MedMicro Profiles:

A Bacteriology LaboratoryIdentification Scheme

Copyright 1994-1997 New York University

Although, currently, automated processes are most commonly used for the speciation of microorganisms, the goal of this module is the presentation of classical procedures for distinguishing among and between microorganisms of medical interest. It is hoped that it will serve to provide students of medical microbiology with an insight into the diversity and complexity of reactions these microscopic organisms possess in their arsenal of capabilities in order to survive in the harsh external environment, to interact with each other, and to sometimes live in harmony with, sometimes attack and invade, some parasitize and sometimes kill various hosts.

Special thanks to Roberto Celis, Ph.D., M.D., ( Elizabeth Fried, Nydia Ortiz, Anne Hansen, Jack Niemiec) for laboratory technical support and provision of culture samples, and to Carolyn Wright for media preparation, Manny Ortiz of the Hippocrates Staff for photography and image processing, and Julio Garcia for the fungi graphics..

The following laboratory identification scheme is used by our medical students for the bacteriology laboratory portion of our medical microbiology course. A restricted sample of medically important bacteria are considered. The scheme presents some simple laboratory procedures which are of proven efficacy in distinguishing among commonly encountered pathogenic bacteria.

Caution: The present scheme is meant for instructional use only and is not to be employed for medical diagnostic or treatment purposes. It does not cover all possible bacterial causes of infectious disease. Even for the organisms covered the scheme is not foolproof; it should be remembered that bacteria belonging to the same genus and species may manifest genetic variability. No one biochemical or morphological test by itself is truly diagnostic.

If you use this document we would appreciate hearing about your experience, criticisms, and/or wish list. Please direct responses to Martin Nachbar, M.D., email: nachbar@popmail.med.nyu.edu

Topics to be developed

1. . Microscopic Morphology
   
   
2. . Gram positive cocci

3. . Gram positive bacilli

4. . Gram negative cocci

5. . Gram negative bacilli

6. . Acidfast and Branched_Rods

7. . Fungi