IPSF: Roosters as a reservoir for Mycoplasma
The male reproductive tract may serve as a reservoir for Mycoplasma synoviae
13 July 2026
1 minute read
By: [Excerpts of a poster presentation by Eniope Oluwayinka and Naola Ferguson-Noel at the University of Georgia, USA, during the 2026 International Poultry Scientific Forum]
Mycoplasma synoviae (MS) is a significant avian pathogen associated with respiratory disease, airsacculitis, and reproductive problems, including decreased egg production, eggshell abnormalities, and infertility in hens, yet its role in male reproductive tract colonization is under-documented.
This study aimed to determine the capacity of virulent field strains of MS to colonize the testes of roosters. Roosters were inoculated with five distinct MS strains isolated from chickens in the United States and observed for two weeks post-challenge. Testicular tissues were collected for both MS culture and strain-specific PCR, air sac and footpad lesions were scored, while the trachea was simultaneously collected for histopathology and PCR.
Necropsy revealed significant airsacculitis and footpad lesions, along with tracheal thickening. Two of the five challenge MS strains, both originating from North Carolina, were isolated from testicular samples, achieving isolation rates of 29.2% and 42.9% in their respective groups. The testicular samples were also confirmed positive via MS-specific PCR. Sequence typing of the vlhA gene indicated that the two testicular isolates represented a distinct genotype.
The testicular isolates showed 99.11% genomic identity with the ATCC reference strain (WVU). Crucially, proteomic comparison with the three other non-testicular isolates revealed non-synonymous mutations in proteins located downstream of the siderophore-mediated iron transport protein, a pathway vital for iron acquisition that influences biofilm formation, motility, and survival. These findings furnish direct evidence that virulent MS strains can colonize rooster testicular tissue.
This colonization suggests the male reproductive tract may serve as an additional reservoir for MS persistence. These results have substantial implications for understanding venereal and potential vertical transmission in poultry breeder flocks and underscore the necessity for further research into the mechanisms of MS dissemination within the male reproductive system.
