Normal Flora

Normal Flora NORMAL FLORA: INTRODUCTION • Normal flora is the term used to describe the various bacteria and fungi that are permanent residents of certain body sites, especially the skin, oropharynx, colon, and vagina. The viruses and parasites, which are the two other major groups of microorganisms, are usually not considered members of the normal flora, although they can be present in asymptomatic individuals. The members of the normal flora vary in both number and kind from one site to another. Although the normal flora extensively populates many areas of the body, the internal organs usually are sterile. Areas such as the central nervous system, blood, lower bronchi and alveoli, liver, spleen, kidneys, and bladder are free of all but the occasional transient organism. Summary of the Members of Normal Flora and Their Anatomic Locations. MembersoftheNormalFlora1 AnatomicLocation Bacteroidesspecies Colon,throat,vagina Candidaalbicans Mouth,colon,vagina Clostridiumspecies Colon Corynebacteriumspecies(diphtheroids) Nasopharynx,skin,vagina Enterococcusfaecalis Colon Escherichiacoliandothercoliforms Colon,vagina,outerurethra Gardnerellavaginalis Vagina Haemophilusspecies Nasopharynx,conjunctiva Lactobacillusspecies Mouth,colon,vagina Neisseriaspecies Mouth,nasopharynx Propionibacteriumacnes Skin Pseudomonasaeruginosa Colon,skin Staphylococcusaureus Nose,skin Staphylococcusepidermidis Skin,nose,mouth,vagina,urethra Viridansstreptococci Mouth,nasopharynx Medically Important Members of the Normal Flora Location ImportantOrganisms1 LessImportantOrganisms2 Skin Staphylococcusepidermidis Staphylococcus aureus, Corynebacterium (diphtheroids), various streptococci, Pseudomonas aeruginosa, anaerobes (e.g., Propionibacterium), yeasts(e.g.,Candidaalbicans) Nose Staphylococcusaureus3 S. epidermidis, Corynebacterium (diphtheroids), variousstreptococci Mouth Viridansstreptococci Variousstreptococci,Eikenellacorrodens Dentalplaque Streptococcusmutans Prevotellaintermedia,Porphyromonasgingivalis Gingival crevices Various anaerobes, e.g., Bacteroides, Fusobacterium, streptococci,Actinomyces Throat Viridansstreptococci Various streptococci (including Streptococcus pyogenes andStreptococcus pneumoniae),Neisseria species,Haemophilusinfluenzae,S.epidermidis Colon Bacteroidesfragilis,Escherichia coli Bifidobacterium, Eubacterium, Fusobacterium, Lactobacillus, various aerobic gram-negative rods, Enterococcus faecalis and other streptococci, Clostridium Vagina Lactobacillus, E. coli,3 groupB streptococci3 Various streptococci, variousgram-negative rods.B. fragilis,Corynebacterium(diphtheroids),C.albicans Urethra S. epidermidis, Corynebacterium (diphtheroids), variousstreptococci,variousgram-negativerods,e.g., E.coli3 Cont,.