Untargeted Metabolomics on Skin Mucus Extract of Channa argus against Staphylococcus aureus: Antimicrobial Activity and Mechanism.

Weijun Leng,Zhiyu Xiong,Xiaoyun Wu,Wengang Jin,Ruichang Gao,Tong Shi,Li Yuan

doi:10.3390/foods10122995

Weijun Leng, Zhiyu Xiong + Show 5 more

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https://doi.org/10.3390/foods10122995

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Abstract

Microbial contamination is one of the most common food safety issues that lead to food spoilage and foodborne illness, which readily affects the health of the masses as well as gives rise to huge economic losses. In this study, Channa argus was used as a source of antimicrobial agent that was then analyzed by untargeted metabolomics for its antibacterial mechanism against Staphylococcus aureus. The results indicated that the skin mucus extract of C. argus had great inhibitory action on the growth of S. aureus, and the morphology of S. aureus cells treated with the skin mucus extract exhibited severe morphological damage under scanning electron microscopy. In addition, metabolomics analysis revealed that skin mucus extract stress inhibited the primary metabolic pathways of S. aureus by inducing the tricarboxylic acid cycle and amino acid biosynthesis, which further affected the normal physiological functions of biofilms. In conclusion, the antimicrobial effect of the skin mucus extract is achieved by disrupting cell membrane functions to induce an intracellular metabolic imbalance. Hence, these results conduce to amass novel insights into the antimicrobial mechanism of the skin mucus extract of C. argus against S. aureus.

Highlights

The genus Staphylococcus, a type of classical and ubiquitous Gram-positive bacteria, are representatives of major communities that settle and live in the skin and mucous membrane of animals [1], among of which Staphylococcus aureus is regarded as the primary determinant for causing a variety of human clinical conditions, such as self-remissive skin infections and life-threatening syndromes [2,3]
NAD-Malic dehydrogenase (NAD-MDH), isocitrate dehydrogenase (ICDHm), α-ketoglutarate dehydrogenase (α-KGDH) reagents were purchased from Solarbio Science & Technology Co., Ltd. (Beijing, China), and Succinate dehydrogenase (SDH), adenosine 5 -triphosphate (ATP), Na+/K+-ATPase assay kits were obtained from Jiancheng Bioengineering Institute (Nanjing, China)
The antibacterial activity of the skin mucus extract against E. coli was assessed by the MIC and MBC values, and the determined values were 25 mg/mL and 50 mg/mL, respectively

Summary

Introduction

The genus Staphylococcus, a type of classical and ubiquitous Gram-positive bacteria, are representatives of major communities that settle and live in the skin and mucous membrane of animals [1], among of which Staphylococcus aureus is regarded as the primary determinant for causing a variety of human clinical conditions, such as self-remissive skin infections and life-threatening syndromes [2,3]. The development of natural and safe alternatives to existing antibiotics against S. aureus infections is still of interest [8]. The mucus, which is complex and rich in antibacterial components, such as lysozymes, immunoglobulins, and agglutinins, could act as the first defense barrier against germs. These compounds play very important roles in discriminating pathogenic microorganisms and the commensal microorganisms that can guard fish against invading pathogens [10]. Liu et al [13] uncovered the antibacterial mechanism of astringent persimmon tannins against methicillin-resistant Staphylococcus aureus isolated from pork by combining transcriptome and metabolomics analysis

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