Comparison of antiaspergillar activity of extracts of Tectona grandis Linn according to two antifungal susceptibility testing

Plants used as antimicrobials in the treatment of infectious diseases in folk medicine are regularly evaluated in different Laboratories. And, the processes of evaluation of antifungal susceptibility are often different to one laboratory to another. This study was undertaken in the goal to compare parameters obtained (MIC and MFC) with two antifungal susceptibility testing. The first one is Agar slant double dilution tubes method (M1) and the second is disc diffusion method /broth dilution according document CLSI M38 -A2 supplemented to 2% glucose (M2). Ethanol (EtOH 70%), Methanol (MeOH) and n-Hexane (n-HexTG) extracts of leaves of Tectona grandis have been tested in comparison to Itraconazole against two clinicals strains of Aspergillus fumigatus 896/AB and Aspergillus flavus 1006/OM isolated to HIV patients. Results showed that on A. flavus, agar slant method (M1) gave MIC ranging between 200 µg/mL and 800 µg/mL while disc diffusion meth/broth dilution (M2) showed growth inhibition between 100 µg/mL and 400 µg/mL. On A. fumigatus, inhibition was observed between 200µg/mL and 400 µg/mL with M2 in contrary M1 gave MIC located between 400 µg/mL and 800 µg/mL. For each strain tested, according method M2, MIC and MFC are identical and with method M1, these parameters were different. Evaluation of Itraconazole on each strain gave with M2, MIC= 50 µg/mL while inhibition has been showed at 100 µg/mL and 200µg/mL with M1. Also considering extracts, hydroalcoholic extract of T. grandis (EtOHTG) showed antifungal susceptibility testing less 2 to 4 efficiency than Itraconazole. Disc diffusion method/broth dilution (M2) according CLSI M38-A2 to evaluate Tectona grandis antifungal susceptibility is the process of evaluation which allo wed having lo west antifungal parameters (MIC and MFC) on A. flavus and A. fumigatus.

VIABILITAS DAN PRODUKTIVITAS SELULOSA DARI INOKULUM KERING Acetobacter xylinum DENGAN SUBSTRAT PEMBAWA BERUPA SERBUK KELAPA PARUT DAN SERBUK AMPAS KELAPA PARUT

Inokulum nata yang berisi kultur Acetobacter xylinum, pada umumnya tersedia dalam bentuk agar slant atau bentuk kultur cair dalam medium air kelapa. Bentuk inokulum tersebut membutuhkan perlakuan khusus dan mahal. Seiring dengan penigkatan kebutuhan inokulum nata de coco, maka bentuk inokulum dikembangkan agar lebih praktis, mudah perlakuannya, penyimpanan dan aman dalam transportasi. Penelitian ini bertujuan untuk mengetahui kemungkinan penyediaan inokulum kering nata de coco dengan substrat pembawa berupa serbuk kelapa parut dan serbuk ampas kelapa parut. Inokulum kering dibuat dengan menginokulasikan kultur cair A. xylinum ke dalam serbuk kelapa parut kering dan serbuk ampas kelapa parut kering kemudian dilakukan pengeringan dengan inkubator dengan suhu 30o C dan 40o C. Inokulum dalam bentuk serbuk kering dengan substrat pembawa berupa serbuk kelapa parut dan serbuk ampas kelapa parut dapat dibuat dengan pengeringan suhu 30o C selama 30 jam dengan perbandingan substrat pembawa : inokulum cair sebanyak 1:2. Inokulum kering dengan substrat pembawa berupa serbuk kelapa parut memiliki kadar air 3,25 %, vabilitas 1,0 x 107 sel/g dan produktivitas selulosa 5,55 g/L. Inokulum kering dengan substrat pembawa berupa serbuk ampas kelapa memiliki kadar air 2,98 %, viabilitas 4,2 x 105 sel/g dan produktivitas selulosanya sebasar 4,92 g/L. Produktivitas selulosa inokulum kering tersebut setara dengan 80% produktivitas selulosa hasil inokulum cair dari isolat A. xylinum asal. <br /><br />nata de coco, inokulum kering, Acetobacter xylinum, selulosa bakteri, substrat pembawa <br /><br /><br /><br />

Characterization of Escherichia coli isolated from samples of different biological and environmental sources

Escherichia coli from 10 different biological and environmental sources were isolated and characterized in the Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh during the period from January to May 2007. A total of 100 samples, 10 from each of human feces and urine, rectal swab of cattle, sheep and goat, cloacal swab of chicken, duck and pigeon, drain sewage and soil were collected aseptically and subjected to primary isolation by propagating in nutrient broth followed by culture on different agar media. Gram's staining and hanging drop techniques were also performed. Biochemical properties of the isolates were studied and reaction in TSI agar slant was also observed. Pathogenicity of 10 representative E. coli isolates, one from each source were determined by lethality assay in 12 day-old embryonated eggs, in day-old chicks and in day-old suckling mice models. E. coli was isolated successfully from all the samples. All the E. coli isolates were found to produce bright pink colonies on MacConkey agar, yellowish green colonies surrounded by an intense yellow green zone on BG agar and characteristic metallic sheen colonies on the EMB agar. In case of E. coli isolated from cattle, slight variation in colony character on EMB agar was observed showing greenish red colonies with faint metallic sheen. In Gram's staining technique, all the isolates were pink coloured, small rod shaped Gram negative bacilli and in the hanging drop technique they were motile. Reactions in TSI agar slant revealed yellow slant and butt with gas but no hydrogen sulphide production. Almost all the E. coli isolates fermented dextrose, maltose, lactose, sucrose and mannitol with the production of both acid and gas except E. coli isolated from drain sewage which did not ferment maltose and isolates from pigeon showed less production of acid and gas during sucrose fermentation. The results of Catalase, MR and indole test of the E. coli isolates were positive but V-P test was negative. In the embryo lethality assay, E. coli isolates from chicken, pigeon, duck, human urine, cattle, sheep and goats were virulent causing 33.33-100% death of the embryo except isolates from human faeces and drain sewage which were moderately virulent and that from soil which was avirulent. E. coli isolate of chicken origin found to be more virulent which caused 100% death of the embryos. Most of the embryos died between day-1 and day-2 PI. Chick lethality assay indicated that all the E. coli isolates were virulent as the mortality rate was more than 50%. In mice lethality assay, all the E. coli isolates were in the killer group causing cent percent death of mice within 10 to 42 h following inoculation. Among these three lethality assay models, avian embryo lethality assay was found to be most suitable to discriminate between virulent and avirulent isolates compared to day-old chick lethality assay and day-old suckling mice lethality assay where inconsistent results were observed. In conclusion, our result showed that E. coli isolated from different biological and environmental sources were found to be varied in virulence and avian embryo lethality assay was assumed to be the best model for discriminating virulent and avirulent E. coli. Key words: Escherichia coli, pathogenicity, human, cattle, poultry, soil DOI = 10.3329/bjvm.v5i1.1305 Bangl. J. Vet. Med. (2007). 5 (1 & 2): 25-32The PDF for this article was corrected and replaced on 9/11/2009.

EFFECT OF CERTAIN VARIATIONS IN DILUENT AND DILUTION PROCEDURE ON SURVIVAL OF PSEUDOMONAS SPECIES GROWN IN VARIOUS MEDIA1

Studies on the effect of various diluents on the level of population of pseudomonads grown in skimmilk, nutrient broth, and on agar slants indicate that with skimmilk cultures usually minor increases or decreases in viable counts occurred. With cultures grown in nutrient broth at 25 C, reductions in numbers after holding in phosphate buffered water or distilled water became more prevalent. The viable population of cell suspensions from agar-slant cultures held in either Standard Methods buffer or distilled water decreased rapidly in most instances. The temperature of the diluent did not have a significant effect on the survival of test cultures in various diluents. Studies on the effect of cell concentration on survival of test cultures in various diluents indicate that in general only minor changes in viable count could be attributed to differences in cell concentration. With respect to pH of the diluting fluid, a diluent at pH 7.0 seemed preferable. Experiments with distilled waters from difference sources indicate that the type of water used as diluent can have a great effect on the viable count.