BIO 326R 1st Edition Lecture 31 Outline of Last Lecture I. Virusesa. Historyb. Growing virusesi. QuantifyingII. Prions Outline of Current Lecture I. Floraa. Normalb. Residentc. TransientII. Relationshipsa. Mutalismb. Commensalismc. ParasitismIII. BenefitsIV. Impaired DefenseV. Opportunistic InfectionVI. Flora Typesa. Skinb. Eyec. Orald. Repiratory Tracte. GI Tractf. Urinary Tractg. Genital (female)VII. Sterile AreasCurrent LectureFlora- Normal Florao Bacteria, fungi, protezoa- Resident FloraThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Permanent- Transient Florao Present for a short period of time- In the womb, baby is sterileo First exposure to bacteria when borno Flora is different if vaginal birth or C-section and if breast fed or formulaRelationships - Mutualism—both benefit- Commensalism—microbe benefits, host unharmed- Parasitism—microbe benefits, host harmedo Disease causingBenefits of Normal Flora- Synthesis and excretion of vitaminso Enteric—vitamin K, B12o Lactic acid—vitamin B- Prevent colonization of pathogenso Compete with space and nutrients- Produce toxins that are harmful to other bacteriao Nonspecific fatty acids, peroxides, and bacteriocinso Inhibit or kill other bacteria- Stimulate the development of certain tissueso The caecum and lymphatic tissues (Peyer’s patches) in the GI tract- Stimulate the production of cross-reactive antibodieso Induce immunoresponseo Out flora are not harmful but have surface components similar to that of some pathogens that cause our bodies to have antibodies for those types of surface components, thus preparing our bodies to recognize a pathogen with the same surface components if presentImpaired Defense- Antibiotics- Irradiation therapy- Surgery, wounds, accidents- AIDSOpportunist Infection- Can be normal Florao Like S. aureas, E. coli- Unharmful until there’s a certain opportunity- Environmental florso Like P. aeruginosa- Example: bacteroides reside in intestine and if there’s a wound present (i.e. post surgery), the opportunity presents itself and bacteroides can produce abscesses- Example: E. coli naturally in the GI tract can cause a UTIFlora Types- Skino ~ 2 square meterso Where moisture content is increased (between toes, airmpits, etc.) density of flora is increasedo Temperature, pH, fatty acids, etc. depend on the flora content present Women tend to have a greater density of flora on their hands than men due to pH differences- Eye Flora—conjunctiva of eyeo Gram + do not make it because lysozyme (in tears) kill themo Less of normal florao Infection is possible because not completely sterile- Oral Florao S. salivarius= 98% until teeth form Can “stick” to saliva but not teetho S. mutans= as long as teeth remain Cause cavitieso Streprococci in gums and cheekso Gingival crevice area—anaerobic bacteria exist here Bacteroides, spirochetes- Respiratory Tracto Upper—nose, nasopharynx Anaerobeso Lower—trachea, bronchi, pulmonary tissues Free of microorganisms Do NOT want an infection here, because that means there are microorganisms where there aren’t normally- Gastrointestinal Tracto Esophagus, stomach (pH 2), small intestine, large intestineo Flora density: Stomach< small intestine< large intestine Mostly anaerobes 1-4% coliform- = Gram-negative non-spore forming bacteria which can ferment lactose with the production of acid and gas Ferment wast, vitamins, produce acids, enzymes, gases (CO2, H2, CH4, H2S) H. pilori stomach ulcers- Present naturally in 50% of people- Urinary Tract Florao Kidney, bladder, urine in bladder—free of microbes, unless UTIo Urethra—carries bacteria- Genital Flora (female)o Uterus, fallopian tubes, ovaries—free of microbeso Vagina—carries lactobacillus Lactobacillus—present in yogurt- Present puberty- menopause (~pH5)- During menopause, pH changes and population drops- More Sterile areaso Blooso Cerebrospinal If not sterile meningitiso Cenobial fluid (between joints)o Deep
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