Levofloxacin combined with cellulase can eradicate bacille Calmette-Guerin biofilm infection / 南方医科大学学报

OBJECTIVE@#To investigate the inhibitory effects of levofloxacin (LEV) combined with cellulase against bacille CalmetteGuerin (BCG) biofilms in vitro.@*METHODS@#The mature growth cycle of BCG biofilms was determined using the XTT method and crystal violet staining. BCG planktonic bacteria and BCG biofilms were treated with different concentrations of LEV and cellulose alone or jointly, and the changes in biofilm biomass were quantified with crystal violet staining. The mature BCG biofilm was then treated with cellulase alone for 24 h, and after staining with SYTO 9 and Calcofluor White Stain, the number of viable bacteria and the change in cellulose content in the biofilm were observed with confocal laser scanning microscopy. The structural changes of the treated biofilm were observed under scanning electron microscopy.@*RESULTS@#The MIC, MBC and MBEC values of LEV determined by broth microdilution method were 4 μg/mL, 8 μg/mL and 1024 μg/mL, respectively. The combined treatment with 1/4×MIC LEV and 2.56, 5.12 or 10.24 U/mL cellulase resulted in a significant reduction in biofilm biomass (P < 0.001). Cellulase treatments at the concentrations of 10.24, 5.12 and 2.56 U/mL all produced significant dispersion effects on mature BCG biofilms (P < 0.001).@*CONCLUSION@#LEV combined with cellulose can effectively eradicate BCG biofilm infections, suggesting the potential of glycoside hydrolase therapy for improving the efficacy of antibiotics against biofilmassociated infections caused by Mycobacterium tuberculosis.

In vitro effect of nystatin, gentian violet and garlic extract on candida albicans isolates from oral cavity

To evaluate in-vitro anticandidal activity of Nystatin. Gentian Violet and Garlic extract on Candida albicans isolates from oral cavity. For screening of antifungal activity of Nystatin. Gentian Violet and Garlic Extract, 100 clinical isolates were collected from the department of Radiotherapy. Jinnah Postgraduate Medical Center and Fatima Jinnah Dental College and Hospital, Karachi. The samples were collected from the oral cavity and the sample site was buccal mucosa, tongue and hard palate. These isolates were finally identified on the basis of morphology and cultural characteristics and confirmed using germ tube method. The antifungal activity of Nystatin, Gentian Violet and Garlic Extract were carried out by disc diffusion method. Result showed that the mean zone of inhibition of Nystatin was 17.9mm, Gentian violet was 16.6mm and Garlic Extract was 16.6mm and all the drugs used were found to be very effective. It can be concluded from the study that all the drugs are very effective against clinical isolates of Candida albicans and secondly the organism had not developed any resistance to these drugs

Potentiality of a new compound for in vitro differentiation between halophilic and non-halophilic vibrios.

Sensitivity of 21 halophilic vibrios and 16 clinical isolates of non-halophilic vibrios was determined against a new possible antivibrio agent, a pyrimidine analogue, 4, 6-dimethylpyrimidine -2-thiol (4,6-DMPT). It appeared to be a vibriocidal agent, having a mean MIC and MBC of 32 microg/ml for halophilic strains and 64 microg/ml for non-halophilic strains and an LD50 of 300 mg/Kg body weight of mice. Thus, 4,6-DMPT may help an in vitro distinction between halophilic and non-halophilic vibrios. Sensitivity of these strains was also studied with respect to pteridine, crystal violet and Tween 80 hydrolysis as further markers distinguishing between these 2 groups which could also be differentiated by their growth on TCBS or/and CLED media.

Biological characterization of Trypanosoma cruzi strains

Biological parameters of five Trypanosoma cruzi strains from different sources were determined in order to know the laboratory behaviour of natural populations. The parameters evaluated were growth kinetics of epimastigotes, differentiation into metacyclic forms, infectivity in mammalian cells grown in vitro and parasite susceptibility to nifurtimox, benznidazole and gentian violet. Differences in transformation to metacyclic, in the percentage of infected cells as well as in the number of amastigotes per cell were observed among the strains. Regarding to pharmacological assays, Y strain was the most sensitive to the three assayed compounds. These data demonstrate the heterogeneity of natural populations of T. cruzi, the only responsible of infection in humans

Chemoprophylaxis in Chagas' disease: potential use of natural products of plant origin and related synthetic compounds

Compounds obtained from plants and by synthesis were studied as to chemoprophylaxis in Chagas' disease against bloodstream forms of trypanosoma cruzi. A broad screening was performed and some have shown trypanocidal activity as for example, claussequinone, 4-methoxy-dalbergione, deoxygoyazensolide, licnophic acid, eremantholide C, Licnopholide, ent-caur-en-19-ol and lepidine dehydrochlo-ride or WR 6026. The most active were claussequinone and lepidine.

Studies on antibacterial properties of gentian violet impregnated silastic.

The antibacterial activity of gentian violet (GV) impregnated silastic discs was studied by measuring the zone of inhibition (ZOI), (in mm) produced by the discs planted on Staphylococcus epidermidis seeded agar plates. The effect of varying concentration of GV, the duration of antibacterial activity and effect of autoclaving were studied. The mean ZOI for 1 per cent GV was 19.28 +/- 0.89 mm and for 2 per cent GV it was 22.55 +/- 0.71 mm (P < 0.001). There was no significant difference between GV concentrations of 2-5 per cent. Over a period of 1-5 wk, no significant difference was found in the antibacterial activity of GV for any of the concentrations. In each of the concentrations there was a significant reduction in the ZOI after multiple autoclavings. The study thus indicates that it is possible to impart antibacterial properties to silastic implants so that their colonization with Staph. epidermidis can be prevented and this finding has obvious clinical implications.

Consideraciones sobre la actividad experimental de nuevos derivados del Violeta de Genciana en Trypanosoma cruzi / Considerations about experimental activity of new gentian violet derivatives in Trypanosoma cruzi

Foram ensaiados, frente a uma cepa boliviana de Trypanosoma cruzi, dois novos derivados trifenilmetânicos obtidos por síntese: T-7A, bis (4-dimetilamino-fenil) 2-benzotienil carbinol e T-7B, tetrafluorborato de bis (4-dimetilamino - fenil) 2-benzotienil carbonio. As experiências foram realizadas em camundongos NMRI através da administraçäo dos produtos por via intraperitoneal. Foram realizados, também, testes de atividade tripanomicida, in vitro, com sangue contaminado e conservado sob refrigeraçäo

Bases bioquímicas de la acción de drogas antichagásicas / Biochemical bases of the action of anti-chagasic

El avance en el conocimiento de la bioquímica de parásitos, que ha ocurrido en los años recientes, ha conducido al desarrollo de nuevas drogas y ha permitido entender el modo de acción de muchas de ellas. La acción de algunas drogas tripanosomicidas se debería a la generación de metabolitos que son radicales libres, incluyendo productos de reducción parcial del oxígeno. El T. cruzi es muy susceptible al daño celular producido por estos metabolitos , ya que las enzimas que destruyen las especies activadas de oxigeno en mamíferos tienen muy baja actividad o no existen en el parásito. Drogas en uso, como son el nifurtimox, el benznidazol y el cristal violeta actuarían generando radicales libres. Otro posible sitio de ataque quimioterapéutico en estudio es la biosíntesis del glutatión, el cual participa en la eliminación de radicales libres y en la conjugación y detoxicación de numerosas drogas. También se estudia la manera de interferir con la reducción del glutatión oxidado que en el T. cruzi, a diferencia del huésped, requiere del cofactor tripanotión. Drogas experimentales como el alopurinol y análogos de purinas basan su modo de acción en la incapacidad del parásito de sintetizar purinas de novo y en una relativa baja especificidad de la enzima succino-AMP sintetasa. La cadena respiratoria del parásito también presenta importantes diferencias con la del huésped

Açäo, "in vitro", da violeta de genciana sobre formas evolutivas do Plasmodium falciparum / In vitro activity of gentian violet on asesenal Plasmodium falciparum

Utilizando a técnica de RIECKMANN e col., os autores realizaram 20 microtestes de sensibilidade, procurando verificar a capacidade da violeta de genciana em impedir, na cultura "in vitro", o desenvolvimento habitual do Plasmodium falciparum. Os resultados mostraram que houve inibiçäo da evoluçäo do protozoário nas concentraçöes de 1/1000, 1/1500, 1/2000, 1/2500, 1/3000 e 1/4000, significando que nas condiçöes da experiência o corante atuou sobre as formas sanguíneas assexuadas do protozoário. Estas verificaçöes sugerem que a violeta de genciana poderia ser usada na profilaxia da malária transfusional

Enfermedad de Chagas y transfusión sanguinea: actividad tripanocida del clorhidrato de maprotilina y del violeta de genciana / Chagas' disease and blood transfusion: trypanocidal activity of maprotiline hydrochloride and gentian violet

Se evaluó por inoculación en ratón la actividad tripanocida del Clorhidrati de Maprotilina comparativamente con la presentada por el Violeta de Genciana cuando estos compuestos se adicionaron a muestras de sangre conteniendo bajas concentraciones de parásitos. Ambas drogas presentaon actividad tripanocida cuando se las utilizó en concentraciónes del orden 10**-3M. Sin embargo, aun empleando esta concentración pudo detectarse esporádicamente infección en alguno de los animales inyectados con muestras de sangre conteniendo 10 o 100 tripomastigotes, despues de haber sido incubadas 24 h a 4-C con uno de ambos compuestos. Debido a la baja solubilidad del Clorhidrato de Maprotilina el presente estudio se realizó con muestras de sangre diluidas al medio siendo imposible evitar esta condición para la concentración 10**-3M de este compuesto. Estos resultados descartan el uso de clorhidrato de Maprotilina en bancos de sangre y previenen sobre la posibilidad eventual de transmitir infección por Trypanosoma cruzi aun con sangre tratada con Violeta de Genciana. De los 3 métodos utilizados para evaluar viabilidad parasitaria remanente en las muestras de sangre químicamente tratadas, el microhematocrito fue el más sensible

Estudo experimental sobre a possibilidade de prevençäo da malária pós-transfusional, através do uso da violeta de genciana / Experimental assay of the possible use of gentian violet in the prevention of post-transfusion malaria

Levando em conta a comprovada açäo preventiva da violeta de genciana quanto à transmissäo da doença de Chagas, por transfusäo de sangue e, também, possível idêntica eficácia a respeito da toxoplasmose, foi empreendida investigaçäo para verificar se esse corante tem, da mesma formas, a capacidade de evitar a malária decorrente de hemoterapia. Foi investigada a infecçäo de camundongos pelo Plasmodium berghei. Usando parasitemia, mortalidade e alteraçöes histopatológico como parâmetros, verificou-se que a violeta de genciana, adicionada ao sangue, nas concentraçöes de 1/1.000 e 1/4.000, opöe-se efetivamente à liçäo infectante do protozoário, após permanência em geladeira (4-C) durante 24 horas. Conclui-se que se abre nova perspectiva quanto à profilaxia da malária induzida, em serviços de hemoterapia

Prevalência da infecçäo chagásica em doadores de sangue no Triângulo mineiro / Prevalence of Trypanosoma cruzi infection in blood donors in Triângulo mineiro

Os autores analisaram a prevalência da infecçäo chagástica em 10988 doadores do Serviço de Hemoterapia do Hospital Escola da Faculdade de Medicina do Triângulo Mineiro, através de três levantamentos realizados no período de dezesseis anos. Observaram queda de prevalência de 16,6% no primeiro levantamento para 6,9% no terceiro e predomínio da infecçäo em negros, no sexo feminino e nas faixas etárias mais avançadas. Discutiram ainda o emprego de medidas profiláticas e o papel do Serviço de Hemoterapia frente ao doador chagástico