Mycoplasma Infection in the Lungs of Cattle: The First Identification of Mycoplasma dispar in Iran

Members of the genus Mycoplasma are known as pathogens causing respiratory disease in cattle world-wide.

The present study aimed to investigate mycoplasmal infection in the lung tissue of cattle slaughtered in Hamadan industrial abattoir, Iran, using molecular and histopathological methods.

A total of 108 tissue samples were collected from the cranioventral parts of the cattle lung during March 2015-February 2016. The specimens were subjected to a polymerase chain reaction (PCR) and histopathological examinations. The PCR-positive samples were tested subsequently for Mycoplasma bovis and Mycoplasma dispar using nested PCR assay.

Nine (8.33%) samples contained the DNA of genus Mycoplasma, among which, five and one showed the DNA sequences of M. bovis and M. dispar, respectively. Pathological changes, such as caseonecrotic lesions, interstitial pneumonia, lobar bronchopneumonia, and bronchial atelectasis were observed in 24 (22.22%) tissue samples. All the PCR-positive lungs demonstrated at least one pathological manifestation. However, not every pathognomonic tissue changes were concomitant with the presence of the DNA of Mycoplasma spp.

It could be concluded that M. bovis and to a lesser extent M. dispar are relatively common in the cattle population of the western part of Iran. Therefore, these pathogens should be taken into consideration whenever respiratory problems are evident in cattle