Development of an ELISA for distinguishing convalescent sera with Mycoplasma hyopneumoniae infection from hyperimmune sera responses to bacterin vaccination in pigs

Honglei Ding; Yukang Wen; Zuobo Xu; Bingqian Zhou; Chaker Tlili; Yaqin Tian; Zhaodi Wang; Yaru Ning; Jiuqing Xin

doi:10.1002/vms3.539

Development of an ELISA for distinguishing convalescent sera with Mycoplasma hyopneumoniae infection from hyperimmune sera responses to bacterin vaccination in pigs

Vet Med Sci. 2021 Sep;7(5):1831-1840. doi: 10.1002/vms3.539. Epub 2021 May 22.

Authors

Honglei Ding^{1

2}, Yukang Wen^{1

2}, Zuobo Xu^{1

2}, Bingqian Zhou^{1

2}, Chaker Tlili³, Yaqin Tian^{1

2}, Zhaodi Wang^{1

2}, Yaru Ning^{1

2}, Jiuqing Xin⁴

Affiliations

¹ Laboratory of Veterinary Mycoplasmology, College of Veterinary Science, Southwest University, Chongqing, China.
² Immunology Research Center, Medical Research Institute, Southwest University, Chongqing, China.
³ Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China.
⁴ State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.

Abstract

Vaccination with inactivated bacterin is the most popular and practical measure to control enzootic pneumonia. After immunisation with inactivated bacterin, Mycoplasma hyopneumoniae colonised on the respiratory tract and lung stimulates the humoural immune responses and produces IgG and IgA antibodies. ELISA is a widely used serological method to detect M. hyopneumoniae antibodies. However, commercial IgG-ELISA kit cannot distinguish between inactivated bacterin-induced hyperimmune sera and convalescent sera stimulated by natural infection. SIgA-ELISA method needs to collect nasal swabs, but collecting nasal swabs is not easy to operate. Establishment of a discriminative ELISA detecting humoural IgG from convalescent sera but not hyperimmune sera facilitates to evaluate the natural infection of M. hyopneumoniae after inactivated bacterin vaccination. We expressed and purified a recombinant protein named Mhp366-N which contains an epitope recognised by the convalescent sera but not hyperimmune sera. The developed discriminative IgG-ELISA could discriminate between inactivated bacterin-induced hyperimmune sera and convalescent sera and was reproducible, sensitive and specific to M. hyopneumoniae antibody produced by natural infection. Compared to SIgA-ELISA method, discriminative IgG-ELISA was more convenient to detect IgG antibody from sera than IgA from nasal swabs, although it has limited sensitivity in the early stages of infection. Additionally, to some extent, it has a potential to avoid the interference of maternally derived IgG antibodies. The established discriminative IgG-ELISA was efficient to judge the serological IgG antibodies induced from natural infection or inactivated vaccine stimulation and provided a useful method to investigate and evaluate the live organism infection after the application of inactivated bacterin.

Keywords: Mycoplasma hyopneumoniae; IgG; convalescent sera; hyperimmune sera; indirect ELISA.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bacterial Vaccines
Enzyme-Linked Immunosorbent Assay / methods
Enzyme-Linked Immunosorbent Assay / veterinary
Mycoplasma hyopneumoniae*
Pneumonia of Swine, Mycoplasmal* / diagnosis
Pneumonia of Swine, Mycoplasmal* / prevention & control
Swine
Swine Diseases* / prevention & control
Vaccination / veterinary

Substances

Bacterial Vaccines