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INTRODUCCIÓN: Los errores de medicación son causa de eventos adversos durante el proceso asistencial. OBJETIVOS: Caracterizar los errores en el proceso de medicación del Hospital Público Materno Infantil de Salta. MÉTODOS: Los errores fueron identificados a partir de la validación farmacéutica de las prescripciones. Se calcularon las tasas de error, y se analizó su asociación con factores del paciente, del tratamiento farmacológico y del recurso humano. RESULTADOS: Entre el 1 de noviembre de 2012 y el 31 de enero de 2013 se validaron 18 203 prescripciones, en las que se detectaron 2989 (96,7%) errores de prescripción, 79 (2,5%) de administración, 6 (0,2%) de transcripción y 18 (0,6%) de dispensa. La tasa de error del Área Perinatológica fue de 13,06 cada 100 días-paciente; se destacaron la omisión de dosis (30%) y la prescripción de dosis incorrecta (23%). En el Área Pediátrica la tasa fue de 8,6 cada 100 días-paciente, con 55% de prescripción de dosis incorrecta, asociada a la edad del niño. Los grupos farmacoterapéuticos involucrados fueron: analgésicos antiinflamatorios no esteroideos, drogas del aparato digestivo y circulatorio, y antiinfecciosos. La mayor parte de los errores se produjo con drogas de uso habitual, con consecuencias potencialmente significativas para los pacientes. La tasa de error fue similar para médicos en formación y de planta. CONCLUSIONES: La farmacovigilancia intensiva permitió identificar un número elevado de errores, cuya caracterización es útil para implementar estrategias de prevención.

INTRODUCTION: Medication errors cause adverse events in health care. OBJECTIVES: To characterize the medication process errors at Hospital Materno Infantil of Salta. METHODS: Errors were identified by pharmaceutical validation of prescriptions. Error rates were calculated, and associations between error and patient factors, drug treatment and human resource were determined. RESULTS: From November 1, 2012 to January 31, 2013 a total of 18 203 prescriptions were validated, identifying 2 989 (96.7%) errors of prescription, 79 (2.5%) of administration, 6 (0.2%) of transcription and 18 (0.6%) of dispensing. The error rate was 13.06 per 100 patient days for the Perinatology Area, with 30% of omission of doses and 23% of incorrect dose prescription. In the Pediatric Area, the rate was 8.6 per 100 patient days, with 55% of wrong doses, associated with child age. The pharmacotherapeutic groups involved were: non-steroidal anti-inflammatory drugs, digestive and circulatory system drugs, and anti-infectives. Most errors occurred with commonly used drugs, with potentially significant consequences for patients. The error rate was similar to doctors in training and permanent staff. CONCLUSIONS: Intensive pharmacovigilance allowed the identification of a large number of errors. Their characterization will permit to establish prevention strategies.

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OBJECTIVE: To study the antimicrobial susceptibility of six vaginal probiotic lactobacilli. METHODS: The disc diffusion method in Müeller Hinton, LAPTg and MRS agars by the NCCLS (National Committee for Clinical Laboratory Standards) procedure was performed. Due to the absence of a Lactobacillus reference strains, the results were compared to those of Staphylococcus aureus ATCC29213. Minimal Inhibitory Concentration (MIC) with 21 different antibiotics in LAPTg agar and broth was also determined. RESULTS: LAPTg and MRS agars are suitable media to study antimicrobial susceptibility of lactobacilli. However, the NCCLS procedure needs to be standardized for this genus. The MICs have shown that all Lactobacillus strains grew at concentrations above 10 microg/mL of chloramphenicol, aztreonam, norfloxacin, ciprofloxacin, ceftazidime, ceftriaxone, streptomycin and kanamycin. Four lactobacilli were sensitive to 1 microg/mL vancomycin and all of them were resistant to 1000 microg/mL of metronidazole. Sensitivity to other antibiotics depended on each particular strain. Conclusions. The NCCLS method needs to be standardized in an appropriate medium to determine the antimicrobial susceptibility of Lactobacillus. Vaginal probiotic lactobacilli do not display uniform susceptibility to antibiotics. Resistance to high concentrations of metronidazole suggests that lactobacilli could be simultaneously used with a bacterial vaginosis treatment to restore the vaginal normal flora.

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Restoration of the balance of different ecological niches has been proposed as a way to control the income of pathogenic microorganisms. The genus Lactobacillus has been used in different human and animal tracts as probiotic microorganisms with this objective in mind. The characteristics of the strains proposed as probiotics have been published or patented under the process of elaboration of different types of products. One of the mechanisms suggested to control the vaginal ecosystem is the production of antagonistic substances (lactic acid, bacteriocins, or H2O2). The H2O2-producing microorganisms present in the vagina of healthy women have been suggested as some of the bacteria responsible for maintenance of ecological balance, mainly in pregnant women. The absence of these microorganisms is related to a higher risk of: bacterial vaginosis, recurrent urinary tract infections by Escherichia coli, and acquisition of human immunodeficiency virus type 1 (HIV-1). Bauer has proposed that H2O2-producing lactobacilli also might exert control over vaginal cancer through specific interactions of reactive oxygen species, such as superoxide anion, hydroxyl radicals, and hypochlorous acid. The conversion of H2O2 into more toxic compounds during the oxidative process is potentiated by peroxidase and halures. This enzyme and some halures, such as chloride and bromide, are present in vaginal washes in sufficient amounts to allow an optimal environment for successful inhibition of pathogens. In vitro tests provide an approach for determining the ability of lactobacilli to produce H2O2. The H2O2 amounts produced in such systems are probably not a direct reflection of what happens in the vaginal tract of women or animals, which is not yet know. However, there is a registered patent with an H2O2-generating L. crispatus strain, also supporting the use of H2O2-producing lactobacilli to restore the vaginal ecosystem.

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Bacteriocins have been defined as proteinaceous, bactericidal substances synthesized by bacteria, which usually have a narrow spectrum of activity, only inhibiting strains of the same or closely related species. The term bacteriocin-like substance is applied to antagonistic substances that are not completely defined or do not fit the typical criteria of bacteriocins. They have been reported to inhibit a wide range of both Gram-positive and Gram-negative bacteria as well as fungi. Lactobacillus species are the dominant microorganisms isolated from the vagina of healthy premenopausal women. In this environment, they exert a protective effect against pathogenic microorganisms by different mechanisms such as production of antimicrobial agents, which include organic acids, hydrogen peroxide, and probably bacteriocins. The production of bacteriocins by vaginal lactobacilli has been demonstrated in vitro; however, it is not yet well established whether they are produced in vivo as another antagonistic mechanism exerted by the normal microflora.Bacteriocin-producing bacteria as well as bacteriocins per se are of growing interest as biological controls in the manufacture of beverages and fermented products, mainly in the area of dairy products. These bacteria have also been proposed as probiotic candidates for human or animal use. The objectives of the present chapter are to describe the methods employed for: 1. Detection of production of bacteriocins among vaginal Lactobacillus strains. 2. Characterization of the bacteriocin or bacteriocin-like substances. 3. Study of the kinetics of production and mode of action of bacteriocins. 4. Determination of the inhibition of pathogenic microorganisms by bacteriocin-producing strains in mixed cultures.

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Lactobacilli are the predominant microorganisms in the vaginal tract of human and some homeothermic animals. They can maintain the ecological equilibrium of the tract by protecting against pathogenic microorganisms. In the last few years, there has been an increased tendency to use probiotic microorganisms to restore the ecological equilibrium and to protect against infections. This principle has been widely applied to the gastrointestinal tract. More recently, some other studies have reported the application of probiotics in different tracts, for example, the urogenital or respiratory tract. One of the objectives of our group is to design probiotic products for the urogenital tract. With this purpose, lactobacilli were isolated from the human vagina, and later some of them were selected for their probiotic characteristics (production of antagonistic substances or adhesion capability). The application of probiotic products in the vaginal tract has been approached empirically; some pharmaceuticals containing these microorganisms are available in the United States or Europe or are protected under the patent process or intellectual property rights. There are not enough studies in humans or animals to determine whether their administration can produce some type of collateral or adverse effect. Using Balb/c mice as the experimental model, the object of the present work was to study (1) whether intravaginal administration of human lactobacilli can produce colonization of the tract; (2) whether such administration produces some type of adverse or collateral effect; and (3) whether probiotics are able to stimulate the local immune system. Keeping in mind that hormones can affect the colonization or persistence ability of microorganisms, and with the purpose of having all animals at the same point in the sexual cycle, animals were cycled with estradiol 48 h before inoculation with lactobacilli. They were then inoculated im with hormones 48 h before beginning microorganism inoculations. Later they were intravaginally inoculated with the appropriate dose of each Lactobacillus strains. The animals were sacrificed on different days after inoculation to perform the following studies: 1. Microbiological assays: To determine the number of lactobacilli in the tract (in vaginal washes or in organ homogenates), by plating the samples in selective media containing antibiotic (to differentiate the resident flora from those administered experimentally).

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For the study of probiotic microorganisms, the in vitro selection tests need to be based on a solid scientific foundation. Surface characteristics, one of the in vitro properties are used to evaluate the potentially probiotic strains of lactobacilli. Bacterial surface properties have been associated with attachment to a variety of substrata. Bacterial adhesion to tissues is considered the first step, and such adhesion can also determine the colonization capability of a microorganism. Through adhesion ability and colonization of tissues, probiotic microorganisms can prevent pathogen access by steric interactions or specific blockage on cell receptors. One of the main characteristics studied is the hydrophobic nature of the bacterial cell surface. To test this property, Rosenberg and Doyle divided microbial cell hydrophobicity assays into two categories. The first includes contact angle measurements (CAMs), partitioning of cells into one or another liquid phase (TTP), and adsorption of individual hydrophobic molecular probes at the cell surface. The second category includes microbial adhesion to hydrocarbons (MATH), hydrophobic interaction chromatography (HIC), and adhesion to polystyrene and other hydrophobic solid surfaces. The tests included in the first category measure hydrophobic properties of the outer cell surface as a whole; those in the second measure hydrophobicity in terms of adhesion. Finally, those bacterium classified as hydrophobic can be considered as able to mediate adhesion. The objective of this chapter is to describe three different methods applied in our laboratory for the study of bacterial surface properties. They can be used to screen characteristics of lactobacillus strains for probiotic purposes. They are: Microbial adhesion to hydrocarbons (MATH); Salt aggregation test (SAT); Hemagglutination (HA) reaction.

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Adhesion of lactobacilli to the epithelium has been described as the first step in the formation of a barrier to prevent undesirable microbial colonization; consequently, it has been defined as a characteristic of interest for selecting probiotic strains. Several methods have been described to predict the adhesion ability of Lactobacillus. Early studies were phenomenological: it was useful to determine whether a particular bacterium could hemagglutinate, or bind to coated particles. Later, studies based on the adhesion of bacteria to epithelial cells in vitro were developed. These last assays were based on the numbers of bacteria attached to epithelial cells, which were determined by counting stained microorganisms under light microscopy or by measuring the radioactivity of previously radiolabeled bacteria. Because the microscope technique, had some disadvantages, a modification was developed in our laboratory. The technique described in this chapter is a modification of the Mardh and Weströn method. The method allows the study of the adhesion ability of bacteria, even if they are aggregating or if they are high-adherent bacteria covering a large area of the epithelial cell surface. Determination of the number of adherent bacteria by counting colonies grown in a selective media avoids the time-consuming, tedious, and hazardous counting under the light microscope and the use of radioactive methods.

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The viability of six different strains of probiotic vaginal Lactobacillus was examined in two different cryoprotective media, during refrigerated versus frozen storage, and using two traditional types of stock cultures for starting the biomass production. Freezing at -20 degrees C and -70 degrees C had much less adverse effect on viability than did storage at 7 degrees C, and the reduction in viability was greater at -20 degrees C than at -70 degrees C. The strains showed variation in the extent of the viability losses during both types of storage. Milk-yeast extract (MYE) was shown to be the more suitable protective medium to maintain viability of the strains during the storage. The vaginal Lactobacillus strains are most stable in MYE at -70 degrees C with only a small decrease of the viability observed under these conditions. The viable cell counts of Lactobacillus paracasei CRL 1251 and CRL 1289, L. crispatus CRL 1266 and L. salivarius CRL 1328 remained around 1 x 10(8) CFU/mL after 24 months of storage at -70 degrees C, or up to 18 months for L. acidophilus CRL 1259.

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Lactic acid bacteria are the dominant bacteria of the vaginal tract in healthy women. Lactobacillus species form a barrier population that protects from pathogen colonisation by mechanisms that include adhesion to epithelial surfaces, self-aggregation and co-aggregation. In this study, factors involved in the self-aggregating ability of vaginal lactobacilli and in the co-aggregation of these microorganisms with Candida spp. are studied. Both self-aggregation and co-aggregation are monitored quantitatively by the decrease in the absorbance of suspensions of the microorganisms and qualitatively by light microscopy. The self-aggregating ability of four vaginal lactobacilli was shown to be caused by a peptide or protein sensitive to trypsin. However, in self-aggregating Lactobacillus acidophilus CRL 1294 the factor was resistant to trypsin and sensitive to pepsin. Among self-aggregating lactobacilli, L. acidophilus CRL 1294 and L. salivarius CRL 1328 were able to co-aggregate with Candida spp. The co-aggregating factor for both strains proved to be peptide of the surface and a peptide on the bacterial surface, while the receptor on the yeast was a carbohydrate. Co-aggregation of both lactobacilli and Candida spp. was inhibited by the addition of mannose but was not affected by other carbohydrates. Self and co-aggregation factors were not able to induce aggregation in non-aggregating lactobacilli.

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The capability of lactobacilli to adhere to vaginal epithelial cells (VEC) has been found to be an important factor in the formation of a barrier to prevent colonization of pathogenic bacteria. The aim of this study was to examine the adhesion ability to VEC, of vaginal Lactobacillus which had been selected for their probiotic properties. A modification of the Mardh and Westr¸n method was employed for this purpose. Adherent bacteria were determined as CFU-grown using selective media. There was a slight degree of difference in the adhesion properties observed among vaginal and non-vaginal Lactobacillus. Different pH values of 4 and 7 did not affect adhesion (P < 0.70). Scanning and transmission electronic microscopy were performed to illustrate the adhesion of the self-aggregating L. salivarius CRL 1328.(AU)

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The capability of lactobacilli to adhere to vaginal epithelial cells (VEC) has been found to be an important factor in the formation of a barrier to prevent colonization of pathogenic bacteria. The aim of this study was to examine the adhesion ability to VEC, of vaginal Lactobacillus which had been selected for their probiotic properties. A modification of the Mardh and Westr÷n method was employed for this purpose. Adherent bacteria were determined as CFU-grown using selective media. There was a slight degree of difference in the adhesion properties observed among vaginal and non-vaginal Lactobacillus. Different pH values of 4 and 7 did not affect adhesion (P < 0.70). Scanning and transmission electronic microscopy were performed to illustrate the adhesion of the self-aggregating L. salivarius CRL 1328.

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In the present paper, the taxonomic classification of 134 lactobacilli isolates from vaginal samples of 200 women of Tucumán, Argentina, is reported. They were clustered in three metabolic groups of the genus Lactobacillus, most belonging to the obligately homofermentative group (56%), mainly represented by Lactobacillus delbrueckii subsp. delbrueckii and L. acidophilus. In the facultatively heterofermentative group (24%), the dominant species were L. paracasei subsp. paracasei and L. agilis, and in the obligately heterofermentative group (20%), L. brevis was the dominant species. All strains were studied for surface characteristics and adhesion-predicting properties. A correlation between the methods employed for hydrophobicity testing of the different isolates (Microbial Adhesion to Hydrocarbons and Salt Aggregation Test) is reported. Most strains were highly hydrophobic. Their hemagglutination capability with human erythrocytes was also tested, which was positive only for a few strains. Some isolates were self-aggregating. From our results, strains that shared the properties assayed were selected for further testing of some other desirable characteristics, such as antagonistic substance production, adhesion to biological substrates, and appropriate technological properties, to suggest the elaboration of a probiotic for the vaginal tract.