Normal flora of human body
- 1. NORMAL FLORA OF HUMAN BODY: Micro organisms that are commonly found on or in body sites of healthy persons are termed as normal flora The term normal flora implies that these microbes are harmless and for the most part they do not cause disease and are even beneficial The micro organisms normally associated with a particular tissue or structure are called the “microbiota” or “indigenous microbial population” or “microbial flora” The normal microbial flora are divided into transients and residents Transient vary from time to time and are impermanent Resident constitutes a constant population which can not be completely removed permanently NORMAL FLORA OF SKIN: The skin contains a wide variety of micro organisms The skin is composed of the epidermis ,dermis layer Epidermis layer is the outer surface layer which consists of dead ,anucleated cells and it is not a favourable environment for colonization by microorganisms The representative genera of microorganisms that inhabit the skin are- acinetobacter,enterobacter,klebsiells,coryebacterium,micrococc us,propionibacterium,proteus,pseudomonas,staphylococcus,stre ptococcu,bacillus,mycobacterium And the fungi are malassezia ,pityrosporum and candida
- 2. VARIOUS FACTORS INFLUENCING THE RESIDENT FLORA: 1.weather -cause increase in skin temperature which increases the density of microflora 2.the age of the host -the young children have more flora than adults 3.personal hygiene-unclean individuals have more microflora than cleaned persons NORMAL MICROBIAL FLORA OF ORAL CAVITY: The microbial flora of mouth are firmly adhere to surface like gums and teeth And mouth is a very confortable environment for the colonization of microflora because of availability of food particles Mouth consists of genera like streptococcus,neisseria,actinomyces,veillonella and lactobacillus and some yeasts are found most microorganisms invading the mouth are aerobic ex:streptococcal sps and obligate anaerobes ex:fusobacterium,prevotella the presence of these bacteria contributes to the eventual formation of dental plaque,dental caries or tooth decay NORMAL MICROFLORA OF RESPIRATORY TRACK: 1.UPPER RESPIRATORY TRACK: It consists of nose,nasopharynx,oropharynx and throat The normal flora of nose occurs just inside the nostrils Consists of staphylococcus,streptococci ,neisseia,haemophilus The nasopharynx contains streptococcus,pneumonia,haemophilus influenza The oropharynx consists of streptococci,neisseria
- 3. 2.LOWER RESPIRATORY TRACK: It includes trachea,bronchiand lungs These are protected by the action of ciliary epithelium cells and the movement of mucous and are normally sterile The microorganisms are removed by phagocytic activity oby macrophages NORMAL FLORA OF GASTROINTESTINAL TRACK: At birth the intestine is sterile but organisms are soon introduced with food Diet has a marked influence on the relative compostion of the flora STOMACH: The stomach receives bacteria from the oral cavity It normally contains a fewer bacteria because of the action of HCL The few organisms are lactobacilli,streptococcus,staphylococcus and yeast(candida) SMALL INTESTINE: Divided into three areas 1.duodenum:adjacent to stomach so resembles stomach in its microbial flora 2.jejunum: contain enterococcus faecalis,lactobacilli,diphtheroids and candida 3.ileum: resembles that of large intestine ,contain anaerobic bacteria and enterobacteriaceaemembers
- 4. LARGE INTESTINE: It contains the largest numer of bacterial community in humans body It consists of bacteria- Ecoli,bifidobacterium,eubacterium,lactobacillus Yeast includes- candida Protozoa-entamoeba,trichomonas ,endolimax nana,lodamoeba. NORMAL MICROBIAL FLORA OF UROGENITAL TRACK: The upper urogentical track(kidneys,urinary bladder,and ureter) is usually free of micro organisms It contains staphylococcus,epidermidis,enterococcus faecalis and corynebacterium species are usually present in the distal portion of the urethra ,neisseria,chlamydias,mycoplasma and some enterobacteriaceaemembers are also found It plays a important role in both health and disease
- 5. The female genital track have large surface area and mucous secretions ,posses complex microflora