Measurements of magnetic field fluctuations in TJ-II plasmas with new in-vessel helical arrays of magnetic coils.

This paper describes two new helical arrays of magnetic coils recently installed inside the TJ-II vacuum vessel. Their main objective is the precise measurement of the spatial periodicity of the magnetohydrodynamic perturbations usually found in the TJ-II plasmas. Given the high probability of coil failures due to the harsh plasma environment and in view of the extremely difficult access to the TJ-II vessel interior for maintenance, the coil system has been divided in two quasi-identical helical arrays. Both arrays consist of 32 triaxial sensors measuring orthogonal components of the local magnetic field along an ideal helical path whose trajectory runs close to the plasma edge. A description of the main characteristics of coils and arrays as well as their nominal positioning along an ideal helical path, inside the vessel, is given. A precise experimental determination of the real spatial orientation of the coils is performed by comparing the signals measured in current ramp-up and ramp-down experiments with calculations based on a filamentary model for the TJ-II magnetic coils. After this fine calibration procedure, it is possible to analyze the dependence of the amplitude of the measured magnetic field and its fluctuations as a function of the coil distance to the last closed flux surface. The study of the phase evolution of the parallel and perpendicular oscillatory components is also enabled. Finally, two examples of mode number determination are shown. One corresponds to a low frequency mode appearing in pure electron cyclotron resonance heating plasma, and the other one shows several modes observed during combined injection of both co and counter neutral beams and identified as shear Alfvén waves.

Beyond orthogeriatric co-management model: benefits of implementing a process management system for hip fracture.

Hip fracture is a major health care problem worldwide. Business process management systems (PMSs) have made significant contributions in health care environments to improve patient care standards. The effectiveness of PMS applied to hip fracture in older adults in the acute phase has been demonstrated. INTRODUCTION: Fragility fracture is a major health care problem worldwide. Business PMSs have made significant contributions in health care environments to improve patient care standards. It is a new way of management that defines a homogeneous application procedure involving eliminating steps that add no value and developing explicit supervision criteria, in addition to identifying the appropriate managers. PURPOSE: The aim of our trial was to assess the effectiveness of the PMS applied to hip fracture versus the orthogeriatric co-management model in the acute phase. METHODS: All consecutive patients aged ≥ 65 who were admitted to Hospital Universitario Infanta Leonor between January 1, 2009, and December 31, 2016, for acute hip fracture surgery were included. We compared the effectiveness indicators in the acute phase between the preprocess period (orthogeriatric co-management) and the process period. RESULTS: One thousand two hundred twenty-two patients were included (76.6% women). Mean age (SD) was 83.9 (6.4) years. Effectiveness management indicators are the following: length of hospital stay, time to admission to the ward from the emergency department, preoperative stay, surgery in < 48 h, and the operating room availability which were all improved in the process period with statistical significance. Effectiveness clinical indicators are the following: the numbers of patients with operated limb loading approved after surgery, discharged to home, and with osteoporosis treatment postfracture at the time of discharge which were statistically significantly higher in the process period, and the number of patients who suffered from delirium was statistically significantly lower in the process period. The number of in-hospital deaths was lower during the process period without statistical significance. CONCLUSION: Our results demonstrated the effectiveness of the PMS applied to hip fracture in older adults compared with an orthogeriatric co-management model in the acute phase, based on both management indicators and clinical indicators.

Rural veterinarian's perception and practices in terms of biosecurity across three European countries.

The implementation of biosecurity measures in the animal health and production context is quite broad and aims at limiting the risk of introduction and spread of diseases. Veterinarians play a major role in biosecurity as key informants on the subject for cattle holders, key players in terms of disease prevention/control and eradication programs, as well as key risk factor in terms of disease dissemination. Many biosecurity studies have highlighted professional visitors such as veterinary practitioners as representing a high-risk factor in terms of disease introduction in animal facilities but, to date, very few studies have focused on the implementation level of biosecurity measures by veterinarians. An online survey was implemented in three European countries (Belgium, France and Spain) to assess the behaviour of rural veterinarians towards biosecurity, as well as their implementation level of the biosecurity measures. A descriptive analysis of data and a scoring system were applied to assess the implementation level of measures. The influence of different factors on the implementation level of biosecurity measures was investigated through a negative binomial regression model. The study identified different strengths, weaknesses, possible constraints and solutions in terms of veterinary perspectives. Veterinarians are considered as key informants by the farmers and could therefore play a more active role in terms of guidance and improvement of biosecurity at farm level. Based on the survey outcomes, two factors seemed to influence significantly the implementation level of measures: the country where he/she practices and the veterinarian's perception level of biosecurity. The biosecurity stages with the lowest application level, therefore representing the biggest threats, were bio-exclusion (increasing the risk of disease introduction) and biocontainment (increasing the risk of inter-herd transmission).

beta-lactam susceptibility of Escherichia coli isolates from urinary tract infections exhibiting different resistance phenotypes.

Susceptibility to beta-lactams was determined in 203 recent Spanish E. coli isolates from urinary tract infections exhibiting different resistance phenotypes: a) susceptible (n = 60); b) quinolone-resistant (n = 45); c) penicillinase (n=64); d) hyperproduction of penicillinase (n=8); e) inhibitor resistant TEM (IRT) (n=18), and f) extended spectrum betalactamase (ESBL) (n=8).Minimum inhibitory concentration (MIC) determination by agar dilution and susceptibility tests for ESBL detection by macrodilution were performed following CLSI recommendations. All the beta-lactams tested showed high activity against susceptible and penicillinase phenotypes, with close to 100 % susceptibility. Hyperproduction of penicillinase increased MIC90 values for all antibiotics except for meropenem, with 100% resistance to cefuroxime and amoxicillin/clavulanic acid, and 100% susceptibility to cefotaxime, piperacillin/tazobactam and meropenem. All the antibiotics, except for amoxicillin/clavulanic acid, exhibited high activity against IRT. Meropenem, cefminox and piperacillin/tazobactam exhibited the highest activity against ESBL, followed by amoxicillin/clavulanic acid. The most active compound among the parenteral antibiotics was meropenem, regardless of the resistance phenotype. Among the oral antibiotics, the most active compound was cefditoren with the exception of ESBL where amoxicillin/clavulanic acid where the MIC90 value was one dilution lower.

â - lactam susceptibility of Escherichia coli isolates from urinary tract infections exhibiting different resistance phenotypes

Susceptibility to â-lactams was determined in 203 recentSpanish E. coli isolates from urinary tract infectionsexhibiting different resistance phenotypes: a) susceptible(n = 60); b) quinolone-resistant (n = 45); c) penicillinase(n=64); d) hyperproduction of penicillinase (n=8); e) inhibitorresistant TEM (IRT) (n=18), and f) extended spectrumbetalactamase (ESBL) (n=8). Minimum inhibitory concentration(MIC) determination by agar dilution and susceptibilitytests for ESBL detection by macrodilution were performedfollowing CLSI recommendations. All the â-lactamstested showed high activity against susceptible and penicillinasephenotypes, with close to 100 % susceptibility.Hyperproduction of penicillinase increased MIC90 values forall antibiotics except for meropenem, with 100% resistanceto cefuroxime and amoxicillin/clavulanic acid, and 100%susceptibility to cefotaxime, piperacillin/tazobactam andmeropenem. All the antibiotics, except for amoxicillin/clavulanicacid, exhibited high activity against IRT. Meropenem,cefminox and piperacillin/tazobactam exhibited thehighest activity against ESBL, followed by amoxicillin/clavulanicacid. The most active compound among the parenteralantibiotics was meropenem, regardless of the resistancephenotype. Among the oral antibiotics, the most activecompound was cefditoren with the exception of ESBL whereamoxicillin/clavulanic acid where the MIC90 value wasone dilution lower (AU)

Se determinó la susceptibilidad a betalactámicos de203 aislados recientes de E. coli procedentes de infeccionesdel tracto urinario en España y que presentaban distintosfenotipos de resistencia: a) susceptible (n = 60);b) resistente a quinolonas (n=45); c) productor de penicilinasa(n=64); d) hiperproductor de penicilinasa (n=8);e) resistente a inhibidores de TEM (IRT) (n=18), y f) productorde betalactamasas de espectro extendido (BLEE)(n=8). La determinación de la concentración mínima inhibitoria(CMI) por dilución en agar y los tests de susceptibilidadpara la detección de BLEE se realizaron siguiendolas recomendaciones del Clinical and Laboratory StandardsInstitute (CLSI). Frente a los fenotipos susceptible yproductor de penicilinasa, todos los betalactámicos ensayadosexhibieron gran actividad, con una sensibilidadcercana al 100% de los aislados. La hiperproducción depenicilinasa incrementó los valores de CMI90 de todos losantibióticos, excepto de meropenem, con un 100% de resistenciaa cefuroxima y amoxicilina/clavulánico y un 100% desensibilidad a cefotaxime, piperacilina/tazobactam y meropenem.Todos los antibióticos, excepto amoxicilina/clavulánico,presentaron gran actividad frente a las cepas IRT.Meropenem, cefminox y piperacilina/tazobactam presentaronla mayor actividad frente a BLEE, seguidas de amoxicilina/clavulánico. Entre los antibióticos parenterales, elcompuesto más activo fue meropenem, con independenciadel fenotipo de resistencia. Entre los antibióticos oralesel compuesto más activo fue cefditoren, excepto frentea las cepas BLEE, donde amoxicilina/clavulánico presentóen un valor de CMI90 una dilución menor (AU)

Evaluation of the in-vitro cidal activity and toxicity of a novel peroxygen biocide: 2-butanone peroxide.

The monomer of 2-butanone peroxide is a novel peroxygen derivative with potential use as biocide in the hospital environment. The aim of this study was to test the biocidal activity of different concentrations of the compound against American Tissue Culture Collection strains from 11 different micro-organisms, including bacteria, mycobacteria, spores, fungi and virus, following the European Standard guidelines. Toxicity tests were also carried out following United States Environmental Protection Agency Standards. 2-Butanone peroxide exhibited biocidal activity at 0.12% against Legionella pneumophila, at 0.5% against Escherichia coli, Pseudomonas aeruginosa and Enterococcus hirae, and at 1% against Staphylococcus aureus after 5 min contact at room temperature. Mycobactericidal activity was obtained at 0.5% after 60 min contact at 20 degrees C, and sporicidal activity was obtained at 4% after 60 min at 40 degrees C. Good fungicidal (against yeasts and moulds) and virucidal (adenovirus and poliovirus) activities were obtained at 0.5% after 60 min contact. Toxicity assessment showed negative results in the acute dermal irritation test, acute eye irritation test and acute oral toxicity test. The skin sensitisation test was negative. The safety profile in the toxicity tests and the basic cidal activity against the strains tested suggest that 2-butanone peroxide in the control of hospital infections.

Evaluation of several fluoroquinolones and beta-lactams in terms of their capability to restrict the selection of fluoroquinolone-resistant Salmonella: in vitro models.

With a view to understanding the interaction between Salmonella and the drugs used to treat it, our aim was to compare the different capacities of various antibiotics to generate mutants resistant to fluoroquinolones following repeated exposure of the microorganisms to subinhibitory concentrations of these drugs. Mutants were generated by repeated exposure to fluoroquinolones and beta-lactams. In order to compare the different capacity to generate resistant mutants, we studied the minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) of the wild-type strains and of the mutants generated. These data were compared with pharmacokinetic parameters. Mutants generated following repeated exposure to fluoroquinolones exhibit an increased MPC as compared to the wild-type strains, both in strains that are nalidixic acid susceptible and in those that are nalidixic acid resistant, with repeated exposure to ciprofloxacin leading to the smallest increases. This increase in MPC is gradual and depends on the number of exposures the bacteria are subjected to. It results in a decrease in the AUC/MPC ratio, although the absolute values vary. Ciprofloxacin is the most active drug, both against nalidixic acid-susceptible and nalidixic acid-resistant strains, although in late mutants of originally nalidixic acid-resistant strains, the AUC/MPC values are low. Repeated exposure to amoxicillin and cefotaxime also produces an increase in the MPC of fluoroquinolones, with ciprofloxacin being the least affected. Exposure to amoxicillin leads to the greatest increase in the MPC of fluoroquinolones. When the AUC/MPC ratios of these mutants are compared, the values are still seen to be high (between 25 and 75). When we compare the MPC data with the antibiotic levels in humans following administration of the usual doses, it can be seen that ciprofloxacin exhibits the highest AUC/MPC and therefore the lowest risk of therapeutic failures. In addition, administration of subinhibitory concentrations of beta-lactams produces a decrease in fluoroquinolone susceptibility, which may lead to an increase in the risk of therapeutic failure if these compounds are subsequently used.

Disminución de la actividad bactericida del ciprofloxacino en mutantes de Salmonella generados tras exposición repetida a diversas fluoroquinolonas / Decrease in bactericidal activity of ciprofloxacin in Salmonella mutants generated following repeated exposure to various fluorquinolones

Después de generar in vitro mutantes de Salmonella spp. con sensibilidad disminuida a las fluoroquinolonas tras su exposición repetida a concentraciones subinhibitorias de estos fármacos y caracterizar las alteraciones del gen gyrA, hemos determinado la modificación de la actividad bactericida que presenta el ciprofloxacino sobre los mutantes obtenidos. La pérdida de la actividad bactericida del ciprofloxacino se detecta en todos los mutantes, pero es mayor en los provenientes de cepas resistentes al ácido nalidíxico. Esto puede ayudar a explicar los fracasos terapéuticos observados con algunos tratamientos con fluoroquinolonas frente a este tipo de cepas. Además, nuestro modelo evalúa las primeras interacciones que se producen entre el microorganismo y los antibióticos, y pone de manifiesto que la pérdida de actividad bactericida del ciprofloxacino es un proceso que se produce tras la exposición a cualquiera de las fluoroquinolonas probadas

Salmonella mutants with reduced fluoroquinolone susceptibility were generated in vitro following repeated exposure to subinhibitory concentrations of the drugs and the alterations in the gyrA gene were characterized. Afterwards, the change in bactericidal activity exhibited by ciprofloxacin against the resulting mutants was determined. A decrease in the bactericidal activity of ciprofloxacin was found in all the mutants, but was more pronounced in mutants of nalidixic acid-resistant strains. This may help to explain the therapeutic failures sometimes described when fluoroquinolones are used in the treatment of these strains. In addition, our model evaluates the first interactions produced between the microorganism and the antibiotics, and demonstrates that the loss of bactericidal activity of ciprofloxacin occurs following exposure to all of the fluoroquinolones tested

Alterations in the gyrA and parC genes in Salmonella spp. following in vitro exposure to fluoroquinolones.

We characterize alterations in the QRDR fragment of gyrA and parC in Salmonella spp. following repeated exposure to different quinolones in two in vitro models. Mutations in QRDR of gyrA were found in only 25% of the mutants. The most frequent mutations were Asp87(R)Asn and Asp87(R)Tyr. Strains with the former mutation had a higher ciprofloxacin MIC than those with the latter. We did not find mutations in parC. Our data confirm that mutation in the QRDR fragment of gyrA is the mechanism that produces the greatest decrease in fluoroquinolone susceptibility. There is a greater reduction in the ciprofloxacin susceptibility of strains that were originally nalidixic acid-resistant than in that of strains that were originally susceptible, and this confirms that there is a greater likelihood of therapeutic failures with such strains.

Utilidad del antígeno de Streptococcus pneumoniae en orina para el diagnóstico de la neumonía en niños / Usefulness of Streptococcus pneumoniae antigen in urine in the diagnosis of pneumonia in children

Pretendemos evaluar la utilidad de la detección de antígenode Streptococcus pneumoniae en orina en el diagnóstico de laneumonía extrahospitalaria en niños que necesitaron ingresohospitalarioMATERIAL Y MÉTODOSEstudio prospectivo durante 15 meses de 61 niños ingresadospor neumonía extrahospitalaria y 21 niños sanos como control.La detección del antígeno se realizó mediante el sistemaBinax Now previa concentración de la orinaRESULTADOSLa técnica mostró una sensibilidad del 100%, una especificidaddel 21.4% El 78.8% de los niños con neumonía presentanantígeno en orina, aunque también se encontraba en el 47%de niños sanos (p=0.005). CONCLUSIONESEstá técnica no es útil en el diagnóstico de este proceso por suescasa especificidad. Sin embargo, la dificultad de establecer unpatrón diagnóstico de la neumonía neumocócica no bacteriémicadificulta la correcta evaluación de esta técnica y otros datossugieren que los datos de especificidad pueden ser superiores

Our aim is to assess the usefulness of the detection ofStreptococcus pneumoniae antigen in urine in the diagnosis ofextrahospital pneumonia in children who require admission tohospitalMATERIAL AND METHODSProspective study over a period of 15 months of 61 childrenadmitted to hospital with extrahospital pneumonia and 21healthy children as controls. The antigen was detected usingthe Binax Now system after concentrating the urineRESULTSThe technique was seen to have a sensitivity of 100%, aspecificity of 21.4%. The antigen in urine was present in 78.8%of the children with pneumonia, and also in 47% of the healthychildren (p=0.005). This technique is not useful because it has a low specificity,but the difficulty in establishing diagnostic guidelines for nonbacteraemiapneumococcus pneumonia makes it difficult toassess this technique properly, although other data indicatethat it may have greater specificity

[Activity of cefpodoxime and other oral beta-lactams against Haemophilus influenzae and Streptococcus pneumoniae with different susceptibilities to penicillin]. / Actividad de cefpodoxima y otros betalactámicos orales frente a Haemophilus influenzae y Streptococcus pneumoniae con distinta sensibilidad a la penicilina.

This study explores the influence on the intrinsic activity of different oral beta-lactams of beta-lactamase production in Haemophilus influenzae and penicillin resistance in Streptococcus pneumoniae. Three substudies were performed: a) a general susceptibility study, analyzing 550 strains received by the Spanish Laboratorio de Referencia de Neumococos throughout February and March 2005; b) a study on the influence of penicillin resistance on the activity of beta-lactams, analyzing 251 penicillin-susceptible strains (MICor=2 mg/l) randomly chosen among those received by the Spanish Laboratorio de Referencia de Neumococos throughout 2005; and c) an H. influenzae susceptibility study analyzing 150 strains received by Instituto Valenciano de Microbiologia throughout 2005. A total of 71% of S. pneumoniae strains were susceptible to penicillin, 21% exhibited intermediate resistance and 8% strains presented full resistance. H. influenzae beta-lactamase production rate was 18.6%. Of the non-beta-lactamase-producing strains, 3% were not susceptible to ampicillin. Cefpodoxime and cefixime exhibited the highest intrinsic activity against H. influenzae, while amoxicillin and cefpodoxime were the most active compounds against S. pneumoniae. All H. influenzae strains were susceptible to oral cephalosporins and amoxicillin/clavulanic acid. The increase in penicillin resistance in S. pneumoniae influenced cefixime, cefaclor and cefuroxime to a higher degree than amoxicillin and cefpodoxime.

Actividad de cefpodoxima y otros betalactámicos orales frente a Haemophilus influenzae y Streptococcus pneumoniae con distinta sensibilidad a la penicilina / Activity of cefpodoxime and other oral beta-lactams against Haemophilus influenzae and Streptococcus pneumoniae with different susceptibilities to penicillin

Estudiamos la influencia de la producción de betalactamasas en Haemophilus influenzae y del grado de sensibilidad a la penicilina en Streptococcus pneumoniae sobre la actividad intrínseca de distintos betalactámicos orales. Realizamos tres subestudios: 1) un estudio general de sensibilidad, analizando 550 aislamientos consecutivos recibidos en el Laboratorio de Referencia de Neumococos durante los meses de febrero y marzo de 2005; 2) un estudio de la influencia de la sensibilidad a la penicilina sobre la actividad del resto de los betalactámicos, analizando la sensibilidad de 251 cepas sensibles a la penicilina (CMI ≤0,06 mg/l), 165 cepas con resistencia intermedia (CMI 0,12-1 mg/l) y 139 resistentes (CMI ≥2 mg/l), elegidas aleatoriamente entre todos los aislamientos recibidos durante el año 2005; y 3) un estudio de sensibilidad de H. influenzae, analizando 150 cepas recibidas por el Instituto Valenciano de Microbiología a lo largo del año 2005. El 71% de las cepas de S. pneumoniae fueron sensibles a la penicilina, el 21% presentaron baja resistencia o resistencia intermedia, y un 8% alta resistencia. La tasa de producción de betalactamasas fue del 18,6% en H. influenzae. El 3% de las cepas no productoras de betalactamasas fueron no sensibles a la ampicilina. La cefpodoxima y la cefixima presentaron la mayor actividad intrínseca frente a H. influenzae, mientras que frente a S. pneumoniae ésta correspondió a la amoxicilina y la cefpodoxima. Mientras que el 100% de las cepas de H. influenzae fueron sensibles a las cefalosporinas orales y a amoxicilina-ácido clavulánico, el aumento de la resistencia a la penicilina en S. pneumoniae afectó en mayor grado a la actividad de la cefixima, el cefaclor y la cefuroxima que a la amoxicilina y la cefpodoxima

This study explores the influence on the intrinsic activity of different oral β-lactams of β-lactamase production in Haemophilus influenzae and penicillin resistance in Streptococcus pneumoniae. Three substudies were performed: a) a general susceptibility study, analyzing 550 strains received by the Spanish Laboratorio de Referencia de Neumococos throughout February and March 2005; b) a study on the influence of penicillin resistance on the activity of β-lactams, analyzing 251 penicillin-susceptible strains (MIC ≤0.06 mg/l), 165 penicillin intermediateresistant strains (MIC 0.12–1 mg/l) and 139 penicillin-resistant strains (MIC ≥2 mg/l) randomly chosen among those received by the Spanish Laboratorio de Referencia de Neumococos throughout 2005; and c) an H. influenzae susceptibility study analyzing 150 strains received by Instituto Valenciano de Microbiología throughout 2005. A total of 71% of S. pneumoniae strains were susceptible to penicillin, 21% exhibited intermediate resistance and 8% strains presented full resistance. H. influenzae β-lactamase production rate was 18.6%. Of the non–β-lactamase-producing strains, 3% were not susceptible to ampicillin. Cefpodoxime and cefixime exhibited the highest intrinsic activity against H. influenzae, while amoxicillin and cefpodoxime were the most active compounds against S. pneumoniae. All H. influenzae strains were susceptible to oral cephalosporins and amoxicillin/clavulanic acid. The increase in penicillin resistance in S. pneumoniae influenced cefixime, cefaclor and cefuroxime to a higher degree than amoxicillin and cefpodoxime

Faecal thiaminase, plasma lactate and pyruvate concentrations and erythrocyte transketolase activity changes in apparently normal replacement ewes after the initiation to the pasture.

A study was made to investigate faecal thiaminase and the thiamine-related biochemical changes in apparently normal replacement ewes with a feed change, after the initiation without adaptation to the new pasture. Twenty-four female ewes were divided into two groups. Group A was managed in a system based on pasture and was compared with group B system based on a diet of concentrate and straw until moving to pasture 9 weeks after. Blood samples for lactate, pyruvate and erythrocyte transketolase activity determinations and faeces for thiaminase estimation were evaluated chronologically. At the end of a 126 days experimental period, live weights of groups were similar. We confirmed that clinically normal sheep may have thiaminase activity in the faeces and concluded that the thiaminase release increased during the diet changes, from concentrate to pasture, and that their continued excretion could develop some degree of thiamine deficiency.

[Decrease in bactericidal activity of ciprofloxacin in Salmonella mutants generated following repeated exposure to various fluorquinolones]. / Disminución de la actividad bactericida del ciprofloxacino en mutantes de Salmonella generados tras exposición repetida a diversas fluoroquinolonas.

Salmonella mutants with reduced fluoroquinolone susceptibility were generated in vitro following repeated exposure to subinhibitory concentrations of the drugs and the alterations in the gyrA gene were characterized. Afterwards, the change in bactericidal activity exhibited by ciprofloxacin against the resulting mutants was determined. A decrease in the bactericidal activity of ciprofloxacin was found in all the mutants, but was more pronounced in mutants of nalidixic acid-resistant strains. This may help to explain the therapeutic failures sometimes described when fluoroquinolones are used in the treatment of these strains. In addition, our model evaluates the first interactions produced between the microorganism and the antibiotics, and demonstrates that the loss of bactericidal activity of ciprofloxacin occurs following exposure to all of the fluoroquinolones tested.

Utilidad de medios de cultivo con sangre de carnero en el aislamiento de Mycobacterium tuberculosis / Usefulness of culture media with ram’s blood in the isolation of Mycobacterium tuberculosis

Introducción:Conocer la utilidad de varios medios en el aislamiento deMycobacterium tuberculosis.Material y metodos:97 cepas de M. tuberculosis se cultivaron en: Agar Columbia,agar tripticasa soja, GC agar y agar infusión corazón-cerebro.Todos tenían 10% de sangre de carnero como suplemento.Resultados:Más del 95% de las cepas crecen, no encontrando diferenciasestadísticamente significativas. La mayoría de las cepascrecen a la tercera semana de incubación.Conclusiones:El crecimiento de M. tuberculosis en medios con agar suplementadoscon sangre de carnero tras incubación prolongadadebe ser tenido en cuenta para mejorar el diagnóstico de estemicroorganismo en muestras escasas o en las que no se sospechóinicialmente la posible implicación de este patógeno. Además,el crecimiento de M. tuberculosis en medios con base deagar debe tenerse en cuenta a la hora de mantener las medidasde seguridad adecuadas en el manejo de estos cultivos

Introduction:To determine the usefulness of various media in the isolationof Mycobacterium tuberculosisMaterial and methods:Ninety seven M. tuberculosis strains were cultured in:Columbia agar, soya-tripticase agar, GC agar and heart braininfusion agar. All are suplemented with 10% ram’s blood.Results:Over 95% of the strains grew, and no statistically significantdifferences were found. Most strains grew during the thirdweek of incubation.Conclusions:The growth of M. tuberculosis in agar media suplementedwith ram’s blood after prolonged incubation should be taken intoaccount in order to improve the diagnosis of this microorganismin small samples or in those in which involvement of thispathogen was not initially suspected. In addition, the growth ofM. tuberculosis in agar base media should be borne in mindwhen maintaining the appropriate safety measures during handlingof these cultures

Mutant prevention concentration of isoniazid, rifampicin and rifabutin against Mycobacterium tuberculosis.

BACKGROUND: Mutant prevention concentration (MPC) is a new parameter that may be of aid in determining the risk of resistant mutants being selected. METHODS: The MPCs of 224 Mycobacterium tuberculosis clinical isolates were estimated by plating more than 10(10) cells on drug-containing agar and determining the concentration that allowed no colony growth. Antibiotics used were isoniazid, rifampicin and rifabutin. RESULTS: The MPC90 of clinical isolates in our setting is 2.4, 2.2 and 0.4 mg/l for isoniazid, rifampicin and rifabutin, respectively. CONCLUSIONS: Isoniazid and rifampicin are two drugs that present a low risk of selection of resistant mutants when used in monotherapy. However, determination of the MPC of each strain can provide data to minimize this risk and thus enable treatment to be optimized.

Usefulness of various antibiotics against Mycobacterium avium-intracellulare, measured by their mutant prevention concentration.

This study looked the selection of resistant mutants in Mycobacterium avium-intracellulare during antibiotic treatment. The mutant prevention concentration (MPC) of 20 Mycobacterium avium and 12 Mycobacterium intracellulare isolates was determined. Fifty percent of Mycobacterium avium strains had MPC (MPC50) values lower than 16, 64, 40, 55 and 60 mg/L for rifabutin, rifampicin, ciprofloxacin, levofloxacin and moxifloxacin, respectively. In the case of Mycobacterium intracellulare, 50% had MPC (MPC50) values below 60, 30, 35, 16, 2.5 and 14 mg/L for linezolid, rifabutin, levofloxacin, gatifloxacin, moxifloxacin and clarithromycin, respectively. The high capacity for selecting resistant mutants of all the antibiotics studied emphasises the need to restore the immune system if necessary and to administer combined treatments in order to cure patients.