang,Xiaolian Wu,Hejie Li,Jan Claesen

doi:10.1128/spectrum.00051-21

Shu Chen, Pingping Zhang + Show 10 more

Open Access

https://doi.org/10.1128/spectrum.00051-21

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Abstract

ABSTRACTThe host defense peptide caerin 1.9 was originally isolated from skin secretions of an Australian tree frog and inhibits the growth of a wide range of bacteria in vitro. In this study, we demonstrated that caerin 1.9 shows high bioactivity against several bacteria strains, such as Staphylococcus aureus, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), and Streptococcus haemolyticus in vitro. Importantly, unlike the antibiotic Tazocin, caerin 1.9 does not induce bacterial resistance after 30 rounds of in vitro culture. Moreover, caerin 1.1, another peptide of the caerin family, has an additive antibacterial effect when used together with caerin 1.9. Furthermore, caerin 1.1 and 1.9 prepared in the form of a temperature-sensitive gel inhibit MRSA growth in a skin bacterial infection model of two murine strains. These results indicate that caerin 1.1 and 1.9 peptides could be considered an alternative for conventional antibiotics.IMPORTANCE Antibiotic-resistant bacteria cause severe problems in the clinic. We show in our paper that two short peptides isolated from an Australian frog and prepared in the form of a gel are able to inhibit the growth of antibiotic-resistant bacteria in mice, and, unlike antibiotics, these peptides do not lead to the development of peptide-resistant bacteria strains.

Highlights

The host defense peptide caerin 1.9 was originally isolated from skin secretions of an Australian tree frog and inhibits the growth of a wide range of bacteria in vitro
We first assessed the MICs of caerin 1.9 against S. aureus, P. aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), A. baumannii, and S. haemolyticus
The results suggested that both caerin 1.1 and caerin 1.9 have a better ability to inhibit the growth of S. aureus and MRSA than the commonly used antibiotic polymyxin B, but this was not significant against S. haemolyticus

Summary

Introduction

The host defense peptide caerin 1.9 was originally isolated from skin secretions of an Australian tree frog and inhibits the growth of a wide range of bacteria in vitro. Caerin 1.1 and 1.9 prepared in the form of a temperature-sensitive gel inhibit MRSA growth in a skin bacterial infection model of two murine strains. These results indicate that caerin 1.1 and 1.9 peptides could be considered an alternative for conventional antibiotics. More than 200 host defense peptides have been isolated and identified from skin secretions of Australian frogs and toads Many of these peptides, including caerin peptides, have antiviral, antitumor, antimicrobial, and/or neuropeptide-type activities [7,8,9,10]. It has been shown that caerin 1.1 and caerin 1.9 peptides have additive effects against human papillomavirus (HPV)-transformed tumor cells and increase the efficacy of a therapeutic vaccine against HPV-related diseases [9, 11, 18, 19]

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