Abstract In canine visceral leishmaniasis, coinfections can aggravate the disease. Our aim was to investigate Brucella canis in dogs infected with Leishmania infantum. One hundred and six L. infantum-seropositive dogs were submitted to serology for B. canis, PCR for B. canis and L. infantum, and histopathological analysis of the genital tract. Anti-B. canis antibodies were detected in seven dogs whose clinical signs, L. infantum load and histological alterations were similar to those of seronegative animals. The circulation of anti-B. canis antibodies was low but demonstrates the exposure of dogs to this bacterium in a visceral leishmaniasis-endemic area.

In this opinion paper, we discuss the potential and challenges of using the symbiont Wolbachia to block mosquito transmitted diseases such as dengue, malaria and chikungunya in Latin America.

O elemento P é um dos elementos transponíveis (TE) mais amplamente estudado. Sua mobilização causa a disgenesia do híbrido que foi primeiramente descrita em D. melanogaster. Apesar dos estudos sobre o elemento P terem sido realizados principalmente com D. melanogaster, acredita-se que D. willistoni foi a espécie hospedeira original deste TE e que ele se transpôs para o genoma de D. melanogaster por transferência horizontal. Nosso estudo visou a comparação do comportamento transcripcional do elemento P em embriões de D. melanogaster, que é a hospedeira recente, com o de embriões de duas linhagens de D. willistoni, uma espécie que é, a longo tempo, hospedeira do elemento P. Em ambas as espécies foram detectados transcritos potenciais da transposase, enzima responsável pela mobilização do TE, bem como transcritos do repressor de 66-kDa e de seqüências truncadas e antisenso, os quais podem ter a habilidade de prevenir a mobilização de TEs. Os transcritos truncados refletem os elementos P truncados presentes no genoma das linhagens e cujo número parece relacionado com o tempo de invasão do genoma pelo TE. Nenhuma diferença qualitativa de transcritos antisenso foi observada entre as espécies, mesmo na linhagem de D. willistoni com alta freqüência de elemento P heterocromático.

The P element is one of the most thoroughly studied transposable elements (TE). Its mobilization causes the hybrid dysgenesis that was first described in Drosophila melanogaster. While studies of the P element have mainly been done in D. melanogaster, it is believed that Drosophila willistoni was the original host species of this TE and that P was transposed to the D. melanogaster genome by horizontal transfer. Our study sought to compare the transcriptional behavior of the P element in embryos of D. melanogaster, which is a recent host, with embryos of two strains of D. willistoni, a species that has contained the P element for a longer time. In both species, potential transcripts of transposase, the enzyme responsible for the TE mobilization, were detected, as were transcripts of the 66-kDa repressor, truncated and antisense sequences, which can have the ability to prevent TEs mobilization. The truncated transcripts reveal the truncated P elements present in the genome strains and whose number seems to be related to the invasion time of the genome by the TE. No qualitative differences in antisense transcripts were observed among the strains, even in the D. willistoni strain with the highest frequency of heterochromatic P elements.