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Métodos Terapéuticos y Terapias MTCI
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J Appl Microbiol ; 112(5): 1020-33, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22372962


AIMS: The objectives of this study were to evaluate the antistaphylococcal effect and elucidate the mechanism of action of orange essential oil against antibiotic-resistant Staphylococcus aureus strains. METHODS AND RESULTS: The inhibitory effect of commercial orange essential oil (EO) against six Staph. aureus strains was tested using disc diffusion and agar dilution methods. The mechanism of EO action on MRSA was analysed by transcriptional profiling. Morphological changes of EO-treated Staph. aureus were examined using transmission electron microscopy. Results showed that 0·1% of terpeneless cold-pressed Valencia orange oil (CPV) induced the cell wall stress stimulon consistent with the inhibition of cell wall synthesis. Transmission electron microscopic observation revealed cell lysis and suggested a cell wall lysis-related mechanism of CPV. CONCLUSIONS: CPV inhibits the growth of Staph. aureus, causes gene expression changes consistent with the inhibition of cell wall synthesis, and triggers cell lysis. SIGNIFICANCE AND IMPACT OF THE STUDY: Multiple antibiotics resistance is becoming a serious problem in the management of Staph. aureus infections. In this study, the altered expression of cell wall-associated genes and subsequent cell lysis in MRSA caused by CPV suggest that it may be a potential antimicrobial agent to control antibiotic-resistant Staph. aureus.

Citrus sinensis/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Antibacterianos/farmacología , Pared Celular/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/citología
J Food Sci ; 74(6): M237-41, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19723207


Listeria monocytogenes (Lm) is a food safety concern that can be associated with ready-to-eat (RTE) meat and poultry products because of its persistence in the processing environment. Listeriosis has a fatality rate of 28% in immuno-compromised individuals. RTE meats receive a lethal heat treatment but may become contaminated by Lm after this treatment. Federal regulators and manufacturers of RTE meats are working to find additional ways to control postprocess contamination by Lm in RTE meats. This research was initiated to validate combinations of antimicrobials that would produce an immediate lethality of at least 1 log of Lm on artificially contaminated frankfurters, and also suppress Lm growth to less than 2 logs throughout the extended shelf life at refrigerated temperatures (4 degrees C). Based on our studies, 22-ppm lauric arginate (LAE, ethyl-N-dodecanoyl-L-arginate hydrochloride) gave more than a 1-log reduction of Lm surface inoculated onto frankfurters within 12 h. The combination of either 1.8%/0.13% or 2.1%/0.15% potassium lactate/sodium diacetate (L/D) in combination with 22 ppm LAE caused more than a 2-log reduction at 12 h. Storage studies revealed that complementary interactions of L/D and LAE also met the 2nd requirement. This combination initially reduced Lm by 2 logs and suppressed growth to less than 2 logs even at the end of the 156-d storage life for frankfurters. These results confirmed that the combination of L/D with LAE as a postprocessing-prepackaging application could be useful in complying with the USDA's Alternative 1 that requires validation for the control of Lm on RTE frankfurters.

Ácido Acético/metabolismo , Antibacterianos/metabolismo , Arginina/metabolismo , Microbiología de Alimentos , Ácido Láctico/metabolismo , Ácidos Láuricos/metabolismo , Listeria monocytogenes/crecimiento & desarrollo , Productos de la Carne/microbiología , Acetato de Sodio/metabolismo , Ácido Acético/administración & dosificación , Animales , Antibacterianos/administración & dosificación , Arginina/administración & dosificación , Recuento de Colonia Microbiana , Aditivos Alimentarios/metabolismo , Contaminación de Alimentos/legislación & jurisprudencia , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/métodos , Microbiología de Alimentos/legislación & jurisprudencia , Humanos , Ácidos Láuricos/administración & dosificación , Listeriosis/prevención & control , Sensación , Acetato de Sodio/administración & dosificación , Factores de Tiempo
J Food Sci ; 74(2): M67-72, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19323760


The objectives of this study were to screen activity of citrus essential oil fractions (EOs) alone and in combination with organic acids against 2 species of Listeria. Five citrus EOs were initially screened by disc diffusion assay for antibacterial activity. Cold pressed terpeneless Valencia orange oil (CP terpeneless oil) had the strongest bacteriostatic (MIC) and bactericidal (MBC) properties at 0.55% and 1.67%, respectively. Four organic acids were tested for effectiveness against Listeria. Citric and malic acids proved to be the most effective with MBC of 1.1% alone. Assays were conducted to determine synergistic effects of EOs and citric or malic acids. There was a significant decrease in MIC and MBC to 0.04% EO plus 0.12% malic or citric acid. EOs from citrus paired with organic acids offer the potential as an all-natural antimicrobial for improving the safety of all-natural foods.

Ácidos Carboxílicos/aislamiento & purificación , Citrus/microbiología , Listeria monocytogenes/aislamiento & purificación , Listeriosis/prevención & control , Aceites de Plantas/química , Aceites de Plantas/normas , Colorimetría , Manipulación de Alimentos/normas , Humanos , Listeria monocytogenes/crecimiento & desarrollo , Terpenos/análisis
J Environ Sci Health B ; 44(6): 571-7, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20183064


A total of 10 ciprofloxacin-sensitive (ciprofloxacin minimum inhibitory concentration, MIC < 0.5 micro g/ml) and 10 ciprofloxacin-resistant (MIC 16 to 32 micro g/ml) presumptive C. jejuni were further characterized and evaluated for their inhibition by natural orange oil fractions. Partial species identification was performed by using a hippuricase gene-based polymerase chain reaction (PCR) assay. One of the isolates appeared to be atypical and failed to hydrolyze hippurate. Of the ciprofloxacin-resistant C. jejuni isolates tested, six were found to have their quinolone resistance determined by a C --> T mutation in codon 86 of gyrA. Both groups of ciprofloxacin-sensitive and -resistant C. jejuni isolates were most susceptible to cold-pressed terpeneless Valencia orange oil (C4) which yielded inhibition zones from 44.0 +/- 1.4 to 80 +/- 0.0 mm. Less inhibitory responses were recorded for 5-fold concentrated Valencia orange oil (C3) and distilled d-limonene (C7) which exerted similar effects on both ciprofloxacin-sensitive and -resistant C. jejuni isolates. In general, ciprofloxacin-resistant and -sensitive C. jejuni isolates were equally susceptible to the respective orange oil fractions.

Antiinfecciosos/farmacología , Campylobacter jejuni/efectos de los fármacos , Ciprofloxacina/farmacología , Farmacorresistencia Bacteriana , Aceites de Plantas/farmacología , Animales , Campylobacter jejuni/genética , Campylobacter jejuni/metabolismo , Cromatografía de Gases , Ciclohexenos/farmacología , Limoneno , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Aceites de Plantas/química , Reacción en Cadena de la Polimerasa , Quinolonas/farmacología , Terpenos/farmacología
Ann Intern Med ; 97(4): 584-98, 1982 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6812475


Recent advances in the diagnosis of epilepsy include the development of a clinically useful classification of epileptic seizures and the recognition of specific epileptic disorders. These advances have been aided by the advent of x-ray computed tomography, long-term electroencephalographic telemetry, and video monitoring. Techniques for functional imaging of the human brain promise even greater diagnostic capabilities. New antiepileptic drugs have improved medical management, and technical and theoretical advances in pharmacokinetics have permitted physicians to design balanced dosing for individual patients. Although currently underused, surgical treatment of partial complex epilepsy can be safe and effective when used appropriately. Operant conditioning of electroencephalography may become another practical alternative therapy. Contributions of basic research to understanding the complications of status epilepticus have influenced treatment protocols and greatly improved the prognosis of this potentially lethal condition.

Epilepsia/diagnóstico , Epilepsia/terapia , Anticonvulsivantes/uso terapéutico , Biorretroalimentación Psicológica , Carbamazepina/uso terapéutico , Clonazepam/uso terapéutico , Clorazepato Dipotásico/uso terapéutico , Condicionamiento Operante , Interacciones Farmacológicas , Electroencefalografía , Humanos , Estado Epiléptico/diagnóstico , Estado Epiléptico/terapia , Telemetría , Televisión , Lóbulo Temporal/cirugía , Tomografía Computarizada por Rayos X , Ácido Valproico/uso terapéutico