The present study describes the molecular epidemiology of Human herpesvirus 8 (HHV-8) among four Indian tribes (Kararao, Arara Laranjal, Tiriyo, and Zo'e) of the Amazon region of Brazil and a group of HIV-1-infected subjects from the urban population of Belem, Para. Infection was characterized by the presence of antibodies using ELISA (measuring antibodies to ORF59, ORF65, K8.1A, K8.1B, and ORF73), and molecular assays (gene amplification of the regions ORF26 and the variable region VR1). Antibodies to HHV-8 were detected in 66 samples of the 221 Brazilian Amerindians, namely, 6 (25%) in the Kararao, 18 (19.6%) in the Arara Laranjal, 24 (42.9%) in the Tiriyo, and 18 (36.7%) in the Zo'e. Among the 477 HIV-1-infected subjects, antibodies to HHV-8 were present in 74 (15.5%) persons. The ORF26 region was amplified in seven samples, one of the Arara Laranjal, one of the Tiriyo, two of the Zo'e, and three of the HIV-1-infected group. Subtyping of HHV-8 described a high multiplicity of molecular subtypes, including C (Zo'e), E (Tiriyo), and B (HIV-1 infected). Serological results confirm the high prevalence of HHV-8 among Amerindians and the presence of three subtypes in the Amazon region of Brazil, including a unique subtype, which favors the idea of HHV-8 as an ancient human infection within this particular geographical region.

The present study intended to characterize the phenotypic and genetic diversity of Brazilian isolates of Chromobacterium violaceum from aquatic environments within the Amazon region. Nineteen isolates showed morphological properties of C. violaceum and the majority grew at 44°C. Low temperatures, in contrast, showed (Ueda et al. 1994, Melo et al. 2000 and anti-Mycobacterium tuberculosis (de Souza et al. 1999) activities. Other properties of C. violaceum include the production of cyanide (Michaels & Corpe 1965), the solubilization of gold (Faramarzi et al. 2004), the production of chitinolytic enzymes (Chernin et al. 1998), the synthesis of bioplastics (Steinbüchel et al. 1993) and environmental detoxification (Carepo et al. 2004). Although it is a valuable biotechnological resource, C. violaceum is a highly virulent opportunistic pathogen to humans and animals (Chen et al. 2003, Brito et al. 2004, de Siqueira et al. 2005). Recombinase A (RecA) is a multifunctional protein involved in general recombination, DNA repair and the SOS response, and it is highly conserved among eubacteria (Cox 2003). Several studies have shown that recA can be used as a molecular tool to study diversity within the Erwinia genus (Waleron et al. 2002), C. violaceum (Scholz et al. 2005, Ochrobactrum anthropi (Scholz et al. 2006) and the Burkholderia cepacia complex (Seo & Tsuchiya 2004), despite this gene's high degree of nucleotide diversity (Casati et al. 2004).The present study aims to further characterize the phenotypic and genetic diversity of Brazilian isolates of C. violaceum from aquatic environments within the Amazon region. MATERIALS AND METHODSIsolates from natural water resources and reference strain -Water samples were collected from domestic wells (less than 15 m in depth) in Barcarena (site 1) and in Vila Bonifácio, municipality of Bragança (site 2). Samples were also collected from rivers within the National Forest of Caxiuana (site 3) and in Belém, the capital of Pará (site 4).Nineteen isolates of C. violaceum were recovered from superficial and underground water using the Membrane Filter (MF) and Most Probable Number (MPN) technique, according to the Standard Methods for the Examination of Water and Wastewater (APHA 2005). The MF technique was performed by the filtraDiversity of C. violaceum in the Brazilian Amazon • LT Dall'Agnol et al. 679tion of water samples through a sterile cellulose ester membrane with 0.45 µm pores. Membranes were transferred to m-Endo-type media with incubation at 37ºC for 24 h. The MPN technique consisted of the inoculation of sequential volumes of water samples in Lactose Broth, followed by incubation at 37ºC for 24-48 h. The colonies that presented a violet pigmentation in the isolation medium were transferred to Agar Stock (storage medium). Prior to biochemical or molecular testing, isolates were grown in Nutrient Broth (NB) for 24 h at 37ºC and placed in Nutrient Agar to re-isolate and confirm the anoxic condition of the culture. The reference strain ATCC 12472 was obtained from the Br...