Mycoplasma hyopneumoniae genetic variability within a swine operation

Area of Science:

• Veterinary Microbiology
• Swine Disease Genetics
• Molecular Epidemiology

Background:

• Mycoplasma hyopneumoniae is a primary cause of respiratory disease in pigs.
• Understanding its genetic diversity is crucial for disease control in intensive swine operations.
• Commingling pigs from different sources can influence pathogen genetic dynamics.

Purpose of the Study:

• To characterize the genetic diversity of Mycoplasma hyopneumoniae in pigs within a commingled swine operation.
• To identify and differentiate Mycoplasma hyopneumoniae variants using molecular typing methods.
• To assess the prevalence and distribution of identified variants across different farms.

Main Methods:

• Collection of bronchial swabs and tracheal aspirates from nursery-to-finish swine.
• Detection of Mycoplasma hyopneumoniae using real-time polymerase chain reaction (PCR).
• Genetic typing of isolates via multilocus variable number tandem repeat analysis (MLVA) targeting P97 and P146 loci.

Main Results:

• Four distinct Mycoplasma hyopneumoniae variants (MVLA 9-15, 11-21, 9-21, 7-15) were identified.
• Variant 9-15 was the most prevalent (79% of rooms) and found on all three farms.
• Variants 9-21 and 7-15 showed limited distribution, suggesting potential in-situ recombination.

Conclusions:

• A limited number of Mycoplasma hyopneumoniae variants and genetic clusters were observed in the studied commingled swine operation.
• The findings suggest restricted genetic variation of this pathogen in commercial swine production environments.
• Further research into recombination events may clarify the evolution of Mycoplasma hyopneumoniae in swine herds.