Rafael Mazioli Barcelos

A deep insight into the whole transcriptome of midguts, ovaries and salivary glands of the Amblyomma sculptum tick

Ticks stand out as the second most important vector of human pathogens and their control is a key issue for public health strategies. The success of these arthropods to parasitize a large range of vertebrate hosts and their importance as a vector of rickettsiosis are intimately related with the physiology of its internal organs. The midguts, ovaries and salivary glands all participate as key sites for rickettsial entry into tick hemolymph, ovarian amplification and transmission to vertebrate hosts, respectively. Although transcriptomic efforts have documented several tick sialomes aspects, very little is known about the repertoire of genes that orchestrate the physiology of midguts and ovaries. The aim of this study was to construct a deep catalogue from the repertoire of genes and putative proteins expressed in the selected internal organs of Amblyomma scultpum, a key vector of spotted fever rickettsiosis, through the employment of a RNAseq strategy. A total of 200 million reads derived from midguts, ovaries and salivary glands and sequenced by Illumina HiSeq, Ion Torrent PGM and 454 pyrosequencing, were assembled into contigs. The mapping of the contigs allowed for the identification of 25,569 CDS expressed in midguts, 21,230 in the ovaries and 10,697 in salivary glands. In depth analysis of the transcriptomes revealed several organ specific metabolic processes that expand the knowledge base of tick biology and its role in infectious diseases. The annotation approach used in this work facilitated the discovery of a higher number of novel genes and processes and gives insight into the roles that they play in the A.scultpum transcriptome.

Sequencing and comparative analysis of the Amblyomma sculptum mitogenome

The mitogenome of Amblyomma sculptum was sequenced, providing important information for understanding the evolutionary relationships among species of the A. cajennense complex. The mitochondrial genome has a circular structure with 37 genes, including 13 coding DNA sequences, two ribosomal RNA genes (12S rRNA and 16S rRNA) and 22 tRNA genes. Comparative analysis with the mitogenomes of six reference species of the genus Amblyomma revealed that the ND5 gene, which is related to energy metabolism, and control regions 1 and 2 of the mitogenomes have polymorphisms that can be exploited as molecular markers to differentiate A. sculptum from other tick species in the Amblyomma cajennense complex as well as other Amblyomma species.

Draft Genome Sequences of Staphylococcus aureus Strains Isolated from Subclinical Bovine Mastitis in Brazil

ABSTRACT Here, we present the draft genome sequences of four Staphylococcus aureus strains isolated from mastitic milk collected from animals with subclinical manifestations. Three of them were typed as sequence type 126 (ST126), a genotype with no genome sequence available. ST126 is found in several herds of southern Brazil and is described as a bovine pathogen strongly associated with milk around the world.

Morphological and molecular diagnosis of Pseudoterranova decipiens (sensu stricto) (Anisakidae) in imported cod sold in Brazil

An anisakid nematode larva found in cod sold in the state of Minas Gerais, Brazil was studied by light and scanning electron microscopy and by a molecular approach. Mitochondrial cytochrome c-oxidase subunit 2 (mtDNA cox-2), 28S rRNA and ITS1, 5.8S and ITS2 regions were amplified using the polymerase chain reaction and sequenced to evaluate the phylogenetic relationships of the larva. The genetic profile confirmed that this larva belongs to the species Pseudoterranova decipiens (sensu stricto). This is the first molecular and ultrastructural study of Pseudoterranova decipiens (sensu stricto) in imported cod sold in Brazil. The health implications of these findings are discussed.

The Nothoaspis amazoniensis Complete Mitogenome: A Comparative and Phylogenetic Analysis

The molecular biology era, together with morphology, molecular phylogenetics, bioinformatics, and high-throughput sequencing technologies, improved the taxonomic identification of Argasidae family members, especially when considering specimens at different development stages, which remains a great difficulty for acarologists. These tools could provide important data and insights on the history and evolutionary relationships of argasids. To better understand these relationships, we sequenced and assembled the first complete mitochondrial genome of Nothoaspis amazoniensis. We used phylogenomics to identify the evolutionary history of this species of tick, comparing the data obtained with 26 complete mitochondrial sequences available in biological databases. The results demonstrated the absence of genetic rearrangements, high similarity and identity, and a close organizational link between the mitogenomes of N. amazoniensis and other argasids analyzed. In addition, the mitogenome had a monophyletic cladistic taxonomic arrangement, encompassed by representatives of the Afrotropical and Neotropical regions, with specific parasitism in bats, which may be indicative of an evolutionary process of cospeciation between vectors and the host.

Occurrence of Ehrlichia canis in free-living primates of the genus Callithrix.

Bacteria of the genus Ehrlichia are Gram-negative and coccoid-shaped microorganisms that cause ehrlichiosis - a serious infectious disease that often leads to death. These bacteria present a strong zoonotic potential and primates may act as reservoir hosts. This study involved a molecular analysis to detect these microorganisms in blood samples collected from nineteen primates of the genus Callithrix living free in an Atlantic Forest fragment in the municipality of Viçosa, state of Minas Gerais, Brazil. One of the 19 primates was found to be infected with Ehrlichia canis. This finding points to a new wild host of E. canis with a strong potential for transmission to humans because of its increasing contact with people. This is the first report of Ehrlichia spp. in primate of the genus Callithrix.