Isolation and identification of mycoplasma from respiratory system of goat

Abstract

In Bangladesh there is no published report of mycoplasmosis in Black Bengal goats. In the present study, attempts have been undertaken to investigate the clinical samples for the isolation and identification of Mycoplasma in goats. In addition, the morphological changes (gross and histopathology) of mycoplasmosis in naturally infected Black Bengal goats and morbidity and mortality rates of mycoplasmosis in goat were also studied. A total of 100 samples, lung exudates, swabs from trachea, nasal cavity and suspected lungs from the slaughter houses were studied. Out of the 100 samples, 27 samples were clinically suspected cases from the USDA funded research goat farm (USDARGF) at the artificial insemination center of BAU and 10 clinically healthy goat’s samples. The rest 63 samples were taken from municipality slaughter houses in Mymensingh district during July to October, 2010. Morbidity and mortality rate of suspected mycoplasmosis in USDARGF were 32.14 and 15%, respectively. Samples were collected in 10% formalin for histopathological study. Swabs were collected in Mycoplasma broth supplemented with horse serum and Kanamycin solution for the isolation of pathogenic goat mycoplasmas. Additionally, Kanamycin solution was added to prevent the growth of gram –ve bacteria. In this study, “possible etiological agent” Mycoplasma was investigated for the first time and found that 8% cases were positive for mycoplasmosis as confirmed by isolation and identification of colony characteristics. The yellowish foci, pea sized nodule and fibrin deposit were in the lung surface. The pulmonary pleura become thickened, fibrin deposit and there were adhesions to the chest wall. In microscopic field the lungs showed bronchopneumonia, fibro-purulent pneumonia with adhesion pleuritis and thickening of the alveolar walls. The Mycoplasma spp. were identified from colony with Gram’s staining and Giemsa staining. Moreover, in this study the organisms were also directly demonstrated in the tissue by the mentioned staining. It seemed from the study that mycoplasmosis is the common disease of the respiratory tract of goats. However, further studies could be carried out to confirm the Mycoplasma by Polymerase Chain Reaction (PCR).

Keywords: Black Bengal goat, pneumonia, bronchopneumonia, fibropurulent pneumonia, Mycoplasma spp., culture.