In vitro and in vivo efficacy of Caenorhabditis elegans recombinant antimicrobial protein against Gram-negative bacteria

Abstract

Antimicrobial peptides (AMPs) are short, positively charged host defense peptides, found in various life forms from microorganisms to humans. AMPs are gaining more attention as substitutes for antibiotics in order to combat the risk posed by multi-drug- resistant pathogens. The nematode Caenorhabditis elegans relies solely on its innate immune defense to cope with its challenging life-style. Bacterial infection in C. elegans leads to induction of antimicrobial proteins, defensins, nemapores, cecropins, and neuropeptide-like proteins, which act to limit bacterial proliferation. This study reports how the C. elegans recombinant antibacterial factor (ABF-1) rapidly inhibited bacterial growth (Salmonella Typhi, Klebsiella pneumonia, Shigella sonnei and Vibrio alginolyticus). The ABF-1 exposure on S. Typhi, showed differential regulation in cell-cycle, DNA repair mechanism, membrane stability, and stress related proteins. The exogenous supply of ABF-1 protein has extended C. elegans survival by reducing the bacterial colony forming units on the nematode intestine. Together, these findings indicate the valuable and potential therapeutic applications of ABF-1 protein as antimicrobial agents against intracellular pathogens.

Keywords:

• ABF-1 protein
• Salmonella
• antibacterial activity
• proteomics

Acknowledgements

The authors thank the Caenorhabditis Genetics Centre, which is funded by the National Institute of Health and the National Centre for Research Resources, for providing the nematode strains. KB thankfully acknowledges the Department of Biotechnology (DBT; Grant No. BT/PR17367/MED/122/44/2016), Ministry of Science and Technology, Government of India, New Delhi, India, for financial assistance. DAM gratefully acknowledges the University Grants Commission (UGC) of India for financial assistance in the form of UGC-PF (F. No. 42-222/2013 (SR)). The computational facility provided by the Bioinformatics Infrastructure Facility, Alagappa University funded by the Department of Biotechnology, Ministry of Science and Technology, Government of India (Grant No.BT/BI/25/015/2012 (BIF)) are thankfully acknowledged. The authors are also grateful for the Alagappa University Scientific Instrumentation Facility provided by the Department of Science and Technology (DST), Government of India through DST PURSE [Grant No. SR/S9Z-415 23/2010/42(G)], DST FIST [Grant No. SR-FST/LSI-087/2008], UGC through SAP-DRS1 [Grant No. F. 3-28/2011(SAP-II)] and RUSA 2.0.

Disclosure statement

The authors declare that they have no conflicts of interest in respect of the contents of this article.