Genotyping of Mycoplasma hyorhinis using multiple-locus variable number tandem repeat analysis

Area of Science:

• Veterinary Microbiology
• Molecular Epidemiology
• Swine Infectious Diseases

Background:

• Mycoplasma hyorhinis is a re-emerging swine pathogen causing substantial economic losses.
• Existing molecular typing methods for M. hyorhinis lack resolution and reproducibility.
• Understanding the genetic variability of M. hyorhinis is crucial for effective disease control.

Purpose of the Study:

• To develop and validate a novel Multiple Loci of Variable Number of Tandem Repeats Analysis (MLVA) typing tool for Mycoplasma hyorhinis.
• To assess the genetic diversity and epidemiological patterns of M. hyorhinis using the developed MLVA assay.
• To provide a reproducible and portable molecular epidemiology tool for M. hyorhinis.

Main Methods:

• Development of an MLVA assay targeting two hypothetical proteins (MHR_0152 and MHR_0298) in the M. hyorhinis genome.
• Analysis of 205 samples, including field isolates and clinical specimens, using the developed MLVA assay.
• Calculation of the Simpson's diversity index to evaluate the discriminatory power of the assay.

Main Results:

• The MLVA assay identified 16 distinct MLVA types among 165 analyzed samples.
• The most prevalent MLVA types were 8-4 (36.9%), 8-3 (11.5%), and 7-4 (11.5%).
• The assay demonstrated high discriminatory power (Simpson's diversity index D=0.814) and reproducibility, with no observed clustering by geographical location, sample type, or time.

Conclusions:

• The developed MLVA assay is a reproducible, portable, and highly discriminatory tool for molecular typing of Mycoplasma hyorhinis.
• This assay will significantly aid in epidemiological investigations and enhance the understanding of M. hyorhinis genetic diversity.
• The MLVA technique can be readily implemented in laboratories for improved swine disease surveillance and management.