Throat Swabs

Background and Introduction

Many microorganisms are permanent residents of the human body. These residents are referred to as the human microbiome. The microbiome is beneficial to human health in many ways. Only a small percentage, less than 10%, of all known bacteria are pathogenic, or able to cause disease in a susceptible host. In order to identify an unknown in the clinical laboratory, a sample must be collected from the patient. In this experiment, partners will collect a swab of one another’s throat and use it to inoculate a blood agar plate. You will see the many different colonies of bacteria that reside in your throat.

Procedure

Results

Most bacteria are part of your normal flora. These are typically gamma and alpha-hemolytic organisms. You might see some beta-hemolysis if you are a carrier of Staphylococcus aureus like ~30% of the population. It's general not a cause for concern unless you are feeling sick.

blood agar plate with throat microbes growing