BacterialInfectionNormalfloraOpportunisticpathogenPathogenicbacteria(virulentbacteria)DysbacteriosisExotoxinsEndotoxinsSeparation&CultureofbacteriaBacteriemiaSepticemiaPyemiaToxemiaEndotoxemiaCarrierColonyToxoidsAntitoxinKeyWordsNotallbacteriacausedisease•Normalflora–Thenormalfloraarebacteriawhicharefoundinoronourbodiesonasemi-permanentbasiswithoutcausingdisease.–Therearemorebacterialivinginoronourbodies,thanwehavecellsofourown.Ahumanbodycontainsaround1013cells.Thehumanbodyishometoaround1014bacteria.–Onefourthoffecalweightismadeofbacteria!–Thenormalfloraareparticularlyimportantinthelargeintestine.Normalfloraarealsofoundinthenose,mouth,throat,skin.•Opportunisticbacteria–canbepartofthenormalflorabutnotpathogenicfornormalpersons,causediseaseonlyinimmunocompromisedpersons,orunderspecificconditions.•Pathogenicbacteria(virulentbacteria)–Normallynotmembersofthenormalflora,havemechanismstopromotetheirowngrowthintheexpenseofhost’stissueororgan’sfunctionThenormalfloraprotectusfromdiseaseby:1.Competingwithinvadersforspaceandnutrients.2.Producingcompounds(bacteriocins)whichkillotherbacteria.3.LoweringthepHsothatotherbacteriacan'tgrow.Inadditiontotheabovewaysofprotectingusfromdiseaseournormalflorahelpusinotherways.Ofcourse,thereisadownsideaswell...TheGoodSide•ProducevitaminsweareunabletoproducesuchasvitaminB12.•Boostourimmunesystem—Germfreeanimals(bornandraisedinagermfreeplastictent)areverysusceptibletodiseasewhenremovedfromthegermfreeenvironmentbecausetheirimmunesystemisunderdeveloped.•Helpdigestfood.TheBadSide•Ifthenormalfloraescapefromtheirnormallocation,theycancausedisease.Forexample,Escherichiacoli,commonlyfoundintheintestine,cancauseurinarytractinfectionsifintroducedintothebladder.•Immunosuppressioncanallowotherwiseharmlessbacteriatocausedisease.AIDS,somecancertreatmentsandtransplantrejectiondrugsallsuppresstheimmunesystemandallowthenormalfloratocauseoccasionallyseriousdisease.Threeconditionscorrelatewithopportunisticinfection:1.ImmuneSystemCompromise2....
