Resumo

Ureaplasmas have been implicated in many diseases and among them Ureaplasma diversum is included among the microorganisms that cause lung infections that bring harm to agriculture. This pathogen colonizes the mucosal surface of the respiratory and urogenital tracts of animals, causing tissue damage. Currently there is no experimental model that can be studied for understanding the immune response involved in the control of infection caused by this microorganism. Thus, mice A/J, Balb/C and C57BL/6 were used to evaluate the inflammatory response to infection by U. diversum. Animals were infected intratracheally with a virulent strain of U. diversum and euthanized 1, 2, 3, 7 and 14 days after infection. Samples of body fluids (bronchoalveolar lavage) were collected and evaluated the number of cells and cytokine production. The total cell count was determined in a Newbauer chamber and further analysis was performed by differential citospin. Characterization of the inflammatory infiltrate was performed by light microscopy and cytokine production by ELISA technique. Lung fragments were assessed by morphometry, as well as by culture and PCR generally, to confirm the presence of U. diversum. An increased number of inflammatory cells in the early hours of infection was observed. Most of these cells are represented by neutrophils. In infected animals was observed increased production of INF-γ, IL-6, IL-1β, TNF-α e IL-10, correlating them with the presence of inflammatory infiltrate. Infected mice showed positive cultures for U. diversum in the lung samples growth. Infection was confirmed by PCR. In the model presented neutrophilic infiltrate and production of proinflammatory cytokines have been associated with protective immunity of animals in response to infection with U. diversum.