Animal and human RNA viruses: genetic variability and ability to overcome vaccines.

RNA viruses, in general, exhibit high mutation rates; this is mainly due to the low fidelity displayed by the RNA-dependent polymerases required for their replication that lack the proofreading machinery to correct misincorporated nucleotides and produce high mutation rates. This lack of replication fidelity, together with the fact that RNA viruses can undergo spontaneous mutations, results in genetic variants displaying different viral morphogenesis, as well as variation on their surface glycoproteins that affect viral antigenicity. This diverse viral population, routinely containing a variety of mutants, is known as a viral 'quasispecies'. The mutability of their virions allows for fast evolution of RNA viruses that develop antiviral resistance and overcome vaccines much more rapidly than DNA viruses. This also translates into the fact that pathogenic RNA viruses, that cause many diseases and deaths in humans, represent the major viral group involved in zoonotic disease transmission, and are responsible for worldwide pandemics.

Antibacterial properties of laser spinning glass nanofibers.

A laser-spinning technique has been used to produce amorphous, dense and flexible glass nanofibers of two different compositions with potential utility as reinforcement materials in composites, fillers in bone defects or scaffolds (3D structures) for tissue engineering. Morphological and microstructural analyses have been carried out using SEM-EDX, ATR-FTIR and TEM. Bioactivity studies allow the nanofibers with high proportion in SiO2 (S18/12) to be classified as a bioinert glass and the nanofibers with high proportion of calcium (ICIE16) as a bioactive glass. The cell viability tests (MTT) show high biocompatibility of the laser spinning glass nanofibers. Results from the antibacterial activity study carried out using dynamic conditions revealed that the bioactive glass nanofibers show a dose-dependent bactericidal effect on Sthaphylococcus aureus (S. aureus) while the bioinert glass nanofibers show a bacteriostatic effect also dose-dependent. The antibacterial activity has been related to the release of alkaline ions, the increase of pH of the medium and also the formation of needle-like aggregates of calcium phosphate at the surface of the bioactive glass nanofibers which act as a physical mechanism against bacteria. The antibacterial properties give an additional value to the laser-spinning glass nanofibers for different biomedical applications, such as treating or preventing surgery-associated infections.

Onychomadesis after a hand, foot, and mouth disease outbreak in Spain, 2009.

Few reports exist regarding the association between onychomadesis and an enterovirus infection presenting clinically as hand, foot, and mouth disease (HFMD). In February 2009, an outbreak of HFMD occurred in a Spanish nursery school, followed by onychomadesis 36-69 days later. Twelve of 17 children with HFMD developed nail shedding; enterovirus was detected in stool samples from eight (47%) of the 17. However, in only three of the children could an enterovirus serotype coxsackievirus B1 be identified. The epidemiological results of this study confirm onychomadesis as a complication in HFMD. In future outbreaks, molecular characterization of enterovirus from appropriate clinical samples should be studied.

Enteroviruses in Spain over the decade 1998-2007: virological and epidemiological studies.

BACKGROUND: Human enteroviruses (HEV) are the commonest cause of viral meningitis as well as other pathologies, therefore HEV characterization is important both in patient management and epidemiological investigation. OBJECTIVES: A 10-year study of patients with enteroviral infection was carried out in Spain to determine the underlying etiology. STUDY DESIGN: HEV were fully typed by microneutralisation tests and/or molecular methods. RESULTS: A collection of 86404 clinical samples were studied in several Spanish laboratories. These were collected from patients with different syndromes, mainly aseptic meningitis (AM), fever, respiratory diseases and acute flaccid paralysis. Of these, 6867 HEV were obtained. At the National Poliovirus Laboratory 2814 were serotypically characterised. Among non-polio enteroviruses, the eight main serotypes were Echovirus 30 (25%), Echovirus 6 (12.4%), Echovirus 13 (8.3%), Echovirus 11 (7.4%) and Echovirus 9 (4.7%), followed by Coxsackievirus B5 (4.2%) and Echovirus 7 and Coxsackievirus A9 (3.7%) each. In AM cases, Echovirus 30 was identified in 39% of them, followed by Echovirus 6 (14%). However, Echovirus 6 was mainly associated with respiratory disease (17%), followed by Echovirus 11 (10%). On the other hand, Echovirus 30, Echovirus 11 and Echovirus 6 contributed equally with 12% of each serotype in the cases of fever. CONCLUSIONS: The present report complements previous data (Trallero et al.(13)), with the results of HEV incidence in Spain from 1998 to 2007. The surveillance described in this study provided valuable information as to which serotypes are in circulation, the emergence of new HEV and association with clinical manifestations.

[Surgical management of dural arteriovenous fistulae in six patients]. / Manejo quirúrgico de las malformaciones arteriovenosas durales craneales. Serie de seis casos.

OBJECTIVES: In this article, we describe our experience in surgical management of dural arteriovenous fistulae (dAVF). MATERIALS AND METHODS: From August 2001 to February 2006 a total of six patients, were admitted at our hospital, 2 women and 4 men with ages between 40 and 68 years. RESULTS: Four of the six cases were entered through the service of Emergency Service by neurological deficit (in two cases) or decrease in the level of consciousness (in two patients); the remaining two patients were referred by lengthy headache and alterations on neuroimaging studies suggestive of dAVF. All of them showed dAVF in different locations which were treated successfully with surgery after angiographic studies. CONCLUSION: Although multiple therapeutic options are available, surgery is the treatment of choice in dAVF which shows aggressive clinical course, especially intracranial hemorrhage.

Proposal of a method for the genetic transformation of Gordonia jacobaea.

AIMS: Gordonia jacobaea is a recently isolated bacterial species with potential industrial application on account of its ability to store large quantities of trans-canthaxanthin. Its genetic manipulation is, however, difficult and cumbersome owing to the presence of mycolic acids in the cell wall and, especially, because of current lack of knowledge about its basic genetics. The present work describes a method for the genetic transformation of G. jacobaea. METHODS AND RESULTS: Gordonia jacobaea was grown in media supplemented with different glycine, penicillin G and isoniazid concentrations. The temperature, carbon source, growth phase and ultrasounds were analyzed for improving the method efficiency. The cells were finally transformed by electroporation. Finally, the method was applied to Brevibacteriumlactofermentum and Gordonia bronchialis. CONCLUSIONS: The growth of G. jacobaea in the presence of glycine and isoniazid is essential for obtaining electrocompetents cells. The temperature, growth phase and ultrasounds appeared as the main factors for increasing the transformation efficiency. The use of shuttle plasmids became necessary. The method described can be used with other Corynebacteria species. SIGNIFICANCE AND IMPACT OF THE STUDY: Because of the importance of the CNM group (Corynebacteria, Nocardia and Mycobacteria genera) in different areas such as industry, bioremediation improve the knowledge of their molecular mechanisms are becoming essential. The method described here improves the genetic manipulation of this group of bacteria.

Genetic basis of microbial carotenogenesis.

The synthesis of carotenoids begins with the formation of a phytoene from geranylgeranyl pyrophosphate, a well conserved step in all carotenogenic organisms and catalyzed by a phytoene synthase, an enzyme encoded by the crtB ( spy) genes. The next step is the dehydrogenation of the phytoene, which is carried out by phytoene dehydrogenase. In organisms with oxygenic photosynthesis, this enzyme, which accomplishes two dehydrogenations, is encoded by the crtP genes. In organisms that lack oxygenic photosynthesis, dehydrogenation is carried out by an enzyme completely unrelated to the former one, which carries out four dehydrogenations and is encoded by the crtI genes. In organisms with oxygenic photosynthesis, dehydrogenation of the phytoene is accomplished by a zeta-carotene dehydrogenase encoded by the crtQ ( zds) genes. In many carotenogenic organisms, the process is completed with the cyclization of lycopene. In organisms exhibiting oxygenic photosynthesis, this step is performed by a lycopene cyclase encoded by the crtL genes. In contrast, anoxygenic photosynthetic and non-photosynthetic organisms use a different lycopene cyclase, encoded by the crtY ( lyc) genes. A third and unrelated type of lycopene beta-cyclase has been described in certain bacteria and archaea. Fungi differ from the rest of non-photosynthetic organisms in that they have a bifunctional enzyme that displays both phytoene synthase and lycopene cyclase activity. Carotenoids can be modified by oxygen-containing functional groups, thus originating xanthophylls. Only two enzymes are necessary for the conversion of beta-carotene into astaxanthin, using several ketocarotenoids as intermediates, in both prokaryotes and eukaryotes. These enzymes are a beta-carotene hydroxylase ( crtZ genes) and a beta-carotene ketolase, encoded by the crtW (bacteria) or bkt (algae) genes.

Characterization of a broad pH range protease of Candida caseinolytica.

AIMS: The study of a protease secreted by Candida caseinolytica for use in future industrial applications. METHODS AND RESULTS: Growth of Candida caseinolytica on a medium containing milk induced a rapid production of an extracellular enzyme able to hydrolyse casein. The crude extract was applied to both Sephacryl S-200 and DEAE-Biogel A columns, obtaining one peak of activity showing a molecular mass of approximately 30 kDa and three active peaks, respectively. These four peaks showed the same biochemical parameters. In all cases, an extremely broad pH range of action was determined. CONCLUSIONS: Candida caseinolytica secretes high levels of an extracellular protease when grown either in rotary shakers or in batch-fermenters. SIGNIFICANCE AND IMPACT OF THE STUDY: The biochemical properties of this enzyme suggest its possible industrial application in the brewing industry, in the formulation of certain type of detergents and in the fur and leather industries, among others.

Analysis of canthaxanthin and related pigments from Gordonia jacobaea mutants.

A collection of 43 mutant strains of the bacterium Gordonia jacobaea was obtained by means of ethyl methanesulfonate treatment, and the strains were selected for their different pigmentation with respect to the wild-type strain. None of the mutants showed auxotrophy. They all showed good genetic stability and a growth rate similar to that of the parental strain. Canthaxanthin and other carotenoids from these mutants were extracted with acetone and ethanol and separated by high-performance liquid chromatography (HPLC). These HPLC analyses, together with spectrophotometric detection at 480 nm, revealed variations in the pigment contents of the different mutant strains.

Isolation and taxonomic study of a new canthaxanthin-containing bacterium, Gordonia jacobaea MV-1 sp. nov.

This article describes the isolation and taxonomic study of a coryneform isolate of a new Gordonia species (G. jacobaea), strain MV-1, which accumulates several carotenoids, including the ketocarotenoid trans-canthaxanthin. Identification of this new isolate by morphobiochemical methods did not allow unambiguous taxon assignment, but sequencing of the 16S rRNA gene clearly pointed to the genus Gordonia, Gordonia sputi being the closest fit. Differences in certain transversions/transitions in otherwise very well-conserved sequences of the described Gordonia species supported the proposal of this new taxon. The fact that both the best growth and best pigmentation were obtained with glucose, an inexpensive carbon source and at an industrially suitable temperature, suggests that this new bacterial strain may have good potential for the industrial production of canthaxanthin.

The genus Rhodosporidium: a potential source of beta-carotene.

Four wild-type species of the genus Rhodosporidium have been studied as as possible sources for the industrial production of beta-carotene. HPLC-based studies showed that their carotenoid composition consisted of almost pure beta-carotene at concentrations ranging from 226 to 685 micrograms/g of dried yeast biomass. These results are consistent with those obtained by spectrophotometry at 480 nm.