Isolation and Identification of Mycoplasma agalactiae by Culture and Polymerase Chain Reaction Methods in the Sheep Herds in Guilan Province, Iran

Contagious agalactia is an infectious syndrome of sheep that is characterized by mastitis with reduction of milk production, arthritis, abortion, and keratoconjunctivitis. The disease is rapidly spread by the contact of the infected animals with the healthy ones. Domestic sheep and goats of both sexes can be infected at an equivalent frequency. Most of the researchers use culture and molecular methods for the isolation and identification of Mycoplasma. Mycoplasma agalactiae is the main cause of the disease in sheep. The aim of this study was to isolate and identify M. agalactiae by using culture and polymerase chain reaction (PCR) assay in the sheep herds in Guilan province, Iran. A total of 71 specimens were collected from seven sheep herds with clinical signs of agalactia disease. All of the seven sheep herds (100%) were positive either in PPLO agar or Mycoplasma PCR test. Out of the 71 specimens, 50 (70.4%) cases were positive; however, 21 (29.6%) samples were negative. Furthermore, 40 (80%) cases of the positive samples were detected for the presence of Mycoplasma by the PCR method; nonetheless, 34 (68%) samples were positive in culture. Additionally, out of the 40 positive samples in Mycoplasma PCR, 11 (27.5%) samples were detected in M. agalactiae-specific PCR. The samples that were positive for Mycoplasma were mostly detected in the ear/vaginal, milk, and ear swab samples, respectively, by culture and PCR methods. The most positive samples of Mycoplasma / M. agalactiae were obtained from the ear and vaginal samples. Our findings demonstrated that Mycoplasma was one of the main etiological agents of the contagious agalactia in Guilan province. In addition, PCR was found to be more successful than the culture method in the detection of Mycoplasma.