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1.
Sci Total Environ ; 912: 169136, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38072273

RESUMO

The use of tailings dams in the mining industry is recurrent and a matter of concern given the risk of collapse. The planning of tailings dam's emplacement usually attends construction design criteria and site geotechnical properties, but often neglects the risk of installing the depositional facilities in potentially unstable landscapes, namely those characterized by steep slopes and(or) high drainage densities. In order to help bridging this gap, the present study developed a framework model whereby geomorphologic vulnerability is assessed by a set of morphometric parameters (e.g., drainage density; relief ratio; roughness coefficient). Using the Ribeirão Ferro-Carvão micro-basin (3265.16 ha) as test site, where six dams currently receive tailings from the mining of iron-ore deposits in the Brumadinho region (Minas Gerais, Brazil) and one has collapsed in 25 January 2019 (the B1 dam of Córrego do Feijão mine of Vale, S.A.), the risk of dam instability derived from geomorphologic vulnerability was assessed and alternative suitable locations were highlighted when applicable. The results made evident the location of five dams (including the collapsed B1) in high-risk regions and two in low-risk regions, which is preoccupying. The alternative locations represent 58 % of Ribeirão Ferro-Carvão micro-basin, which is a reasonable and workable share. Overall, the study exposed the fragility related with tailings dams' geography, which is not restricted to the studied micro-basin, because dozens of active tailings dams exist in the parent basin (the Paraopeba River basin) that can also be vulnerable to geomorphologically-dependent hydrologic hazards such as intensive erosion, valley incision or flash floods. Attention to this issue is therefore urgent to prevent future tragedies related with tailings dams' breaks, in the Paraopeba River basin or elsewhere, using the proposed framework model as guide.

2.
Sci Rep ; 13(1): 6238, 2023 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-37069157

RESUMO

Polymyxin-carbapenem-resistant Klebsiella pneumoniae (PCR-Kp) with pan (PDR)- or extensively drug-resistant phenotypes has been increasingly described worldwide. Here, we report a PCR-Kp outbreak causing untreatable infections descriptively correlated with bacterial genomes. Hospital-wide surveillance of PCR-Kp was initiated in December-2014, after the first detection of a K. pneumoniae phenotype initially classified as PDR, recovered from close spatiotemporal cases of a sentinel hospital in Rio de Janeiro. Whole-genome sequencing of clinical PCR-Kp was performed to investigate similarities and dissimilarities in phylogeny, resistance and virulence genes, plasmid structures and genetic polymorphisms. A target phenotypic profile was detected in 10% (12/117) of the tested K. pneumoniae complex bacteria recovered from patients (8.5%, 8/94) who had epidemiological links and were involved in intractable infections and death, with combined therapeutic drugs failing to meet synergy. Two resistant bacterial clades belong to the same transmission cluster (ST437) or might have different sources (ST11). The severity of infection was likely related to patients' comorbidities, lack of antimicrobial therapy and predicted bacterial genes related to high resistance, survival, and proliferation. This report contributes to the actual knowledge about the natural history of PCR-Kp infection, while reporting from a time when there were no licensed drugs in the world to treat some of these infections. More studies comparing clinical findings with bacterial genetic markers during clonal spread are needed.


Assuntos
Infecções por Klebsiella , Polimixinas , Humanos , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Klebsiella pneumoniae , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/genética , Brasil , Genoma Bacteriano , Surtos de Doenças , Carbapenêmicos/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Testes de Sensibilidade Microbiana , beta-Lactamases/genética , Proteínas de Bactérias/genética
3.
Environ Res ; 215(Pt 1): 114147, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36063907

RESUMO

Mercury (Hg) toxicity in soils depends on Hg species and other physical and chemical attributes, as selenium (Se) hotspots in soils, particularly relevant in Amazonian soils. The study of Hg species and their relations in representative locations of the Amazon rainforest biome is critical for assessing the potential risks of Hg in this environment. This work aimed to determine the concentration of total Hg and its species (Hg0, Hg22+ and Hg2+), and to correlate Hgtotal concentration with total elemental composition, magnetic susceptibility, and physicochemical attributes of Amazon soils. Nine sites in the Amazon rainforest biome, Brazil, were selected and analyzed for their chemical, physical, and mineralogical attributes. The clay fraction of the studied Amazon soils is dominated by kaolinite, goethite, hematite, gibbsite, and quartz. Mica was also found in soils from the States of Acre and Amazonas. Hgtotal ranged from 21.5 to 208 µg kg-1 (median = 104 µg kg-1), and the concentrations did not exceed the threshold value established for Brazilian soils (500 µg kg-1). The Hg2+ was notably the predominant species. Its occurrence and concentration were correlated with the landscape position and soil attributes. Hgtotal was moderately and positively correlated with TiO2, clay, and Se. The findings showed that geographic location, geological formation, and pedological differences influence the heterogeneity and distribution of Hgtotal in the studied soil classes. Thus, a detailed characterization and knowledgment of the soil classes is very important to clarify the complex behavior of this metal in the Amazon rainforest biome.


Assuntos
Mercúrio , Selênio , Poluentes do Solo , Brasil , Argila , Ecossistema , Monitoramento Ambiental , Caulim , Mercúrio/análise , Quartzo , Floresta Úmida , Selênio/análise , Solo/química , Poluentes do Solo/análise
4.
Nursing (Ed. bras., Impr.) ; 25(291): 8352-8363, ago.2022.
Artigo em Inglês, Português | LILACS, BDENF - Enfermagem | ID: biblio-1392115

RESUMO

Objetivo: Caracterizar perfil de pacientes encaminhadas para a UTI materna de um hospital público do Distrito Federal. Método: estudo quantitativo de caráter descritivo, transversal e analítico, pautado em dados secundários retroativos obtidos através do livro de admissões da UTI Materna do Hospital Materno Infantil de Brasília, realizando um comparativo entre o ano de criação junho de 2013-2014 e junho de 2019-2020. A Análise estatística descritiva foi realizada por meio de frequência absoluta e frequência relativa. Resultados: Os dados evidenciaram público atendido é exclusivamente feminino, com maior prevalência da faixa etária entre 20 e 29 anos de idade, com média de 30,27 anos de idade. O diagnóstico prevalente foi de Pré-eclâmpsia (17,12%). A transferência para outros setores do mesmo hospital foi o principal desfecho. Conclusão: As causas obstétricas diretas representam a maior parte das internações no setor. Em geral, são mulheres jovens e com diagnostico prioritário de Síndromes Hipertensivas.(AU)


Objective: To characterize the profile of patients referred to the Maternal ICU of a public hospital in the Federal District. Method: quantitative study of descriptive, cross-sectional and analytical nature, based on retrospective secondary data obtained through the Maternal ICU admissions book of the Materno Infantil Hospital of Brasilia, making a comparison between the year of creation June 2013-2014 and June 2019-2020. Descriptive statistical analysis was performed using absolute frequency and relative frequency. Results: The data evidenced public attended is exclusively female, with a higher prevalence of the age group between 20 and 29 years old, with an average of 30.27 years old. The prevalent diagnosis was preeclampsia (17.12%). Transfer to other sectors of the same hospital was the main outcome. Conclusion: Direct obstetric causes represent most of the hospitalizations in the sector. In general, they are young women and with priority diagnosis of hypertensive syndromes.(AU)


Objetivo: Caracterizar el perfil de las pacientes referidas a la UCI materna de un hospital público del Distrito Federal. Método: estudio cuantitativo de carácter descriptivo, transversal y analítico, basado en datos secundarios retrospectivos obtenidos a través del libro de ingresos de la UCI Materna del Hospital Materno Infantil de Brasilia, realizando una comparación entre el año de creación junio 2013-2014 y junio 2019-2020. El análisis estadístico descriptivo se realizó mediante la frecuencia absoluta y la frecuencia relativa. Resultados: Los datos evidencian que el público atendido es exclusivamente femenino, con una mayor prevalencia del grupo de edad entre 20 y 29 años, con una media de 30,27 años. El diagnóstico más frecuente fue la preeclampsia (17,12%). El traslado a otros sectores del mismo hospital fue el principal resultado. Conclusión: Las causas obstétricas directas representan la mayor parte de las hospitalizaciones del sector. En general, son mujeres jóvenes y con diagnóstico prioritario de Síndromes Hipertensivos.(AU)


Assuntos
Perfil de Saúde , Unidades de Terapia Intensiva , Obstetrícia
5.
Environ Sci Pollut Res Int ; 28(9): 11279-11288, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33113065

RESUMO

The heavy metal mercury (Hg) is one of the most complex and toxic pollutants. When present in soils, it may impair plant growth, but the intensity of damage depends on the physical-chemical properties of the soil such as pH, clay, and organic matter content, which in turn affects Hg sorption and bioavailability. Understanding Hg potential damage to staple food crops is of paramount relevance. Here, we evaluated the physiological effects of Hg in Phaseolus vulgaris (common bean) and Avena sativa (oat) cultivated in two Oxisols with contrasting properties: Rhodic Acrudox (RA) and Typic Hapludox (TH). We performed four independent experiments (one per species/soil combination) that lasted 30 days each. Treatments were composed by HgCl2 concentrations in soils (0 to 80 mg kg-1 Hg). At the end of the experiment, we determined the impact of Hg on photosynthesis, nutritional status, and oxidative stress. Cultivation in TH contaminated with Hg resulted in oxidative stress in common bean and decreased photosynthesis/P accumulation in oat. No deleterious effects on physiological variables were detected in both species when cultivated in the RA soil. In general, we conclude that the lower Hg sorption in the TH soil resulted in toxicity-like responses, while acclimation-like responses were observed in plants cultivated in RA, reinforcing soil physical-chemical properties as key features driving Hg toxicity in Oxisols. Graphical abstract.


Assuntos
Mercúrio , Phaseolus , Poluentes do Solo , Avena , Mercúrio/análise , Solo , Poluentes do Solo/análise
6.
Chemosphere ; 254: 126904, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957297

RESUMO

Estimating bioaccessible content of mercury in soils is essential in evaluating risks that contaminated soils pose. In this study, soil samples spiked with HgCl2 through adsorption were used to test the effects of liming, soil organic matter, soil depth, and Hg concentration on the following bioaccessibility tests: dilute nitric acid at room temperature, dilute nitric acid at body temperature, Simplified Bioaccessibility Extraction Test (SBET) method, and gastric phase of the In vitro Gastrointestinal (IVG) protocol. Soil and sediment samples from Descoberto, Minas Gerais (Brazil), a city with a well-known record of Hg contamination from artisanal mining, were subjected to these bioaccessibility tests for the first time, and the different methods of estimating bioaccessible content were compared. Bioaccessible fractions in spiked samples ranged from 10% to 60%, and this high bioaccessibility was due to the highly soluble species of Hg and the short time under adsorption. In general, clay and organic matter decreased bioaccessible content. Although the soil in Descoberto is undoubtedly polluted, mercury bioaccessibility in that area is low. In general, dilute nitric acid estimated higher bioaccessible content in soil samples, whereas the SBET method estimated higher bioaccessible content in sediment samples. In multivariate analysis, two groups of bioaccessibility tests arise: one with the two nitric acid tests, and the other with SBET and the gastric phase of the IVG protocol. The addition of pepsin and glycine in the last two tests suggests a more reliable test for assessing mercury bioaccessibility.


Assuntos
Argila/química , Substâncias Húmicas/análise , Mercúrio/análise , Mineração , Poluentes do Solo/análise , Solo/química , Adsorção , Disponibilidade Biológica , Brasil , Cidades , Mucosa Gástrica/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Mercúrio/metabolismo , Modelos Biológicos , Ácido Nítrico/química , Poluentes do Solo/metabolismo
7.
Water Res ; 185: 116210, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32731079

RESUMO

Stenotrophomonas can survive in a wide range of environments and is considered an opportunistic pathogen. Because of its intrinsic resistance to beta-lactams, this genus is considered irrelevant in studies addressing the environmental spread of antimicrobial resistance genes of medical importance. Consequently, studies on environmental Stenotrophomonas carrying acquired carbapenemase-encoding genes are scarce, though not inexistent. Here, we investigated the frequency and diversity of Stenotrophomonas spp. carrying genes encoding carbapenemases of medical relevance in coastal waters with distinct pollution degrees over one year. Among 319 isolates recovered, 220 (68.9%) showed blaKPC. The frequency of blaKPC-positive Stenotrophomonas spp. was not correlated with thermotolerant counts in coastal waters evaluated. All isolates were susceptible to minocycline, levofloxacin, and trimethoprim-sulfamethoxazole. PFGE typing of 101 blaKPC-positive isolates revealed 55 pulsotypes with 5 subtypes, all of which carried the blaKPC-2 variant. Interspecies differentiation of pulsotypes' representatives revealed 55 isolates belonging to the S. maltophilia complex (91.7%) and 5 S. acidaminiphila (8.3%). The blaKPC-2 gene was more frequently harbored on transposable elements found in enterobacteria of clinical origin, especially Tn4401b. Even though beta-lactams are no therapeutic options to treat Stenotrophomonas infections, the occurrence of a highly relevant antimicrobial resistance determinant harbored on mobile genetic elements in a diverse collection of these ubiquitous microorganisms is noteworthy. Therefore, Stenotrophomonas may act as acceptor, stable reservoirs, and potential vectors of antimicrobial resistance in environmental settings, especially aquatic matrices, and should not be neglected.


Assuntos
Infecções por Bactérias Gram-Negativas , Stenotrophomonas maltophilia , Antibacterianos/farmacologia , Humanos , Levofloxacino , Testes de Sensibilidade Microbiana , Stenotrophomonas/genética , Stenotrophomonas maltophilia/genética
8.
Chemosphere ; 257: 127114, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32480084

RESUMO

Problems related to specificity and re-precipitation of metals in sequential chemical extractions can impair their routine use. In order to test the efficiency of a sequential chemical procedure, model compounds composed by soil components commonly found in tropical soils such as goethite, Al-goethite, ferrihydrite, hematite, bauxite, and humic acid were incubated with either Hg(NO3)2 or HgSO4 and submitted to chemical extraction. The procedure aims to assess: (i) water soluble Hg; (ii) bioaccessible Hg at pH near human stomach; (iii) Hg associated with organic matter; (iv) reduced Hg; (v) Hg associated with Fe, Al, and Mn oxides; and, (vi) residual Hg. This procedure was also tested via single and sequential extractions using the surface and subsurface samples of two tropical soils, i.e., a Rhodic Acrudox and a Typic Hapludox, with and without lime application. Soil samples were submitted to an adsorption experiment with HgCl2 and a high adsorption percentage was observed. The majority of Hg at both single and sequential procedure was extracted by an acetic acid solution (pH = 2). Liming, soil depth, and soil type were not determinative on Hg extractability. The sequential extraction applied showed a lack specificity of Hg fractions, confirmed by the model components.


Assuntos
Mercúrio/análise , Poluentes do Solo/análise , Adsorção , Compostos de Cálcio , Fracionamento Químico , Humanos , Óxidos , Solo/química , Água
9.
Ecotoxicology ; 29(3): 305-313, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32076927

RESUMO

Lead (Pb) in soils can be transferred to plants, animals, and even humans. The toxicity of Pb is worrisome and therefore environmental quality criteria, established by laws to support the management of contaminated sites, have been developed to prevent its deleterious effects in a wide range of soils, uses, and occupations. In Brazil, the CONAMA Resolution 420/2009 established that Brazilian states may define their prevention values (PV) for metals in soils. However, the established values should be well studied, since a wide variation of sensitivity of species exposed to Pb is reported and several have a high tolerance. We aimed to evaluate Pb toxicity to validate the suitability of the current Brazilian Pb-prevention value. A trial was carried with two plant species (sorghum and soybean) grown in two tropical soils (Typic Hapludox and Rhodic Acrudox), following ISO 11.269-2 protocols (ISO 2012). The tested soils were contaminated with Pb-acetate at the following concentrations: 0, 200, 400, 800, 1200, 1600, 2200, 2800, and 3200 mg kg-1 of dry soil. Differences regarding species sensitivity were observed and sorghum seemed to be less sensitive to Pb concentration in soils. Soil characteristics as higher clay and organic matter content were responsible for decreasing the overall availability of Pb for plants. Using data from this study and from the literature, we constructed a species sensitivity distribution curve and calculated the HC5 (hazardous concentration to 5% of variables evaluated). The HC5 was 132.5 mg kg-1, which suggests that the PV currently used in Brazil (72 mg kg-1) is sufficiently protective for Brazilian soils.


Assuntos
Biodegradação Ambiental , Chumbo/toxicidade , Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Brasil , Fabaceae/fisiologia , Humanos , Solo
10.
Microb Drug Resist ; 26(6): 652-660, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31851584

RESUMO

KPC-producing Klebsiella pneumoniae (KPC-Kp) has become an important public health issue. The previous intestinal colonization by KPC-Kp has been an important risk factor associated with the progression to infections. The objective of this study was to assess the genetic characterization of KPC-Kp isolates recovered from human rectal swabs in Brazil. We selected 102 KPC-Kp isolates collected during 2009-2013 in 11 states. Antimicrobial susceptibility was determined by disk diffusion, E-test, and broth microdilution. The resistance and virulence genes were investigated by PCR. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The isolates were mostly resistant to ß-lactams, sulfonamides, chloramphenicol, quinolones, and aminoglycosides but susceptible to fosfomycin/trometamol, polymyxin B, and tigecycline. The blaKPC-2 was mostly associated with Tn4401b. Besides that, the isolates carried blaCTX-M, blaSHV, blaTEM, and aac(6')-Ib in high frequency and aac(3')IIa and qnr genes in moderate frequency. The PFGE revealed 26 pulsotypes and MLST performed in representative strains revealed 23 sequence types, 45% belonging to clonal complex 258 (CC258). Isolates of CC258 were found in all states. Seventy percent of the 102 KPC-Kp isolates belonged to CC258-associated pulsotypes. We describe the dissemination of KPC-2-Kp associated with Tn4401b belonging to CC258 colonizing patients in Brazil, which is also prevalent in infected patients, suggesting a clear colonization-infection correlation.


Assuntos
Antibacterianos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Farmacorresistência Bacteriana Múltipla/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Brasil/epidemiologia , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Genes Bacterianos , Humanos , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem Molecular , Tipagem de Sequências Multilocus
11.
Environ Sci Pollut Res Int ; 26(1): 483-491, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30406589

RESUMO

Mercury is a metal which is potentially toxic for the environment. Many factors control its retention in the soil, such as cation exchange capacity, pH, clay content, organic matter, and redox potential. It is important to know the phytotoxic effects of soil Hg to prevent environmental contamination and its entry into the food chain. Several analytical methods are used to measure metal phytoavailability in soils, but none has been reported for Hg in Oxisols, the most common soil class in Brazil and a very important soil class throughout the tropics. The aim of this study was to select the chemical extractor that best correlated the Hg levels in plants and the Oxisols. The soils used were classified as Dystrophic Red-Yellow Oxisol (LVAd) and Dystroferric Red Oxisol (LVdf), which were collected in the 0-0.2-m soil layer. The species selected for cultivation were a monocotyledon, oat (Avena sativa L. cv. São Carlos) and a eudicotyledon, common bean (Phaseolus vulgaris L. cv. Madrepérola). Each test plot was composed of a 500 cm3 pot filled with soil samples contaminated with HgCl2. Treatments were arranged in a completely randomized design, with four replications. The experiment was conducted for 30 days. Mercury contents were separately extracted with the following extractors: USEPA 3051A, Mehlich-1, Mehlich-3, DTPA, and water. Mercury was determined by hydride generation atomic absorption spectroscopy. The extracted contents were correlated with the contents in the tissues of the plants' aerial part by the Pearson correlation. Although it is not considered a standard procedure to evaluate metal phytoavailable contents, the method that presented the best correlations between soil Hg and plant Hg was USEPA 3051A (r = 0.75*). As expected, the worst correlation was with water (r = 0.57* for common bean and r = 0,05ns for oat).


Assuntos
Monitoramento Ambiental , Mercúrio/análise , Poluentes do Solo/análise , Solo/química , Brasil , Metais , Espectrofotometria Atômica
13.
Artigo em Inglês | MEDLINE | ID: mdl-28167564

RESUMO

We characterized NDM-1-producing Klebsiella isolates from Rio de Janeiro, Brazil. PCR was applied for resistance and virulence determinants. The genetic context of blaNDM was determined by S1 nuclease pulsed-field gel electrophoresis (PFGE) and hybridization. Genotyping was performed by PFGE and multilocus sequence typing (MLST). Most isolates carried multiple resistance genes and remained susceptible to amikacin, fosfomycin-trometamol, polymyxin B, and tigecycline. The spread of NDM-1-producing Klebsiella pneumoniae was not associated with clonal expansion and appears to be associated with Tn3000.


Assuntos
Antibacterianos/farmacologia , Elementos de DNA Transponíveis , Farmacorresistência Bacteriana Múltipla/genética , Klebsiella pneumoniae/genética , beta-Lactamases/genética , Amicacina/farmacologia , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , Células Clonais , Eletroforese em Gel de Campo Pulsado , Fosfomicina/farmacologia , Expressão Gênica , Genótipo , Humanos , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/transmissão , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Minociclina/análogos & derivados , Minociclina/farmacologia , Tipagem de Sequências Multilocus , Filogenia , Plasmídeos/química , Plasmídeos/metabolismo , Polimixina B/farmacologia , Tigeciclina , beta-Lactamases/metabolismo
15.
Antimicrob Agents Chemother ; 60(11): 6969-6972, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27620478

RESUMO

We aimed to investigate polymyxin B (PMB) resistance and its molecular mechanisms in 126 Klebsiella pneumoniae isolates from rectal swabs in Brazil. Ten isolates exhibited PMB resistance with interruption of mgrB gene by insertion sequences or missense mutations. Most of the PMB-resistant isolates harbored blaKPC-2 (n = 8) and belonged to clonal complex 258 (CC258) (n = 7). These results highlight the importance of monitoring the spread of polymyxin-resistant bacteria in hospitals, since few options remain to treat multidrug-resistant isolates.


Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Polimixina B/farmacologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Mutação , Reto/microbiologia , beta-Lactamases/genética
16.
Mem Inst Oswaldo Cruz ; 110(4): 580-2, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26061151

RESUMO

The emergence of multidrug-resistant Enterobacteriaceae strains producing carbapenemases, such as NDM-1, has become a major public health issue due to a high dissemination capacity and limited treatment options. Here we describe the draft genome of three NDM-1-producing isolates: Providencia rettgeri (CCBH11880), Enterobacter hormaechei subsp. oharae (CCBH10892) and Klebsiella pneumoniae (CCBH13327), isolated in Brazil. Besides blaNDM-1, resistance genes to aminoglycosides [aadA1, aadA2, aac(6')-Ib-cr] and quinolones (qnrA1, qnrB4) were observed which contributed to the multidrug resistance profile. The element ISAba125 was found associated to the blaNDM-1 gene in all strains.


Assuntos
Enterobacter/genética , Genoma Bacteriano/genética , Klebsiella pneumoniae/genética , Providencia/genética , beta-Lactamases/genética , Sequência de Bases , Brasil , Farmacorresistência Bacteriana/genética , Enterobacter/enzimologia , Humanos , Klebsiella pneumoniae/enzimologia , Dados de Sequência Molecular , Providencia/enzimologia , Análise de Sequência de DNA
17.
Antimicrob Agents Chemother ; 59(8): 4453-6, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25987619

RESUMO

Enzymes of the OXA-48 family have become some of the most important beta-lactamases in the world. A new OXA-48 variant (OXA-370) was first described for an Enterobacter hormaechei strain isolated in Rio Grande do Sul (southern region of Brazil) in 2013. Here we report detection of the blaOXA-370 gene in 24 isolates belonging to three Enterobacteriaceae species (22 Klebsiella pneumoniae isolates, 1 Enterobacter cloacae isolate, and 1 Enterobacter aerogenes isolate) collected from five hospitals in Rio de Janeiro, Brazil, in 2013 and 2014. The isolates showed a multidrug resistance profile, and 12.5% were resistant to polymyxin B. Besides blaOXA-370, no other carbapenemase genes were observed by PCR, whereas blaOXA-1 was found in all isolates and 22 isolates (91.6%) possessed blaCTX-M-15. Molecular typing of the K. pneumoniae isolates by pulsed-field gel electrophoresis (PFGE) showed the presence of two clonal groups, i.e., KpA (21 isolates) and KpB (1 isolate). KpA was characterized as sequence type 16 (ST16) and KpB as ST1041 by multilocus sequence typing (MLST). ST16 has been observed for KPC-producing K. pneumoniae in Rio de Janeiro. Plasmid analysis performed with six representative OXA-370-producing isolates showed plasmids harboring the blaOXA-370 gene in all strains, ranging from 25 kb to 150 kb. This study suggests that there is an urgent need to investigate the presence of OXA-370 and dissemination of the K. pneumoniae ST16 clone carrying this gene in Brazil.


Assuntos
Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , beta-Lactamases/genética , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana/métodos , Brasil , Farmacorresistência Bacteriana Múltipla/genética , Plasmídeos/genética
18.
Diagn Microbiol Infect Dis ; 82(4): 326-30, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25935630

RESUMO

In Brazil, since 2009, there has been an ever increasing widespread of the bla(KPC-2) gene, mainly in Klebsiella pneumoniae. This study aims to assess the molecular epidemiology and genetic background of this gene in Enterobacteriaceae (non-K. pneumoniae) species from 9 Brazilian states between 2009 and 2011. Three hundred eighty-seven isolates were analyzed exhibiting nonsusceptibility to carbapenems, in which the bla(KPC-2) gene was detected in 21.4%. By disk diffusion and E-test, these isolates exhibited high rates of resistance to most of the antimicrobials tested, including tigecycline (45.6% nonsusceptible) and polymyxin B (16.5%), the most resistant species being Enterobacter aerogenes and Enterobacter cloacae. We found great clonal diversity and a variety of bla(KPC-2)-carrying plasmids, all of them exhibiting a partial Tn4401 structure. Therefore, this study demonstrates the dissemination of KPC-2 in 9 Enterobacteriaceae species, including species that were not previously described such as Pantoea agglomerans and Providencia stuartii.


Assuntos
Carbapenêmicos/farmacologia , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Tipagem Molecular , Resistência beta-Lactâmica , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Brasil/epidemiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Variação Genética , Genótipo , Humanos , Epidemiologia Molecular , beta-Lactamases/genética
19.
Microb Drug Resist ; 21(2): 234-6, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25473727

RESUMO

The most important resistance mechanism against ß-lactam drugs is the production of carbapenemases. In this study, we report the first identification of Klebsiella pneumoniae carbapenemase (KPC)-2 and New Delhi metallo-ß-lactamase (NDM)-1 in Enterobacter hormaechei subps. oharae from Brazil. The detection of carbapenemases was done by phenotypic assays, PCR, and DNA sequencing, whereas the identification was performed by conventional techniques, sequencing of the 16S rDNA gene, and hsp60-genotyping. Molecular typing was performed using pulsed-field gel electrophoresis, and antimicrobial susceptibility was surrogated by the Etest methodology. Using the whole genome sequencing approach, we searched for resistance genes, plasmid incompatibility group genes, and the genetic environment of blaNDM and blaKPC. The plasmid identification was done by restriction digests with the S1 nuclease followed by hybridization using digoxigenin labeled specific probes. The isolate was considered multiresistant, being susceptible to amikacin and polymyxin B. We observed the following resistance genes: blaCTX-M-15, blaACT-7, blaTEM-1, blaOXA-1, aadA1, aadA2, strA, strB, aac(3)-II, qnrB1, and aac(6')-Ib-cr and incompatibility group plasmid genes IncA/C, IncHI2, and IncN. The blaKPC gene was found associated to the transposon Tn4401 isoform b in plasmid with 50 kb (IncN) and blaNDM-1 was flanked by a truncated ISAba125 and bleMBL in plasmid with 160 kb (IncA/C). This study showed the coproduction of two important carbapenemases (KPC-2 and NDM-1) associated with mobile genetic elements of worldwide epidemiological importance (Tn4401 and ISAba125, respectively), reinforcing the idea that urgent measures are necessary to reduce and prevent the spreading of these carbapenemases primarily in the hospital settings.


Assuntos
Enterobacter/genética , beta-Lactamases/genética , Adulto , Amicacina/uso terapêutico , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Brasil , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Enterobacter/efeitos dos fármacos , Feminino , Genótipo , Humanos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Plasmídeos/genética , Polimixina B/uso terapêutico , beta-Lactamas/farmacologia
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