Hepcidin, a cysteine-rich cationic antibacterial peptide, plays an important 
role in human defense against pathogen infection. However, its role in reptile 
immune response and whether it is involved in antibacterial immune have not yet 
been proven. In order to study the antibacterial activity of Crocodylus 
siamensis hepcidin (Cshepc), a common reptile which lives in topic region of 
Southeast Asia, a cDNA sequence of Cshepc was cloned, which included an open 
reading frame (ORF) of 300 bp encoding a 99 amino acid preprohepcidin. Cshepc 
has eight cysteines formed four conserved disulfide bridges, similarly to that 
of human's. Sequence analysis showed that Cshepc mature peptide was more 
conserved than that of preprohepcidin. Tissue expression analysis indicated that 
Cshepc transcripts were highly expressed in the liver, muscle and heart of C. 
siamensis. Recombinant expressed hepcidin could significantly inhibit the growth 
of the Gram-negative bacteria Escherichia coli and Aeromonas sobria as well as 
the Gram-positive bacterium Staphylococcus aureus, and Bacillus subtilis in 
vitro, suggesting that Cshepc, like human hepcidin could play a role in the 
antibacterial function in hosts innate immune response.