Up to this point in time, why has the study of the microbiota of the skin has be

Question

Up to this point in time, why has the study of the microbiota of the skin has been limited? Hint – it has to do with the focus of medical research.

Introduction The first line of defense against bacterial infections are the skin and mucous membranes (found in the respiratory system). In humans, the skin has an average surface area of almost 2 m2 and has a variable thickness of between 0.05 mm and 0.33 mm. The dry outer layer of the skin consists of numerous rows of dead epidermis called keratin. On the keratin layer perspiration and sebum (skin oil) form what is referred to as the acid mantle (so-called because of the range of pH which is from 4 to 5.5) The respiratory system contains a set of defenses. The cilia move unwanted particles up from the lower respiratory system to upper respiratory system to exit from the throat. That mechanism is called the ciliary escalator. Microorganisms that actually reach the lungs are destroyed by alveolar macrophages. Additionally, IgA antibodies are in the secretions of respiratory mucus, saliva, and tears. The system of microphages and antibodies are referred to as microbial antagonism In spite of the body's defenses, there are bacteria that thrive in these inhospitable environments. Today in lab, you will culture and attempt to identify microbes that you collect from yourselves in lab. Mannitol salt agar is a differential medium that will turn yellow when being fermented by staphylococci. One of the most abundant microbes found on human skin is Staphylococcus aureus. Today in lab, you will collect skin swabs and culture them on mannitol salt agar The catalase test can be used to differentiate staphylococci (produces catalase and bubbles in the prescen of hydrogen peroxide) and streptococci (which do not produce catalase). You will perform the catalase test in both procedures. Aseptically place a loopful of bacteria on a clean slide then apply one drop of hydrogen peroxide onto the bacteria. If bubbles are produced, then the organism is positive for the presence of catalase PROCEDURE: Microbial collection from the skin: 1. Aseptically open the tube containing the swab and push the swab against the wall of the tube to release excess saline. If there is too much saline, it may not pick up a good amount of microbiota on the skin. 2. Swab 1/3 of the mannitol salt agar plate with the swab 3. Using a sterile loop, streak the rest of the plate 4. Incubate for 24-48 hours. 5. Examine the colonies and record any pigment SWAB production. (On Report Page) Perform Catalase Test on one colony Perform a Gram stain of any colonies that have yellow halo. Record the Gram reaction (On Report Page). 6. 7. SECOND STREAK FIRST

Explanation / Answer

The skin is the largest organ in the human body and colonized by abundant and diverse collection of bacteria, fungi and viruses inhabit the human skin in that most of them are harmless or beneficial to their host and Only little microorganisms are harmful. Also the composition of the skin microbiome has been shown to be diverse, loosely organized and variable between different locations of the skin. So due to different niches present in the
different part of the skin leads to difficult in study of the microbiota of the skin. Also change in genetics or in the environment makes the microbiota can change rapidly.

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