Antibacterial and anti-biofilm effects of fatty acids extract of dried Lucilia sericata larvae against Staphylococcus aureus and Streptococcus pneumoniae in vitro

Abstract

Development of new effective antimicrobial drugs is still a big challenge to date due to microbial infection remains an inevitable problem against human health. In this study, fatty acids extract of Lucilia sericata larvae (LFAs) was obtained and evaluated by gas chromatograph-mass spectrometry (GC-MS), and its antibacterial activity against Staphylococcus aureus (S. aureus) and Streptococcus pneumoniae (S. pneumoniae) was investigated. We found that LFAs exhibited effective antibacterial activity against S. aureus and S. pneumoniae with minimal inhibitory concentrations (MICs) of 125 μg/mL and 100 μg/mL, respectively. The bacterial wall and membrane were the main targets, which was confirmed by fluorescence microscopy, scanning electron microscopy and transmission electron microscopy. Furthermore, a notable anti-biofilm activity against S. aureus and S. pneumoniae was also observed, which was able to both prevent biofilm formation and eradicate mature biofilms of these bacteria. As a promising antibacterial agent, LFAs showed good application prospects in clinical practice.

GRAPHICAL ABSTRACT

Keywords:

• Fatty acids extract
• Lucilia sericata larvae
• antibacterial
• anti-biofilm
• Staphylococcus aureus
• Streptococcus pneumoniae

Disclosure statement

The authors declare no conflicts of interest or financial interests.

Additional information

Funding

This work was supported by National Natural Science Foundation of China (81702995, 81573734 and 81403230), National Natural Science Foundation of Liaoning Province (2014023020 and 2015020310), Scientific Project of Dalian City (2014E14SF167), Clinical Capability Construction Project for Liaoning Provincial Hospitals (LNCCC-A04-2014), LiaoNing Revitalization Talents Program (XLYC1802014), Distinguished Professor Project of Liaoning Province, Program for Liaoning Excellent Talents in University and Hundred, Thousand and Ten Thousand Talent Project of Liaoning Province.