You are interested in obtaining Staphylococcus aureus for a study investigating the prevalence of methicillin-resistant Staphylococcus aureus in the general population. You have received several samples and are ready to start your isolation procedures. Describe the personal protective equipment that would be needed and three different culturing techniques that can be used to obtain organisms to produce pure cultures.

State if you use general or selective media and which specific media you would choose. How would you determine if the culture was contaminated? What is the first step you would take if you detected contamination?

 

Staphylococcus aureus is a pathogenic, gram-positive bacterium that primarily causes skin diseases. The normal personal protective equipment, including gloves, mouth mask and eye protection goggles, sterile equipment and work area, will be personal equipment.

One type of culture of microbial species involve pure culture. The following methods are preferred for the isolation of only one form of microbial culture:

• Method of the streak plate
• Method of pour plate
• Method of spread plate

The most common media for growing Staphylococcus aureus is tryptic soy broth and luria bertani because it forms distinctive gold color colonies on media that also helps to easily figure out the contamination.

One of the most important precaution you should take to stop getting sick and spreading germs like MRSA when you detect contamination is to keep you hands clean. If available, use soap and water to clean your hands. Scrub your hands for a minimum of 20 seconds after wetting your hands and applying soap. Using an alcohol based hand sanitizer that contains at least 60% alcohol to clean hands if you are unable to access soap nd water. Rub your hands together, attempt to cover all the surfaces of your hands and fingers until your hands are cleaned, and apply the sanitizer to one hand.