Genes that encodes NAGT, MIF1 and MIF2 are not virulence factors for kala-azar caused by Leishmania infantum

Introduction Kala-azar is a disease resulting from infection by Leishmania donovani and Leishmania infantum. Most patients with the disease exhibit prolonged fever, wasting, anemia and hepatosplenomegaly without complications. However, some patients develop severe disease with hemorrhagic manifestations, bacterial infections, jaundice, and edema dyspnea, among other symptoms, followed by death. Among the parasite molecules that might influence the disease severity are the macrophage migration inhibitory factor-like proteins (MIF1 and MIF2) and N-acetylglucosamine-1-phosphotransferase (NAGT), which act in the first step of protein N-glycosylation. This study aimed to determine whether MIF1, MIF2 and NAGT are virulence factors for severe kala-azar. Methods To determine the parasite genotype in kala-azar patients from Northeastern Brazil, we sequenced the NAGT genes of L. infantum from 68 patients as well as the MIF1 and MIF2 genes from 76 different subjects with diverse clinical manifestations. After polymerase chain reaction (PCR), the fragments were sequenced, followed by polymorphism identification. Results The nucleotide sequencing of the 144 amplicons revealed the absence of genetic variability of the NAGT, MIF1 and MIF2 genes between the isolates. The conservation of these genes suggests that the clinical variability of kala-azar does not depend upon these genes. Additionally, this conservation suggests that these genes may be critical for parasite survival. Conclusions NAGT, MIF1 and MIF2 do not alter the severity of kala-azar. NAGT, MIF1 and MIF2 are highly conserved among different isolates of identical species and exhibit potential for use in phylogenetic inferences or molecular diagnosis. .

Biological and chemical control of Sclerotinia sclerotiorum using Trichoderma spp. and Ulocladium atrum and pathogenicity to bean plants

Four isolates of Sclerotinia sclerotiorum were tested for pathogenicity in IPA-10 variety bean plants (Phaseolus vulgaris L.), and all were pathogenic. Biological control in vitro was evaluated using eight isolates of Trichoderma spp. and, one of Ulocladium atrum. Chemical control in vitro with fungicides Thiophanate methyl, Iprodione and Carbendazim was also tested. Except U. atrum, all Trichoderma isolates showed antagonistic potential against S. sclerotiorum, where isolate 3601 presented the best performance. Thiophanate methyl chemical control was the most efficient. This fungicide and isolate 3601were compared in vivo in greenhouse. There was statistical difference between the treatments, and the application of fungicide and antagonist before the pathogen was the most efficient approach, reducing the percentage of pathogenicity to 32.94 percent and 37.04 percent, respectively.

Quatro isolados de Sclerotinia sclerotiorum, foram testados quanto à patogenicidade em plantas de feijão, variedade IPA-10 sendo que todos se mostraram patogênicos. Foram avaliados o controle biológico e químico in vitro, utilizando-se oito isolados de Trichoderma e um de Ulocladium atrum, e o controle químico in vitro, com os fungicidas Tiofanato metílico, Iprodione e Carbendazim. Com exceção de U. atrum todos os isolados dos antagonistas mostraram potencial antagônico contra S. sclerotiorum, destacando-se o isolado 3601 como o de melhor desempenho. No controle químico, Tiofanato metílico foi o mais eficiente, sendo este fungicida e o isolado 3601 comparados in vivo em casa-de-vegetação. Foram observadas diferenças estatísticas entre os tratamentos, sendo que a aplicação do fungicida e do antagonista antes da introdução do patógeno foi mais eficiente, com redução do percentual de incidência em 32,94 por cento e 37,04 por cento, respectivamente.