Recognition of multiple Mycoplasma bovis antigens by monoclonal antibodies

Development and evaluation of temperature-sensitive Mycoplasma anserisalpingitidis clones as vaccine candidates

Mycoplasma anserisalpingitidis is economically the most important pathogenic Mycoplasma species of waterfowl in Europe and Asia. The lack of commercially available vaccines against M. anserisalpingitidis had prompted this study with the aim to produce temperature-sensitive (ts⁺) clones as candidates for an attenuated live vaccine. The production of ts⁺ clones was performed by N-methyl-N'-nitro-N-nitrosoguanidine (NTG)-evoked mutagenesis of Hungarian M. anserisalpingitidis field isolates. The clones were administered via eye drop and intracloacally to 33-day-old geese. Colonisation ability was examined by PCR and isolation from the trachea and cloaca, while the serological response of the birds was tested by ELISA. Pathological and histopathological examinations were performed at the eighth week after inoculation. Whole-genome sequence (WGS) analysis of the selected clone and its parent strain was also performed. NTG-treatment provided three ts⁺ mutants (MA177/1/11, MA177/1/12, MA271). MA271 was detected at the highest rate from cloacal (86.25%) and tracheal (30%) samples, while MA177/1/12 and MA271 elicited remarkable serological responses with 90% of the animals showing seroconversion. Re-isolates of MA271 remained ts⁺ throughout the experiment. Based on these properties, clone MA271 was found to be the most promising vaccine candidate. WGS analysis revealed 59 mutations in the genome of MA271 when compared to its parent strain, affecting both polypeptides involved in different cellular processes and proteins previously linked to bacterial fitness and virulence. Although further studies are needed to prove that MA271 is in all aspects a suitable vaccine strain, it is expected that this ts⁺ clone will contribute to the control of M. anserisalpingitidis infection.

Development of a direct competitive ELISA for the detection of Mycoplasma bovis infection based on a monoclonal antibody of P48 protein

Background

Mycoplasma bovis (M. bovis) is a major, but often overlooked, pathogen documented to cause respiratory disease, mastitis, and arthritis in cattle throughout China since 2008. Here, we report the development of a direct competitive enzyme-linked immunosorbent assay (Dc-ELISA) to detect M. bovis antibody.

Results

We used a recombinant P48 protein and monoclonal antibody (mAb) 10E. MAb 10E, prepared against the recombinant P48 protein of M. bovis, identified all M. bovis strains with no cross-reactivity with other related pathogens. Coating micro plates with P48 protein instead of whole M. bovis cells as well as the use of mAb 10E produced a specific and sensitive Dc-ELISA for M. bovis antibody detection with a cut-off percent inhibition (PI) value of 32%. Compared with two commercial indirect ELISA (i-ELISA) kits, our Dc-ELISA offered a higher positive detection rate in 165 clinical bovine serum samples.

Conclusions

A rapid, sensitive, and reliable serological diagnosis method was developed for M. bovis, which can facilitate M. bovis surveillance, assisting researchers in understanding the ecology and epidemiology of M. bovis.