Insights Into Limnothrix sp. Metabolism Based on Comparative Genomics.

Currently only four genome sequences for Limnothrix spp. are publicly available, and information on the genetic properties of cyanobacteria belonging to this genus is limited. In this study, we report the draft genome of Limnothrix sp. CACIAM 69d, isolated from the reservoir of a hydroelectric dam located in the Amazon ecosystem, from where cyanobacterial genomic data are still scarce. Comparative genomic analysis of Limnothrix revealed the presence of key enzymes in the cyanobacterial central carbon metabolism and how it is well equipped for environmental sulfur and nitrogen acquisition. Additionally, this work covered the analysis of Limnothrix CRISPR-Cas systems, pathways related to biosynthesis of secondary metabolites and assembly of extracellular polymeric substances and their exportation. A trans-AT PKS gene cluster was identified in two strains, possibly related to the novel toxin Limnothrixin biosynthesis. Overall, the draft genome of Limnothrix sp. CACIAM 69d adds new data to the small Limnothrix genome library and contributes to a growing representativeness of cyanobacterial genomes from the Amazon region. The comparative genomic analysis of Limnothrix made it possible to highlight unique genes for each strain and understand the overall features of their metabolism.

Complete Genome Sequence of Porphyrobacter sp. Strain CACIAM 03H1, a Proteobacterium Obtained from a Nonaxenic Culture of Microcystis aeruginosa.

Here, we present a complete genome sequence and annotation of Porphyrobacter sp. strain CACIAM 03H1, which was obtained from a nonaxenic culture of Microcystis aeruginosa, a cyanobacterium isolated from an Amazonian freshwater environment.

Draft Genome Sequence of Alkalinema sp. Strain CACIAM 70d, a Cyanobacterium Isolated from an Amazonian Freshwater Environment.

In order to increase the genomic data of cyanobacterial strains isolated in Brazil, we hereby present the draft genome sequence of the Alkalinema sp. strain CACIAM 70d, isolated from an Amazonian freshwater environment. This report describes the first genome available for this genus.

Draft Genome Sequence of Microcystis aeruginosa CACIAM 03, a Cyanobacterium Isolated from an Amazonian Freshwater Environment.

Given its toxigenic potential, Microcystis aeruginosa is an important bloom-forming cyanobacterium. Here, we present a draft genome and annotation of the strain CACIAM 03, which was isolated from an Amazonian freshwater environment.

Molecular analysis reveals the diversity of Hepatozoon species naturally infecting domestic dogs in a northern region of Brazil.

This study aimed to optimize molecular methods for detecting DNA of Hepatozoon spp. as well as identify the phylogenetic relationships of Hepatozoon strains naturally infecting domestic dogs in Belém, Pará, northern Brazil. Blood samples were collected from 138 dogs, and screened for Hepatozoon spp. using a new nested PCR assay. Positive samples were subjected to genetic characterization based on amplification and sequencing of approximately 670bp of the Hepatozoon spp. 18S rRNA. Of the positive dogs, four shared the haplotype Belém 01, one dog presented the haplotype Belém 02 and two dogs shared the haplotype Belém 03. A Bayesian inference indicates that haplotypes Belém 01 and Belém 02 are phylogenetically related to H. canis, while Belém 03 is related to H. americanum. Overall, based on the first molecular evidence of H. americanum in Brazilian domestic dogs, the proposed protocol may improve the epidemiological investigation of canine hepatozoonosis.

Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria.

Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here.

Draft Genome Sequence of Flavihumibacter sp. Strain CACIAM 22H1, a Heterotrophic Bacterium Associated with Cyanobacteria.

Here, we present a draft genome and annotation of Flavihumibacter sp. CACIAM 22H1, isolated from Bolonha Lake, Brazil, which will provide further insight into the production of substances of biotechnological interest.

Optimization of a molecular method for the diagnosis of canine babesiosis.

Babesiosis is a hemolytic disease caused by protozoans of the genus Babesia (Apicomplexa). This disease occurs worldwide and is transmitted by ticks to a variety of mammals, including humans. The objective of the present study was to optimize a molecular approach for the detection of a fragment of 18S rDNA of Babesia canis, Babesia vogeli, Babesia rossi or Babesia gibsoni based on a single semi-nested Polymerase Chain Reaction (PCR), and compare the efficiency of this approach with that of a simple PCR protocol. To this end, 100 blood samples collected from dogs with suspected hemoparasite infections were analyzed. A comparison of the results of simple PCR and semi-nested PCR indicated a highly significant difference (p value = 0.0000). While only five (5%) of the samples tested positive using the simple protocol, 22 (22%) were positive using the snPCR technique. The results of this study reinforce the findings of previous studies, which have demonstrated the greater sensitivity of tests based on nested or semi-nested PCR. Therefore, to avoid false-negative results due to low levels of parasitemia, we suggest the preferential use of this protocol in epidemiological studies of canine babesiosis, particularly those that require reliable estimates of the prevalence of infection.

Optimization of a molecular method for the diagnosis of canine babesiosis / Otimização de método molecular para diagnóstico da babesiose canina

Babesiosis is a hemolytic disease caused by protozoans of the genus Babesia (Apicomplexa). This disease occurs worldwide and is transmitted by ticks to a variety of mammals, including humans. The objective of the present study was to optimize a molecular approach for the detection of a fragment of 18S rDNA of Babesia canis, Babesia vogeli, Babesia rossi or Babesia gibsoni based on a single semi-nested Polymerase Chain Reaction (PCR), and compare the efficiency of this approach with that of a simple PCR protocol. To this end, 100 blood samples collected from dogs with suspected hemoparasite infections were analyzed. A comparison of the results of simple PCR and semi-nested PCR indicated a highly significant difference (p value = 0.0000). While only five (5%) of the samples tested positive using the simple protocol, 22 (22%) were positive using the snPCR technique. The results of this study reinforce the findings of previous studies, which have demonstrated the greater sensitivity of tests based on nested or semi-nested PCR. Therefore, to avoid false-negative results due to low levels of parasitemia, we suggest the preferential use of this protocol in epidemiological studies of canine babesiosis, particularly those that require reliable estimates of the prevalence of infection.

A babesiose é uma doença hemolítica de ocorrência mundial, causada por protozoários do gênero Babesia (Apicomplexa), que são transmitidos por carrapatos a diversos mamíferos, incluindo o homem. O objetivo deste estudo foi otimizar um método molecular para a detecção de fragmento do 18S rDNA de Babesia canis, Babesia vogeli, Babesia rossi ou Babesia gibsoni com base em uma única semi-nested (snPCR), comparando sua eficiência com um protocolo de PCR simples. Para isso, 100 amostras de sangue de cães com suspeita de hemoparasitoses foram analisadas e, enquanto o protocolo de PCR simples indicou somente 5% (5/100) de amostras positivas, o protocolo de snPCR, com 22% (22/100) de amostras positivas, apresentou maior sensibilidade (p valor = 0,0000). Este resultado está de acordo com outros estudos que mostram a maior sensibilidade de detecção dos testes baseado em nested ou snPCR. Assim, como uma forma de prevenir resultados falso-negativos devido à baixa parasitemia, sugere-se que este protocolo seja preferencialmente usado nos estudos epidemiológicos de babesiose canina, em especial naqueles que tratam da sua prevalência.

Detection of Ehrlichia canis and Anaplasma platys DNA using multiplex PCR.

We hereby propose a novel sensitive, specific, and cost-efficient method to detect Ehrlichia canis and Anaplasma platys DNA from canine whole blood samples by multiplex PCR. Blood samples from hemoparasited dogs attending the Veterinary Hospital at the Universidade Federal Rural da Amazônia-UFRA, Belém, Brazil, were collected in tubes containing EDTA. Amplification of E. canis and A. platys 16S rDNA by nested (n) PCR was successfully achieved by using primers specific to the Anaplasmataceae in the first round of PCR, followed by a second round of PCR using E. canis-specific primers in conjunction with A. platys-specific primers. The amplicons obtained were cloned and sequenced, yielding sequences of 478 and 473 bp (including primers) pertaining to regions of the 16S rDNA of E. canis and A. platys, respectively. The protocol we here propose may help to measure the prevalence of canine monocytic ehrlichiosis (CME) and canine cyclic thrompocytopenia, not only in northern Brazil, where there is no data available, but also elsewhere.