Diagnóstico, avaliação epidemiológica e molecular de Leishmania spp. e Mycoplasma spp. em granjas avícolas do estado de Pernambuco

Abstract

The objective of this work was to detect molecularly the presence of Leishmania spp. in the blood of commercial laying hens and to diagnose and epidemiologically evaluate Mycoplasma spp. in commercial laying hens and broiler chickens from poultry farms in the State of Pernambuco. Samples were obtained from 22 lots from nine farms, three from broiler chickens and six from commercial laying hens. From each flock, blood samples were obtained for serological tests (n = 344) serological such as, Rapid Plate Agglutination (RPA), Hemagglutination inhibition (HI) e Enzyme Linked ImmunonoSorbent Assay (ELISA); whole blood (n = 120), tracheal swabs (n = 220) and trachea (n = 66) were used to perform molecular tests (PCR). None sample, submitted to PCR, showed positivity for Leishmania spp. In the questionnaires carried out, other animals’ species were observed in the six sampled flocks, being wild birds and rats present in all flocks and dogs and cattle in two flocks. As far as manure was concerned, all the farms carried out the removal when it reached the height of the cages in the Californian type aviaries, except for the automated shed in which the feces were separated by automatic mats. Many flies and mosquitoes were reported in the surroundings and inside the aviaries. All farms carried out control of flies and mosquitoes through chemical control, by the application of adulticides and larvicides. In the Mycoplasma spp. serology diagnosis, 14.82% (51/344) of the samples were positive for MG, whereas 28,4% (98/344) samples were positive for MS in the SAR, 1:10 dilution. In the HI test, 8.72% (30/344) and 20.35% (70/344) were positive for MG and MS, respectively. In ELISA, 45,64% (177/344) presented seropositivity for MG and 57,26% (189/344) for MS. Of the trachea and trachea swab samples submitted to PCR, 25.9% (57/220) and 42.27% (31/67) were positive for MG, respectively. 10% (22/220) of the tracheal swab specimens, while 18.2% (12/66) of the trachea had MS positivity. In the vaccine PCR, 56.14% (32/57) of the MG tracheal swab samples were from the MG-F strain, whereas 40.62% (13/32) of the positive trachea were vaccine strains. Based on the research questionnaires carried out on the farms, we could observe the presence of several vector attraction factors, being important new researches on the role of commercial poultry production in the epidemiology of Leishmaniasis. Was observed the importance of the use of serological and molecular tools in the diagnosis of MG and MS, as it was possible to detect the DNA of the agent in flocks that did not seroconverted in the serological tests and vice versa. In addition to conventional PCR, the vaccine differentiation PCR is fundamental because of the ability to detect different strains in a flock of birds.