MICROBIOLOGY (4)

Author: BALSALOBRE ARENAS M. LUZ.
Year: 2005.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: S.pneumoniae is the major causative agent of the community-acquired pneumonia and a major cause of bacterial meningitis. El aumento de aislados resistentes a penicilina ya otros antibióticos empleados como alternativa a la misma ha complicado su tratamiento y ha impulsado el desarrollo de fármacos más activos, del grupo de las fluoroquinolonas (Fqs). The resistance of Fqs is mainly due to the alteration of DNA topoisomerasas type II, topoisomerasa IV (mole IV) encoded by parC and parE and DNA girasa coded gyrA and gyrB. The frequency of isolated S.pneumoniae resistant Fqs in Spain during 2002 was 2.6%, these isolates were selected among the clones of pneumococcus already established in the population and the 6.7% of those presenting a structure in certain recombinant the genes of the DNA topoisomerass. It has been shown that streptococcus viridans group mitis are the donors of genetic material that recombinción originated both the presence of the gene ant in the region intergénica parE-parC like structure in mosaic parC, parE and gyrA in these isolated recombinant S . pneumoniae. The resistant isolates Fqs of S.pneumoniae not presented any disadvantage with respect to sensitive in the absence of selective pressure. So even when consumption Fqs decrease, pneumococcus resistant clones are maintained in the population. Also, the presence of a mosaic structure of genes coding the mole IV and / or presence of the gene prev not interfere with the transcription of genes from the top IV or decrease the biological effectiveness of recombinants isolated. Therefore, these isolates could spread favoring the spread of resistance to Fqs.

Author: JIMÉNEZ PAJARES M. SOLEDAD.
Year: 2005.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE BIOLÓGICAS.
Place of preparation: FACULTAD DE BIOLÓGICAS. UNVIERSIDAD COMPLUTENSE DE MADRID.

Summary: The identification at the species level of the isolates of Mycobacterium genus has been and remains essential to assess the clinical significance of a positive culture and to establish appropriate therapy. The number of species of this genus is very large, it is now recognized more than 100 species, and the increasing frequency with the described species, we make a special genre of taxonomic complexity. Traditionally, the identification of mycobacteria has been based on the study of phenotypic characters simple, but given that require a long time to achieve them, that reading is sometimes interpreted ambiguous and subjective, and that quite often are obtained resutlados variables in strains of the same species, makes it difficult and sometimes impossible to identify with just this kind of study, it has become necessary to implement methods of molecular identification. The objective of this study was to evaluate alternative methods of identification technique so previously described by other authors to identify, with those who have a greater capacity for discrimination, some schemes that would allow identification of the most simple, fast and at the same time accurate identification of all strains of the genus Mycobacterium species level, taking into account the development of these schemes both phenotypic and genotypic aspects, as well as the frequency with which each of the isolated species of mycobacteria, related to pathology producing, and those of a higher incidence, studying the phenotypic and genotypic variation of the strains within the same species. The implementation of these proposed schemes has enabled the identification of species at all strains studied the complex tuberculous) 9,554), with a 100% sensitivity and specificity. In the species most often associated with illness, know a large number of phenotypic and genotipicas which have served to fully characterize the kind mycobacterial (3009 strains of 8 species bacterinas), the frequency of isolation of each species (3 887 strains belonging to 30 species of slow growth and 37 fast-growing) and finally reveal the existence of strains belonging to the genus Mycobacterium but that could not be second to any of the accepted species (47), bringing together strains unidentifiable VII in both groups for their phenotypic resemblance as genotypic (8 strains in Group I, 5 in the second, 3 in the third, 7 in the fourth, 4 in the V, 2 in the sixth, 2 in the seventh and 16 of strains could not be grouped by introducing unique features). With the data obtained in this study proposes a scheme identification polifásica in three stages: the first includes the study of the rate of growth of the strains: the second phenotypic testing and analysis of gene hps65 by PCR-RFLP, and in the third, which is used only in cases that do not reach the identification of the species were studied using sequencing of the gene 16S ARNr. In implementing this scheme were able to identify the 98.8% of the strains MNT.

Author: JIMENEZ DIAZ MARIA BELEN.
Year: 2005.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: Malaria caused by Plasmodium falciparum causes more than 1 million deaths annually. With the exception of non-human primates, there are no animal models of malaria caused by infection with P.falciparum because of their extreme specificity for his guest. Practical considerations, ethical and economic make use of primates is very difficult or unaffordable for the vast majority of the researchers working on malaria. As a result, the development of new antimalarial treatment and study of the biology of the parasite in vivo are severely hampered. In this context, the development of a mouse model P.falciparum would have a major impact on research into malaria. However, none of the approaches taken so far have led to the development of a useful model, due essentially to a lack of reproducibility. Indeed, the published results have generated a great deal of skepticism in the possibility practical realization of this mouse model. This paper describes the first reproducible model of malaria P.falciparum in mice NODscidbeta2microglobulina- /-to which were transplanta erythrocytes humans. To ensure that they are present in high concentrations in the peripheral blood of mice, was selected a strain of mice capable of accepting and maintaining human cells when they were injected daily by intraperitoneal route. Of the strains tested, NIIH-III and NODscidbeta2m- /-, the latter proved to be easily transfused with human erythrocytes. Subsequently, we selected conditions inoculation of human erythrocytes and developed a technique of cytometry to measure accurately the parasitemias by Plasmodiun in murine models. The latter was based on the use of YOYO-1, dye for DNA and autofluorescencia induced in the sample by the process of staining. With these elements began a process of infections intraperitoneales in animals with 40-50% of cells in peripheral blood. Once detected the presence of parasites replicándose peripheral blood, it was shown that they could be transmitted in vivo continuously in 100% of the animals infected but the kinetics of growth observed in each was little reproducible. To increase the reproducibility showed that the infection could be maintained in vivo through intravenous infections. In parallel we developed a new method of flow cytometry use SYTO-16, a coloring DNA permeable membranes to, which allowed quantify accurately and rapidly concentrating eritorictos infected and other forms of blood. Using this technique was demonstrated that the growth of the parasite in vivo was kept stable within human erythrocytes and was dose-related infectious used. To develop a model for evaluating therapies antimalarial a dose was selected to provide a value of parasitemia clinically relevant (1%) being of 20x10 6 erythrocytes this human parasitados. He then showed that the growth of the parasite followed an exponential kinetic reaching a limit value growth to 7-10 days after infection. The kinetics of growth was highly reproducible and provoked an intense anemia for the selective destruction of human erythrocytes not infected. Ultimately, this leads to anemia with a dynamic cyclical periods of growth and cleared the parasite in which the eradication of the same does not occur. The animal model presented can be used for the evaluation of compounds with activity antimalárica. The parasite maintained in vivo has been used to generate a strain evaluation can be criopreservada and maintained in vitro susceptibility to drugs on the market, which allows the direct comparison of resutlado 8 s obteni 1c7 two in vivo and in vitro with the same strain of parasite.

Author: BARAHONA RONDÓN LUCÍA.
Year: 2005.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of preparation: MEDICINA.

Summary: Objectives To describe the clinical features, epidemiological and microbiological characteristics of invasive pneumococcal disease in a sample of patients admitted to the Foundation Jimenez Diaz in Madrid, from January 1993 to June 2004. Among the specifics were analyzing the factors associated with mortality, describing the distribution of cases by age, sex and disease base more frequently, describe symptoms, the clinical forms, analytical employed invasive methods, known developments in the time and the dominance of seasonal invasive disease, serotype distribution and frequency of susceptibility and resistance to antibiotics employees (with an emphasis on penicillin and eritomicina). MATERIALS AND METHODS Patients went to the emergency department of the Jimenez Diaz Foundation insulated S.pneumoniae isolated from blood and other samples taken from a location usually sterile (CRL, or peritoneal fluid articulation) with a diagnosis of meningitis, pneumonia, bacteremia and sepsis. They were identified as a first step in the records of microbiology and then collected their data in a standardized clinical sheet, recording mortality data evolution clínica-microbiológica and relapses in patients. In a first phase analyzed the association of mortality withthe independent variables by univariate analysis. The categorical variables were analyzed by testing the X2 or Fisher's exact test. The continuous variables were compared using the test or the Mann-Whitney test. In a second step analyzed the factors associated with mortality, the variables had a statistically significant p less 0.1 in the first analysis were entered into a conditional logistic regression analysis, through an explanatory model using statistical program SSPS V. 9. RESULTS From January 1993 to June 2004 were detected 304 episodes of invasive disease in 302 episodes of invasive disease in 304 patients by Streptococcus pneumoniae (pneumonia, meningitis, sepsis, bacteremia without focus and oligoartritis). With predominance of pneumonia (237, 77.96%), meningitis (33, 10.85%) and bacteremia without focus (21, 6.91%). Less frequently noted instances of sepsis (9, 2.96%) and arthritis (4, 1.32%). Most (65.8%) of cases of pneumonia occurred in the six months from October to March, as is the case with most respiratory infections. The dominant serotypes were 19, 3.4 and 6 (pneumonia), 19 (meningitis), and 6, 23 and 4 (bacteremia without focus). Between comorbilidads most commonly associated with invasive disease but had no statistical significance were hypertension (20.7%), being the bearer of antigen of hepatitis C (13.8%) and diabetes mellitus (8.6% ). With regard to antibiotic susceptibility, 69.4% of the isolates were sensitive to apenicilina, a 96.1% sensitive to cefotaxime and 87.6% to erythromycin, no longer statistically significant in the univariate analysis as a factor or predispose mortality . The overall mortality was 11.2%. Mortality from highest to lowest was next in sepsis (33.3%), pneumonia (10.5%), bacteremia without focus (9.5%) and meningitis (6.1%). They died 2 of the 4 patients with septic arthritis. In analyzing the mortality of pneumonia were found as factors related statistically significant (univariate analysis): age, length of illness in the days since the diagnosis, number of days since the diagnosis, number of days since the diagnosis until hospitalization, arterial pH and white blood cell count. The variables associated with mortality in pneumonia in the logistic regression analysis in this study with p less 0.05 were: neurological semiology (p = 0004), the presence of altered renal function (p = 0048), the use of mechanical ventilation ( p less 0001), Ph blood acid (p = 0004). Conduct a treatment according to antibiogram was a protective factor for not dying of pneumonia. The analysis of mortality in meningitis only showed 8 diferenc 488 ias significant when evaluated the number of days from diagnosis to the hospital (variable quantitative), there were no differences between categorical variables. The analysis of mortality in spesis, bacteremia without focus and septic arthritis showed no significant factors or analysis divariado nor the logistic regression with mortality probably due to small numbers of cases. Conclusions Patients with increased risk of mortality from invasive pneumococcal disease is critically ill, without leukocytosis, severe respiratory disease or neurological and subjected to invasive methods such as mechanical ventilation and tracheostomy. KEYWORDS S.pneumoniae, mortality, invasive disease.

Author: MEDINA VAYÁ ANGEL.
Year: 2006.
University: VALENCIA [www.uv.es].
Place of defense: BIBLIOTECA DEL CAMPUS DE BURJASSOT.
Place of preparation: FACULTAD DE CIENCIAS BIOLÓGICAS - UNIVERSITAT DE VALÈNCIA.

Summary: This Doctoral thesis focuses on the study of various aspects of Ochratoxin A (OTA), mycotoxin nefrotóxica, carcinogenic and neurotoxic, two food products widely consumed in our country, such as wine and beer. After an extensive introduction to the current status of the item, the thesis provides insights developed methodologies for the detection of this mycotoxin in products of interest, trying to get cheaper and methodologies with the same characteristics as other more expensive. Also methodologies more respectful of the environment so that the contamination of resíduos is lower. Later deals with the study of the species ocratoxigénicas present in the raw materials used in manufacturing these fermented beverages, gaining as a result more meaningful characterization for the first time in A. Tubingensis as producing species ochratoxin A. Once isolated species responsible for the presence of ochratoxin A in these products, study the effect of various abiotic factors on the production of these isolated OTA study the effect of different sugars used as a source of carbon and the presence of different amino acids . It also describes the positive effect that holds the addition of bee pollen from the culture medium for the production of OTE. Lastly In order to monitor the presence of OTE in raw materials was studied the effect of the presence of different fungicides added to the medium, not only in the growth of the fungus but also in terms of the production of OTE. We studied 2 fungicides the first one widely usaado in viniculture, carbendazima and the second of them a naturally occurring fungicide used in some food products for human consumption, natamycin or pimaricin.

Author: MONICA BLANCO GONZALEZ.
Year: 2006.
University: CANTABRIA [www.unican.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: The family pasteurellacea consists of three genres, Haemophilus, Pasteurella and Actinobacilus. Haemophilus and Actinobacilus are patónenosporcinos of great relevance. The use of antibiotics to treat infections caused by these pathogens and as additives in animal feed has led to the emergence of resistant strains. We intend to undertake a study of resistance to some of losantibióticos most commonly used in the treatment of these infections. The objectives of this thesis quantification of the level of resistance, the determination of their genetic bases and analysis of the mechanisms of spread. Collections will be used strains of Actinobacillus pleuropneumoniae and Haemophilus paranuis Department of Animal Pathology at the University of Leon. Antibiotics selected for the study are tetracyclines (broad spectrum antibiotics and low cost, so they are often used in the treatment of these infections and other pathogens) and quinolones (relatively new antibiotics and use). The pathogens are selected Actinobacillus peluropneumoniae and Haemophilus parasuis. Initially it will carry out a study of phenotypic resistance to antimicrobial susceptibility testing by the method of dissemination and identifying concenctraciones minimum inhibitory (WCC) to tetracyclines and fluoroquinolones. It will select resistant strains. There will be a characterization of the determinants of resistance to tetracycline (Tet) using PCR and hybridization techniques. The resistance genes to be sequenced are insulated. It was also quantified expression in the presence of tretraciclina and will explore presistencia of resistance phenotype. It will explore the mechanism of spread of Tet genes on the basis of their location (plasmídica or chromosome), its composition and sequencing of the contiguous regions. The primary mechanism of resistance to fluoroquinolones is altering its targets molecuares (DNA girasa and DNA topoisomerasa) although some bacteria have the ability to expel the antibiotic outside the bacterial cell. High levels of resistance observed in some isolates are due to the accumulation of mutations in the genes gyra and parc to either a dual mechanism that includes alteration of the target and pumping. In Gram-negative bacteria mutations accumulate in some specific regions of genes gyra and parc called QRDR. Only one study has been published, very preliminary, genetic characterization of quinolone resistance in bacteria of the family Pasteurellaceae. There will be molecular characterization of resistance to ciprofloxacin through the following steps cloning of locus gyr and parc in reference strains sensitive to quinolones A pleuropneumoniae and H. Parsauis. It was conducted by PCR using primers designed for a mixture from sequences of the genes counterparts of Pasteurella multocida and H. Influenze. Sequencing of the regions QRDR in the isolates resistant strains and reference. Mapping of possible mutations in locuas gyrA and parC. Analysis of the transmissibility of the resistance.

Author: GONZÁLEZ DÍEZ ROCÍO.
Year: 2006.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE FARMACIA.

Summary: Infection with the hepatitis B virus represents a major public health problem. The current prevalence in Spain is less than 1%, while the blood donations have a residual risk of HBV transmission. The objective of this study was to improve the knowledge of the epidemiology of HBV in Spain and to obtain new data to better assess their impact on safety transfusion. It has conducted a concurrent study, observational, cross descriptive blood donors who have come to Red Cross consecutively in the period 1995 to 2005. It has been determined the presence of HBsAG and serum ALT and other serological markers of HBV and viral DNA. The prevalence of HBsAg in the 166537 blood donors for the first time in Red Cross Madrid has been a 0.16%, with a significant decrease over time (0.34% in 1995 to 0.06% in 2005 ). The prevalence was highest among male donors, among older people, and foreigners (4 times). The primary acute for HBV infections were extremely rare. The 79% showed ALT values in the range of normality. When techniques were used high sensitivity (NAT), 90% of the carriers showed active viral replication. The 42% of total donations contaminated with HBV in 2005 months detected only through molecular technology. HBV genotypes found most frequently (92%) were A and D. The specificity of the techniques employed for HBsAg was about 99.9%. In conclusion, donors repeaters are the safest source of blood and the routine use of molecular techniques could increase viral safety of transfusion. The profile of chronic infection with anti-HBe was majority among donors infected. The genotypes were similar to those found among the general population was very low and the waste of donations by false reagents with the technical HBsAg.

Author: FRESNO DE PRADO SANDRA.
Year: 2006.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: The lipopolisacerido (LPS) is a major virulence factors in Klebsiella pneumoniae. The LPS is divided into lipid A, and core antigen O. They had earlier given the complete structure of oligosacárido kernel and the evidence suggests that he was kept in the different serotypes of the bacterium. This paper presents the sequencing of the group, region of the chromosome containing the genes involved in the synthesis of the core of LPS, K.pneumoniae 52145, and have been assigned duties to all the genes in the cluster. This has enabled us to know that this strain has a different type of nucleus to the known so far. It has also been observed that the waste acid galactuosico which contains the kernel, providing the negative charges by which joins the capsule to the cell surface through the ionic interaction with the core of LPS.

Author: MENGS GONZÁLEZ GERARDO.
Year: 2006.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: The main objective of this work is to study the specific factors involved in the process of bioremediation of soils and water contaminated with PCH; isolation and identification of bacterial growth optimization, identification of the catabolism of PCH: transportation and mineralization, characterization route catabólicas of PCH . Various systems have been used for tying cell, for application in biological decontamination systems, formation of biofilm. Subsequently have developed systems cells immobilized in bioremediation processes at the laboratory. Results have been achieved allowing evidence that the strains identified degrade propacloro efficiently. We have identified two new routes biodegradativas for propacloro. The formation of the biopelicula in detention cell offers advantages compared to cell culture in suspension. The development of a pilot-scale bioreactor, which has immobilized biomass lifted the index maintains a biodegradability and cell viability.

Author: MARTÍNEZ MARÍN CARMEN.
Year: 2006.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: The OM is one of the most common infections in infancy, being responsible for almost a third of the visits to health centers and is a major cause of morbidity in children. This is the most common microbial infection of the respiratory tract. At present, very few diseases are treated as controversial as the WCO. Despite that can be produced by microorganisms producing betalactamasas, amoxicillin remains the antibiotic of choice for treatment. More than 80% of the OMAs heal spontaneously, and only 13% will be affected by the treatment. Moreover, the widespread use of antibiotics increases healthcare costs and produces numerous side effects including selection of mutants resistant to antibiotics. For all these reasons have been suggested new strategies to minimize the unnecessary prescription of antibiotics. One approach would be to delay the treatment 48-72 h after diagnosis to determine if there is a spontaneous clinical improvement. Since it has not conducted a comprehensive study on the effect of antibiotic treatment delayed, the main objective of this work was to study the effect of delayed administration of amoxicillin during the WCO pilot caused for different strains of S.pneumoniae different sensitivities of this antibiotic.

Author: NAVARRO LAFUENTE ELENA.
Year: 2006.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: By serological and molecular characterization of isolates Spanish necrotic of nanovirus yellowing of the bean (FBNYV) and the production of a polyclonal antiserum specific face the same, this work contributes to the characterization of nanovirus in general and FBNYV in particular. The deepening of the knowledge of various aspects of the etiology and pathogenesis of the virus, contributing to the development of effective control measures against the disease.

Author: MATA CONTRERAS YASMINA NOHEMÍ.
Year: 2006.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: FACULTAD DE CIENCIAS BIOLÓGICAS.

Summary: This paper has conducted an exhaustive experimentation that has led to Gels pectin gelificados calcium that are suitable for the immobilization of biomass. These gels were obtained through process optimization and extraction of pectins demethylation of the beet pulp, a residue of the sugar industry. It has been characterized behavior in discontinuous bioadsorción cadmium, lead, copper and gold with different biaadsorbentes (Gels alginate and pectin with and without immobilized algae, brown algae Fucus vesiculosus and beet pulp) by kinetic models and layout the isotherms of Langmuir-adjusted model, from which is extracted the maximum adsorption capacities and the affinity of the metals by different materials. Biomass was characterized before and after the bioadsorción through techniques of infrared spectroscopy, scanning electron microscopy, elemental microanalysis and X-ray diffraction In the case of gold, it has been observed that the biomass of algae not only absorbs estemetal but also reduces, leaving a state in the colloidal and dissolved precipitated on biomass. It has been optimized in the process of adsorption continuous solutions monometálicas and trimetálicas cadmium, lead and copper with pectin gels with and without biomass, drawing curves break and calculating the respective parameters. It has studied the process of dropping acid and metals such a system regeneration of biomass. The pectin gels in addition to being good support for the immobilization of biomass and its use in bioadsorción continuous processes are in themselves good bioadsorbentes cadmium, lead and copper. Finally, it has made nine cycles adsorción-desorción-regeneración of solutions trimetálicas continuously with the immobilized algae in the pectin gels. The immobilized in seaweed gels lifted pectin has a potential as bioadorbente for decontamination and recovery of metals effluent, recording high adsorption capacity and easy regeneration, resisting successive cycles adsorción-desorción-regeneración.

Author: DIAZ ROSALES PATRICIA.
Year: 2006.
University: MÁLAGA [www.uma.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS: UNIVERSIDAD DE MÁLAGA.

Summary: Photobacterim damselae subsp.piscida is a gram-negative bacterium can survive as an intracellular pathogen within phagocytes sole, thanks to the protective activities of superoxide dismutase and catalase. These enzymes confer resistance to the pathogen versus reactive oxygen radicals produced within the phagocytes is called for respiratory outbreak. Therefore, both enzymatic activities can be considered important factors in virulence of this pathogen, facilitating its invasion and the establishment of the disease, pseudotuberculosis. The strategy developed for the prevention of this disease has been focused on the search for microorganisms capable of stimulating outbreak of respiratory phagocytes sole. The microorganisms were tested Micro Porphyridium cruentum and two potentially probiotic bacteria. The results are promising because both the microalgae, as one of the bacteria tested, Pdp11, are capable of stimulating the respiratory outbreak and thus contribute to the resistance to the disease. It opens, therefore, a new field in the fight against pseudotuberculosis: implementation of substances from seaweed, as well as bacterial components, which could be considered probiotics.