Cysteine/Histidine-Dependent Amidohydrolase/Peptidase (CHAP)-Displayed Nano Phages: Antimicrobial Function against Methicillin-Resistant Staphylococcus aureus (MRSA)

Emergence and prevalence of multi drug resistance strains such as Methicillin-Resistant Staphylococcus aureus (MRSA) call for new antibacterial option. Endolysins as a new option is suggested. The phage display technique is suggested for production of recombinant endolysins. The recombinant endolysins displayed nano phages specifically lysis bacteria, which penetrate to the depth of tissue and the effective dose is reduced.

CHAPK gene was ligated in T7Select vector arms in T7Select10-3b cloning kit. To produce recombinant nano phages, ligation reaction was added directly to the packaging extract. Recombinant nano phages were amplified by Double Layer Agar assay (DLA). The recombinant nano phages were characterized using TEM. Size of recombinant nano phages was determined using DLS. The spot test was performed to confirm CHAPk -displayed on the surface of nano phages. The turbidimetry was used to investigate lytic activity of recombinant nano phages against MRSA ATCC No. 33591.

The results showed recombinant nano phages belonged to order Caudovirales and family Podoviridae with titer 2×107 PFU/ml. According to the results of DLS, size of recombinant nano phages was 71 nm. Formation inhibition zone confirmed the presence of CHAPk on the surface of nano phage phenotypically. The turbidimetry showed lytic activity recombinant nano phages against MRSA after 5 min.

This study suggests that CHAPk -displayed nano phages can be effective in MRSA infections.