Pyrolysis–gas–liquid chromatography of some dermatophytes

1972 ◽  
Vol 18 (10) ◽  
pp. 1593-1601 ◽  
Author(s):  
Awatar S. Sekhon ◽  
J. W. Carmichael

Dermatophytes belonging to Nannizzia, Arthroderma, and Microsporum were examined by pyrolysis–gas–liquid chromatography. Replicate samples from the same colony, or samples from another colony of the same strain, yielded closely similar pyrograms, but the curves were not quite superimposable. Effects on the pyrolysis patterns of sample size, age of colony, and type of medium were investigated. Pyrograms of the plus and minus mating types of the species of Nannizzia and Arthroderma were similar to each other, but they did differ in some respects. The patterns of Microsporum audouini and M. canis differed considerably from each other. Quantitative analysis of the pyrochromatographic data, using several procedures, did not yield satisfactory results. It was found that variation between replicates was often as great as between species.

1973 ◽  
Vol 19 (4) ◽  
pp. 403-407 ◽  
Author(s):  
J. W. Carmichael ◽  
Awatar S. Sekhon ◽  
Lynne Sigler

Samples from dried colonies of 21 strains of Nannizzia and Arthroderma were analyzed by pyrolysis–gas–liquid chromatography. Characteristic peak patterns produced by all the strains were used as markers to correct random drift in retention time so that corresponding peaks in different pyrograms could be homologized. Variation in sample size was compensated for by comparing peaks on each pyrogram with a particular major component and scoring them simply as 0 (absent), 1 (small), or 2 (large). Proximities were calculated and analyzed for clusters by the TAXMAP procedure. The analysis always grouped replicate samples together in the same cluster. Opposite mating types of the same species were sometimes placed in the same cluster and sometimes in separate clusters. The (+) mating type of Arthroderma benhamiae was placed in a cluster with both mating types of Nannizzia gypsea and N. obtusa, while the (−) mating type replicates of A. benhamiae were placed in a cluster by themselves. Finding a greater difference between pyrograms of different mating types of one species than between pyrograms of different species was unexpected and requires further investigation.


1980 ◽  
Vol 26 (5) ◽  
pp. 497-505 ◽  
Author(s):  
Takashi KANEDA ◽  
Atsuko NAKAJIMA ◽  
Kenshiro FUJIMOTO ◽  
Tadashi KOBAYASHI ◽  
Shuhachi KIRIYAMA ◽  
...  

1982 ◽  
Vol 45 (3) ◽  
pp. 229-233 ◽  
Author(s):  
NORMAN J. STERN

Pyrolysis gas-liquid chromatography (PGLC) and stepwise discriminant analysis (SDA) were ineffective when used to differentiate selected genera, species and strains of foodborne microorganisms. Each of 18 individual bacterial strains analyzed was grown, harvested and subjected to PGLC analysis. The resulting pyrolysis products were separated on a high resolution capillary column and the elution patterns (pyrograms) were subjected to stepwise discriminant analysis of 26 (a–z) characteristic peaks. Classification with the combination of PGLC and SDA was 87% accurate for gram-negative strains of bacteria and 94% accurate for gram-positive strains of bacteria. PGLC-stepwise discriminant· analysis correctly discriminated 80% of the bacterial strains according to the known gram-stain reactions. Only 63% were correctly classified to the genus level when all samples were compared. These findings point out the weak points for this method of bacterial analysis.


1979 ◽  
Vol 27 (9) ◽  
pp. 2203-2206 ◽  
Author(s):  
MICHIYA KIMURA ◽  
TOSHIO YAMAMOTO ◽  
KOICHI NAGASAWA ◽  
MASAHIKO TOHMA

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