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A diagram showing different regions of the body. Each region has a pie chart that shows which bacteria are most prevalent. The most common bacterium in each region: Glabella (corynebacterineae), Alar Crease (propionibacterineae), External auditory canal (propionibacterineae), Nare (other actinobacteria), manubrioum (propionibacterineae), Axillary vault (proteobacteria), antecubital fossa (proteobacteria), Volar forearm (proteobacteria), interdigital web space (proteobacteria), hypothenar palm (proteobacteria), inguinal crease (corynebacterineae), umbilicus (corynebacterineae), toe web space (corynebacterineae, , propionibacterineae, and staphylococcaceae), reticular crease (propionibacterineae), occiput (staphylococcaceae, back (propionibacterineae), buttock (proteobacteria), gluteal crease (corynebacterineae), popliteal fossa (staphylococcaceae), plantar heel (staphylococcaceae).  Second part of the image shows that different subjects have different bacterial percentages and that these percentages change over time.
The normal microbiota varies on different regions of the skin, especially in dry versus moist areas. The figure shows the major organisms commonly found in different locations of a healthy individual’s skin and external mucosa. Note that there is significant variation among individuals. (credit: modification of work by National Human Genome Research Institute)
  • What are the four most common bacteria that are part of the normal skin microbiota?

Infections of the skin

While the microbiota of the skin can play a protective role, it can also cause harm in certain cases. Often, an opportunistic pathogen residing in the skin microbiota of one individual may be transmitted to another individual more susceptible to an infection. For example, methicillin-resistant Staphylococcus aureus ( MRSA ) can often take up residence in the nares of health care workers and hospital patients; though harmless on intact, healthy skin, MRSA can cause infections if introduced into other parts of the body, as might occur during surgery or via a post-surgical incision or wound. This is one reason why clean surgical sites are so important.

Injury or damage to the skin can allow microbes to enter deeper tissues, where nutrients are more abundant and the environment is more conducive to bacterial growth. Wound infections are common after a puncture or laceration that damages the physical barrier of the skin. Microbes may infect structures in the dermis , such as hair follicles and glands , causing a localized infection, or they may reach the bloodstream, which can lead to a systemic infection.

In some cases, infectious microbes can cause a variety of rashes or lesions that differ in their physical characteristics. These rashes can be the result of inflammation reactions or direct responses to toxins produced by the microbes. [link] lists some of the medical terminology used to describe skin lesions and rashes based on their characteristics; [link] and [link] illustrate some of the various types of skin lesions. It is important to note that many different diseases can lead to skin conditions of very similar appearance; thus the terms used in the table are generally not exclusive to a particular type of infection or disease.

Some Medical Terms Associated with Skin Lesions and Rashes
Term Definition
abscess localized collection of pus
bulla (pl., bullae ) fluid-filled blister no more than 5 mm in diameter
carbuncle deep, pus-filled abscess generally formed from multiple furuncles
crust dried fluids from a lesion on the surface of the skin
cyst encapsulated sac filled with fluid, semi-solid matter, or gas, typically located just below the upper layers of skin
folliculitis a localized rash due to inflammation of hair follicles
furuncle ( boil ) pus-filled abscess due to infection of a hair follicle
macules smooth spots of discoloration on the skin
papules small raised bumps on the skin
pseudocyst lesion that resembles a cyst but with a less defined boundary
purulent pus-producing; suppurative
pustules fluid- or pus-filled bumps on the skin
pyoderma any suppurative (pus-producing) infection of the skin
suppurative producing pus; purulent
ulcer break in the skin; open sore
vesicle small, fluid-filled lesion
wheal swollen, inflamed skin that itches or burns, such as from an insect bite

Questions & Answers

is it better to study microbiology and then medicine it makes no difference to go directly to medicine?
Jessee Reply
Dray's mathdme cell wall konse color k hote he
Jinal Reply
what is dray's mathdme cell wall
Prabhat
I confused. please help me
Karen
just confused
Raj
l don't understand it please explain it for me.
Karen Reply
epitopes are present on the surface of
Rohit Reply
at the tip of variable region on the antibody...where antigen and antibody binding sites combine...
Fiza
The term that is used refer to moving microbes under a microscope are referred to as?
Lee Reply
Members of the genus Neisseria cause which of the folowing human diseases?
Farah Reply
genital infections
Kamaluddeen
gonorrhoea
sandip
gonorrhoea
Jessee
4. Which of the following specimens should not be refrigerated? a. Urine b. Urogenital swab
Zahraa Reply
urine
Muuse
urine
Agatha
Urine
Tean
urine
Yasser
Urine
Ebtehal
urine
anamika
urine
Puja
urine
Inemesit
urine
Samuel
Urine
Muhammad
Details about McConkey agar
Muhammad
urine
SK
urine
what is bacteria
anamika Reply
a member of large number of unicellular microorganism which have cell wall but lack of cell organelles an oranised nucleus including somewhat can cause disease
Sukhdeep
Bacteria are usually composed of one cell onl to that are neither plants nor animals, microscopic, that may cause diseases or may be beneficial(in gut)... it depends upon their weapons. Nearly all animal life is dependent on Bacteria for their survival
Fiza
thanks
anamika
what factor make bacteria colony large and how could we sterlise it in large scale
fatty
nutrient concentration temp gaseous conc ph ion or salt concentration mositure condition factors contribute to make large colony. by autoclaving we will sterilize bactetia
Sukhdeep
Colony is actually visible growth of Bacteria that is as a result of suitable environment for growth i.e optimal conditions for growth, temperature, moisture etc. there're many methods to get rid of bacteria. If We stop giving them optimal conditions for living Bacteria will die soon .
Fiza
what's the difference between an antigen and a pathogen?
Pathogens are organisms that cause disease in other organisms whereas Antigen is a part of a pathogen that triggers the immune response..
Rajat
so it is the antigen that dendritic cells present to the T cells and not the pathogen itself?
no no antigen are the west product or part of the pathogen. in such case bacteria it self fight with over immune response & in another case bacteria release antigens
vasava
& other antigen like pollan grain, dust particles etc.....
vasava
pathogen are microbes that can infect the body and causw illness....antigens are the part of pathogens that alert the body to an infection
Sukhdeep
antigen is a part of blood and pathogen is foreign particle which causes diseases
Yogyata
antigen could be non microorganism.... where as pathogen is mixroorganism
tadesse
Thanks
Karen
a pathogen is a disease causing organism while an antigen is a protein in the white blood cells which combats pathogens.
Jessee
what type of widal test
sobhit Reply
this test determine for typhoid in this test if H,O antigen are present that indicate the positive test bac. are salmonella typhy
vasava
what h.o denotes
Iqra
o: body of bacteria, h: flagellate
Explain Mould
Chinenye Reply
Explain mycoses and it's classification
Chinenye
why do we have hiccups?
Manisha Reply
shakey diaphragm
Curlisse
The antibody binding site is formed primarily by:
Asalla Reply
How many types of MICROORGANISMS do we have?
Hope Reply
Hello friends
Hope
microorganisms are divided into seven type Bacteria archaea protozoa algae fungi virus and multicellular animal parasites
Raj
What's pathogenesity
Usman Reply
something that causes disease
Anietie
who is the father of microbiology?
Hope
antonie van leeuwenhoek
vasava
it is the severity of the effects caused by a pathogen
Jessee

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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