RESUMO
Porcine enzootic pneumonia (PEN), caused by Mycoplasma hyopneumoniae (Mh), has been described in pigs in all geographic areas. The disease is characterized by high morbidity and low mortality rates in intensive swine production systems. A morphologic and immunohistochemical study was done to determine the cellular populations present in lung parenchyma of infected pigs, with special attention to the bronchus-associated lymphoid tissue (BALT). Polyclonal and monoclonal antibodies were used for the detection of antigens of Mh, T lymphocytes (CD3+, CD4+, and CD8+), IgG+ or IgA+ lymphocytes, and cells containing lysozyme, S-100 protein, major histocompatibility complex class II antigen or myeloid-histiocyte antigen. Findings in lung tissues associated with Mh infection were catarrhal bronchointerstitial pneumonia, with infiltration of inflammatory cells in the lamina propria of bronchi and bronchioles and alveolar septa. Hyperplasia of mononuclear cells in the BALT areas was the most significant histologic change. The BALT showed a high morphologic and cellular organization. Macrophages and B lymphocytes were the main cellular components of germinal centers. T lymphocytes were primarily located in perifollicular areas of the BALT, lamina propria and within the airway epithelium, and plasma cells containing IgG or IgA at the periphery of the BALT, in the lamina propria of bronchi and bronchioles, in alveolar septa, and around bronchial submucosal glands. The hyperplastic BALT in PEN cases consisted of macrophages, dendritic cells, T and B lymphocytes, and IgG+ and IgA+ plasma cells. CD4+ cells predominated over CD8+ cells. Local humoral immunity appears to play an important role in the infection.
Assuntos
Brônquios/microbiologia , Brônquios/patologia , Tecido Linfoide/microbiologia , Tecido Linfoide/patologia , Infecções por Mycoplasma/patologia , Infecções por Mycoplasma/veterinária , Mycoplasma/fisiologia , Animais , Brônquios/ultraestrutura , Imuno-Histoquímica , Tecido Linfoide/ultraestrutura , Infecções por Mycoplasma/microbiologia , Suínos , Doenças dos Suínos/microbiologia , Doenças dos Suínos/patologiaRESUMO
A bicephalic Honduran milk snake (Lampropeltis hondurensis) with tracheal duplication and malformation and Salmonella arizonae infection is described. There were atypically wide collapsed tracheal rings with necrotizing tracheitis and abundant necrotic epithelial debris and inflammatory cells obstructing the lumen in one of the duplicate tracheae. Salmonella arizonae was cultured from the malformed duplicate trachea and was considered to be the etiologic agent causing necrosis.