skin flora

Examples of skin flora in the following topics:

• Microbiota of the Skin

  • The skin flora, more properly referred to as the skin microbiome or skin microbiota, are the microorganisms that reside on the skin.
  • The skin flora, more properly referred to as the skin microbiome or skin microbiota, are the microorganisms that reside on the skin.
  • Skin flora are usually non-pathogenic, and either commensals (are not harmful to their host) or mutualistic (offer a benefit).
  • There are three main ecological areas for skin flora: sebaceous, moist, and dry.
  • Describe the types of skin flora and how they can be beneficial for the organism

• Bacterial Skin Diseases

  • Impetigo is a highly contagious bacterial skin infection most common among pre-school children.
  • Dried streptococci in the air are not infectious to intact skin.
  • The erythematous skin lesion enlarges rapidly and has a sharply demarcated raised edge.
  • Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken.
  • Group A Streptococcus and Staphylococcus are the most common of these bacteria, which are part of the normal flora of the skin, but normally cause no actual infection while on the skin's outer surface.

• Overview of Human-Microbial Reactions

  • Gut flora consists of microorganisms that live in the digestive tracts of animals and is the largest reservoir of human flora.
  • Bacteria make up most of the flora in the colon and up to 60% of the dry mass of feces.
  • The skin microbiota are composed mostly of bacteria of which there are around 1000 species upon human skin from 19 phyla.
  • Skin flora are usually non-pathogenic and either commensal or mutualistic.
  • The benefits of bacteria include preventing transient pathogenic organisms from colonizing the skin surface, either by competing for nutrients, secreting chemicals against them, or stimulating the skin's immune system.

• Normal Genitourinary Microbiota

  • Those that are expected to be present and that under normal circumstances do not cause disease, but instead participate in maintaining health, are deemed members of the normal flora.
  • Populations of microbes inhabit the skin and mucosa.
  • It is estimated that 500 to 1000 species of bacteria live in the human gut and a roughly similar number on the skin.
  • Normal flora bacteria can act as opportunistic pathogens at times of lowered immunity.The vaginal microflora consist mostly of various lactobacillus species .
  • Disturbance of the vaginal flora can lead to bacterial vaginosis.

• Innate Resistance

  • The skin and respiratory tract secrete antimicrobial peptides such as the β-defensins.
  • Populations of microbes (such as bacteria and yeasts) inhabit the skin and mucosa.
  • Yeasts are also present on the skin, particularly Malassezia species, where they consume oils secreted from the sebaceous glands.
  • The gut flora is the human flora of microorganisms that normally live in the digestive tract and can perform a number of useful functions for their hosts.
  • It is the largest reservoir of human flora.

• Ecological Associations Among Microorganisms

  • For example, the presence of over one thousand bacterial species in the normal human gut flora of the intestines can contribute to gut immunity.
  • The presence of this gut flora also inhibits the growth of potentially pathogenic bacteria (usually through competitive exclusion), and these beneficial bacteria are consequently sold as probioticdietary supplements.
  • Some organisms, such as Staphylococcus or Streptococcus, can cause skin infections, pneumonia, meningitis and even overwhelming sepsis, a systemic inflammatory response producing shock, massive vasodilation, and death.
  • Yet these organisms are also part of the normal human flora and usually exist on the skin or in the nose without causing any disease at all.

• Control of Nosocomial Infections

  • Two categories of micro-organisms can be present on health care workers' hands: transient flora and resident flora.
  • These are often capable of surviving on the human skin and sometimes to grow.
  • They are capable of surviving on the human skin and of growing freely on it.
  • The skin of workers is colonized by 3.9 x 104 – 4.6 x 106 cfu/cm2.
  • The goal of hand hygiene is to eliminate the transient flora with a careful and proper performance of hand washing, using different kinds of soap, both normal and antiseptic, and alcohol-based gels.

• Penetrating Host Defenses

  • The human microbiome (or human microbiota) is the aggregate of microorganisms that reside on the surface and in deep layers of skin, in the saliva and oral mucosa, in the conjunctiva, and in the gastrointestinal tracts.
  • Organisms that are expected to be present, and that under normal circumstances do not cause disease, but participate in maintaining health, are deemed members of the normal flora.
  • Many of the bacteria in the digestive tract, collectively referred to as the gut flora, are able to break down certain nutrients such as carbohydrates that humans otherwise could not digest.
  • Normal flora bacteria can act as opportunistic pathogens at times of lowered immunity.
  • S. aureus is commonly found in minor skin infections, such as boils, and some healthy people harbor it in their nose.

• Fusobacteria

  • The Fusobacterium are associated with infection and disease including periodontal diseases, topical skin ulcers and Lemierres's syndrome.
  • Fusobacteria are normal flora within the oropharyngeal and can clearly result in disease if conditions are optimal.

• Bacteroidetes and Chlorobi

  • Bacteroidetes are capable of thriving in numerous environments that include soil, sediments, sea water, and in the guts and on skin of animal hosts.
  • The bacteria categorized as bacteroidetes are opportunistic and are rarely pathogenic as they constitute part of the normal flora.