ABSTRACT. Babesiosis is an infectious hemolytic disease that occurs worldwide, and is caused by a protozoan of the Babesia genus (Apicomplexa). Little is known about this genus; therefore, this study conducted a molecular characterization of Babesia spp in naturally infected dogs in northern Brazil. Blood samples were collected from 172 dogs from metropolitan Belém, and screened for Babesia spp using semi-nested polymerase chain reactions. Subsequently, 18S rDNA gene fragments were amplified and sequenced. Alignments of the 27 nucleotide sequences returned fragments measuring 1023 bp in size, which did not include any polymorphic sites (100% identity). This genotype was very similar to the 18S rDNA gene in B. vogeli. This study provides an important molecular characterization of the parasite responsible for canine babesiosis in naturally infected dogs in metropolitan Belém. In addition, the 18S rDNA gene in B. vogeli may represent the most common genotype occurring in South America.

In the present study, we evaluated the prevalence of occult hepatitis B (OBI) in a population from the Brazilian Amazon region, identify circulating genotypes, and mutations in the S gene. One hundred eighty-one patients with negative serology for HBsAg and anti-HBs and positive serology for anti-HBc participated in the study. Detection of viral DNA, genotyping by sequencing, and analysis of nucleotide sequences to detect possible mutations were performed. HBV DNA was detected in 14.36% of the patients. Genotyping revealed genotype A in 88.46% of HBV DNA-positive subjects, with subgenotype A1 being the most prevalent (78.26%) followed by subgenotype A2 (21.74%). Genotype F was detected in 11.54% (all of them subgenotype F2). Amino acid substitutions were observed in the amplified S gene in individuals with OBI compared to HBsAg-positive individuals (evident infection). In conclusion, the results show a high prevalence of OBI in the population studied, with a pattern of genotypes A and F that circulate in the Brazilian Amazon region. Amino acid substitutions were detected in part of the S gene in patients with OBI. Further studies on the molecular epidemiology of HBV in this region are important to identify patients considered healthy but who are potential transmitters of the disease.

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.

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.

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.

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.