RESUMEN
Clove essential oil, used as an antiseptic in oral infections, inhibits Gram-negative and Gram-positive bacteria as well as yeast. The influence of clove essential oil concentration, temperature and organic matter, in the antimicrobial activity of clove essential oil, was studied in this paper, through the determination of bacterial death kinetics. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were the microorganisms selected for a biological test. To determine the temperature effect, they were assayed at 21° and 37° C. The concentration coefficient was determined with 0.4%, and 0.2% of essential oil. The influence of the presence of organic matter was determined with 0.4% of essential oil. The results obtained demonstrated that Escherichia coli were more sensitive even though the essential oil exerted a satisfactory action in three cases. In the three microbial species, 0.4% of essential oil at 21º C have reduced the bacterial population in 5 logarithmic orders. Organic matter reduces the antibacterial activity even though the bactericide efficacy was not lost. Clove essential oil can be considered as a potential antimicrobial agent for external use.(AU)
Asunto(s)
Aceite de Clavo , Antibacterianos , Antiinfecciosos/química , Escherichia/clasificación , Staphylococcus/clasificaciónRESUMEN
Clove essential oil, used as an antiseptic in oral infections, inhibits Gram-negative and Gram-positive bacteria as well as yeast. The influence of clove essential oil concentration, temperature and organic matter, in the antimicrobial activity of clove essential oil, was studied in this paper, through the determination of bacterial death kinetics. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were the microorganisms selected for a biological test. To determine the temperature effect, they were assayed at 21° and 37° C. The concentration coefficient was determined with 0.4%, and 0.2% of essential oil. The influence of the presence of organic matter was determined with 0.4% of essential oil. The results obtained demonstrated that Escherichia coli were more sensitive even though the essential oil exerted a satisfactory action in three cases. In the three microbial species, 0.4% of essential oil at 21º C have reduced the bacterial population in 5 logarithmic orders. Organic matter reduces the antibacterial activity even though the bactericide efficacy was not lost. Clove essential oil can be considered as a potential antimicrobial agent for external use.
Asunto(s)
Antiinfecciosos Locales/análisis , Antibacterianos/análisis , Antibacterianos/aislamiento & purificación , Bioensayo/métodos , Aceite de Clavo/análisis , Oleum Caryophyllatum/análisis , MétodosRESUMEN
An antimicrobial coating was evaluated in this work for its antimicrobial efficacy against common food-borne pathogens. Dodecyl-di(aminoethyl)-glycine, an organic disinfectant, was immobilized in a silicon oxide matrix to generate thin films over surfaces by means of the sol-gel process. Tetraethoxysilane was used as the polymeric precursor. No alteration of optical transparency on the covered surfaces was observed. Topographic images obtained with atomic force microscopy showed a homogeneous film with no additional roughness added by the polymer to the surface. The attenuated total reflectance-Fourier transform infrared spectral data showed the presence of dodecyl-di(aminoethyl)-glycine in the silicon oxide network after a normal cleaning procedure. The antimicrobial efficacy test was performed by exposing coated slides to suspensions of common food-borne pathogens: Escherichia coli, Staphyloccocus aureus, E. coli O157:H7, Salmonella typhi, S. cholerasuiss, Listeria innocua and L. monocytogenes. The coating activity was not only bacteriostatic but also bactericidal. The percent reduction of viable microorganism exposure over 24 h to the coated surface ranged between 99.5%, for the more resistant gram-positive bacteria, and over 99.999%, for most gram-negative bacteria. The silicon matrix itself did not account for any reduction of viable microbial, even more an increase was observed.
Asunto(s)
Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Desinfectantes/farmacología , Microbiología de Alimentos , Geles/farmacología , Glicina/análogos & derivados , Tensoactivos/farmacología , Antiinfecciosos/química , Recuento de Colonia Microbiana , Desinfectantes/química , Industria de Alimentos/métodos , Geles/química , Glicina/química , Glicina/farmacología , Microscopía de Fuerza Atómica , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Tensoactivos/químicaRESUMEN
The antimicrobial compound dodecyl-di(aminoethyl)-glycine was immobilized in a silicon oxide xerogel matrix and used for glass surface coating. Coated glasses were tested for surface antimicrobial activity. The utilization of tetraethoxysilane (TEOS) as a silicon oxide polymer precursor, using the dip-coating process, allowed for the generation of transparent thin films over glass surfaces. Different concentrations of the antimicrobial compound were used to generate the coatings. The presence of dodecyl-di(aminoethyl)-glycine on coated and uncoated slides was analyzed by FT-IR spectra. Coated glass slides were exposed to suspensions of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus for 24 h. Surface contamination was evaluated by the microbial plate count technique. When antimicrobial-coated glasses were compared with antimicrobial-free coated glasses, the former showed greater than 99% reduction of colony-forming units (cfu) for E. coli and P. aeruginosa, when 1% of antimicrobial was present in the coating solution. The same percentage of reduction for S. aureus was achieved when 1.5% of the antimicrobial was present in the coating solution. In a direct inhibition test on agar plates, no inhibitory zone was observed, indicating that the antimicrobial did not diffuse into the media.
Asunto(s)
Antiinfecciosos/farmacología , Desinfectantes/farmacología , Vidrio/química , Antiinfecciosos/química , Desinfectantes/química , Relación Dosis-Respuesta a Droga , Escherichia coli/efectos de los fármacos , Glicina/análogos & derivados , Glicina/química , Glicina/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Silanos/química , Staphylococcus aureus/efectos de los fármacosRESUMEN
By means of bioluminiscence ATP present in a sample can be quantified. Thus, it would be a method able to evaluate microbiological or organic matter (from vegetal or animal origin) contamination. The present work analyzes the possibility to assess--from the microbiological point of view--the air of pharmaceutical clean rooms by means of bioluminiscence, using the luminomiter HY-LITE 2 [Merck]. It is thought that the use of this methodology versus microbiological classical methods, will allow to obtain results in the working day. Classical methods demand a minimum of 72 hs incubation to read results. But the real conclusion is that with the used technology, it is not possible to evaluate microbiologically the air of pharmaceutical clean rooms.
Asunto(s)
Ambiente Controlado , Monitoreo del Ambiente/métodos , Mediciones Luminiscentes , Bacterias/química , Industria Farmacéutica , Escherichia coli/química , Staphylococcus aureus/químicaRESUMEN
Há muitos anos, tenta-se implantar a fitoterapia no município de Maringá, o que só foi possível em 2000, com a criação de uma comissão específica, definição das plantas segundo critérios epidemiológicos, literatura disponível e adoção do formato de farmácia de manipulação. Foram padronizados os fitoterápicos nas formas de infusão (espinheira-santa, guaco, cavalinha, hortelã e funcho), gel (própolis e calêndula) e em cápsulas gelatinosas duras (valeriana). Encontrou-se problemas com fornecedores, com diversos lotes insatisfatórios quanto à qualidade, mas ao longo do tempo o programa foi muito bem aceito. Nestes três anos de funcionamento, já foram dispensados mais de 50.000 unidades de produtos, com destaque à aceitação e eficácia da valeriana como ansiolitico, dos géis de própolis e calendula como antimicrobiano e cicatrizante, da espinheirasanta em gastrites e úlceras e do guaco como broncodilator e expectorante. Confirma-se, assim, o valor da fitoterapia no apoio às atividades básicas de saúde.
There are many years, it tries to implant the phytotherapy in the municipal district of Maringá. That implantation was only possible in 2000, with the creation of specific commission, definition of the plants according to epidemic criteria and available literature, and adoption of the format of manipulation drugstore. We have standardized the phytotherapics in the infusion forms (espinheira-santa, guaco, cavalinha, mint and fennel), gel (própolis and calendula) and in hard gelatinous capsules (valerian). There were problems with suppliers, with several unsatisfactory lots as for the quality, but along the time the program was very well accepted. On these three years of operation, there were already released more than 50.000 units of products, with prominence to the acceptance and effectiveness of the valerian as ansiolitic, two gels of propolis and calendula as antimicrobial and healing, of the espinheirasanta in gastritis and ulcers and of the guaco as broncodilator and expectorant. It is confirmed, like this, the value of the phytotherapy in the support to the basic activities of health.
RESUMEN
This paper presents a simple method for determining both the presence and concentration of Listeria monocytogenes in dairy products. The method involves application of the Most Probable Number (MPN) technique and enrichment of a 25 g sample. Our tests showed that the MPN correlates with the Colony Forming Units (CFU), and estimated concentrations of as low as 1 bacterium/gr or less. We also studied the influence of Listeria innocua as an accompanying flora. We detected L. monocytogenes, even in the presence of concentrations of 4 times as much L. innocua. Nonetheless, L. monocytogenes could not be detected when the concentration of L. innocua surpassed 90%.
Asunto(s)
Técnicas Bacteriológicas , Productos Lácteos/microbiología , Contaminación de Alimentos , Microbiología de Alimentos , Listeria monocytogenes/aislamiento & purificación , Animales , Bovinos , Medios de Cultivo , Fermentación , Tamizaje Masivo , Leche/microbiologíaRESUMEN
Se estudió la influencia del añadido de crema de leche y leche parcialmente descremada sobre la cinética de crecimiento de Listeria monocytogenes en caldos de enriquecimiento para listerias, conteniendo diferentes concentraciones de acriflavina (15 y 7,5 mg/l). El crecimiento de Listeria monocytogenes en los caldos de enriquecimiento sufrió un retardo atribuible, al menos parcialmente, a la presencia de acriflavina. El añadido de crema de leche o leche parcialmente descremada al caldo de enriquecimiento que contiene 7,5 mg/l de acriflavina produjo un alargamiento de la fase de adaptación, pero las cosechas máximas alcanzadas a las 48 h no mostraron diferencias significativas. En presencia de 15 mg/l de acriflavina, se observó una pérdida inicial de la viabilidad de los cultivos, que fue potenciada por el agregado de crema de leche o leche parcialmente descremada al caldo de enriquecimiento. Además, la leche descremada produjo una disminución de la velocidad máxima de crecimiento que impidió alcanzar la cosecha máxima dentro de las 48 h. Los resultados obtenidos sugieren la necesidad de validar la metodología de recuperación de L. monocytogenes para cada producto, pues la eficiencia de recuperación podría ser afectada por la composición del mismo, sobre todo cuando la carga microbiana es baja
Asunto(s)
Acriflavina/análisis , Productos Lácteos , Listeria monocytogenes/crecimiento & desarrolloRESUMEN
We have studied the influence of the incorporation of milk cream and skim milk on the growth kinetic of Listeria monocytogenes in listeria enrichment broth with 15 mg/l or 7.5 mg/l of acriflavine. Acriflavine was responsible, at least partially, for delayed growth of Listeria monocytogenes in the enrichment broths. A longer lag phase of the growth was produced by the addition of milk cream or skim milk to the enrichment broth containing 7.5 mg/l of acriflavine. However, the maximum population obtained at 48 h did not show significant differences. In the presence of 15 mg/l of acriflavine, we observed a decrease of the viable counts during the early phase of the growth cycle, which was enhanced by the addition of milk cream or skim milk. Moreover, the maximum growth rate was reduced by the addition of skim milk and maximum population was not reached at 48 h. These results suggest the need to validate the methodology of recuperation of Listeria monocytogenes from each dairy product, since its efficiency may be affected by product composition, specially when the sample biocharge is low.
Asunto(s)
Medios de Cultivo/farmacología , Productos Lácteos , Listeria monocytogenes/efectos de los fármacos , Acriflavina/farmacología , Animales , Técnicas Bacteriológicas , Bovinos , Femenino , Listeria monocytogenes/crecimiento & desarrollo , LecheRESUMEN
Ozone and chlorine are agents that disinfect by destroying, neutralizing or inhibiting the growth of pathogenic microorganisms. The treatment of drinking water with ozone has shown to be more efficient against spores of Bacillus subtilis. It was observed that the ozone already in dose of 0.35 mg/l produced the reduction of at least 5 log in populations of approximately 1 x 10(6) cells/ml of Escherichia coli, Vibrio cholerae, Salmonella typhi, Yersinia enterocolitica, Pseudomonas aeruginosa, Aeromonas hydrophila, Listeria monocytogenes and Staphylococcus aureus. With a dose of 0.50 mg/l of chlorine, the reduction was much smaller for the tested microorganisms (except Vibrio cholerae), while the effect of 2 mg/l of chlorine was similar to the ozone treatment. For spores of Bacillus subtilis, the reduction observed with ozone concentrations of 0.35 and 0.70 mg/l was of almost 3 log, while no considerable effect was obtained with chlorine in the tested conditions. Our results have shown that both disinfectans were consumed during the treatment period, probably because of the own water demand and the added bacterial mass.
Asunto(s)
Bacterias/efectos de los fármacos , Desinfectantes/farmacología , Ozono/farmacología , Hipoclorito de Sodio/farmacología , Microbiología del Agua , Enterobacteriaceae/efectos de los fármacos , Listeria monocytogenes/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Tiosulfatos/farmacología , Vibrionaceae/efectos de los fármacosRESUMEN
Ozone and chlorine are agents that disinfect by destroying, neutralizing or inhibiting the growth of pathogenic microorganisms. The treatment of drinking water with ozone has shown to be more efficient against spores of Bacillus subtilis. It was observed that the ozone already in dose of 0.35 mg/l produced the reduction of at least 5 log in populations of approximately 1 x 10(6) cells/ml of Escherichia coli, Vibrio cholerae, Salmonella typhi, Yersinia enterocolitica, Pseudomonas aeruginosa, Aeromonas hydrophila, Listeria monocytogenes and Staphylococcus aureus. With a dose of 0.50 mg/l of chlorine, the reduction was much smaller for the tested microorganisms (except Vibrio cholerae), while the effect of 2 mg/l of chlorine was similar to the ozone treatment. For spores of Bacillus subtilis, the reduction observed with ozone concentrations of 0.35 and 0.70 mg/l was of almost 3 log, while no considerable effect was obtained with chlorine in the tested conditions. Our results have shown that both disinfectans were consumed during the treatment period, probably because of the own water demand and the added bacterial mass.
RESUMEN
The natural biocidal activity of lemon juice was studied in order to explore its possible use as a disinfectant and inhibitor of Vibrio cholerae in drinking water for areas lacking water treatment plants. From January through July 1993, water samples of varying alkalinity and hardness were prepared artificially, and underground and surface water samples were obtained from a number of different rural and urban areas in Argentina's Buenos Aires Province. After measuring the latter samples' hardness and alkalinity, a range of concentrations of lemon juice and other acidifiers were added to each sample, and the resulting pH as well as the samples' ability to destroy V. cholerae were determined. The results show that lemon juice can actively prevent survival of V. cholerae but that such activity is reduced in markedly alkaline water. For example, treatment of underground drinking water, which is characterized as having the greatest degree of alkalinity in our area, will typically destroy V. cholerae if the alkalinity of the water is the equivalent of that produced by 200 mg CaCO3 per liter, if enough lemon juice is added to bring the lemon juice concentration to 2%, and if the lemon juice is allowed to act for 30 minutes. All this points up the need to determine the alkalinity of water from any local source to be treated in the process of assessing the minimum concentration of lemon juice required.
Asunto(s)
Citrus , Vibrio cholerae , Microbiología del Agua , Purificación del Agua , Argentina , Desinfección , Técnicas In VitroRESUMEN
The effects of chlorine at varying pH, culture media and incubation temperatures on one type and two wild type strains of Yersinia enterocolitica were studied. Exposure to 1 and 5 mg 1(-1) did not diminish viability, even after prolonged exposure. A level of 10 mg 1(-1) was required to achieve a 5-log reduction in 120 s for the type strain and 80 s for the wild strains. There was an increase of more than 30% in the rate of disinfection with a 10 degrees C rise, a remarkable increase in antimicrobial activity at pH 5-log reduction in 20 s, as well as marked neutralization of the effect in the presence of 0.1% peptone. Younger cells were more susceptible than older ones, and those from liquid medium more resistant than those from solid medium. Incubation temperature of a 24-h inoculum failed to show any influence. Lastly, there was a noteworthy demand for free chlorine by bacterial biomass, with agreement of the curve depicting the drop in free chlorine in the presence of inoculum with biphasic kinetics of survival curves.
Asunto(s)
Hipoclorito de Sodio/farmacología , Yersinia enterocolitica/efectos de los fármacos , Supervivencia Celular , Concentración de Iones de Hidrógeno , Concentración Osmolar , Peptonas/farmacología , Especificidad de la Especie , Temperatura , Tiosulfatos/farmacología , Yersinia enterocolitica/crecimiento & desarrolloRESUMEN
Heliotropium curassavicum var. argentinum is widely employed in gout, rheumatism, neuralgias, arteriosclerotic disorders, muscular algias, phlebitis, varix and other illnesses. In order to analyze the genotoxic effect produced in vitro by this medicinal plant, chromosomal aberrations (CA), mitotic index (MI) and anaphase delay (AD) were studied in the CHO cell line, with and without the addition of S9 mix. Prepared according to the Argentine pharmacopeia 0.1, 1, 10 and 100 micrograms/ml plant decoction (aqueous extract) were assayed. One hundred cells per culture were studied for CA and AD, while MI was calculated for 2000 nuclei. The results revealed a significant increase in the percentage of abnormal metaphases (p less than 0.001) and in total aberrations (p less than 0.001). Both the MI and the AD affected the cell cycle. All results were enhanced by the addition of an S9 fraction. The toxic effect could be associated with pyrrolizidine alkaloids and their N-oxides, which through a process of in vitro metabolism become activated by microsomal oxidation and change into pyrrolic derivatives.
Asunto(s)
Aberraciones Cromosómicas/genética , Mutagénesis , Extractos Vegetales/toxicidad , Plantas Medicinales , Plantas Tóxicas , Alcaloides de Pirrolicidina/toxicidad , Senecio , Valeriana , Análisis de Varianza , Anafase/efectos de los fármacos , Animales , Argentina , Células CHO , Fragilidad Cromosómica , Cricetinae , Cricetulus , Activación Enzimática , Extractos Hepáticos , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología , Índice Mitótico/efectos de los fármacos , Pruebas de Mutagenicidad/métodos , Óxidos de Nitrógeno/toxicidad , Alcaloides de Pirrolicidina/química , Ratas , Ratas EndogámicasAsunto(s)
Saccharomyces cerevisiae/genética , Contaminantes Químicos del Agua/toxicidad , Estudios de Evaluación como Asunto , Conversión Génica/efectos de los fármacos , Concentración de Iones de Hidrógeno , Mitosis/efectos de los fármacos , Mutación , Poliestirenos , Saccharomyces cerevisiae/efectos de los fármacos , Factores de Tiempo , Contaminantes Químicos del Agua/análisisAsunto(s)
Monitoreo del Ambiente/métodos , Mutágenos/análisis , Saccharomyces cerevisiae/genética , Contaminantes Químicos del Agua/toxicidad , Contaminantes del Agua/toxicidad , Conversión Génica/efectos de los fármacos , Mitosis/genética , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/efectos de los fármacosRESUMEN
A counterimmunoelectrophoretic (CIE) technique was developed to detect botulinic toxin type A, and the method was compared with the mouse bioassay. A 100 LD50 concentration was detected within 2 h. Crossed reactions were observed with antitoxins of types B and F. As regards other Clostridium species, precipitin lines were seen between C. sporogenes and antitoxin type A. Foodstuffs artificially contaminated with C. botulinum type A were assayed by means of CIE and mouse bioassay, without recording interference by substances normally contained in foodstuffs.
Asunto(s)
Toxinas Botulínicas/análisis , Contaminación de Alimentos/análisis , Animales , Bioensayo , Contrainmunoelectroforesis , Reacciones Cruzadas , Humanos , Ratones , Valor Predictivo de las PruebasRESUMEN
The effect of tryptophan and uracil starvation on the viability of the transformant B. subtilis BSA 170 trp- ura- and its parent strains Bacillus subtilis PB 168 trp -C and Bacillus subtilis PB 3308 ura- was examined. These studies were performed at the conditions for competence development, during 16 hours. Our results showed that B. subtilis BSA 170 was resistant to tryptophan-less death during all the assay and was also resistant to uracil-less death during three hours. After this time, viability measurements revealed less colony forming units per milliliter, and decrease of the culture absorbances. The uracil-less death required the presence of tryptophan suggesting that protein synthesis is needed. The parental strains exhibit similar behavior. Bacillus subtilis PB 168 was resistant to tryptophan-less death and B. subtilis PB 3308 showed decrease of the viability after uracil starvation comparable to that of the transformant strain.
Asunto(s)
Bacillus subtilis/metabolismo , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/genética , Proteínas Bacterianas/biosíntesis , Triptófano/farmacología , Uracilo/farmacologíaRESUMEN
This study showed that encapsulation of piperacillin (PIP) and gentamicin (GE) by liposomes prepared with phosphatidylcholine and cholesterol (1:1) enhanced the antibiotic activity against gram negative bacilli. This was demonstrated by growth inhibition of Escherichia coli and Pseudomonas aeruginosa in the presence of the liposomal preparations containing either PIP or GE at 50 per cent MIC. Mixtures of liposomes containing buffer and either PIP or GE also exhibited an enhanced activity of the drug against the micro-organisms.
Asunto(s)
Escherichia coli/efectos de los fármacos , Gentamicinas/farmacología , Piperacilina/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Portadores de Fármacos , Farmacorresistencia Microbiana , Liposomas , Resistencia a las PenicilinasRESUMEN
El óxido de etileno es un potente inductor de daño al material genético ensayado en sistemas tales como vegetales, Drosophila, rata y líneas celulares humanas. Al ser usado como esterilizante en instrumental de cirugía, se realiza el estudio del personal expuesto al mismo, detectándose un aumento significativo en la frecuencia de aberraciones cromosómicas hepático en los mencionados individuos