Biology ETDs

Publication Date



The intent in undertaking this thesis project was to set up a practical, economic, and reliable method of species identification for Mycobacteria. This was directed specifically at the clinical laboratory setting.

I began by testing the commonly published identification

tests for accuracy and reproduceability. For many of the commonly used tests the reliability left much to be desired. Several months after beginning my research I learned of an evaluation method developed by Dr. Eugene Rypka at Lovelace Foundation. The evaluation method developed by Dr. Rypka (1960) is based on a separation of characters by considering positive, negative or variable results. This evaluation is based on characters with the most concise separation of positive and negative results being highest on the list of reliable tests.

After consideration of all commonly published tests for separation of characteristics of Mycobacteria, I determined that eleven tests on the character order list were highly reliable and easily used in a clinical laboratory setting, these are: (1) nitrate reduction, (2) >45mm catalase production, (3) pigment production in light, (4) 5% NaCl tolerance, (5) Tween 80 hydrolysis, (6) growth rate, (7) pigment production in dark, (8) pH 7, 68°C catalase production, (11) niacin production, (14) growth on MacConkey agar, (18) growth temperature of 42°C. This set of tests will separate all clinically significant typical species of Mycobacteria.

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

William Clarence Martin

Second Committee Member

Larry L. Barton

Third Committee Member

John August Ulrich

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Biology Commons