114 research outputs found
Persistence and dispersion of Acinetobacter spp. in the urban water cycle
Dissertação de mestrado em Genética MolecularAs bactérias do género Acinetobacter são ubíquas no solo, esgotos e água. Tendo como objectivo avaliar a persistência e possíveis rotas de dispersão das Acinetobacter spp. no ciclo urbano da água, uma colecção de 254 isolados foram recuperados da água de uma estação de tratamento de águas (ETA) e de 12 torneiras. Numa triagem inicial, os isolados foram identificados preliminarmente usando primers específicos para 16S ARNr de Acinetobacter spp., levando à selecção de 179 isolados. Depois desta triagem, foi usado um esquema de mini-Multilocus Sequencing Typing (MLST) de maneira a conseguir a identificação ao nível da espécie, e quando possível, avaliar padrões de variação intra-específica. Foi determinada a resistência aos antibióticos amoxicilina, ticarcilina, cefalotina, ceftazidime, meropenemo, gentamicina, ciprofloxacina, sulfametoxazol, sulfametoxazol/trimetoprim, tetraciclina, sulfato de colistina e estreptomicina, pelo método de difusão de disco. Os padrões do mini-MLST e os perfis de resistência a antibióticos foram analisados como função do local de isolamento. Visto que não foram observados tipos de sequências (ST) idênticos nos dois ambientes amostrados, concluiu-se que Acinetobacter spp. isolados de torneiras não tinham origem na ETA. Não obstante, foi possível inferir a existência de uma fonte comum de Acinetobacter spp. nas torneiras, visto ter sido observado o mesmo ST em diferentes torneiras, assim como em distintos sistemas de distribuição de água. A respeito da persistência de Acinetobacter spp. nos diferentes locais de amostragem, os isolados com sequências de rpoB ou recA idênticas, que foram observadas nos diferentes períodos, foram distinguidos pelo fenótipo de resistência a antibióticos. Além disso, os dados obtidos sugerem que a densidade de Acinetobacter spp. no ciclo urbano da água pode aumentar durante o período de Verão, diminuindo durante o Inverno, podendo haver uma nova colonização no ano seguinte. Sete isolados pertencentes ao mesmo grupo de ST, apresentavam distintos perfis de resistência a antibióticos, sugerindo que, ou essas resistências foram adquiridas após a colonização do sistemas de águas, ou o método de tipagem tem baixa resolução. Neste aspecto, admite-se que a análise de sequências nucleotídicas de outros genes contribuirá para uma melhor diferenciação de estirpes e portanto, permitirá ultrapassar a referida limitação.Members of the genus Acinetobacter are ubiquitous in soil, sewage and water. Aiming the assessment of the persistence and possible routes of dispersion of Acinetobacter spp. in the urban water cycle, a collection of 254 bacterial isolates were recovered from two different types of water, from a water treatment plant (WTP) and from 12 taps. In the initial screening, isolates were presumptively identified using an Acinetobacter spp. specific 16S rRNA primer, leading to the selection of a set of 179 isolates. After this screening, a mini-MLST approach was used in order to achieve the identification to the species level and, whenever possible, to assess patterns of intra-specific variation. The antibiotic resistance to amoxicillin, ticarcillin, cephalothin, ceftazidime, meropenem gentamicin, ciprofloxacin, sulphamethoxazole, sulphamethoxazole/trimethoprim, tetracycline, colistin-sulphate, and streptomycin was determined using the diffusion disc method. The mini-MLST patterns and the antibiotic resistance profile were analyzed as a function of the isolation site. Given that no identical sequencing type (ST) was observed in both types of sampling site, it was concluded that Acinetobacter spp. isolated from the taps did not have origin in the WTP. Nevertheless, a common source of tap water Acinetobacter spp. was hinted by the observation of the same ST in different taps and water distribution systems (WDS).
In respect to Acinetobacter spp. persistence in the different sampling sites, the isolates with identical rpoB or recA nucleotide sequences in the different sampling periods, were distinguished by antibiotics resistance patterns. Moreover, it was suggested that the presence of Acinetobacter spp. in the urban water cycle rises during the summer period and vanishes during winter, with a new colonization in the following year. Seven isolates belonging to the same ST group, could be distinguished on basis of the antibiogram phenotype, suggesting either that those resistance phenotypes were acquired after the water system colonization, or that the typing method had a the poor resolution . The use of additional gene sequences for strain differentiation will contribute to overcome this limitation
Partir e ficar : Dinâmicas nos processos de migraçao e imigraçao no norte de Minas Gerais- Brasil
This proposal assumes that the migration process is a socio-spatial process. Where desires, goals, fears and hopes of migrating become identities, social constructs that ultimately lead to ways of belonging. Place is a form of interaction, whether between man and the environment, or the man with a specific space. Place demand belonging. Belonging demand identity. Migration then became a strategy, a resistance, an eternal possibility or impossibility of staying or leaving. The displacements eventually cause changes in the relationships and interactions of individuals in their most different spaces. In this sense, they grasp the shifting process of an individual or social group, it is seen that migration and immigration is a process beyond "of being in different social spaces", is a mode of social reproduction defined in relations of time and space, emphasizing the duality of being in motion. Therefore, this proposal seeks to emphasize the dynamics of migration and immigration process in their contexts, as well as highlight the economic social constructions arising from these proceedings, in its social, cultural, political and, thus characterizing the various identities of individualsA presente proposta parte do princípio de que, o processo migratório é um processo sócio-espacial. Onde os desejos, os objetivos, os medos e esperanças dos que migram se tornam identidades, construçoes sociais que acabam por acarretar em formas de pertencimento. Lugar é uma forma de interaçao, seja do homem com o ambiente, ou do homem com um espaço específico. Lugar demanda pertencimento. Pertencimento demanda identidade. A migraçao tornou-se entao uma estratégia, uma resistência, uma eterna possibilidade ou impossibilidade de ficar ou sair. Os deslocamentos acabam por provocar modificaçoes nas relaçoes e interaçoes dos indivíduos nos seus mais diferentes espaços. E0 neste sentido, que apreender o processo de deslocamento de um indivíduo ou grupo social, é constatar que a migraçao e imigraçao é um processo que para além "do estar em espaços sociais diferentes", é um modo de reproduçao social definido nas relaçoes de tempo e espaço, enfatizando a dualidade de se estar em movimento. Portanto, a presente proposta procura enfatizar as dinâmicas do processo migratório e imigratório em seus contextos, bem como, evidenciar as construçoes sociais advindas destes processos, em seu âmbito social, cultural, político e econômico, caracterizando assim, as diversas identidades dos indivíduo
Avaliação da qualidade de acabamento superficial da madeira de messassa para três tipos de vernizes
The aim of this study was to evaluate the performance of the messassa wood Brachystegia spiciformis and Julbernardia globiflora for three types of finishing products for use in the furniture and frames industries. Coating performance was assessed by adhesion strength, impact deformation resistance, abrasiveness, gloss and overall color variation tests based on technical standards. Copal painting application was higher for gloss, adhesion and lower abrasiveness compared to water based and polyurethane. The impact deformation was higher for polyurethane than water-based and copal for both species. The darkening of wood for Brachystegia spiciformis and a slight lightening of wood by Julbernardia globiflora characterize the overall color variation after application of the coating products. According to these results, the varnishes can be used to add value to the messassa wood as a finish in solid wood furniture and frames.O objetivo deste estudo foi avaliar o desempenho da madeira das messassas Brachystegia spiciformis e Julbernardia globiflora perante três tipos de produtos de acabamento superficial para utilização na indústria moveleira e de molduras. Foram utilizados como acabamento o verniz Copal, verniz base de água e verniz poliuretano. O acabamento foi avaliado através de ensaios de resistência à aderência (pull-off), impacto, abrasividade, brilho e medição de variação da cor com base em normas técnicas. As espécies apresentaram resultados satisfatórios nos ensaios para todos os vernizes. Houve variação da cor após a aplicação do acabamento caracterizada pelo escurecimento da madeira para espécie Brachystegia spiciformis e um ligeiro clareamento para madeira da Julbernardia globiflora. Conclui-se que os três vernizes podem ser utilizadas nestas espécies para agregação do valor da madeira como acabamento em móveis e molduras de madeira sólida
blaTEM and vanA as indicator genes of antibiotic resistance contamination in a hospital–urban wastewater treatment plant system
Four indicator genes were monitored by quantitative PCR in hospital effluent (HE) and in the raw and
treated wastewater of the municipal wastewater treatment plant receiving the hospital discharge. The
indicator genes were the class 1 integrase gene intI1, to assess the capacity of bacteria to be involved in
horizontal gene transfer processes; blaTEM, one of the most widespread antibiotic resistance genes in the
environment, associated with Enterobacteriaceae; vanA, an antibiotic resistance gene uncommon in the
environment and frequent in clinical isolates; and marA, part of a locus related to the stress response in
Enterobacteriaceae. Variation in the abundance of these genes was analysed as a function of the type of
water, and possible correlations with cultivable bacteria, antimicrobial residue concentrations, and
bacterial community composition and structure were analysed. HE was confirmed as an important
source of blaTEM and vanA genes, and wastewater treatment showed a limited capacity to remove these
resistance genes. The genes blaTEM and vanA presented the strongest correlations with culturable
bacteria, antimicrobial residues and some bacterial populations, representing interesting candidates as
indicator genes to monitor resistance in environmental samples. The intI1 gene was the most abundant
in all samples, demonstrating that wastewater bacterial populations hold a high potential for gene
acquisitioninfo:eu-repo/semantics/acceptedVersio
Bacterial community and antibiotic resistance dynamics in a full-scale wastewater treatment plant with UV disinfection
info:eu-repo/semantics/publishedVersio
Bacterial lineages putatively associated with the dissemination of antibiotic resistance genes in a full-scale urban wastewater treatment plant
Urban wastewater treatment plants (UWTPs) are reservoirs of antibiotic resistance. Wastewater treatment changes the bacterial community and inevitably impacts the fate of antibiotic resistant bacteria and antibiotic resistance genes (ARGs). Some bacterial groups are major carriers of ARGs and hence, their elimination during wastewater treatment may contribute to increasing resistance removal efficiency. This study, conducted at a full-scale UWTP, evaluated variations in the bacterial community and ARGs loads and explored possible associations among them. With that aim, the bacterial community composition (16S rRNA gene Illumina sequencing) and ARGs abundance (real-time PCR) were characterized in samples of raw wastewater (RWW), secondary effluent (sTWW), after UV disinfection (tTWW), and after a period of 3 days storage to monitoring possible bacterial regrowth (tTWW-RE). Culturable enterobacteria were also enumerated.
Secondary treatment was associated with the most dramatic bacterial community variations and coincided with reductions of ~2 log-units in the ARGs abundance. In contrast, no significant changes in the bacterial community composition and ARGs abundance were observed after UV disinfection of sTWW. Nevertheless, after UV treatment, viability losses were indicated ~2 log-units reductions of culturable enterobacteria. The analysed ARGs (qnrS, blaCTX-M, blaOXA-A, blaTEM, blaSHV, sul1, sul2, and intI1) were strongly correlated with taxa more abundant in RWW than in the other types of water, and which associated with humans and animals, such as members of the families Campylobacteraceae, Comamonadaceae, Aeromonadaceae, Moraxellaceae and Bacteroidaceae.
Further knowledge of the dynamics of the bacterial community during wastewater treatment and its relationship with ARGs variations may contribute with information useful for wastewater treatment optimization, aiming at a more effective resistance control.info:eu-repo/semantics/acceptedVersio
SERVIÇO PÚBLICO DE LIMPEZA EM CRISE: POLÍTICA NACIONAL DE RESÍDUOS SÓLIDOS E ASPECTOS DA ECONOMIA CIRCULAR PARA A LOGÍSTICA REVERSA
Os serviços públicos de limpeza já passavam por uma crise, agravada pelo COVID-19, há a questão orçamentária e o aumento dos gastos necessários para medidas de proteção. O objetivo do artigo é demonstrar as perspectivas da economia circular para auxiliar na logística reversa ante a crise nos serviços públicos de limpeza urbana. Utilizou-se a técnica de pesquisa bibliográfica e o método dedutivo. Os principais resultados demonstram a necessidade de adoção de novas perspectivas para geração de renda e logística reversa; principais conclusões destacam a relevância da economia circular no Brasil, para alcance do ciclo reverso e dos objetivos da legislação
Diversity and antibiotic resistance of Acinetobacter spp. in water from the source to the tap
Acinetobacterspp. are ubiquitous bacteria in the environment.Acinetobacterspp. isolated from a municipal drinking water treatment plant and from connected tap waterwere identified to the species level on the basis ofrpoB genepartial sequence analysis. Intraspecies variation wasassessed based on the analysis of partial sequences of house-keeping genes (rpoB,gyrB, andrecA). Antibiotic resistancewas characterized using the disk diffusion method and iso-lates were classified as wild or non-wild type (non-WT),according to the observed phenotype. The strains ofAcinetobacterspp. were related to 11 different validly pub-lished species, although three groups of isolates, presentinglowrpoB sequence similarities with previously describedspecies, may represent new species. Most of the isolateswere related to the speciesA. johnsoniiandA. lwoffii.These two groups, as well as others related to the speciesA. parvusandA. tjernbergiae, were detected in the watertreatment plant and in tap water. Other strains, related to thespeciesA. pittiiandA. beijerinckii, were isolated only fromtap water. Most of the isolates (80 %) demonstrated wild type (WT) to all of the 12 antibiotics tested. Non-WT fortetracycline, meropenem, and ceftazidime, among others,were observed in water treatment plant or in tap watersamples. Although, in general, this study suggests a lowprevalence of acquired antibiotic resistance in waterAcinetobacterspp., the potential of some species to acquireand disseminate resistance via drinking water is suggested.info:eu-repo/semantics/publishedVersio
Diversity and antibiotic resistance of Acinetobacter spp. in water from the source to the tap
Valorization of Wastes for Biodiesel Production: The Brazilian Case
This chapter intends to bring an overview about the Brazilian researches and their contributions to the production of biodiesel from wastes. Currently, the main obstacles to spread the use of biodiesel are its high cost of production and the competition between biodiesel and food industries. So, the use of wastes plays an important role in reducing the biodiesel costs and reusing the materials that have no other applications, as deodorization residues, neutralization soap sticks, and animal fats, among others. Then, we present a review about Brazilian studies involving waste oils and fatty–acid-rich raw materials that helped the advancement in this field of knowledge during the last few years
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