T2 Skin Normal Flora

normal flora definition

population of microbes that permanently inhabit areas exposed to the environment in a healthy person

normal flora is what type of pathogen

opportunistic

resident flora

microbes regularly found in a given area at a given age, re-established if disturbed

transient flora inhabits ______ and is derived from ______

skin or mucous membranes; environment

microbiota

collection of living microbes in a defined environment

palm has high density of ______ glands

eccrine sweat

average skin pH

below 5

acid skin pH (4-4.5) promotes

attachment of resident bacterial flora to skin

alkaline skin pH (8-9) promotes

dispersal of resident bacterial flora from skin

sweat ion composition

sodium, potassium, calcium, magnesium, chloride

sweat helps with immunity due to its composition of ______

lysozyme and antimicrobial peptide

fatty acid in sebum helps with immunity due to its ______

fungistatic activity

4 phyla of most common skin bacteria from most to least

actinobacteria, firmicutes, proteobacteria, bacteroidetes

bacterial resident microbes

non-hemolytic staphylococci, alpha-hemolytic streptococci, enterococci, diphtheroid bacilli, spore-forming bacilli, coliform bacilli, acinetobacter

fungal resident microbes

candida, malasseszia, trichosporon

examples of viruses endogenous to skin microbiota

human papillomavirus, merkel cell polyomavirus

resident flora vs transient flora

resident usually permanent, transient usually come and go

advantages of normal flora

inhibit pathogen and block pathogenesis by acting as antagonist, regulate immune response

pathogen inhibition and pathogenesis blocking mechanisms

produce byproduct (enzyme, bacteriocin, acid), competitive exclusion (nutrient, attachment site)

regulation of immune response mechanism

educate adaptive immunity, enhance innate immunity (produce AMPs, decrease inflammation)

disadvantages of normal flora

odor (convert nonvolatile into volatile), contamination, infection

microbiome

microbes and their genomic elements in an environment

16s rRNA

prokaryotes

18s rRNA and internal transcribed spacer

eukaryotes

eubiosis

interspecies balance of microbiota community

dysbiosis

disturbance of eubiosis

skin dysbiosis treatment methods

drug, probiotic, microbiota transfer therapy

normal flora found where

skin, hair follicle, gi, respiratory

gram -/+ more found on skin

positive