RESUMO
X-linked dystonia parkinsonism (XDP) is a neurogenetic combined movement disorder involving both parkinsonism and dystonia. Complex, overlapping phenotypes result in difficulties in clinical rating scale assessment. We performed wearable sensor-based analyses in XDP participants to quantitatively characterize disease phenomenology as a potential clinical trial endpoint. Wearable sensor data was collected from 10 symptomatic XDP patients and 3 healthy controls during a standardized examination. Disease severity was assessed with the Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS) and Burke-Fahn-Marsden dystonia scale (BFM). We collected sensor data during the performance of specific MDS-UPDRS/BFM upper- and lower-limb motor tasks, and derived data features suitable to estimate clinical scores using machine learning (ML). XDP patients were at varying stages of disease and clinical severity. ML-based algorithms estimated MDS-UPDRS scores (parkinsonism) and dystonia-specific data features with a high degree of accuracy. Gait spatio-temporal parameters had high discriminatory power in differentiating XDP patients with different MDS-UPDRS scores from controls, XDP freezing of gait, and dystonic/non-dystonic gait. These analyses suggest the feasibility of using wearable sensor data for deriving reliable clinical score estimates associated with both parkinsonian and dystonic features in a complex, combined movement disorder and the utility of motion sensors in quantifying clinical examination.
Assuntos
Distúrbios Distônicos , Doenças Genéticas Ligadas ao Cromossomo X , Aprendizado de Máquina , Dispositivos Eletrônicos Vestíveis , Humanos , Distúrbios Distônicos/diagnóstico , Distúrbios Distônicos/fisiopatologia , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Masculino , Adulto , Pessoa de Meia-Idade , Transtornos Parkinsonianos/fisiopatologia , Transtornos Parkinsonianos/diagnóstico , Índice de Gravidade de Doença , Feminino , MarchaRESUMO
OBJECTIVE: A cross-sectional study was performed to evaluate whether quantitative oculomotor measures correlate with disease severity in late-onset GM2 gangliosidosis (LOGG) and assess cognition and sleep as potential early nonmotor features. METHODS: Ten patients with LOGG underwent quantitative oculomotor recordings, including measurements of the angular vestibulo-ocular reflex (VOR), with results compared to age- and sex-matched controls. Disease severity was assessed by ataxia rating scales. Cognitive/neuropsychiatric features were assessed by the cerebellar cognitive affective syndrome (CCAS) scale, Cerebellar Neuropsychiatric Rating Scale, and sleep quality evaluated using subjective sleep scales. RESULTS: Oculomotor abnormalities were found in all participants, including 3/10 with clinically normal eye movements. Abnormalities involved impaired saccadic accuracy (5/10), abnormal vertical (8/10) and horizontal (4/10) pursuit, reduced optokinetic nystagmus (OKN) responses (7/10), low VOR gain (10/10), and impaired VOR cancellation (2/10). Compared to controls, the LOGG group showed significant differences in saccade, VOR, OKN, and visually enhanced VOR gains. Severity of saccadic dysmetria, OKN, and VOR fixation-suppression impairments correlated with ataxia scales (p < 0.05). Nine out of ten patients with LOGG had evidence of the CCAS (5/10 definite, 2/10 probable, 2/10 possible). Excessive daytime sleepiness was present in 4/10 and 8/10 had poor subjective sleep quality. CONCLUSIONS: Cerebellar oculomotor abnormalities were present in all patients with LOGG, including those with normal clinical oculomotor examinations. Saccade accuracy (dorsal cerebellar vermis localization), fixation suppression, and OKN gain (cerebellar flocculus/paraflocculus localization) correlated with disease severity, suggesting that quantitative oculomotor measurements could be used to track disease progression. We found evidence of the CCAS, suggesting that cerebellar dysfunction may explain the cognitive disorder in LOGG. Sleep impairments were prevalent and require further study.
Assuntos
Movimentos Oculares , Gangliosidoses GM2/diagnóstico , Adulto , Encéfalo/diagnóstico por imagem , Cognição , Estudos de Coortes , Estudos Transversais , Feminino , Gangliosidoses GM2/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos da Motilidade Ocular/diagnóstico , Transtornos da Motilidade Ocular/etiologia , Transtornos da Motilidade Ocular/fisiopatologia , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Sono , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/etiologia , Transtornos do Sono-Vigília/fisiopatologiaRESUMO
Knowledge of novel antibiotic resistance genes aids in the understanding of how antibiotics function and how bacteria fight them. This knowledge also allows future generations of an antibiotic or antibiotic group to be altered to allow the greatest efficacy. The method described here is very simple in theory. The bacterial strains are screened for antibiotic resistance. Cultures of the strain are grown, and DNA is extracted. A partial digest of the extraction is cloned into Escherichia coli, and the transformants are plated on selective media. Any colony that grows will possess the antibiotic resistance gene and can be further examined. In actual practice, however, this technique can be complicated. The detailed protocol will need to be optimized for each bacterial strain, vector, and cell line chosen.
Assuntos
Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Escherichia coli , Animais , Clonagem Molecular , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/métodos , Análise de Sequência de DNARESUMO
Various natural environments have been examined for the presence of antibiotic-resistant bacteria and/or novel resistance mechanisms, but little is known about resistance in the terrestrial deep subsurface. This study examined two deep environments that differ in their known period of isolation from surface environments and the bacteria therein. One hundred fifty-four strains of bacteria were isolated from sediments located 170-259 m below land surface at the US Department of Energy Savannah River Site (SRS) in South Carolina and Hanford Site (HS) in Washington. Analyses of 16S rRNA gene sequences showed that both sets of strains were phylogenetically diverse and could be assigned to several genera in three to four phyla. All of the strains were screened for resistance to 13 antibiotics by plating on selective media and 90% were resistant to at least one antibiotic. Eighty-six percent of the SRS and 62% of the HS strains were resistant to more than one antibiotic. Resistance to nalidixic acid, mupirocin, or ampicillin was noted most frequently. The results indicate that antibiotic resistance is common among subsurface bacteria. The somewhat higher frequencies of resistance and multiple resistance at the SRS may, in part, be due to recent surface influence, such as exposure to antibiotics used in agriculture. However, the HS strains have never been exposed to anthropogenic antibiotics but still had a reasonably high frequency of resistance. Given their long period of isolation from surface influences, it is possible that they possess some novel antibiotic resistance genes and/or resistance mechanisms.
Assuntos
Bactérias/efeitos dos fármacos , Bactérias/genética , Farmacorresistência Bacteriana , Sedimentos Geológicos/microbiologia , Bactérias/isolamento & purificação , Testes de Sensibilidade Microbiana , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , South Carolina , WashingtonRESUMO
Tet 42, a novel tetracycline resistance determinant from deep subsurface bacteria, was characterized and found to have a 30% sequence similarity to TetA(Z). The protein is a putative efflux pump that shares characteristics with previously characterized pumps, including a divergently transcribed TetR repressor, a conserved GxxSDRxGRR motif, and transmembrane domains.
Assuntos
Antiporters/genética , Bactérias/isolamento & purificação , Proteínas de Bactérias/genética , Sedimentos Geológicos/microbiologia , Resistência a Tetraciclina/genética , Sequência de Aminoácidos , Antibacterianos/farmacologia , Antiporters/química , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Proteínas de Bactérias/química , Sequência de Bases , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Tetraciclina/farmacologiaRESUMO
Phenotypic and phylogenetic studies were performed on a novel sulfate-reducing bacterium, strain D41(T), isolated as part of a methanogenic syntrophic culture from a gas condensate-contaminated aquifer undergoing intrinsic bioremediation. The bacterium was a Gram-negative, non-spore-forming, curved rod, motile by a single polar flagellum, which oxidized several alcohols incompletely, including methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 3-methyl-1-butanol (isoamyl alcohol), ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, phenylethanol and benzyl alcohol. Additionally, the strain oxidized H(2)/CO(2), formate, lactate, pyruvate, maleate, malate and fumarate. Sulfate, thiosulfate and sulfite were used as electron acceptors. The DNA G+C content was 63 mol%. Based on phylogenetic and phenotypic evidence, the novel species Desulfovibrio carbinoliphilus sp. nov. is proposed. The type strain is D41(T) (=ATCC BAA-1241(T) =DSM 17524(T)).
Assuntos
Álcool Benzílico/metabolismo , Desulfovibrio/classificação , Desulfovibrio/isolamento & purificação , Água Doce/microbiologia , Sulfatos/metabolismo , Poluição Química da Água , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/análise , DNA Ribossômico/análise , Desulfovibrio/genética , Desulfovibrio/metabolismo , Genes de RNAr , Dados de Sequência Molecular , Oxirredução , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie , Bactérias Redutoras de Enxofre/classificação , Bactérias Redutoras de Enxofre/genética , Bactérias Redutoras de Enxofre/isolamento & purificação , Bactérias Redutoras de Enxofre/metabolismoRESUMO
For extremely ionizing radiation-resistant bacteria, survival has been attributed to protection of proteins from oxidative damage during irradiation, with the result that repair systems survive and function with far greater efficiency during recovery than in sensitive bacteria. Here we examined the relationship between survival of dry-climate soil bacteria and the level of cellular protein oxidation induced by desiccation. Bacteria were isolated from surface soils of the shrub-steppe of the US Department of Energy's Hanford Site in Washington State. A total of 63 isolates were used for phylogenetic analysis. The majority of isolates were closely related to members of the genus Deinococcus, with Chelatococcus, Methylobacterium and Bosea also among the genera identified. Desiccation-resistant isolates accumulated high intracellular manganese and low iron concentrations compared to sensitive bacteria. In vivo, proteins of desiccation-resistant bacteria were protected from oxidative modifications that introduce carbonyl groups in sensitive bacteria during drying. We present the case that survival of bacteria that inhabit dry-climate soils are highly dependent on mechanisms, which limit protein oxidation during dehydration.
Assuntos
Alphaproteobacteria/crescimento & desenvolvimento , Proteínas de Bactérias/metabolismo , Deinococcus/crescimento & desenvolvimento , Clima Desértico , Dessecação , Microbiologia do Solo , Alphaproteobacteria/classificação , Alphaproteobacteria/genética , Alphaproteobacteria/metabolismo , Deinococcus/genética , Deinococcus/isolamento & purificação , Deinococcus/metabolismo , Raios gama , Methylobacterium/genética , Methylobacterium/crescimento & desenvolvimento , Methylobacterium/isolamento & purificação , Methylobacterium/metabolismo , Dados de Sequência Molecular , Oxirredução , Estresse Oxidativo , RNA Ribossômico 16S/genética , Tolerância a Radiação , Radiação Ionizante , Análise de Sequência de DNA , WashingtonRESUMO
At many uranium processing and handling facilities, including sites in the US Department of Energy (DOE) complex, high levels of nitrate are present as co-contamination with uranium in groundwater. The daunting prospect of complete nitrate removal prior to the reduction of uranium provides a strong incentive to explore bioremediation strategies that allow for uranium bioreduction and stabilization in the presence of nitrate. Typical in situ strategies involving the stimulation of metal-reducing bacteria are hindered by low-pH environments and require that the persistent nitrate must first and continuously be removed or transformed prior to uranium being a preferred electron acceptor. This work investigated the possibility of stimulating nitrate-indifferent, pH-tolerant microorganisms to achieve bioreduction of U(VI) despite nitrate persistence. Enrichments from U-contaminated sediments demonstrated nearly complete reduction of uranium with very little loss of nitrate from pH 5.7-6.2 using methanol or glycerol as a carbon source. Bacterial 16S rRNA genes were amplified from uranium-reducing enrichments (pH 5.7-6.2) and sequenced. Phylogenetic analyses classified the clone sequences into four distinct clusters. Data from sequencing and terminal-restriction fragment length polymorphism (T-RFLP) profiles indicated that the majority of the microorganisms stimulated by these enrichment conditions consisted of low G+C Gram-positive bacteria most closely related to Clostridium and Clostridium-like organisms. This research demonstrates that the stimulation of a natural microbial community to immobilize U through bioreduction is possible without the removal of nitrate.
Assuntos
RNA Bacteriano/classificação , Urânio/metabolismo , Poluentes Radioativos da Água/metabolismo , Biodegradação Ambiental , Ecossistema , Nitratos/metabolismo , Filogenia , RNA Ribossômico 16S , TennesseeRESUMO
Alkaline, sulfidic, 54 to 60 degrees C, 4 to 53 million-year-old meteoric water emanating from a borehole intersecting quartzite-hosted fractures >3.3 km beneath the surface supported a microbial community dominated by a bacterial species affiliated with Desulfotomaculum spp. and an archaeal species related to Methanobacterium spp. The geochemical homogeneity over the 650-m length of the borehole, the lack of dividing cells, and the absence of these microorganisms in mine service water support an indigenous origin for the microbial community. The coexistence of these two microorganisms is consistent with a limiting flux of inorganic carbon and SO4(2-) in the presence of high pH, high concentrations of H2 and CH4, and minimal free energy for autotrophic methanogenesis. Sulfide isotopic compositions were highly enriched, consistent with microbial SO4(2-) reduction under hydrologic isolation. An analogous microbial couple and similar abiogenic gas chemistry have been reported recently for hydrothermal carbonate vents of the Lost City near the Mid-Atlantic Ridge (D. S. Kelly et al., Science 307:1428-1434, 2005), suggesting that these features may be common to deep subsurface habitats (continental and marine) bearing this geochemical signature. The geochemical setting and microbial communities described here are notably different from microbial ecosystems reported for shallower continental subsurface environments.
Assuntos
Desulfotomaculum/isolamento & purificação , Sedimentos Geológicos/microbiologia , Methanobacterium/isolamento & purificação , Microbiologia da Água , Desulfotomaculum/classificação , Desulfotomaculum/genética , Methanobacterium/classificação , Methanobacterium/genética , Filogenia , Reação em Cadeia da Polimerase , RNA Bacteriano/genética , RNA Ribossômico 16S/genéticaRESUMO
A novel solvent-producing, anaerobic clostridium, strain P7(T), was isolated from sediment from an agricultural settling lagoon after enrichment with CO as the substrate. The metabolism of this Gram-positive, motile, spore-forming rod was primarily acetogenic. Acetate, ethanol, butyrate and butanol were the end-products of metabolism. Strain P7(T) grew on CO, H(2)/CO(2), glucose, galactose, fructose, xylose, mannose, cellobiose, trehalose, cellulose, starch, pectin, citrate, glycerol, ethanol, propanol, 2-propanol, butanol, glutamate, aspartate, alanine, histidine, asparagine, serine, betaine, choline and syringate as sole substrates. Growth was not supported by methanol, formate, D-arabinose, fucose, lactose, melibiose, amygdalin, gluconate, lactate, malate, arginine, glutamine or vanillate. Nitrate reduction, production of indole, gelatin hydrolysis and aesculin hydrolysis were not observed. Analysis of the 16S rRNA gene sequence of the isolate showed that it was closely related to Clostridium scatologenes ATCC 25775(T) (99.7% sequence similarity) and clostridial strain SL1(T) (99.8% sequence similarity). Strain SL1 had been classified as a strain of C. scatologenes. However, DNA-DNA reassociation analysis showed that both strain P7(T) and strain SL1 represented novel clostridial species. It is proposed that strain P7(T) (=ATCC BAA-624(T)=DSM 15243(T)) be classified as the type strain of Clostridium carboxidivorans sp. nov. and that strain SL1(T) (=ATCC BAA-623(T)=DSM 12750(T)) be reclassified as the type strain of Clostridium drakei sp. nov.
Assuntos
Ácido Acético/metabolismo , Agricultura , Monóxido de Carbono/metabolismo , Clostridium/classificação , Sedimentos Geológicos/microbiologia , Solventes/metabolismo , Microbiologia da Água , Técnicas de Tipagem Bacteriana , Clostridium/genética , Clostridium/crescimento & desenvolvimento , Clostridium/isolamento & purificação , DNA Bacteriano/análise , DNA Ribossômico/análise , Genes de RNAr , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Novosphingobium aromaticivorans, a unique ubiquitous bacterium that metabolizes xenobiotics and activates environmental estrogens, has been suggested as a pathogenic factor in the development of primary biliary cirrhosis (PBC). To define the molecular basis of PBC sera reactivity, we investigated the characteristic of the bacterial antigens involved. We cloned and sequenced four genes from N. aromaticivorans coding for immunoreactive proteins, arbitrarily named Novo 1 through Novo 4. We subsequently analyzed these proteins for their homology to known mitochondrial proteins and defined their reactivity using monoclonal antibodies (mAbs), rabbit anti-lipoic acid antibody, and PBC/control sera. Moreover, we studied their phylogenetic relation with the known PBC autoantigens. Novo proteins have an extraordinary degree of amino acid homology with all of the major human mitochondrial autoantigens PDC-E2 (Novo 1 and 2), OGDC-E2 (Novo 3), and BCOADC-E2 (Novo 4). Moreover, Novo 1-4 contain a lipoylated domain, are recognized by AMA-positive sera, and react with specific mAbs to mitochondrial antigens. Interestingly, the phylogenetic relation of the proteins emphasizes the conservation of the lipoylated domain. In conclusion, our data provide a high degree of confidence that N. aromaticivorans may potentiate the breakdown of self tolerance in genetically susceptible individuals.
Assuntos
Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Lipoproteínas/genética , Homologia de Sequência de Aminoácidos , Sphingomonadaceae/genética , Aciltransferases/genética , Aciltransferases/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Bactérias/imunologia , Autoantígenos/genética , Autoantígenos/imunologia , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Proteínas de Bactérias/imunologia , Di-Hidrolipoil-Lisina-Resíduo Acetiltransferase , Evolução Molecular , Humanos , Lipoproteínas/imunologia , Cirrose Hepática Biliar/genética , Cirrose Hepática Biliar/imunologia , Mimetismo Molecular/genética , Mimetismo Molecular/imunologia , Dados de Sequência Molecular , Filogenia , Complexo Piruvato Desidrogenase/genética , Complexo Piruvato Desidrogenase/imunologia , Sphingomonadaceae/imunologia , Ácido Tióctico/genética , Ácido Tióctico/imunologiaRESUMO
Previous studies have demonstrated that metal-reducing microorganisms can effectively promote the precipitation and removal of uranium from contaminated groundwater. Microbial communities were stimulated in the acidic subsurface by pH neutralization and addition of an electron donor to wells. In single-well push-pull tests at a number of treated sites, nitrate, Fe(III), and uranium were extensively reduced and electron donors (glucose, ethanol) were consumed. Examination of sediment chemistry in cores sampled immediately adjacent to treated wells 3.5 months after treatment revealed that sediment pH increased substantially (by 1 to 2 pH units) while nitrate was largely depleted. A large diversity of 16S rRNA gene sequences were retrieved from subsurface sediments, including species from the alpha, beta, delta, and gamma subdivisions of the class Proteobacteria, as well as low- and high-G+C gram-positive species. Following in situ biostimulation of microbial communities within contaminated sediments, sequences related to previously cultured metal-reducing delta-Proteobacteria increased from 5% to nearly 40% of the clone libraries. Quantitative PCR revealed that Geobacter-type 16S rRNA gene sequences increased in biostimulated sediments by 1 to 2 orders of magnitude at two of the four sites tested. Evidence from the quantitative PCR analysis corroborated information obtained from 16S rRNA gene clone libraries, indicating that members of the delta-Proteobacteria subdivision, including Anaeromyxobacter dehalogenans-related and Geobacter-related sequences, are important metal-reducing organisms in acidic subsurface sediments. This study provides the first cultivation-independent analysis of the change in metal-reducing microbial communities in subsurface sediments during an in situ bioremediation experiment.
Assuntos
Bactérias , Ecossistema , Água Doce/microbiologia , Sedimentos Geológicos/microbiologia , Nitratos/metabolismo , RNA Ribossômico 16S/genética , Urânio/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , DNA Ribossômico/análise , Deltaproteobacteria/classificação , Deltaproteobacteria/genética , Deltaproteobacteria/crescimento & desenvolvimento , Geobacter/classificação , Geobacter/genética , Geobacter/crescimento & desenvolvimento , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Poluição da ÁguaRESUMO
Sediments from a high-level nuclear waste plume were collected as part of investigations to evaluate the potential fate and migration of contaminants in the subsurface. The plume originated from a leak that occurred in 1962 from a waste tank consisting of high concentrations of alkali, nitrate, aluminate, Cr(VI), (137)Cs, and (99)Tc. Investigations were initiated to determine the distribution of viable microorganisms in the vadose sediment samples, probe the phylogeny of cultivated and uncultivated members, and evaluate the ability of the cultivated organisms to survive acute doses of ionizing radiation. The populations of viable aerobic heterotrophic bacteria were generally low, from below detection to approximately 10(4) CFU g(-1), but viable microorganisms were recovered from 11 of 16 samples, including several of the most radioactive ones (e.g., >10 microCi of (137)Cs/g). The isolates from the contaminated sediments and clone libraries from sediment DNA extracts were dominated by members related to known gram-positive bacteria. Gram-positive bacteria most closely related to Arthrobacter species were the most common isolates among all samples, but other phyla high in G+C content were also represented, including Rhodococcus and Nocardia. Two isolates from the second-most radioactive sample (>20 microCi of (137)Cs g(-1)) were closely related to Deinococcus radiodurans and were able to survive acute doses of ionizing radiation approaching 20 kGy. Many of the gram-positive isolates were resistant to lower levels of gamma radiation. These results demonstrate that gram-positive bacteria, predominantly from phyla high in G+C content, are indigenous to Hanford vadose sediments and that some are effective at surviving the extreme physical and chemical stress associated with radioactive waste.
Assuntos
Bactérias/classificação , Sedimentos Geológicos , Resíduos Radioativos , Microbiologia da Água , Poluentes Radioativos da Água/análise , DNA Ribossômico/análise , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
Iron(III)-reducing bacteria have been demonstrated to rapidly catalyze the reduction and immobilization of uranium(VI) from contaminated subsurface sediments. Thus, these organisms may aid in the development of bioremediation strategies for uranium contamination, which is prevalent in acidic subsurface sediments at U.S. government facilities. Iron(III)-reducing enrichment cultures were initiated from pristine and contaminated (high in uranium, nitrate; low pH) subsurface sediments at pH 7 and pH 4 to 5. Enumeration of Fe(III)-reducing bacteria yielded cell counts of up to 240 cells ml(-1) for the contaminated and background sediments at both pHs with a range of different carbon sources (glycerol, acetate, lactate, and glucose). In enrichments where nitrate contamination was removed from the sediment by washing, MPN counts of Fe(III)-reducing bacteria increased substantially. Sediments of lower pH typically yielded lower counts of Fe(III)-reducing bacteria in lactate- and acetate-amended enrichments, but higher counts were observed when glucose was used as an electron donor in acidic enrichments. Phylogenetic analysis of 16S rRNA gene sequences extracted from the highest positive MPN dilutions revealed that the predominant members of Fe(III)-reducing consortia from background sediments were closely related to members of the Geobacteraceae family, whereas a recently characterized Fe(III) reducer (Anaeromyxobacter sp.) and organisms not previously shown to reduce Fe(III) (Paenibacillus and Brevibacillus spp.) predominated in the Fe(III)-reducing consortia of contaminated sediments. Analysis of enrichment cultures by terminal restriction fragment length polymorphism (T-RFLP) strongly supported the cloning and sequencing results. Dominant members of the Fe(III)-reducing consortia were observed to be stable over several enrichment culture transfers by T-RFLP in conjunction with measurements of Fe(III) reduction activity and carbon substrate utilization. Enrichment cultures from contaminated sites were also shown to rapidly reduce millimolar amounts of U(VI) in comparison to killed controls. With DNA extracted directly from subsurface sediments, quantitative analysis of 16S rRNA gene sequences with MPN-PCR indicated that Geobacteraceae sequences were more abundant in pristine compared to contaminated environments,whereas Anaeromyxobacter sequences were more abundant in contaminated sediments. Thus, results from a combination of cultivation-based and cultivation-independent approaches indicate that the abundance/community composition of Fe(III)-reducing consortia in subsurface sediments is dependent upon geochemical parameters (pH, nitrate concentration) and that microorganisms capable of producing spores (gram positive) or spore-like bodies (Anaeromyxobacter) were representative of acidic subsurface environments.
Assuntos
Bacillaceae/classificação , Deltaproteobacteria/classificação , Deltaproteobacteria/isolamento & purificação , Ecossistema , Compostos Férricos/metabolismo , Água Doce/microbiologia , Sedimentos Geológicos/microbiologia , Bacillaceae/genética , Bacillaceae/isolamento & purificação , Bacillaceae/metabolismo , Contagem de Colônia Microbiana , Meios de Cultura , DNA Ribossômico/análise , Deltaproteobacteria/genética , Deltaproteobacteria/metabolismo , Água Doce/química , Concentração de Íons de Hidrogênio , Oxirredução , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética , Urânio , Poluentes Químicos da ÁguaRESUMO
Infectious and environmental agents have been proposed as immunologic triggers for primary biliary cirrhosis (PBC). Recently, a ubiquitous organism that metabolizes organic compounds and estrogens, Novosphingobium aromaticivorans, has been defined. Importantly, 2 bacterial proteins have homology with the E2 component of the pyruvate dehydrogenase complex (PDC-E2). Sera from 97 patients with PBC, 46 first-degree relatives, 10 spouses, and 195 controls were studied for reactivity against N. aromaticivorans and Escherichia coli. The reactivity was defined by absorption, affinity purification, and using monoclonal antibodies to PDC-E2. Stool samples from 20 patients with PBC and 34 controls were analyzed by polymerase chain reaction (PCR) for the presence of N. aromaticivorans. Sera from 100% of anti-PDC-E2 positive (77/77), 33% of anti-BCOADC E2 positive (1/3), and 12% of antimitochondrial antibody (AMA) negative patients with PBC (2/17) reacted with titers up to 10(-6) against two known lipoylated bacterial proteins (47 and 50 kd) from N. aromaticivorans, including patients with early disease. This titer was approximately 100- to 1,000-fold higher than against E. coli and verified by absorption, use of affinity-purified sera, and monoclonal antibody reagents. Moreover, 78 of 80 AMA-positive and 5 of 17 AMA-negative patients with PBC had antibodies against 3 other N. aromaticivorans proteins. In contrast, 0 of 195 control sera reacted against N. aromaticivorans. Approximately 25% of patients and controls had N. aromaticivorans in their fecal specimens. In conclusion, based on protein homology, capacity to metabolize xenobiotics as well as modulate estrogens, its presence in feces, and specific immunologic response, we propose that N. aromaticivorans is a candidate for the induction of PBC.
Assuntos
Alphaproteobacteria/imunologia , Alphaproteobacteria/metabolismo , Cirrose Hepática Biliar/imunologia , Cirrose Hepática Biliar/microbiologia , Xenobióticos/metabolismo , Alphaproteobacteria/isolamento & purificação , Sequência de Aminoácidos/genética , Infecções Bacterianas/complicações , Proteínas de Bactérias/genética , Estudos de Casos e Controles , Di-Hidrolipoil-Lisina-Resíduo Acetiltransferase , Fezes/microbiologia , Feminino , Humanos , Cirrose Hepática Biliar/genética , Masculino , Mimetismo Molecular , Dados de Sequência Molecular , Complexo Piruvato Desidrogenase/genética , Homologia de Sequência de AminoácidosRESUMO
We characterized the diversity of sulphate-reducing bacteria (SRB) associated with South African gold mine boreholes and deep aquifer systems in Washington State, USA. Sterile cartridges filled with crushed country rock were installed on two hydrologically isolated and chemically distinct sites at depths of 3.2 and 2.7 km below the land surface (kmbls) to allow development of biofilms. Enrichments of sulphate-reducing chemolithotrophic (H2) and organotrophic (lactate) bacteria were established from each site under both meso- and thermophilic conditions. Dissimilatory sulphite reductase (Dsr) and 16S ribosomal RNA (rRNA) genes amplified from DNA extracted from the cartridges were most closely related to the Gram-positive species Desulfotomaculum thermosapovorans and Desulfotomaculum geothermicum, or affiliated with a novel deeply branching clade. The dsr sequences recovered from the Washington State deep aquifer systems affiliated closely with the South African sequences, suggesting that Gram-positive sulphate-reducing bacteria are widely distributed in the deep subsurface.