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9-Hydroxycrisamicin A, a new cytotoxic isochromanquinone antibiotic produced by Micromonospora sp. SA246.

9-Hydroxycrisamicin A, a new cytotoxic isochromanquinone antibiotic, was isolated from a soil microorganism SA246 which was identified as Micromonospora sp. The molecular formula of 9-hydroxycrisamicin A was determined as C32H22O13 based on the HRFAB-MS analysis, and the structure was determined by various NMR experiments. 9-Hydroxycrisamicin A showed weak antimicrobial activity against Gram-positive bacteria and strong cytotoxic activity against some human cancer cell lines such as SK-OV-3 (ovarian), HCT15 (colon), SK-MEL-2 (melanoma), A549 (lung), XF498 (central nervous system) with ED50 of 0.47-0.65 microgram/ml.

Anti-Bacterial Agents↗

UK-3A, a novel antifungal antibiotic from Streptomyces sp. 517-02: fermentation, isolation, structural elucidation and biological properties.

A novel antifungal antibiotic, UK-3A, was obtained from the mycelial cake of Streptomyces sp. 517-02. UK-3A was very similar in structure to UK-2A, a structural relative of antimycin A. The antifungal spectrum of UK-3A was relatively broad (MICs for yeasts and filamentous fungi: 1.56-6.25 and 0.39-1.56 micrograms/ml, respectively). The cytotoxic activity of UK-3A was weak (IC50: 18-100 micrograms/ml).

Antibiotics, Antineoplastic↗

Antimicrobial susceptibility pattern of clinical isolates of non-fermentative bacteria.

152 nonfermentative bacteria were isolated from a total number of 965 clinical samples processed routinely in the laboratory of Microbiology Department, M.K.C.G Medical College in South Orissa accounting to a prevalence rate of 15.75%. Pseudomonas spp. (both pigmented and non-pigmented strains) were isolated in maximum percentage (73.6%) followed by Acinetobacter spp. (19.7%) and Alkaligenes faecalis (4.6%). Rarely encountered species were Eikenella corrodens (1.3%) and Stenotrophomonas maltophila (0.6%). Pus from various sites was the major source (116; 76%). 81% of all isolates were sensitive to amikacin and 74% to ofloxacin. Sensitivity to cefotaxime, ciprofloxacin, tobramycin, gentamicin and netlimycin ranged from 53% to 68%. Least effective drugs were carbenicillin and ceftriaxone (48% each).

Bacteria↗

The carbohydrate metabolism of Brugia pahangi microfilariae.

Evidence is presented that the microfilariae of Litomosoides carinii, Dipetalonema viteae and Brugia pahangi have an aerobic requirement for motility, but possibly not for survival. In addition, the data suggest that in an in vitro anaerobic environment, B. pahangi microfilariae ferment glucose only as far as lactate. In an aerobic environment, however, the data are consistent with a portion of glucose being dissimilated via a one step oxidative decarboxylation of pyruvate formed from glycolysis to acetate and CO2. In addition, a low level of complete oxidation, possibly via a tricarboxylic acid cycle pathway, may be occurring. Finally, if B. pahangi microfilariae are immobilized with levamisole in an aerobic atmosphere, the drug appears to alter the aerobic glucose metabolism of the parasite both qualitatively and quantitatively. A decreased glucose utilization occurs, together with a shift to a more nearly homolactate fermentation. It is suggested that the effects of levamisole on the metabolism of the microfilariid are secondary to the observed paralysis.

Aerobiosis↗

[Effect of the quality of fat substrate on the dynamics of fatty acid utilization during biosynthesis of cephalosporin C].

Influence of the quality of the fats used on their utilization in the process of cephalosporin C fermentation and accumulation was studied. A decrease in the level of all the fractions of the fatty acids was observed during the fermentation process. The antibiotic yield with the use of oxidized fats was lower. Treatment of the fats with gaseous nitrogen prevented their oxidation. It was supposed that the decreased yields of the antibiotic were associated with the influence of the oxidized fats on the biosynthetic processes.

Acremonium↗

[Method for developing a controlled process. Study of the possible regulation of rifamycin B biosynthesis].

A procedure for developing a controlled process for biosynthesis of secondary metabolites is described with reference to rifamycin B as an example. The response of the antibiotic producing culture to changed concentrations of the main nutrients in the initial medium was determined. Mathematical processing of the experimental findings with design of the experiment resulted in defining nutrients such as ammonium sulfate and cornsteep liquor useful for further development of the controlled process.

Ammonium Sulfate↗

[Selected properties of lactose-fermenting and non-fermenting Salmonella agona strains isolated from specimens from hospitalized infants].

The aim of this study was to compare some of the properties of 28 lactose-positive and 28 lactose-negative Salmonella agona strains isolated from faeces of infants hospitalized in the same hospital. Some of biochemical properties, sensitivity to 14 antibiotics and chemotherapeutic agents and sensitivity to bacteriophages used for typing of this Salmonella genus were tested. Results of biochemical examinations revealed that lactose-fermenting strains retain the remaining of Salmonella of subspecies I. Two biochemical features are of particular importance: the ability to ferment lactose on all lactose containing media and a lack of the ability to produce H2S on Kligler medium. These two features differentiate lactose-fermenting strains of Salmonella from non-lactose fermenting ones. Antibiotic sensitivity pattern differed between lactose-positive and lactose-negative strains. Lactose-positive strains showed higher degree of resistance than lactose-negative strains. The differences in resistance were seen in the case of chloramphenicol, doxycycline, gentamicin and tetracycline. Both lactose-positive and lactose-negative strains were sensitive to colistin, neomycin, nitrofurantoin and nalidixic acid. They were resistant to ampicillin, cloxacillin, rifampicin, streptomycin, sulfatiazol and biseptol. Bacteriophage typing revealed that all lactose-negative strains isolated in this study from clinical samples belonged to the same phage pattern V. Lactose-positive strains belonged to two phage types VB and XI. Type VB prevailed.

Anti-Bacterial Agents↗

[Effect of the seeding culture media on the biosynthesis of eremomycin].

Relationship of eremomycin biosynthesis to the quantity and quality of the inoculate (age, aeration rate, number of subcultures) was studied. The seed medium composition for cultivating the inoculate was defined. A procedure for cultivation of the seed material for biosynthesis of eremomycin providing an increase in the antibiotic yield by 24 per cent was developed.

Actinomyces↗

[Selection of methods of detecting lactose-fermenting Salmonella strains and evaluating their usefulness for diagnostic studies].

Salmonella rods of subspecies I, lactose-fermenting were first isolated in Poland in 1980. They were isolated from a plus sample taken from a brain abscess of a child. Next strains were isolated from faeces of newborn and hospitalized children. Growth characteristic of colonies of lactose-fermenting Salmonella strains on selective-differentiating media (Mac Conkey's Levine, SS, Sołtys) recommended for inoculation of clinical material resembled Escherichia coli. So far these type of colonies were omitted in diagnostic examinations. Lactose-fermenting variants showed on Bismuth sulfate agar "Difco" (WB) typical for Salmonella growth pattern. They grew on this medium after 48 hr of incubation in a form of black, medium sized colonies, with some metallic brilliance and characteristic blackening of the medium undercolonies. Precise knowledge of biochemical properties of lactose-fermenting Salmonella allows to supplement so far used diagnostic scheme with additional tests permitting differentiation of lactose-fermenting variants of Salmonella from the other members of Enterobacteriaceae family. Taking into consideration biochemical variants in diagnostic procedure i.e. lactose-fermenting Salmonella, allowedns to isolate in the years 1983-1985 lactose-positive strains in 1305 out of 2773 (47%) individuals positive for S. agona. In 1987, 246 persons (28.3%) out of 869 with lactose-fermenting Salmonella of various serotypes were simultaneously infected with lactose-negative variant. Lactose-fermenting strains of Salmonella belonged most frequently to the following genera: S. agona, S. enteritidis, S. oranienburg, S. typhimurium, and S. goldcoast. It was found that the modified diagnostic procedure makes possible the isolation and the identification of lactose-positive varians of Salmonella.

Bacteriological Techniques↗