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...
Introduction: Brazil has registered more than 62,000 confirmed cases of leptospirosis between 2001 and 2017, with more than 2,000 cases confirmed in the State of Pará. Despite a large number of cases, no study has been conducted to trace the spatio-temporal profile of the disease. Methodology: Confirmed cases of leptospirosis from 2001 to 2017 from the state of Pará were the basis for this space-time study. The database of the Department of Informatics of the Ministry of Health was used to access data on leptospirosis. The spatio-temporal analysis was performed in the SaTScan software for the detection of clusters, and maps were generated in the QGIS software. Results: The municipalities of Belém and Santarém were among the ones with the highest incidence rates of leptospirosis for the whole study period. Increased number of cases in Soure, Inhangapi, São João da Ponta and Magalhães Barata, Ponta de Pedras, Breves, Bragança, Castanhal, and São Domingos do Capim were identified in different time periods. Santarém and Belém are the main foci of leptospirosis because they are the most urbanized and densely populated municipalities in the State. The cases found in smaller municipalities may be associated with periods of more frequent rainfall and circulation of Leptospira sp. in marsupials and cattle, in the northeastern part of the State. Conclusion: Further studies are needed to help identify the risk factors that contribute to the occurrence of leptospirosis in the State of Pará, particularly in areas with lower population density.
The present study verified the quality of the water of Água Preta Lake, which is part of the public supply for the Northern Brazilian municipality of Belém (Pará State). Six samples were collected from each of six sampling points. The concentration (NMP) of coliforms was determined by Multiple-tube fermentation Technique. The isolates of Escherichia coli obtained from the samples were tested for susceptibility to the antibiotics (cefoxitin, ampicillin, imipenem, gentamicin, and amikacin). Furthermore, was analyzed the presence of diagnostic genes for the diarrheagenic strains of E. coli. None of the genes was identified, however, the recorded concentrations of thermo-tolerant coliforms were within the recommended limits for standing water sources used for public supplies. Nevertheless, the highest concentrations of total and thermo-tolerant coliforms were recorded at two points, one adjacent to the most densely-populated area of the lake margin, and the other near the catchment area for water from the Guamá River. The susceptibility testing indicated the presence of six resistance phenotype profiles, including multi-resistant strains. The results of the study reinforce the need for the systematic monitoring of this water source, in order to provide guidelines for the development of effective management policies for public water supplies, as well as the prevention of water-borne diseases.
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