Clinical Specimens from the Respiratory Tract

Now that you have had some experience with the normal flora and the most common bacterial pathogens of the respiratory tract, you will have an opportunity to apply what you have learned to the laboratory diagnosis of respiratory infections. In Experiments 23.1 and 23.2 you will prepare cultures of a throat swab and a sputum specimen, each simulating material that might be obtained from a sick patient. These cultures should be examined with particular attention to the “physician’s” stated tentative diagnosis. Significant organisms that may be isolated must be identified and reported. If organisms that you consider to be part of the normal flora are isolated, report as “normal flora.”

In Experiment 23.3, you will set up an antimicrobial susceptibility test on an organism isolated from one of the clinical specimens previously cultured, and prepare a report of the results for the “physician.”