Novel Semi-Synthetic Media for Isolation of Aerobic Actinomycetes

2016 ◽  
Vol 11 (4) ◽  
pp. 74-79
Author(s):  
Ashwaq Y. Noori ◽  
Huda S. Khuder ◽  
Abduljaleel H. Mohammed
2021 ◽  
Vol 7 (6) ◽  
pp. 489
Author(s):  
Somanon Bhattacharya ◽  
Natalia Kronbauer Oliveira ◽  
Anne G. Savitt ◽  
Vanessa K. A. Silva ◽  
Rachel B. Krausert ◽  
...  

Chronic meningoencephalitis is caused by Cryptococcus neoformans and is treated in many parts of the world with fluconazole (FLC) monotherapy, which is associated with treatment failure and poor outcome. In the host, C. neoformans propagates predominantly under low glucose growth conditions. We investigated whether low glucose, mimicked by growing in synthetic media (SM) with 0.05% glucose (SMlowglu), affects FLC-resistance. A > 4-fold increase in FLC tolerance was observed in seven C. neoformans strains when minimum inhibitory concentration (MIC) was determined in SMlowglu compared to MIC in SM with normal (2%) glucose (SMnlglu). In SMlowglu, C. neoformans cells exhibited upregulation of efflux pump genes AFR1 (8.7-fold) and AFR2 (2.5-fold), as well as decreased accumulation (2.6-fold) of Nile Red, an efflux pump substrate. Elevated intracellular ATP levels (3.2-fold and 3.4-fold), as well as decreased mitochondrial reactive oxygen species levels (12.8-fold and 17-fold), were found in the presence and absence of FLC, indicating that low glucose altered mitochondrial function. Fluorescence microscopy revealed that mitochondria of C. neoformans grown in SMlowglu were fragmented, whereas normal glucose promoted a reticular network of mitochondria. Although mitochondrial membrane potential (MMP) was not markedly affected in SMlowglu, it significantly decreased in the presence of FLC (12.5-fold) in SMnlglu, but remained stable in SMlowglu-growing C. neoformans cells. Our data demonstrate that increased FLC tolerance in low glucose-growing C. neoformans is the result of increased efflux pump activities and altered mitochondrial function, which is more preserved in SMlowglu. This mechanism of resistance is different from FLC heteroresistance, which is associated with aneuploidy of chromosome 1 (Chr1).


2021 ◽  
Vol 64 (3) ◽  
pp. 33-35
Author(s):  
Deborah G. Johnson ◽  
Nicholas Diakopoulos

Seeking to reap the positive uses of synthetic media while minimizing or preventing negative societal impact.


1954 ◽  
Vol 32 (1) ◽  
pp. 306-318
Author(s):  
Raymond C. Parker ◽  
George M. Healy ◽  
Dorothy C. Fisher

The replicate culture assay procedures of Earle and his associates have been adapted for use in evaluating the effectiveness of synthetic media. For this purpose, use has also been made of Earle's L strain mouse cells. Washed and continuously stirred suspensions of these or similar strains of cells may be dispensed, with reasonable assurance of uniformity, into a series of replicate cultures, the number depending on the volume of the suspension and the capacity and effectiveness of the stirring and dispensing unit. For use with synthetic media, the original procedures for the preparation and care of the replicate cultures and for their subsequent treatment for the counting of isolated, stained nuclei have been modified considerably. This paper describes the procedures that were finally adopted and also describes a relatively simple screening procedure in which washed cell suspensions may be used to advantage in making preliminary assays of synthetic media and in testing the relative toxicity or growth stimulating effects of substances added to, or derived from, natural media.


1954 ◽  
Vol 32 (3) ◽  
pp. 306-318 ◽  
Author(s):  
Raymond C. Parker ◽  
George M. Healy ◽  
Dorothy C. Fisher

The replicate culture assay procedures of Earle and his associates have been adapted for use in evaluating the effectiveness of synthetic media. For this purpose, use has also been made of Earle's L strain mouse cells. Washed and continuously stirred suspensions of these or similar strains of cells may be dispensed, with reasonable assurance of uniformity, into a series of replicate cultures, the number depending on the volume of the suspension and the capacity and effectiveness of the stirring and dispensing unit. For use with synthetic media, the original procedures for the preparation and care of the replicate cultures and for their subsequent treatment for the counting of isolated, stained nuclei have been modified considerably. This paper describes the procedures that were finally adopted and also describes a relatively simple screening procedure in which washed cell suspensions may be used to advantage in making preliminary assays of synthetic media and in testing the relative toxicity or growth stimulating effects of substances added to, or derived from, natural media.


1983 ◽  
Vol 42 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Jill E. Ogden ◽  
Morris Grindle

SUMMARYHeterokaryons ofN. crassawere synthesized from homokaryotic strains differing in sterol composition and sensitivity to the polyene antibiotic nystatin. Mycelia of the nystatin-sensitive strainerg-1+contained ergosterol and episterol, and the nystatin-resistant mutanterg-1 contained fecosterol and lichesterol. Mycelia of heterokaryons with different proportions oferg-1+:erg-1 nuclei contained various proportions of the four sterols. Ergosterol was the principal sterol in heterokaryons with more than 5%erg-1+nuclei.Heterokaryons with various proportions oferg-1+:erg-1 nuclei were grown for several weeks along tubes of synthetic media. Growth rates were stable on minimal medium and nutritionally supplemented media but nuclear proportions often fluctuated. Growth rates fell sharply on nystatin-supplemented media and there were adaptive increases in proportions of mutanterg-1 nuclei which resulted in selection of nystatin-resistant homokaryotic mycelia.


1987 ◽  
Vol 65 (3) ◽  
pp. 598-606 ◽  
Author(s):  
M. J. Milligan ◽  
P. G. Williams

This paper reports the field isolation of orchidaceous rhizoctonias similar to those found recently in pot cultures of vesicular–arbuscular endophytes. The paper describes the morphology and growth of field and pot-culture isolates on different natural and synthetic media and reports light microscope observations on the nuclei and septal pores of hyphal cells. All isolates were the same in regard to the utilisation of simple and complex carbohydrates and different forms of nitrogen. They were all multinucleate and had an inconspicuous septal pore. Consistent differences were found among isolates in the morphology and frequency of chlamydospores and monilioid hyphae and in the rate of growth, shape, type of margin, and colour of colonies. By using these criteria, the fungi were segregated into 10 entities. The observations are discussed in relation to the natural distribution of the fungi and their resemblance to other fungi in the form-genus Rhizoctonia.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Csilla Putz-Bankuti ◽  
Harald H. Kessler ◽  
Thomas Valentin ◽  
Eva Leitner ◽  
Emina Talakic ◽  
...  

Nocardiosis is an infrequent but serious pulmonary infection caused by Gram-positive aerobic actinomycetes. In this paper, we report on a 48-year-old patient with pleuropulmonary nocardiosis and cirrhosis due to chronic hepatitis C virus infection treated with triple antiviral treatment complicated by prolonged neutropenia.


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