RESUMEN
Bench press (i.e. arm-based) and half-squat (i.e. leg-based) are exercises commonly used to increase and evaluate muscular strength. In addition to differences in the location of the muscles that participate in each exercise, the total muscle mass required for the latter is larger than that involved in the former. The aim of this study is to analyze the effects of a maximal incremental strength test when performed by bench press and by half-squat on myocellular damage, oxidative damage and the inflammatory cytokine response. Ten male athletes were subjected to half-squat and bench press incremental strength tests. Blood samples were collected at rest, 15-minutes and 24â¯h post-test. Hydroperoxide and malondialdehyde concentrations were determined as lipid peroxidation markers. Lactate dehydrogenase (LDH) and creatine kinase isoenzyme MB (CK-MB) activities were determined as markers of muscle damage. α-Actin concentration was determined as a marker of sarcomeric damage. Serum interleukin (IL) 6, IL10, and tumor necrosis factor alpha (TNFα) were determined to assess the inflammatory response. LDH and CK-MB values were greater at 15â¯min and 24â¯h post bench press exercise (pâ¯<â¯0.05). No differences were found in lipid peroxidation or α-actin. Interestingly, IL10 values were greater in response to the press bench at 24â¯h post-test (pâ¯<â¯0.05). Our results suggest that, at equivalent workloads, an arm-based exercise induced higher anti-inflammatory effects and more severe muscle damage compared with a leg-based exercise.
Asunto(s)
Mediadores de Inflamación/sangre , Interleucina-10/sangre , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Actinas/sangre , Brazo/fisiología , Forma MB de la Creatina-Quinasa/sangre , Humanos , Peróxido de Hidrógeno/sangre , Interleucina-6/sangre , L-Lactato Deshidrogenasa/sangre , Pierna/fisiología , Masculino , Malondialdehído/sangre , Contracción Muscular/fisiología , Fuerza Muscular/fisiología , Factor de Necrosis Tumoral alfa/sangre , Adulto JovenRESUMEN
Brown rot on peaches and nectarines caused by Monilinia spp. results in significant economic losses in Europe. Experiments were conducted to study the effects of temperature (0-33 °C) on the temporal dynamics of decay and mycelium development and the subsequent sporulation on peaches and nectarine fruit infected by M. laxa and M. fructicola. The rates of decay and mycelium development increased with temperature from 0 °C to 25 °C for both Monilinia species. At 0 °C, decay was faster for M. laxa (0.20 cm2 days-1) than for M. fructicola (0.07 cm2 days-1); indeed, M. laxa was able to develop mycelia and sporodochia, but M. fructicola was not. At 4 and 20 °C, there were no differences in decay and mycelia development between the two Monilinia species. When temperature increased from 25 to 33 °C, the rates of fungal decay and mycelium development decreased. At 30 and 33 °C, M. fructicola decayed faster (0.94 and 1.2 cm2 days-1, respectively) than M. laxa (0.78 and 0.74 cm2 days-1, respectively) and could develop mycelia and produce sporodochia, whereas M. laxa failed at 33 °C. These results indicated that M. fructicola is better adapted to high temperatures, whereas M. laxa is better adapted to low temperatures. These results can be used to predict the relative importance of the two species during the season at a given site and to improve management strategies for brown rot in areas where both species are present.
Asunto(s)
Ascomicetos/fisiología , Frutas/microbiología , Calor , Micelio/crecimiento & desarrollo , Enfermedades de las Plantas/microbiología , Frío , Europa (Continente) , Enfermedades de las Plantas/prevención & control , Prunus/microbiología , Prunus persica/microbiología , Esporas Fúngicas/crecimiento & desarrolloRESUMEN
The aim of this study was to investigate whether intratracheal administration of a new synthetic surfactant that includes the cationic, hydrophobic 21-residue peptide KLLLLKLLLLKLLLLKLLLLK (KL4), might be effective in reducing ischaemia-reperfusion injury after lung transplantation. Single left lung transplantation was performed in Landrace pigs 22 h post-harvest. KL4 surfactant at a dose of 25 mg total phospholipid·kg body weight⻹ (2.5 mL·kg body weight⻹) was instilled at 37°C to the donor left lung (n = 8) prior to explantation. Saline (2.5 mL·kg body weight⻹; 37°C) was instilled into the donor left lung of the untreated group (n = 6). Lung function in recipients was measured during 2 h of reperfusion. Recipient left lung bronchoalveolar lavage (BAL) provided native cytometric, inflammatory marker and surfactant data. KL(4) surfactant treatment recovered oxygen levels in the recipient blood (mean ± sd arterial oxygen tension/inspiratory oxygen fraction 424 ± 60 versus 263 ± 101 mmHg in untreated group; p=0.01) and normalised alveolar-arterial oxygen tension difference. Surfactant biophysical function was also recovered in KL4 surfactant-treated lungs. This was associated with decreased C-reactive protein levels in BAL, and recovery of surfactant protein A content, normalised protein/phospholipid ratios, and lower levels of both lipid peroxides and protein carbonyls in large surfactant aggregates. These findings suggest an important protective role for KL4 surfactant treatment in lung transplantation.
Asunto(s)
Trasplante de Pulmón/métodos , Péptidos/farmacología , Adsorción , Animales , Lavado Broncoalveolar , Proteína C-Reactiva/metabolismo , Carbono/química , Inflamación , Péptidos y Proteínas de Señalización Intercelular , Peroxidación de Lípido , Pulmón/efectos de los fármacos , Oxígeno/química , Fosfolípidos/química , Surfactantes Pulmonares/química , Daño por Reperfusión , Propiedades de Superficie , PorcinosRESUMEN
AIMS: This study evaluated the effect of temperature (0-38 degrees C) and water activity (a(w): 0.87-0.99) on the lag phase prior to germination and the percentage of germination over time for Monilinia laxa, Monilinia fructicola and Monilinia fructigena. METHODS AND RESULTS: More than 80% of viable conidia germinated at 25 degrees C and 0.99 a(w) within 2 h for M. fructicola and M. fructigena and 4 h for M. laxa. There was no germination at 38 degrees C, and all three Monilinia spp. germinated at 0 degrees C. At the lowest a(w) (0.87), none of the Monilinia spp. was able to germinate at any of the incubation temperatures studied. Whereas at 0.90 a(w), conidia were only able to germinate at 15, 25 and 30 degrees C for the three species studied, except for M. fructicola at 15 degrees C. In contrast, at 0.95, 0.97 and 0.99 a(w), germination occurred at all studied temperatures less 38 degrees C. Generally, the lag phase was longer at low levels of a(w) (0.90-095), and differences were more evident as temperatures were far from the optimum (0-5 degrees C). CONCLUSIONS: Germination and lag phase period were markedly influenced by temperature and a(w), and in general when conditions of temperature and a(w) were suboptimal, the lag phase was longer and the percentage of germination was lower. SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge of the germination requirements of this fungus is important in order to understand their behaviour in natural situations and to provide baseline data required for the construction of new prediction models. Our study might be used to develop a predictive model to understand and control the disease caused by Monilinia spp.
Asunto(s)
Ascomicetos/crecimiento & desarrollo , Esporas Fúngicas/crecimiento & desarrollo , Calor , AguaRESUMEN
Disinfection of surface facilities during postharvest handling operation is an important practice to avoid secondary fruit infections at stone fruit packinghouses. The aim of this work was to evaluate the effect of six environmental friendly disinfectants against Monilinia fructicola, Penicillium expansum, Rhizopus spp., and Alternaria spp. on plastic and wood surfaces. Hydrogen peroxide, peracetic acid, sodium hypochlorite, Mico-E-pro®, Proallium FRD-N®, and DMC Clean-CNS® were used as the disinfectants. Untreated and surfaces treated with water were used as controls. Plastic and wood surfaces were sampled with Rodac plates at 2 and 24 h after treatments and the number of colonies were counted. In general, all disinfectants reduce the number of viable conidia from all studied surfaces. Hydrogen peroxide used in a concentration of 150 mg L-1 was the less effective disinfectant in all studied pathogens. The commercial product Mico-E-pro® composed of oregano, onion, and orange extract at a dose of 10 mg L-1 was the most effective disinfectant. Rhizopus spp. was the pathogen more resistant to the disinfectants followed by P. expansum, M. fructicola, and Alternaria spp. Water decreased the number of conidia adhered to the surface. In addition, the untreated control showed substantial conidia reduction after 24 h of artificial inoculation.
Asunto(s)
Desinfectantes/farmacología , Desinfección/métodos , Microbiología de Alimentos , Frutas/microbiología , Hongos/efectos de los fármacos , Propiedades de Superficie , Citrus sinensis , Desinfectantes/química , Ambiente , Manipulación de Alimentos , Hongos/crecimiento & desarrollo , Humanos , Cebollas , Origanum , Plásticos , Hipoclorito de Sodio , Esporas Fúngicas/efectos de los fármacos , MaderaRESUMEN
The solubility of hydrophobic pulmonary surfactant proteins in different organic solvents and organic solvent/water combinations has been analyzed. Three organic solvents have been selected: methanol (MetOH), acetonitrile (ACN) and trifluoroethanol (TFE). Porcine SP-B showed very similar calculated secondary structure when dissolved in methanol, 60% ACN or 70% TFE and reconstituted in lysophosphatidylcholine (LPC) micelles or dipalmitoylphosphatidylcholine (DPPC) vesicles, as deduced from circular dichroism studies. SP-B was calculated to possess around 45% of alpha-helix in all these systems. The fluorescence emission spectrum of SP-B has been also characterized in aqueous solvents and lipids. It always showed a splitting of the tryptophan contribution into two components with different emission maxima. SP-C had a very different structure in 80% ACN or 70% TFE. While alpha-helix was the main secondary structure of SP-C in ACN/water mixtures--around 50%--, it had almost exclusively beta-structure when dissolved in 70% TFE. The CD spectrum of SP-C in TFE showed dependence on the protein concentration, suggesting that protein-protein interactions could be important in this beta-conformation. SP-C reconstituted in LPC micelles or DPPC vesicles had a CD spectrum qualitatively similar to that one in aqueous ACN, with a dominant alpha-helical structure. The alpha-helical content of SP-C in micelles of LPC and vesicles of DPPC, 60 and 70%, respectively, was calculated to be higher than the alpha-helical content of the protein dissolved in any aqueous organic solvent.
Asunto(s)
Proteolípidos/química , Surfactantes Pulmonares/química , 1,2-Dipalmitoilfosfatidilcolina , Acetonitrilos , Secuencia de Aminoácidos , Animales , Metanol , Micelas , Datos de Secuencia Molecular , Proteolípidos/aislamiento & purificación , Surfactantes Pulmonares/aislamiento & purificación , Solubilidad , Solventes , Porcinos , Trifluoroetanol , AguaRESUMEN
The structure of hydrophobic pulmonary surfactant-associated proteins SP-B and SP-C have been studied in different acetonitrile (ACN)/water and trifluorethanol (TFE)/water mixtures by circular dichroism and fluorescence spectroscopy to analyze the conformational flexibility of these proteins in response to changes in solvent composition. SP-B presented a very stable conformation in all the assayed ACN/water mixtures and in TFE/water mixtures containing until 70% TFE, showing around 40% alpha-helix. When SP-B was transferred to mixtures containing more than 70% TFE, the percent of alpha-helix in SP-B increased up to 60%. The fluorescence emission spectra of SP-B in the different solvents showed that tryptophan residues are more sensitive to solvent changes than those of tyrosine, reflecting differential effects on different protein microenvironments. The effect of solvent changes on the two tryptophan populations detected by fluorescence spectra was also different. A model for the folding of SP-B dimers, dominated by intra- and intermolecular disulphide bonds, is proposed. Surfactant protein SP-C revealed a secondary structure much more sensitive to solvent composition than SP-B. It had a main alpha-helical conformation in ACN/water solvents which was up to 63% in mixtures containing more than 60% ACN. When the protein was transferred to solvents containing less than 60% ACN, its secondary structure possessed less percent of alpha-helix and an increased percent of beta-structure. On the other hand, SP-C had a main beta-sheet secondary structure in all the assayed TFE/water mixtures, with 30-40% alpha-helix and around 50% beta-structure. The strong dependence of SP-C conformation on the nature of the solvent is interpreted to arise from its high hydrophobicity and the possible occurrence of protein-protein interactions.
Asunto(s)
Proteolípidos/química , Surfactantes Pulmonares/química , Secuencia de Aminoácidos , Dicroismo Circular , Datos de Secuencia Molecular , Conformación Proteica , Estructura Secundaria de Proteína , Solventes , Espectrometría de FluorescenciaRESUMEN
Alterations in the lipid composition of lung microsomal membranes occur in oleic acid-induced respiratory distress. The marked decrease in the phosphatidylcholine/lysophosphatidylcholine molar ratio could be related with an altered metabolism of lysophosphatidylcholine in these membranes. Results revealed that the activity of phospholipase A increased whereas that of acyl-CoA:lysophosphatidylcholine acyltransferase decreased. Microsomal lysophospholipase activity remained unchanged. On the other hand, the microsomal enzyme system involved in the de novo synthesis of diacylglycerol was impaired, and cholinephosphotransferase activity was lowered. These changes in the activity of some membrane-bound enzymes were not caused by changes in the membrane lipid fluidity since lipid structural order parameter (SDPH) did not change and neither did the major factors on which the fluidity depends. The possible significance of microsomal lipid alterations in the pathogenesis of respiratory distress induced by oleic acid is discussed.
Asunto(s)
Membranas Intracelulares/metabolismo , Lisofosfatidilcolinas/metabolismo , Lípidos de la Membrana/metabolismo , Microsomas/ultraestructura , Ácidos Oléicos , Síndrome de Dificultad Respiratoria/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferasa/metabolismo , Animales , Diglicéridos/metabolismo , Glicerofosfatos/metabolismo , Masculino , Fluidez de la Membrana , Ácido Oléico , Fosfatidilcolinas/metabolismo , Fosfolipasas A/metabolismo , Fosfolípidos/metabolismo , Conejos , Síndrome de Dificultad Respiratoria/inducido químicamente , Triglicéridos/metabolismoRESUMEN
The present study compares the phospholipid distribution and protein content in bronchoalveolar lavage, purified extracellular surfactant and lamellar bodies isolated from rabbits killed at intervals of 2.5, 12 and 24 h after oleic acid administration. The data suggest that the alteration of pulmonary surfactant could be partially due to the type II cell response to the injury.
Asunto(s)
Surfactantes Pulmonares/metabolismo , Síndrome de Dificultad Respiratoria/metabolismo , Animales , Líquido del Lavado Bronquioalveolar/análisis , Cuerpos de Inclusión/metabolismo , Lisofosfatidilcolinas/metabolismo , Masculino , Ácido Oléico , Ácidos Oléicos , Fosfolípidos/metabolismo , Conejos , Síndrome de Dificultad Respiratoria/inducido químicamente , Esfingomielinas/metabolismoRESUMEN
OBJECTIVE: To evaluate the trend in incidence of Pseudomonas aeruginosa bacteremia, underlying conditions of patients, mortality rate, and factors associated with poor outcome. PATIENTS AND METHODS: Medical charts of 189 consecutive episodes of P aeruginosa bacteremia, detected between January 1, 1991, and December 31, 1994, were prospectively evaluated. Associated risk factors, treatment, and outcome were recorded. RESULTS: Pseudomonas aeruginosa bacteremia represented 5.7% of the total number of bacteremias, 6.9% of nosocomial bacteremias, and 23.6% of nosocomial gram-negative bacteremias. There were 1.5 episodes per 1000 discharges. These numbers were slightly lower than those recorded at our hospital 10 years earlier. Human immunodeficiency virus infection was the most frequent underlying disease (28/189 [15%]). Overall mortality was 18% (34/189). The presence of fatal underlying disease (P < .001), surgery (P = .001), pneumonia (P = .02), and severe sepsis (P < .001) were associated with poor prognosis, the mortality of the patients with these variables being 28%, 28%, 47%, and 62%, respectively. The presence of inappropriate definitive antimicrobial treatment became an independent factor predictive of death (P = .04) only when the subset of patients with intravenous catheter-associated bacteremia was excluded from the analysis. The survival rate was no greater in patients who received 2 or more antibiotics active in vitro against P aeruginosa than in those who received only 1. Neutropenia was not associated with increased mortality. The use of colony-stimulating factors did not affect the outcome of the neutropenic patients. CONCLUSIONS: The rate of P aeruginosa bacteremia is falling slightly at our hospital. The emergence of the human immunodeficiency virus epidemic has had a considerable impact on both epidemiology and mortality. The presence of severe underlying disease, surgery, pneumonia, and, especially, severe sepsis are associated with a poor outcome. With the exclusion of patients with intravenous catheter-associated P aeruginosa bacteremia, the administration of an appropriate antimicrobial therapy is essential to a good outcome. Treatment with 1 active antibiotic seems to be sufficient.
Asunto(s)
Bacteriemia , Infecciones por Pseudomonas , Anciano , Bacteriemia/complicaciones , Bacteriemia/diagnóstico , Bacteriemia/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Infecciones por Pseudomonas/complicaciones , Infecciones por Pseudomonas/diagnóstico , Infecciones por Pseudomonas/tratamiento farmacológicoAsunto(s)
Bacteriemia/microbiología , Infecciones por Burkholderia/diagnóstico , Burkholderia cepacia/aislamiento & purificación , Enfermedades Fetales/microbiología , Amniocentesis , Líquido Amniótico/microbiología , Bacteriemia/tratamiento farmacológico , Infecciones por Burkholderia/tratamiento farmacológico , Burkholderia cepacia/efectos de los fármacos , Burkholderia cepacia/crecimiento & desarrollo , Cesárea , Femenino , Enfermedades Fetales/tratamiento farmacológico , Edad Gestacional , Humanos , Masculino , Meropenem/farmacología , Meropenem/uso terapéutico , Persona de Mediana Edad , EmbarazoRESUMEN
INTRODUCTION: Malnutrition is associated with an increased risk of mortality and morbidity, longer hospital stays and general loss of quality of life. The aim of this study is to assess the impact of dietary counseling for malnourished hospital patients. PATIENTS AND METHODS: Prospective, randomized, open-label study of 106 hospital patients with malnutrition (54 in the control group and 52 in the intervention group). The intervention group received dietary counseling, and the control group underwent standard treatment. We determined the patients' nutritional state (body mass index, laboratory parameters, malnutrition universal screening tool), degree of dependence (Barthel index), quality of life (SF-12), degree of satisfaction (CSQ-8), the number and length of readmissions and mortality. RESULTS: The patients who underwent the "intervention" increased their weight at 6 months, while the controls lost weight (difference in body mass index, 2.14kg/m(2); p<.001). The intervention group had better results when compared with the control group in the Malnutrition Universal Screening Tool scores (difference, -1.29; p<.001), Barthel index (difference, 7.49; p=.025), SF-12 (difference, 13.72; p<.001) and CSQ-8 (difference, 4.34, p<.001) and required fewer readmissions (difference, -0.37; p=.04) and shorter stays for readmissions (difference, -6.75; p=.035). Mortality and laboratory parameters were similar for the 2 groups. CONCLUSIONS: Nutritional counseling improved the patients' nutritional state, quality of life and degree of dependence and decreased the number of hospital readmissions.
RESUMEN
Binding of polyclonal and monoclonal antibodies, quantitated by enzyme-linked immunosorbent assay, to porcine SP-B reconstituted in different phospholipid bilayers has been used to assess differences in protein structure due to lipid-protein interactions. SP-B bound significantly more antibodies when it was reconstituted in bilayers made of anionic phospholipids (phosphatidic acid, cardiolipin, phosphatidylglycerol, phosphatidylinositol or phosphatidylserine) than in zwitterionic bilayers (phosphatidylcholine, phosphatidylcholine/cholesterol, or phosphatidylethanolamine) or in fatty acid micelles (made of salts of palmitic or stearic acids). These differences in immunoreactivity can be important in the development of quantitation methods for SP-B in clinical samples based on immunological techniques.
Asunto(s)
Antígenos/inmunología , Antígenos/metabolismo , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Proteolípidos/inmunología , Proteolípidos/metabolismo , Surfactantes Pulmonares/inmunología , Surfactantes Pulmonares/metabolismo , Animales , Aniones/química , Aniones/metabolismo , Anticuerpos Monoclonales/inmunología , Ensayo de Inmunoadsorción Enzimática , Sueros Inmunes/inmunología , Micelas , Ácido Palmítico/metabolismo , Fosfolípidos/química , Fosfolípidos/metabolismo , Electricidad Estática , Ácidos Esteáricos/metabolismo , PorcinosRESUMEN
Surfactant protein A (SP-A) is thought to play a role in the modulation of lung inflammation during acute respiratory distress syndrome (ARDS). However, SP-A has been reported both to stimulate and to inhibit the proinflammatory activity of pulmonary macrophages (Mphi). Because of the interspecies differences and heterogeneity of Mphi subpopulations used may have influenced previous controversial results, in this study, we investigated the effect of human SP-A on the production of cytokines and other inflammatory mediators by two well-defined subpopulations of human pulmonary Mphi. Surfactant and both alveolar (aMphi) and interstitial (iMphi) macrophages were obtained from multiple organ donor lungs by bronchoalveolar lavage and enzymatic digestion. Donors with either recent history of tobacco smoking, more than 72 h on mechanical ventilation, or any radiological pulmonary infiltrate were discarded. SP-A was purified from isolated surfactant using sequential butanol and octyl glucoside extractions. After 24-h preculture, purified Mphi were cultured for 24 h in the presence or absence of LPS (10 microg/mL), SP-A (50 microg/mL), and combinations. Nitric oxide and carbon monoxide (CO) generation (pmol/microg protein), cell cGMP content (pmol/microg protein), and tumor necrosis factor alpha (TNFalpha), interleukin (IL)-1, and IL-6 release to the medium (pg/microg protein) were determined. SP-A inhibited the lipopolysaccharide (LPS)-induced TNFalpha response of both interstitial and alveolar human Mphi, as well as the IL-1 response in iMphi. The SP-A effect on TNFalpha production could be mediated by a suppression in the LPS-induced increase in intracellular cGMP. In iMphi but not in aMphi, SP-A also inhibited the LPS-induced IL-1 secretion and CO generation. These data lend further credit to a physiological function of SP-A in regulating alveolar host defense and inflammation by suggesting a fundamental role of this apoprotein in limiting excessive proinflammatory cytokine release in pulmonary Mphi during ARDS.
Asunto(s)
Citocinas/metabolismo , Macrófagos Alveolares/efectos de los fármacos , Macrófagos Alveolares/metabolismo , Proteolípidos/farmacología , Surfactantes Pulmonares/farmacología , Adulto , Líquido del Lavado Bronquioalveolar/citología , Monóxido de Carbono/metabolismo , Células Cultivadas , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , GMP Cíclico/farmacología , Citocinas/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Lipopolisacáridos/farmacología , Masculino , Persona de Mediana Edad , Óxido Nítrico/metabolismo , Proteolípidos/metabolismo , Proteína A Asociada a Surfactante Pulmonar , Proteínas Asociadas a Surfactante Pulmonar , Surfactantes Pulmonares/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
OBJECTIVE: To determine whether non-epidemiologically related, antibiotic-resistant isolates of Acinetobacter baumannii from different geographical origins possess common type 1 integrons. METHODS: The epidemiologic relationships between seven A. baumannii strains recovered from different Spanish hospitals were established by pulsed-field gel electrophoresis, the presence of integrons being determined by PCR and DNA sequencing. RESULTS: Integron analysis showed the presence of four different integrons, containing six different known genes (aacC1, aacA4, aadA1, aadB, oxa21 and oxa37) plus an ORF. It was found that the same integron was present in different unrelated strains and that related strains could have different integrons. CONCLUSION: These results show the potential risk of integron dissemination among different strains of A. baumannii.
Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Farmacorresistencia Bacteriana Múltiple/genética , Integrones/genética , Infecciones por Acinetobacter/microbiología , ADN Bacteriano/química , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Humanos , Pruebas de Sensibilidad Microbiana , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , EspañaRESUMEN
The clinical variables associated with isolation of oxacillin- and methicillin-resistant, coagulase-negative staphylococci (CNS) from blood cultures of hospitalized patients were studied. One hundred CNS strains (49 oxacillin-susceptible; 51 oxacillin-resistant) isolated consecutively from one of two or more sets of blood cultures were collected. Only two variables were independently associated with recovery of oxacillin/methicillin-resistant strains by a multivariate analysis: length of hospital stay > 10 days (OR 5.2, 95% CI = 1.7-15.7), and administration of antimicrobial agents in the previous 14 days (OR 4.5, 95% CI = 1.7-11.7). Analysis of the antibiotics administered indicated that only beta-lactams were associated with a statistically significant risk of resistance to oxacillin/methicillin (OR of beta-lactams vs no antibiotics = 6.94, 95% CI = 1.9-25.3; OR of non-beta-lactams vs no antibiotics = 2.64, 95% CI = 0.8-8.3). Length of hospital stay (especially > 10 days) and prior administration of antimicrobial agents (mainly beta-lactams) independently predicted the presence of oxacillin/methicillin-resistant CNS in blood cultures.
Asunto(s)
Infección Hospitalaria/prevención & control , Meticilina/uso terapéutico , Oxacilina/uso terapéutico , Penicilinas/uso terapéutico , Infecciones Estafilocócicas/prevención & control , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Femenino , Humanos , Tiempo de Internación , Masculino , Resistencia a la Meticilina , Persona de Mediana Edad , Resistencia a las Penicilinas , Factores de Riesgo , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiologíaRESUMEN
BACKGROUND: Concentration of microorganisms in blood is low in bacteremia from extravascular sources. The best yield from blood cultures is achieved by culturing a minimum of 10-20 ml, although in some processing blood culture systems such as Bactec NR-860, smaller volume is used. The objectives of the present study were to establish the frequency in which inadequate small blood volumes are employed for culturing and to analyze the relation between the cultured blood volume in Bactec 6A bottles and the yield achieved. MATERIAL AND METHODS: We weighed 2000 Bactec 6A bottles pertaining to consecutive blood cultures obtained from untreated patients with clinical suspicion of Infection. The cultured blood volume was estimated subtracting the mean empty bottle weight. RESULTS: Microorganisms were recovered from 251 bottles (12.5%). One hundred and thirty one (6.8%) isolates were considered as clinically significant and 115 (5.7%) as contaminant. The inoculated blood volume in both significant (5.532 +/- 1.587 ml) and non-significant (5.471 +/- 1.563 ml) recoveries was superior than that of bottles without microbiologic growth (5.209 +/- 1.575 ml, p = 0.016 and p = 0.06, respectively). A linear positive trend was found between the cultivated blood volume and the rate of recoveries (p = 0.008). Within the range of 1 up to 10 ml, the rate of recoveries increased 2.28% for each additional ml of cultivated blood (r = 0.953, p < 0.0001). Out of the 2,000 weighed bottles 127 (6.3%) contained less than 3 ml of blood and 576 (29%) between 3 and 5 ml. CONCLUSIONS: We have proved that the rate of recoveries from Bactec 6A bottles increased with the volume of cultured blood. In untreated patients, this increase is maintained up to volumes of 7 to 10 ml.
Asunto(s)
Bacterias/aislamiento & purificación , Técnicas Bacteriológicas/instrumentación , Sangre/microbiología , Adulto , Estudios de Evaluación como Asunto , HumanosRESUMEN
AIMS: To study the improvement of tolerance to low water activity (aw) and desiccation during spray drying in Pantoea agglomerans cells subjected to mild osmotic stress during growth. METHODS AND RESULTS: The micro-organism was cultured in an unmodified liquid (control) or in aw-modified media, and viability of these cells was evaluated on unstressed (0.995) and 0.96 aw stressed solid media, in order to check total viability and aw stress tolerance respectively. Significant improvements in viability on unmodified medium were observed with cells grown for 24 h in NaCl 0.98 aw, glycerol 0.98 aw and 0.97 aw and for 48 h in NaCl 0.98 aw and 0.97 aw modified media. Both yield improvements and water stress tolerance were achieved with low aw media. Cells grown for 24 h in NaCl 0.98 aw or for 48 h in NaCl 0.98 aw, 0.97 aw and 0.96 aw, glucose 0.97 aw and glycerol 0.97 aw showed improved aw stress tolerance in comparison with control cells. The best results were obtained with NaCl treatments (0.98 aw and 0.97 aw) which also exhibited better survival rates than control cells during spray-drying process and maintained their efficacy against postharvest fungal pathogens in apples and oranges. CONCLUSIONS: NaCl treatments are very appropriate for improving P. agglomerans low aw tolerance obtaining high production levels and maintaining biocontrol efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: Improving stress tolerance of biocontrol agents could be an efficient way to obtain consistency and maintain efficacy of biological control under practical conditions.