Expression of hypoxia-inducible factor 1 alpha in mononuclear phagocytes infected with Leishmania amazonensis

Increasing evidence indicates that hypoxia-inducible factor 1 alpha (HIF-1 alpha) can be upregulated indifferent cell types by nonhypoxic stimuli such as growth factors, cytokines, nitric oxide, lipopolysaccharides and a range of infectious microorganisms. In this study, the ability of the following mononuclear phagocytes to express HIF-1 alpha is reported: mouse macrophages (mM Phi)), human macrophages (W(D) and human dendritic cells (DC), parasitized in vitro with Leishmania amazonensis; as assessed by immunofluorescence microscopy. A logical explanation for HIF-1 alpha expression might be that the mononuclear phagocytes became hypoxic after L. amazonensis infection. Using the hypoxia marker pimonidazole, observation revealed that L. amazonensis-infected cells were not hypoxic. In addition, experiments using a HIF-1 alpha inhibitor, CdCl2, to treat L. amazonensis-infected macrophage cultures showed reduced parasite survival. These studies indicated that HIF-1 alpha could play a role in adaptative and immune responses of mononuclear phagocytes presenting infection by the parasite L. amazonensis. (c) 2007 Elsevier B.V. All rights reserved.114211912

Seroprevalence of Salmonella and Mycoplasma in commercial broilers, backyard chickens, and spent hens in the region of Triângulo Mineiro, State of Minas Gerais, Brazil

Avian salmonellosis and mycoplasmosis are infectious diseases that, in addition of causing lack of flock uniformity, represent a hazard to human health. The objective of the present study was to evaluate the seroprevalence of mycoplasmosis and salmonellosis in commercial broilers, backyard chickens, and spent hens slaughtered at a processing plant with local health inspection in Uberlândia, MG, Brazil. A total of 210 samples were randomly collected at the time of bleeding. Samples were submitted to rapid plate serum agglutination test (RSA) for the classification of Salmonella pullorum, Salmonella gallinarum, Mycoplasma gallisepticum and Mycoplasma synoviae. In order to increase result specificity, mycoplasmosis-positive samples were submitted to hemagglutination inhibition test (HI). No samples presented detectable antibodies against Salmonella pullorum or Salmonella gallinarum in the RSA test. Only Mycoplasma synoviae was detected in 14% of the backyard chickens and 0.74% in commercial broilers, whereas no antibodies were detected in spent hens. The seroprevalence rates found in the present study emphasize the need of keeping chicken flocks free from disease using effective biosafety systems