RESUMEN
PURPOSE: To evaluate prospectively the functional outcomes of tibiotalocalcaneal (TTC) arthrodesis with a contemporary retrograde intramedullary nail after a minimum follow-up of five years. METHODS: Sixty-one patients with a mean age of 51.3 (range, 18-79) years were included in the study. Functional outcome was assessed using the American Orthopaedic Foot and Ankle Society Ankle Hindfoot score (AOFAS), Short-Form 12-item Health Survey (SF12), and visual analog scales (VAS) for both pain and patient satisfaction. Radiographic evaluation was also assessed. RESULTS: The mean post-operative follow-up was 6.8 (range, 5-8) years. Mean AOFAS and SF12 scores significantly improved at the final follow-up (p < 0.001), and the mean VAS for pain significantly decreased (p < 0.001). At the final follow-up, only five (8.2%) patients gave an AOFAS score of less than 50, 52 (85.2%) were satisfied with their surgery, and 32 (52.4%) returned to their employment. There were two tibiotalar joint nonunions that required re-operations, and another patient required re-operation for screw removal. There was no deep infection. CONCLUSIONS: The retrograde intramedullary nail provided a stable TTC arthrodesis with a high union rate, acceptable functional outcomes, and a low severe complication rate. This procedure appears to offer a reliable salvage option for TTC arthrodesis in patients with severe ankle and hindfoot degeneration.
Asunto(s)
Articulación del Tobillo , Artrodesis , Adolescente , Adulto , Anciano , Articulación del Tobillo/diagnóstico por imagen , Articulación del Tobillo/cirugía , Clavos Ortopédicos , Tornillos Óseos , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Estudios Retrospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
This study is aimed to assess the formation of photosynthetic biofilms on and within different natural stone materials, and to analyse their biogeophysical and biogeochemical deterioration potential. This was performed by means of artificial colonisation under laboratory conditions during 3 months. Monitoring of microbial development was performed by image analysis and biofilm biomass estimation by chlorophyll extraction technique. Microscopy investigations were carried out to study relationships between microorganisms and the mineral substrata. The model applied in this work corroborated a successful survival strategy inside endolithic microhabitat, using natural phototrophic biofilm cultivation, composed by cyanobacteria and algae, which increased intrinsic porosity by active mineral dissolution. We observed the presence of mineral-like iron derivatives (e.g. maghemite) around the cells and intracellularly and the precipitation of hausmannite, suggesting manganese transformations related to the biomineralisation.
Asunto(s)
Biopelículas/crecimiento & desarrollo , Materiales de Construcción/microbiología , Cianobacterias/crecimiento & desarrollo , Eucariontes/crecimiento & desarrollo , Biodegradación Ambiental , Clorofila/análisis , Materiales de Construcción/análisis , Microscopía Electrónica de Rastreo , Fotosíntesis , PorosidadRESUMEN
In the last few years, the microbial colonisation of mural paintings in ancient monuments has been attracting the attention of microbiologists and conservators. The genus Rubrobacter is commonly found in biodeteriorated monuments, where it has been reported to cause rosy discolouration. However, to date, only three species of this genus have been isolated, all from thermophilic environments. In this paper, we studied three monuments: the Servilia and Postumio tombs in the Roman Necropolis of Carmona (Spain), and Vilar de Frades church (Portugal), in search of Rubrobacter strains. In all cases, biodeterioration and the formation of efflorescences were observed, and five Rubrobacter strains were isolated. These isolates showed different physiology and migration in denaturing gradient gel electrophoresis, suggesting they might represent new species within this genus. The isolates reproduced some biodeterioration processes in the laboratory and revealed their biomediation in crystal formation.
Asunto(s)
Actinobacteria/genética , Actinobacteria/aislamiento & purificación , Arquitectura , Ritos Fúnebres/historia , Mundo Romano , Actinobacteria/clasificación , Cartilla de ADN , ADN Bacteriano/aislamiento & purificación , Historia Antigua , Filogenia , ARN Bacteriano/genética , ARN Bacteriano/aislamiento & purificación , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/aislamiento & purificaciónRESUMEN
In the last decades, damages on building materials and mural paintings were observed in Roman catacombs. The damages were due to extensive formation of biofilms induced by artificial illumination and humidity. Microenvironmental data (temperature, CO(2) concentration, humidity, and atmospheric pressure) clearly showed the negative influence of visitors. Increasing heat, light and water vapour condensation into corridors and cubicles favoured biofilm development. The composition of biofilms was different and depended mainly on distance to illumination sources and humidity, thus denoting the influence of light on the growth of phototrophic microorganisms in the catacombs. In addition, biofilm distribution was governed by the type of material to be colonised. This study shows that countermeasures are needed to prevent deterioration of hypogean environments.
Asunto(s)
Bacterias/aislamiento & purificación , Materiales de Construcción/microbiología , Cianobacterias/aislamiento & purificación , Bacterias/clasificación , Bacterias/genética , Biopelículas/clasificación , Materiales de Construcción/análisis , Cianobacterias/clasificación , Cianobacterias/genética , Arquitectura y Construcción de Instituciones de Salud , Humanos , Humedad , Iluminación , Microclima , Microscopía Electrónica de Rastreo , Porosidad , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis , Ciudad de Roma , Análisis de Secuencia de ARN , ViajeRESUMEN
Two strains were isolated from tuff, a volcanic rock that forms the walls of the Roman Catacombs of Saint Callixtus in Rome, Italy. A polyphasic approach using nutritional and physiological tests, reactions to antibiotics, fatty acid profiles, DNA base ratios, DNA-DNA reassociation and 16S rRNA gene sequence comparisons showed that the two isolates belong to a novel species within the genus Phyllobacterium. The species Phyllobacterium catacumbae sp. nov. is proposed. The type strain is CSC19(T) (=CECT 5680(T)=LMG 22520(T)).
Asunto(s)
Alphaproteobacteria/clasificación , Alphaproteobacteria/aislamiento & purificación , Sedimentos Geológicos/microbiología , Prácticas Mortuorias , Alphaproteobacteria/genética , Alphaproteobacteria/fisiología , Técnicas de Tipificación Bacteriana , ADN Bacteriano/análisis , ADN Ribosómico/análisis , Genes de ARNr , Historia Antigua , Italia , Datos de Secuencia Molecular , Fenotipo , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
In the present study the induction of biofilms on the open rock faces of quartz quarries is reported as a feasible method of correcting the visual impact generated by the industry. Experiments were carried out to colonize quartz samples with microorganisms isolated directly from aged quarry faces. The results demonstrated the viability of inducing colonisation on quartz, which is not the most favourable material for such treatment. Furthermore, biofilm development caused a significant change in the colour of the surface of the quartz samples to greenish- or reddish yellow, which may be quantified by a colorimeter for solids. The notable change in the colour is sufficient to attenuate the bright white aspect of the quartz faces and therefore to correct the visual impact generated.
Asunto(s)
Biopelículas , Cuarzo , Visión Ocular/fisiología , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Color , Humanos , Propiedades de SuperficieRESUMEN
The taxonomic position of Agromyces fucosus subsp. hippuratus is revised on the basis of molecular and phenotypic data. Phylogenetic analysis based on 16S rRNA gene sequences, DNA-DNA relatedness values and differences from other species in phenotypic traits revealed in this and earlier studies suggested reclassification of A. fucosus subsp. hippuratus as a separate species, Agromyces hippuratus sp. nov., comb. nov. The type strain is VKM Ac-1352T (= JCM 9087T). An emended description of Agromyces fucosus is given.
Asunto(s)
Actinomycetales/clasificación , Actinomycetales/genética , Pared Celular/química , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , ADN Ribosómico/química , ADN Ribosómico/aislamiento & purificación , Ácidos Grasos/análisis , Ácidos Grasos/aislamiento & purificación , Genes de ARNr , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Ácidos Teicoicos/químicaRESUMEN
We propose a strategy for the efficient screening of large libraries of amplified 16S rRNA genes from complex environmental samples. It consists of processing sets of multiple clones simultaneously. This strategy saves up to 90% of the costs and labor spent in the process of screening a 16S rDNA library.
Asunto(s)
Dermatoglifia del ADN/métodos , ADN Bacteriano/análisis , Microbiología Ambiental , Biblioteca de Genes , ARN Ribosómico 16S/análisis , ADN Bacteriano/química , ADN Bacteriano/genética , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genéticaRESUMEN
The active stalactites from Grotta dei Cervi, Porto Badisco, southeastern Italy, were sampled to investigate the microbial communities present in these speleothems. Sampling was carried out in a transect about 150 m long in the central gallery, where numerous Gram-positive bacteria were isolated. Actinomycetes of the genus Streptomyces were the most abundant, followed by members of the genus Bacillus. Further isolates were assigned to the genera Amycolatopsis, Arthrobacter; Agromyces. Micrococcus, Nocardiopsis and Rhodococcus of the order Actinomycetales. The ability of actinomycetes to colonize subterranean environments is discussed.
Asunto(s)
Carbonato de Calcio , Espacios Confinados , Bacterias Grampositivas/aislamiento & purificación , Arte , Técnicas Bacteriológicas , ADN Bacteriano/genética , ADN Ribosómico/genética , Ecología , Humanos , Italia , Reacción en Cadena de la Polimerasa , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Homología de Secuencia de Ácido Nucleico , Temperatura , ViajeRESUMEN
The Sierra de la Plata is an Aljibe yellow sandstone formation from the Acheulian period. There are a few shelters, some of them with rock art paintings. The most representative one, and subjected to anthropogenic pressure, is that of Atlanterra, situated in a residential area. This shelter contains some rock art paintings made with iron oxides. The bacteria present in these paintings were isolated and identified using an automatic method: fatty acid methyl esters profiling. Most of the bacteria belong to the Bacillus genus, B. megaterium being the most abundant species. The isolated strains are able to reduce hematite. This is significant due to the fact that Fe(III)-(hydr)oxides are the most abundant pigments in rock art.
Asunto(s)
Bacillus/aislamiento & purificación , Microbiología Ambiental , Sedimentos Geológicos/microbiología , Pinturas , Paleontología , Bacillus/química , Bacillus/clasificación , Ácidos Grasos/análisis , Compuestos Férricos/metabolismo , EspañaRESUMEN
The culturable microbial populations in dripping waters from Altamira cave were studied and compared with those of the ceiling rock. Water communities have low proportions of gram-positive bacteria, and are mainly composed of gram-negative rods and cocci (Enterobacteriaceae and Vibrionaceae), while those of ceiling rocks are mainly Streptomyces spp. The community differences are probably related to environmental cave conditions: high humidity, relatively low and stable temperature, water pH close to neutrality and nature of the organic matter. All these factors seem to favor colonization and long-term growth of actinomycetes over other heterotrophic bacteria on ceiling rocks.
Asunto(s)
Ecosistema , Sedimentos Geológicos/microbiología , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Microbiología del Agua , Microbiología Ambiental , Bacterias Gramnegativas/clasificación , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/clasificación , Bacterias Grampositivas/crecimiento & desarrollo , EspañaRESUMEN
A gene (lat) encoding lysine 6-aminotransferase was found upstream of the pcbAB (encoding alpha-aminoadipylcysteinyl-valine synthetase) and pcbC (encoding isopenicillin N synthase) genes in the cluster of early cephamycin biosynthetic genes in Nocardia lactamdurans. The lat gene was separated by a small intergenic region of 64 bp from the 5' end of the pcbAB gene. The lat gene contained an open reading frame of 1,353 nucleotides (71.4% G + C) encoding a protein of 450 amino acids with a deduced molecular mass of 48,811 Da. Expression of DNA fragments carrying the lat gene in Streptomyces lividans led to a high lysine 6-aminotransferase activity which was absent from untransformed S. lividans. The enzyme was partially purified from S. lividans(pULBS8) and showed a molecular mass of 52,800 Da as calculated by Sephadex gel filtration and polyacrylamide gel electrophoresis. DNA sequences which hybridized strongly with the lat gene of N. lactamdurans were found in four cephamycin-producing Streptomyces species but not in four other actinomycetes which are not known to produce beta-lactams, suggesting that the gene is specific for beta-lactam biosynthesis and is not involved in general lysine catabolism. The protein encoded by the lat gene showed similarity to ornithine-5-aminotransferases and N-acetylornithine-5-aminotransferases and contained a pyridoxal phosphate-binding consensus amino acid sequence around Lys-300 of the protein. The evolutionary implications of the lat gene as a true beta-lactam biosynthetic gene are discussed.
Asunto(s)
Ácido 2-Aminoadípico/genética , Antibacterianos/química , Cefamicinas/química , Genes Bacterianos , Familia de Multigenes , Nocardia/genética , Transaminasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Vectores Genéticos , L-Lisina 6-Transaminasa , Datos de Secuencia Molecular , Peso Molecular , Sistemas de Lectura Abierta , Ornitina-Oxo-Ácido Transaminasa/genética , Precursores de Proteínas/genética , Homología de Secuencia de Ácido Nucleico , Streptomyces/genética , Especificidad por Sustrato , Transaminasas/biosíntesisRESUMEN
The isopenicillin N synthase (cyclase) of Streptomyces lactamdurans (syn. Nocardia lactamdurans) has been purified to near homogeneity as judged by SDS-PAGE and isoelectric focusing. This enzyme catalyses the oxidative cyclization of the tripeptide delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine to isopenicillin N. The enzyme required DTT, Fe2+ and oxygen and it was greatly stimulated by ascorbic acid. It was strongly inhibited by Co2+, Zn2+ and Mn2+. Optimal pH and temperature were 7.0 and 25 degrees C (with the assay conditions used), respectively. The apparent Km of isopenicillin N synthase for delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine was 0.18 mM. The enzyme is a monomer with an Mr of 26,500 +/- 1000 and a pI of 6.55.
Asunto(s)
Enzimas/aislamiento & purificación , Oxidorreductasas , Streptomyces/enzimología , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Electroforesis en Gel de Poliacrilamida , Enzimas/metabolismo , Concentración de Iones de Hidrógeno , Punto Isoeléctrico , Cinética , Peso MolecularRESUMEN
The deacetoxycephalosporin C (DAOC) synthase (expandase) of Streptomyces lactamdurans was highly purified, as shown by SDS-PAGE and isoelectric focusing. The enzyme catalysed the oxidative ring expansion that converts penicillin N into DAOC. The enzyme was very unstable but could be partially stabilized in 25 mM-Tris/HCl, pH 9.0, in the presence of DTT (0.1 mM). The enzyme required 2-oxoglutarate, oxygen and Fe2+, but did not need ATP, ascorbic acid, Mg2+ or K+. The optimum temperature was between 25 and 30 degrees C. The DAOC synthase showed a high specificity for the penicillin substrate. Only penicillin N but not isopenicillin N, penicillin G or 6-aminopenicillanic acid served as substrates. 2-Oxoglutarate analogues were not used as substrates although 2-oxobutyrate and 3-oxoadipate inhibited the enzyme by 100% and 56% respectively. The enzyme was strongly inhibited by Cu2+, Co2+ and Zn2+. The apparent Km values for penicillin N, 2-oxoglutarate and Fe2+ were 52 microM, 3 microM and 71 microM respectively. The enzyme was a monomer with a molecular mass of 27,000 Da +/- 1,000.