DIVERSITY IN THE HUMAN MICROBIOME The human Microbiome Project has examined bacteria on 242 lable 10-1 people. Some of the microbes living in and on the human body: Propionibacterium acnes lives on the skin and nose of Streptococcus dominates ost people the oral cavity Bacteroides is the most abundant genus in the gut of almost Staphylococcus healthy subjects epidermidis colonizes external body sites E. coli is present in the Lactobacillus gut of the majority of species are healthy subjects but at predominant very low abundance in the vagina SOURCE: Human Microbiome Project
Table 10-1
Copyright o The McGraw-Hill Companes lne. Permission required for ction or dsplay TABLE 13.1 Sites That Harbor a Normal Flora Sites of normal Skin and its contiguous mucous membranes Microbiota Upper respiratory tract Gastrointestinal tract (various parts Outer opening of urethra External genitalia Copyright o The McGeaw-Hill Companies, Ine. Permission required for reproduction or diply · Vagina TABLE 13.2 Sterile(Microbe-Free) Anatomical · External ear canal Sites and fluids External eye(lids, conjunctiva) All Internal Tissues and organs Heart and circulatory system Kidneys and bladder Lungs Brain and spinal cord Muscles Microbe-free sites Ovaries /testes Glands(pancreas, salivary, thyroid) Sinuses Middle and inner ear ab|e10-1 Internal eye Fluids Within an Organ or Tissue Blood Urine in kidneys, ureters, bladder Cerebrospinal fluid Saliva prior to entering the oral cavity Semen prior to entering th e urethra Amniotic fluid surrounding the embryo and fetus
Sites of Normal Microbiota Table 10-1 Microbe-free sites
● Extemal auditory Retroauricular O O Nare Occiput● Table 10-1 Normal ● Manubrium Bacterial Microbiota O Axillary vault dO Antecubital Gluteal O Differs in the different MAAN pliteal fossa O v location HYpothenar Plantar heel O web space O Inguinal crease UMbilicus O Toe web space □ Corynebacteriaceae Micrococcaceae Other actinobacteria Other firmicutes ● Sebaceous Moist O Dry C Butel Is, Morse SA M TA: Jawetz, Melnick, Adelberg's Micrebialogy,25thEdition:www.accessmedicine.co
Table 10-1 Normal Bacterial Microbiota Differs in the different location
Microbes and humans Disease can come about in several overlapping ways 1. Entirely adapted to the pathogenic way of life in humans, and never be part of the normal flora but may cause subclinical infection, e.g. M.tuberculosis 2. Part of the normal flora acquire extra virulence factors making them pathogenic, e.g. E. coll 3. Part of the normal flora can cause disease if they gain access to deep tissues by trauma, surgery, lines, e.g.s epidermIdIS 4. In immunocompromised patients many free-living bacteria and components of the normal flora can cause disease, especially if introduced into deep tissues, e.g Acinetobacter
Microbes and humans Disease can come about in several overlapping ways 1. Entirely adapted to the pathogenic way of life in humans, and never be part of the normal flora but may cause subclinical infection, e.g. M . tuberculosis 2. Part of the normal flora acquire extra virulence factors making them pathogenic, e.g. E. coli 3. Part of the normal flora can cause disease if they gain access to deep tissues by trauma, surgery, lines, e.g. S. epidermidis 4. In immunocompromised patients many free-living bacteria and components of the normal flora can cause disease, especially if introduced into deep tissues, e.g. Acinetobacter
Normal microbiota All body surfaces possess a rich normal bacterial flora especially the mouth, nasopharynx, gastrointestinal tract vagina, skin This can be a nuisance v contaminate specimens cause disease This is beneficial protect against infection by preventing pathogens colonising epithelial surfaces(colonisation resistance) v removal of the normal flora with antibiotics can cause superinfection, usually with resistant microbes Endogenous viruses reside in the human genome worries about similar pig viruses in xenografts
Normal microbiota • All body surfaces possess a rich normal bacterial flora, especially the mouth, nasopharynx, gastrointestinal tract, vagina, skin… – This can be a nuisance contaminate specimens cause disease – This is beneficial protect against infection by preventing pathogens colonising epithelial surfaces (colonisation resistance) removal of the normal flora with antibiotics can cause superinfection, usually with resistant microbes • Endogenous viruses reside in the human genome – worries about similar pig viruses in xenografts