RESUMEN
Three new heterometallic metal-organic frameworks, namely, {(Ph4P)2[MnCu3(Hmesox)3Br(H2O)]·H2O}n (1), {(Ph4P)2[CoCu3(Hmesox)3Br]}n (2) and {(Ph4P)2[ZnCu3(Hmesox)3Br]·2.5H2O}n (3) were prepared and their structure and magnetic properties were investigated (H4mesox = mesoxalic acid, Ph4P+ = tetraphenylphosphonium). The structure of all the compounds consist of two interpenetrating opposite-chirality supramolecular cationic and polymeric anionic 3-D (10,3)-a networks, which results in chiral compounds. The anionic network is formed from the polymerization of [Cu3(Hmesox)3Br]4- units, working as three connectors, and M(ii) cations, working as three-connecting nodes, M = Mn(ii), Co(ii) and Zn(ii). The Ph4P+ cations build the cationic chiral supramolecular network opposite to the anionic one. Compounds 1 and 2 exhibit long-range magnetic ordering with critical temperatures of 7.2 K and 6.9 K, respectively. However, compound 3 does not display long-range order, but shows ferromagnetic and antiferromagnetic coupling among the Cu(ii) ions. The magnetic interactions are studied by DFT calculations and compared with related Cu(ii)-mesoxalate compounds previously reported.
RESUMEN
CASOS CLÍNICOS: Varón de 4 años y mujer de 25 años, con agudeza visual de 1, que presentaban una lesión macular unilateral, temporal a la fóvea, hipopigmentada, en forma de torpedo. La tomografía óptica de coherencia mostraba atenuación de la señal del epitelio pigmentario (EPR), y en la mujer un desprendimiento neurosensorial, atrofia del EPR y adelgazamiento de las capas retinianas. La lesión era hipoautofluorescente e hiperfluorescente con la angiografía fluoresceínica. DISCUSIÓN: La maculopatía en torpedo es una lesión asintomática característica, a considerar en el diagnóstico diferencial de las lesiones maculares en niños o pacientes jóvenes
CASE REPORTS: The cases concern a 4 year-old boy and 25 year-old female with 20/20 visual acuity, who presented with a unilateral non-pigmented macular lesion, temporal to the fovea, a torpedo shaped defect in the retinal pigment epithelium (RPE). Optical coherence tomography showed attenuation of the RPE signal, and in the second patient there proved to be a neurosensory detachment, RPE atrophy, and thinning of the retinal layers. The lesion was hypoautofluorescent and hyperfluorescent on fluorescein angiography. DISCUSSION: Torpedo maculopathy is an asymptomatic characteristic lesion which should be considered in the differential diagnosis of macular lesions in children and young patients
Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Adulto , Enfermedades de la Retina/diagnóstico , Tomografía de Coherencia Óptica , Diagnóstico Diferencial , Epitelio Pigmentado de la Retina/fisiopatologíaRESUMEN
CASE REPORTS: The cases concern a 4 year-old boy and 25 year-old female with 20/20 visual acuity, who presented with a unilateral non-pigmented macular lesion, temporal to the fovea, a torpedo shaped defect in the retinal pigment epithelium (RPE). Optical coherence tomography showed attenuation of the RPE signal, and in the second patient there proved to be a neurosensory detachment, RPE atrophy, and thinning of the retinal layers. The lesion was hypoautofluorescent and hyperfluorescent on fluorescein angiography. DISCUSSION: Torpedo maculopathy is an asymptomatic characteristic lesion which should be considered in the differential diagnosis of macular lesions in children and young patients.
Asunto(s)
Degeneración Macular/patología , Desprendimiento de Retina/patología , Epitelio Pigmentado de la Retina/patología , Adulto , Enfermedades Asintomáticas , Atrofia , Preescolar , Diagnóstico Diferencial , Femenino , Angiografía con Fluoresceína , Humanos , Degeneración Macular/diagnóstico por imagen , Masculino , Imagen Óptica , Desprendimiento de Retina/diagnóstico por imagen , Epitelio Pigmentado de la Retina/diagnóstico por imagen , Tomografía de Coherencia ÓpticaRESUMEN
BACKGROUND: Transient, unilateral mydriasis has been reported in migraine patients, and this has been regarded as a possible co-morbidity between migraine and Adie's tonic pupil. Mydriasis that outlasts the duration of migraine attacks is rare. METHODS: Through an eight-year period we have studied all patients referred to our neurological clinic because of migraine attack with mydriasis. All the patients underwent thorough neurologic and ophthalmologic examinations including MRI of the brain and testing of the pupil response to ocular instillation of dilute pilocarpine (0.125%). RESULTS: Seven women and two men, with a mean age of 33.8 ± 12.3 years (range: 19-52) were included. The patients presented during one hemicranial migraine attack with an ipsilateral mydriasis that persisted for a mean of three months, while migraine headaches remained with their typical episodic course. In all the patients a cholinergic supersensitivity in the symptomatic pupil was demonstrated, thus pointing to a dysfunction of the ipsilateral ganglionic parasympathetic fibers. CONCLUSIONS: Synchronous co-localization of the features suggests a pathogenic link between the pupil dysfunction and migraine, rather than a simultaneous coexistence of two independent disorders. Likely explanations include a latent Adie's pupil that could have been triggered during a particular migraine attack; a ciliar ganglionic lesion/dysfunction produced by the migrainous process; an ophthalmoplegic migraine with selective parasympathycoparesis; or an episodic ciliar ganglionitis with migrainous features. Ciliary ganglioplegic migraine is proposed as a nominal term pointing to the possible anatomic source of the migrainous-related pupil dysfunction; the pathogenesis remains unknown.
Asunto(s)
Trastornos Migrañosos/complicaciones , Midriasis/complicaciones , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos Migrañosos/fisiopatología , Midriasis/fisiopatología , Adulto JovenRESUMEN
PURPOSE: A guidelines for the management of retinal vein occlusion is presented. This is necessary because at this moment several therapeutic alternatives have been developed although their role is not yet sufficiently defined. METHODS: Review of the literature for evidence published up to date. Relevant literature was identified and the level of evidence graded. Evidence was then assessed for consistency, applicability and clinical impact. The information was contrasted with those guides published in other countries. RESULTS: Taking into account the different options of treatment that are currently used, several modes of action are suggested. The role of the various complementary examinations are discussed and it is recommended that criteria for the treatment are based on clinical, angiographic, and tomographic findings. CONCLUSIONS: Although there is no overall consensus, these guidelines promote a good standard of clinical practise and provide an update of the management of retinal vein occlusion.
Asunto(s)
Oclusión de la Vena Retiniana/terapia , Corticoesteroides/uso terapéutico , Anciano , Anciano de 80 o más Años , Algoritmos , Inhibidores de la Angiogénesis/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Bevacizumab , Enfermedades Cardiovasculares/complicaciones , Retinopatía Diabética/diagnóstico , Retinopatía Diabética/terapia , Medicina Basada en la Evidencia , Angiografía con Fluoresceína , Glaucoma de Ángulo Abierto/complicaciones , Fármacos Hematológicos/uso terapéutico , Humanos , Coagulación con Láser , Fotocoagulación , Edema Macular/complicaciones , Edema Macular/cirugía , Edema Macular/terapia , Persona de Mediana Edad , Oclusión de la Vena Retiniana/diagnóstico , Oclusión de la Vena Retiniana/tratamiento farmacológico , Oclusión de la Vena Retiniana/etiología , Oclusión de la Vena Retiniana/fisiopatología , Oclusión de la Vena Retiniana/cirugía , Factores de Riesgo , Trombofilia/complicaciones , Tomografía de Coherencia ÓpticaRESUMEN
Propósito: Se presenta una guía de manejo de las oclusiones venosas retinianas. Esto se hace necesario en un momento en el que han aparecido varias alternativas terapéuticas cuyo papel aún no está completamente definido.MétodosSe revisa la literatura publicada hasta el momento identificando los artículos más relevantes, clasificándolos en base al nivel de evidencia.ResultadosTeniendo en cuenta las distintas opciones de tratamiento que existen en la actualidad, se sugieren varias líneas de actuación. Se discute el papel de las exploraciones complementarias y se recomiendan pautas de tratamiento en base a los hallazgos clínicos, angiográficos y tomográficos.Conclusionesaunque no existe un consenso total, esta guía promueve un estándar de buena práctica clínica y proporciona una actualización del manejo de las oclusiones venosas retinianas (AU)
Purpose: A guidelines for the management of retinal vein occlusion is presented. This is necessary because at this moment several therapeutic alternatives have been developed although their role is not yet sufficiently defined.MethodsReview of the literature for evidence published up to date. Relevant literature was identified and the level of evidence graded. Evidence was then assessed for consistency, applicability and clinical impact. The information was contrasted with those guides published in other countries.ResultsTaking into account the different options of treatment that are currently used, several modes of action are suggested. The role of the various complementary examinations are discussed and it is recommended that criteria for the treatment are based on clinical, angiographic, and tomographic findings.ConclusionsAlthough there is no overall consensus, these guidelines promote a good standard of clinical practise and provide an update of the management of retinal vein occlusion(AU)
Asunto(s)
Humanos , Oclusión de la Vena Retiniana/diagnóstico , Oclusión de la Vena Retiniana/patología , Oclusión de la Vena Retiniana/terapia , Retina/anatomía & histología , Retina/patología , Retina/fisiopatología , Edema Macular/complicaciones , Edema Macular/patología , Edema Macular/terapia , Fotocoagulación/instrumentación , Fotocoagulación/métodos , Fotocoagulación , Angiografía/métodos , Angiografía , Tomografía de Coherencia Óptica/instrumentación , Tomografía de Coherencia Óptica/métodosRESUMEN
En el presente trabajo se estudiaron los cambios que provocó el lavado de cinco suelos afectados por sales sobre la actividad biológica (número de bacterias g-1y producción de CO2) y enzimática (catalasa, deshidrogenasa, ureasa y fosfotriesterasa) de los mismos. El lavado disminuyó la conductividad eléctrica (CE) y modificó el tipo de sales dominantes en los suelos. La producción de CO2 y la actividad de la fosfotriesterasa fue significativamente mayor (p<0,05) en un suelo lavado (Torrifluventes Típicos Centenario); el incremento fue del 88% y 71%, respectivamente. Los resultados demostraron que la disminución de la salinidad por lavado no ocasionó comportamientos significativamente diferentes, en la mayoría de los parámetros bióticos estudiados, bajo las condiciones en que se realizó este estudio.
Changes in the biological activity (number of bacteria g-1and CO2 production) and in the enzymatic activity (catalase, deshidrogenase, urease and phosphotriesterase) caused by the leaching of five soils affected by salts have been studied. The leaching decreased the electric conductivity (CE) and modified the type of dominant salts in the soils. Production of CO2and the activity of the phosphotriesterase was significantly higher (p<0,05) in a leached soil (Torrifluventes Typical Centennial); the increment were 88% and 71%, respectively. The results showed that the decrease of the salinity by leaching did not produce significantly different results in most of the biotic parameters analised.
Asunto(s)
Bacterias Aerobias/aislamiento & purificación , Proteínas Bacterianas/análisis , Microbiología del Suelo , Sales (Química)/análisis , Suelo/análisis , Argentina , Bacterias Aerobias/enzimología , Calcio/análisis , Dióxido de Carbono/análisis , Catalasa/análisis , Cloruros/análisis , Oxidorreductasas/análisis , Hidrolasas de Triéster Fosfórico/análisis , Sodio/análisis , Sulfatos/análisis , Ureasa/análisisRESUMEN
Cognitive impairment, depression and delirium are problems of high prevalence in older patients. The geriatric convalescence unit (GCU) is a hospitalization facility offering an interdisciplinary geriatric intervention program that may be more appropriate for these patients. This study intended to analyze the functional improvement (FI) in older patients with cognitive impairment, depression and/or delirium admitted to a GCU. A group of 107 patients received specific nurse care, habitually performed in GCU and they also were included in a rehabilitation program. Cognitive impairment, depression and delirium were diagnosed according to standardized protocols. The analyzed variables were: age, functional status (Barthel index) before admission (BBA), at admission (BA) and at discharge(BD), diagnostic categories, cognitive function (mini mental state examination: MMSE) and post-discharge destination. The corrected Heinemann index (CHI) was used to evaluate FI obtained during GCU-stay, where CHI = 100 x (BD-BA)/(BBA-BA), and the efficiency index(El) was used to analyze the relationship between FI and the length of stay in the GCU,where El = (BD-BA)/(days in GCU). According to CHI, patients were divided in three groups. Group I: CHI = 0 or negative (patients who lost functional capacity during hospitalization,those who died or were transferred to hospital owing to acute deterioration. Group II: CHI < 35 % (high FI). Mean age was 77.6 +/- 9.1 years, the diagnostic categories were: fractures/orthopedics 49 (45.7 %), neurological 27(25.2 %), pulmonary/cardiologic 6 (5.6 %) and other cases 25 (23.3 %). Mean MMSE and BA scores were 16.9 +/- 9.4 and 29.6 +/- 18.9, respectively. Post-discharge destinations were:63 patients (58.8 %) returned home, 28 (26.1 %) were definitively institutionalized, 11 (10.2%) died and finally 5 (4.6 %) were transferred to acute care hospital. In-Group I, there were 35 patients (32.7 %) with a mean value of the El = 0.12 +/-1.1; in Group II, 13 (12.1 %) and 0.26 +/- 0.38; in Group III, 59 (55.1 %) and 0.94 +/- 0.97, respectively. In spite of the presence of cognitive impairment, depression and/or delirium, a high proportion of patients (67.2 %)obtained a significant improvement in their functional capacity.35 % (moderate FI). Group III: CHI >/=
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Trastornos del Conocimiento/rehabilitación , Convalecencia , Delirio/rehabilitación , Depresión/rehabilitación , Anciano , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/epidemiología , Comorbilidad , Delirio/epidemiología , Depresión/epidemiología , Femenino , Servicios de Salud para Ancianos/estadística & datos numéricos , Estado de Salud , Hospitalización/estadística & datos numéricos , Humanos , Institucionalización/estadística & datos numéricos , Masculino , Pruebas Neuropsicológicas , Evaluación de Resultado en la Atención de Salud , Alta del Paciente/estadística & datos numéricos , Prevalencia , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: The authors have observed a group of patients complaining of periorbital pain, emanating from the trochlear area, in absence of trochleitis or other orbital or systemic disease. All were previously diagnosed and treated as different types of headaches, but pain was not controlled until local treatment on the sore trochlea was performed. The authors have investigated the role of the trochlear area in causing and modulating headache. METHODS: Observational case series. Trochlear pain was defined as pain on this area, exacerbated upon examination and looking in supraduction. Pain was studied after trochlear injections of lidocaine, corticosteroids, and placebo. Secondary orbital pain was ruled out. RESULTS: Seventeen women and one man were evaluated (mean age: 44 years). All presented unilateral pain in the trochlear area (60% reported more extended headache), for more than 1 year in 70%. Neither ocular autonomic signs nor motility restrictions were observed. Imaging examinations were normal in 100%. The temporal pattern was either chronic or remitting, with acute exacerbations. Pain increased at night in 55%. A total of 62% presented concurrent headaches. Locally injected corticosteroids relieved the pain within 48 hours in 95% and also improved concurrent headaches, by decreasing attack frequency and analgesics intake. Placebo was not helpful. Relapses were observed in 45% (average 8 months). CONCLUSIONS: The trochlear region is the origin of a specific and unrecognized headache, which we have named primary trochlear headache. Local treatment on the trochlear area is also useful for other concurrent primary headaches with inadequate response to oral therapy.
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Cefalea/diagnóstico , Enfermedades Orbitales/diagnóstico , Enfermedades del Nervio Trigémino/diagnóstico , Corticoesteroides/uso terapéutico , Adulto , Anciano , Anestésicos Locales/uso terapéutico , Técnicas de Diagnóstico Neurológico , Femenino , Cefalea/complicaciones , Cefalea/tratamiento farmacológico , Humanos , Lidocaína/uso terapéutico , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Enfermedades Orbitales/complicaciones , Enfermedades Orbitales/tratamiento farmacológico , Estudios Prospectivos , Recurrencia , Remisión Espontánea , Terminología como Asunto , Resultado del Tratamiento , Enfermedades del Nervio Trigémino/complicaciones , Enfermedades del Nervio Trigémino/tratamiento farmacológicoRESUMEN
Changes in intraocular pressure (IOP) elicited by a Valsalva manoeuvre were studied in 11 male patients (mean age 39.8 years) suffering from episodic cluster headache (CH), and 12 healthy male controls (mean age 39.9 years). The tests were performed at rest and while exhaling hard through a mouthpiece connected to a mercury manometer. In the CH group, during symptomatic periods, between attacks, Valsalva manoeuvre elicited an asymmetric increase in IOP with significantly higher values on the symptomatic side (P = 0011), whereas no asymmetric increments in IOP were found during asymptomatic periods. Outside the cluster period the IOP values both baseline and with Valsalva manoeuvre did not differ from controls. The increment in IOP took place within a few seconds, as in spontaneous CH attacks, thus pointing to a rapid increase in intraocular blood volume or vasodilatation. These findings may reflect a latent increased vascular reactivity of the symptomatic orbit during CH period.
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Cefalalgia Histamínica/fisiopatología , Presión Intraocular/fisiología , Maniobra de Valsalva/fisiología , Adulto , Humanos , Masculino , Persona de Mediana Edad , Estadísticas no ParamétricasRESUMEN
Changes in the biological activity (number of bacteria g(-1) and CO2 production) and in the enzymatic activity (catalase, deshydrogenase, urease and phosphotriesterase) caused by the leaching of five soils affected by salts have been studied. The leaching decreased the electric conductivity (CE) and modified the type of dominant salts in the soils. Production of CO2 and the activity of the phosphotriesterase was significantly higher (p<0.05) in a leached soil (Torrifluventes Typical Centennial); the increment were 88% and 71%, respectively. The results showed that the decrease of the salinity by leaching did not produce significantly different results in most of the biotic parameters analysed.
Asunto(s)
Bacterias Aerobias/aislamiento & purificación , Proteínas Bacterianas/análisis , Sales (Química)/análisis , Microbiología del Suelo , Suelo/análisis , Argentina , Bacterias Aerobias/enzimología , Calcio/análisis , Dióxido de Carbono/análisis , Catalasa/análisis , Cloruros/análisis , Oxidorreductasas/análisis , Hidrolasas de Triéster Fosfórico/análisis , Sodio/análisis , Sulfatos/análisis , Ureasa/análisisRESUMEN
Changes in the biological activity (number of bacteria g(-1) and CO2 production) and in the enzymatic activity (catalase, deshydrogenase, urease and phosphotriesterase) caused by the leaching of five soils affected by salts have been studied. The leaching decreased the electric conductivity (CE) and modified the type of dominant salts in the soils. Production of CO2 and the activity of the phosphotriesterase was significantly higher (p<0.05) in a leached soil (Torrifluventes Typical Centennial); the increment were 88
and 71
, respectively. The results showed that the decrease of the salinity by leaching did not produce significantly different results in most of the biotic parameters analysed.
RESUMEN
BACKGROUND: We studied the incidence and clinical characteristics of persistent diplopia related to anaesthesia for cataract surgery in a general hospital. METHODS: This was a retrospective review of anaesthesia for 3587 cataract surgeries. Of all the cases of diplopia referred to the ocular motility clinic after cataract surgery, those involving anaesthesia-related diplopia lasting longer than 1 month were studied. RESULTS: During the study period, 3450 cataract surgeries were performed by phacoemulsification and 137 by extracapsular extraction. Retrobulbar block was used in 2024 cases, peribulbar block in 98, topical anaesthesia in 1420 and general anaesthesia in 43. Twenty-six cases of persistent diplopia were found (0.72% incidence), nine of which (0.25%) were considered to be related to anaesthetic factors; five of the latter involved the left eye. Five were caused by paresis of the inferior rectus muscle and three by fibrosis. In one patient, the inferior oblique muscle was affected. Anaesthesia was by retrobulbar block in eight cases (0.39%) and by peribulbar block in one. No diplopia was found in patients who had topical or general anaesthesia. Treatment was with surgery in two patients and with prisms in six. One patient continues to be studied. CONCLUSIONS: Persistent diplopia can occur after cataract surgery using retrobulbar block predominantly through direct damage to the inferior rectus muscle. The overall incidence of anaesthesia-related diplopia in this series was 0.25%.
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Anestesia Local/efectos adversos , Extracción de Catarata , Diplopía/inducido químicamente , Bloqueo Nervioso/efectos adversos , Anciano , Anciano de 80 o más Años , Anestesia de Conducción/efectos adversos , Anestesia de Conducción/métodos , Anestesia Local/métodos , Diplopía/cirugía , Movimientos Oculares , Femenino , Humanos , Implantación de Lentes Intraoculares/efectos adversos , Masculino , Bloqueo Nervioso/métodos , Facoemulsificación/efectos adversos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
A total of 26 episodes of V-1 trigeminal neuralgia attacks have been recorded in two female patients. Autonomic phenomena were assessed according to a semiquantitative scale. Attacks lasted 17 +/- 5 s. Mild lacrimation without conjunctival hyperaemia, rhinorrhea or ptosis was observed, even in relatively long lasting episodes. This is in clear contradiction with SUNCT (shortlasting, unilateral, neuralgiform headache with conjunctival injection, tearing and rhinorrhea) attacks that are always dramatically accompanied by both lacrimation and conjunctival injection of the symptomatic side from the very onset of symptoms. Carbamazepine provided complete and sustained relief of symptoms in both patients. Herein we will show differential autonomic features of V-1 trigeminal neuralgia vs. SUNCT that will both aid the clinician to distinguish both syndromes and stress that both entities are nosologicaly different.
Asunto(s)
Nervio Oftálmico/fisiopatología , Lágrimas/metabolismo , Neuralgia del Trigémino/fisiopatología , Anciano , Blefaroptosis/etiología , Carbamazepina/uso terapéutico , Conjuntiva/patología , Diagnóstico Diferencial , Femenino , Cefalea/complicaciones , Cefalea/diagnóstico , Humanos , Hiperemia/etiología , Persona de Mediana Edad , Mucosa Nasal/metabolismo , Presión/efectos adversos , Recurrencia , Neuralgia del Trigémino/complicaciones , Neuralgia del Trigémino/diagnóstico , Neuralgia del Trigémino/tratamiento farmacológico , Neuralgia del Trigémino/etiologíaRESUMEN
A survey of the changes in populations of heterotrophic bacteria, coliform microorganisms and S. meliloti was conducted in samples taken from the water irrigation channels of the Neuquén River (Argentina). Fifty-six water samples were collected during the spring-summer seasons of 1997-1999 years. Both the heterotrophic plate count bacterial and the number of coliforms oscillated between 110-5050 CFU/ml and 8-1400 CFU/100 ml, respectively, during the period this study was carried out. Fecal coliforms were detected in 91.1% of the water samples investigated. Moreover, the results showed that S. meliloti capable of nodulating alfalfa (Medicago sativa L.) Cuf 101 were present in 68% of the water samples and in effectiveness studies, no isolate out of 25 evaluated could be classified as superior N fixers. That is, they did not produce plants equal in weight to nitrate-grown plants (KNO3 0.05%). All the S. meliloti strains were resistant to novobiocin and bacitracin, while 72% of the microsymbionts demonstrated resistance to between seven and ten antibiotics. Results presented in this study showed that irrigation waters of the Neuquén river could act as dispersal agents of both ineffective S. meliloti strains and thermotolerant coliform bacteria.
Asunto(s)
Enterobacteriaceae/aislamiento & purificación , Sinorhizobium meliloti/aislamiento & purificación , Microbiología del Agua , Contaminación del Agua/análisis , Argentina , Bacitracina/farmacología , Farmacorresistencia Microbiana , Resistencia a Múltiples Medicamentos , Calor , Medicago sativa/microbiología , Fijación del Nitrógeno , Novobiocina/farmacología , Estaciones del Año , Sinorhizobium meliloti/efectos de los fármacos , Sinorhizobium meliloti/fisiologíaRESUMEN
A survey of the changes in populations of heterotrophic bacteria, coliform microorganisms and S. meliloti was conducted in samples taken from the water irrigation channels of the NeuquÚn River (Argentina). Fifty-six water samples were collected during the spring-summer seasons of 1997-1999 years. Both the heterotrophic plate count bacterial and the number of coliforms oscillated between 110-5050 CFU/ml and 8-1400 CFU/100 ml, respectively, during the period this study was carried out. Fecal coliforms were detected in 91.1 of the water samples investigated. Moreover, the results showed that S. meliloti capable of nodulating alfalfa (Medicago sativa L.) Cuf 101 were present in 68 of the water samples and in effectiveness studies, no isolate out of 25 evaluated could be classified as superior N fixers. That is, they did not produce plants equal in weight to nitrate-grown plants (KNO3 0.05). All the S. meliloti strains were resistant to novobiocin and bacitracin, while 72 of the microsymbionts demonstrated resistance to between seven and ten antibiotics. Results presented in this study showed that irrigation waters of the NeuquÚn river could act as dispersal agents of both ineffective S. meliloti strains and thermotolerant coliform bacteria.
Asunto(s)
Enterobacteriaceae , Contaminación del Agua/análisis , Sinorhizobium meliloti , Microbiología del Agua , Argentina , Bacitracina , Calor , Medicago sativa , Fijación del Nitrógeno , Novobiocina , Resistencia a Múltiples Medicamentos , Farmacorresistencia Microbiana , Estaciones del Año , Sinorhizobium melilotiRESUMEN
A survey of the changes in populations of heterotrophic bacteria, coliform microorganisms and S. meliloti was conducted in samples taken from the water irrigation channels of the NeuquUn River (Argentina). Fifty-six water samples were collected during the spring-summer seasons of 1997-1999 years. Both the heterotrophic plate count bacterial and the number of coliforms oscillated between 110-5050 CFU/ml and 8-1400 CFU/100 ml, respectively, during the period this study was carried out. Fecal coliforms were detected in 91.1 of the water samples investigated. Moreover, the results showed that S. meliloti capable of nodulating alfalfa (Medicago sativa L.) Cuf 101 were present in 68 of the water samples and in effectiveness studies, no isolate out of 25 evaluated could be classified as superior N fixers. That is, they did not produce plants equal in weight to nitrate-grown plants (KNO3 0.05). All the S. meliloti strains were resistant to novobiocin and bacitracin, while 72 of the microsymbionts demonstrated resistance to between seven and ten antibiotics. Results presented in this study showed that irrigation waters of the NeuquUn river could act as dispersal agents of both ineffective S. meliloti strains and thermotolerant coliform bacteria.(AU)
Asunto(s)
RESEARCH SUPPORT, NON-U.S. GOVT , Enterobacteriaceae/aislamiento & purificación , Sinorhizobium meliloti/aislamiento & purificación , Microbiología del Agua , Contaminación del Agua/análisis , Argentina , Bacitracina/farmacología , Farmacorresistencia Microbiana , Resistencia a Múltiples Medicamentos , Calor , Medicago sativa/microbiología , Fijación del Nitrógeno , Novobiocina/farmacología , Estaciones del Año , Sinorhizobium meliloti/efectos de los fármacos , Sinorhizobium meliloti/fisiologíaRESUMEN
A survey of the changes in populations of heterotrophic bacteria, coliform microorganisms and S. meliloti was conducted in samples taken from the water irrigation channels of the Neuquén River (Argentina). Fifty-six water samples were collected during the spring-summer seasons of 1997-1999 years. Both the heterotrophic plate count bacterial and the number of coliforms oscillated between 110-5050 CFU/ml and 8-1400 CFU/100 ml, respectively, during the period this study was carried out. Fecal coliforms were detected in 91.1
of the water samples investigated. Moreover, the results showed that S. meliloti capable of nodulating alfalfa (Medicago sativa L.) Cuf 101 were present in 68
of the water samples and in effectiveness studies, no isolate out of 25 evaluated could be classified as superior N fixers. That is, they did not produce plants equal in weight to nitrate-grown plants (KNO3 0.05
). All the S. meliloti strains were resistant to novobiocin and bacitracin, while 72
of the microsymbionts demonstrated resistance to between seven and ten antibiotics. Results presented in this study showed that irrigation waters of the Neuquén river could act as dispersal agents of both ineffective S. meliloti strains and thermotolerant coliform bacteria.