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Construction and evaluation of a novel triple cell epitopebased polypeptide vaccine against cow mastitis induced by Staphylococcus aureus, Escherichia coli and Streptococcus


Xiang Liu
Chunlin Chen
Chen Chen
Gregory Marslin
Rui Ding
Sanqiao Wu

Abstract

Purpose: To construct a novel triple cell epitope-based polypeptide vaccine against cow mastitis induced by Staphylococcus aureus, Escherichia coli and  Streptococcus and to reduce the use of antibiotics.
Methods: Based on bioinformatics approach, a novel triple epitope-based polypeptide (CM-TEP) was designed and subjected to Ni-NTA flow resin purification. Purified CM-TEP was immunized into mice to prepare a polyclonal antibody. Pull-down assays and enzyme-linked immunosorbent assay (ELISA) were used to detect the interaction between CM-TEP antibodies and S. aureus, E. coli and Streptococcus. Active immunity mice and challenge of bacterial pathogens were used to detect immune protection of CM-TEP. Additionally, the optimal expressing conditions of CM-TEP strain were analyzed using orthogonal test design.
Results: A novel cow mastitis triple cell epitope-based polypeptide (CM-TEP) with a MW of 36 kDa was designed, purified and used to immunize mice to prepare a  polyclonal antibody. Pull-down assays and ELISA data showed that CM-TEP  antibodies directly interacted with S. aureus, E. coli and Streptococcus. CM-TEP displayed a significant immune protective effect against infection by S. aureus (50 %, p < 0.05) and E. coli (54.54 %, p < 0.05) and provided some immune protective effect (30.78 %, p > 0.05) against Streptococcus. The optimum expressing conditions of CM-TEP were as follows: IPTG concentration of 0.3 mmol/L, strain OD600 value of 1, inducing temperature of 37 oC, and inducing time of 8 h.
Conclusion: The findings suggest that epitope-based vaccine of CM-TEP may be a useful strategy for treating cow mastitis induced by S. aureus, E. coli and Streptococcus.


Keywords: Cow mastitis, Epitope vaccine, Immunogenicity, Immune protective


Journal Identifiers


eISSN: 1596-9827
print ISSN: 1596-5996