DifferencesEukaryoteProkaryoteDrugsNuclearMembraneYesNoOrganellesBoundUnboundDigestivevacuolesYesNoChromosomesMultipleSingleDNA gyrasecan betargeted withquinoloneslikeciprofloxacinMembranesterolsYesNoPeptidoglycanNoYesPenicillins,cephalosporinsRibosomes80s70sAminoglycosides,MacrolidesMicrobiology BasicsPrionVirusBacteriaFungusParasiteNoNoYesYesYesNucleic AcidNoRNA/DNARNA and DNARNA and DNARNA and DNANucleusNoneNoneProkaryoticEukaryoticEukaryoticRibosomesNoneNone70s80s80sMitochondriaNoneNoneNoneYesYesOuterSurfaceNoneProteincapsidEnvelopeRigid wallPeptidoglycanRigid wallChitinFlexiblemembraneReplicationAggregatesRequireshostBinary fissionBudding ormitosisMitosisFunctions of normal flora•Prevent colonizationand infection withpathogens•Produce B vitamins andVitamin K in theintestine•Deconjugatebile acidsTyphoid Mary:first person identified as a healthycarrier ofSalmonella typhiin the United States.She infected 75 people over the course of 7 yearsSiteNormal FloraProblem ColonizersSkin•S.epidermidis•Diptheroids•Proprionobacteriumacnes•Candida•S.Aureus•Pseudomonas aeruginosaNose•S. epidermis•Diptheroids•Streptococci•S. Aureus•MRSAClostridium perfinginsHumans normally have permanent, nonpathogenic residentbacteria and yeast on skin and mucosa. Their numbers are about10 times the number of human cells. The blood, lower respiratorytract, CSF, pleural fluid, peritoneal fluid, and urine are sterile anddo not contain any normal flora.Nile Law: California state law thatrequires the screening of all high-riskpatients for MRSA. High-risk criteriainclude: inpatient surgery, burn, ICU,dialysis, hospitalized or nursing homeShe infected 75 people over the course of 7 yearsas a cook and was quarantined for 26 years.Mouth•S.viridans•Bacteroides•Fusobacterium•Streptococcus mutans•PorphyromonasgingivalisThroat•S.viridans•Neisseriaspp.•Haemophilusspp.•S. pyogenies(Group A)•MeningococciColon•Bacteroidesfragilis•Enterobacteriaecae•Lactobacillus•Enterococci•Clostridium•C.difficile•Vancomycin-resistantenterococciVagina•Lactobacillus•Streptococci•B. Fragilis•Enterobacteriacae•Candida•GroupB StreptococciClostridium perfinginsfrom the normal bowelflora can causemyonecrosisifinoculated into ananaerobic environmentin a wound.AttachmentColonizationInvasionEvasion ofhost defensesHost damageand InfectionSteps in Microbial PathogenesisSelecting antibiotics:choose an antibiotic towhich the pathogen islikely sensitive, butwhich has the mostlimited spectrum so asto limit thedevelopment ofresistance.
