Bio 171 Microbiology Exam 5 Question and Answer elaborations (100% CORRECT SOLUTIONS)

Document Content and Description Below

M5:Module5Exam -RequiresRespondus LockDownBrowser+Webcam Attempt Time Score LATEST Attempt 1 36 minutes 96 out of 100 Scoreforthisquiz:96outof10 SubmitedAug1 at1 :24pm Thisatempto k36minutes. ... Theconceptoftreatingalsamples,whetherknownorunknown,aspotentialy hazardous(orpathogenic)materialsisknownas . YourAnswer: universalprecautions Universalprecautions Listatleast3observationsaresearcherwouldbesuretonotewhileassessingan unknownmicrobialsample. YourAnswer: 1.anymotility 2.size/shape 3. gram status(gram-positiveorgram-negative) 4.presenseofanychemicalreactions 5.changesincolor Alabresearcherwouldbecertaintonote: 1. Sizeandshape 2.Anyobservablemotility 3.Gram status(positiveornegative) 4.Thepresenceofanychemicalreactions 5.Changesincolorlocalizedtotheorganism orthesurounding media 6.Capture(ordraw)imagesofanyofthecharacteristicsdescribed above Whileobservinganunknownsampleoflimitedamounts,aresearchermustdetermine thefolowingobservations:(1)thepresenceofanymotilityand(2)itsGram statususing thesamesample—theliquidsamplecan otbedivided.Whichwouldyoudeterminefirst andwhy? YourAnswer: Youwouldne dtodeterminethemotilitybeforegram status.Youcanobservemotility onawetmountandthenheatfixyoursampletogram stainyoursample.Ifyouwereto beginwithusinggram staining,youwouldkilyoursamplewithheatfixing,youwould notbeabletoobserveanymotility. YoumustdeterminemotilitybeforedeterminingtheGram status.Motilityrequires awetmount,whileGram stainingrequiresheatfixingthesample.Ifonewereto beginwiththeGram staintheheatfixationproces wouldkiltheorganism, makinganyobservationsregardingmotilityimpos ible.Thecorectap roach wouldbetoplacetheliquidcultureonaglas slideanddetermineitsmotility status.Next,thesameliquidculturecanbeheatfixedandGram stained. Afacultativeanaerobeisamicro rganism capableofgrowthunderwhatconditions? YourAnswer: aerobicandanaerobicconditions Afacultativeanaerobeiscapableofgrowthunderaerobic(withoxygen)and anaerobic(withoutoxygen)conditions. AsStreptococusiscatalasenegativewouldithriveordieinthepresenceof peroxides?Why? YourAnswer: Streptococuswouldthriveinthepresenceofperoxidesbecauseitdoesnotbub le whenitcomesincontact.Streptococusisgram negative,anaerobic. Catalasenegative=nobub leformation catalasepositive=bub leformation Streptococ uswouldnotsurviveinthepresenceofperoxides—itisunableto breakdownperoxides(catalasenegative).Leftunchecked,peroxideswould damagethecelularintegrityofStrepcausinglysis/celdeath. Streptococusismostoftenstreakedonto: Chocolateagar EMBagar Blo dagar StrepisoftenculturedonBlo dagarplatestodetermineitshemolyticproperties,whichaidsin theclassification(anddifferentiation)process. SpiritBlueagar TrueorFalse.TheLancefieldgroupsareusedtosubdivideantigenicgroupsofgamma- hemolyticStreptococus. True False TheLancefieldgroupingsareusedtosubdividebeta-hemolyticStrep. ThedistinctionsforLancefieldsubgroupingslieinits:(selectalthatap ly) Hemolyticactivity Catalaseactivity Carbohydratecompositionofantigens CarbohydratecompositionofantigenspresentinthecelwaldeterminestheLancefield groupings(A,B,C,etc).Note,AL strepunderLancefieldgroupingsare(bydefinition)catalase negativeandbeta-hemolytic.Thus,answersAandCcan otbeusedtosubdividestreptococal species. Aloftheabove Leftuntreated,strepthroatcanprogressto ,whichdisplays hemolytic activity. Strep.Septicemia;gamma Strep.Pharyngitis;alpha Rheumaticfever;beta Strepthroat(alsoknownasstrep.Pharyngitis)canleadtoRheumaticfeverifleftuntreated. Strep.Pharyngitisdisplaysbeta-hemolyticactivity. Strep.Pharyngitis;beta TrueorFalse.Undermostcircumstances,staphylococuscanbefoundin~80% of humanpopulationwhereitremainsnon-symptomatic. True False Staphylococusinonlyfound(non-symptomatic)in~30% ofthehumanpopulation. Definecommensalbacteria. YourAnswer: commensalbacteria:bacterianeitherharmsnorbenefitsfrom thehostfrom whichit obtainsnutrients. Thebacterium neitherharmsnorbenefitsfrom thehostfrom whichitobtains nutrients. Matchthestepofinfectiontoitsdescription. Invasion CorectAnswer Pathogenpassesthroughorbetwe ncelstoacessde pertissuesandnutrients Evasion CorectAnswer Pathogensup resseshost’simmunesystem soitcancontinuereplicating Transmis ion Matchthefolowingdiseaseswiththeirespectivesymptoms: 1.foliculitis A.Childho dskindiseasenearmouth/nose 2.scalded-skinsyndrome B.Infectionofthin,transparentscleraltissue 3.impetigo C.Infectionocursatimeofbirth 4.conjunctivitis D.Pus-filedlesionsonskinorhair 5.ophthalmianeonatorum E.Rupturedpustules;treatedwithpenicilin 1 2 3 4 5 TrueorFalse.Thecausativeagentofconjunctivitiscanbeeitherbacterialorviral. True Therearebacterial(staph)andviralformsofconjunctivitis,bothresultingintheinflammationof theconjunctivaand‘pinkeye.’ False TrueorFalse.Anacid-faststainisbestsuitedtoidentifytuberculosis(asop osedtoa Gram stain). True TBshowsapo rGram stainandshouldbescre nedviaanacid-faststain. False TrueorFalse.AlthoughTBmustbeinhaledandresideinthelunginordertocause infection,TBcanalsospreadtothebrain,spine,andkidneys. True TBcanmovesystemicalythroughtheblo dtoinfectotherareas(brain,spineandkidney). However,whenlocatedoutsideofthelung,TBtendstobenon-infectious. False Identifythediseasebasedonthefolowing(selectalthatap ly): Itisasmal,acid-fastrodusualyremainingasymptomaticforupto20years.Itaffects theskin,nerves,up erespiratorytract,andeyesofinfectedindividuals. Bacterialconjunctivitis Scalded-skinsyndrome Leprosy Hansen’sdisease Tuberculosis BandD.Hansen’sdiseaseissimplyanothernameforLeprosy.Leprosyis characterizedbyitsabilitytoremaindormantforupto20yearsaswelastheeffects observedrelativetothepatientsskin,nerves,lungsandeyes. TrueorFalse.Directlyingestingclostridium oritsassociatedsporeswilnotcause ilnessinadults. CorectAnswer True False A5-month-oldchildisgivenhoneyatbreakfastandbeginsshowingsymptoms consistentwithbotulism.Wouldthechild’silnessbeclassifiedasfo dborne,infant,or woundbotulism? Explainwhyyouchosethisanswer. YourAnswer: Infantbotulism.Thehoneywasimproplycan ed/jarredandisalowacidfo dunder anaerobicconditions.Honeyisapotentialcarrierofclostridium.TheGItractofinfantsis notdevelopedenoughtoingesthoney. Infant.Althoughfo d(honey)isconsumed,fo dbornebotulism isderivedfrom improperlycan ed,lowacidfo dsunderanaerobicconditions.Suchconditions werenotdescribed.Nopuncturewoundsorinjuriesweredescribed,rulingout wound.Thechildissufferingfrom infantbotulism,ashoneyisapotentialcarier ofclostridium.Theintestinaltrackofyoungchildrenisstildevelopingand clostridium isabletocolonizeandproducetheas ociatedtoxin. TrueorFalse.Althoughthereisnocurefortetanus,itcanbepreventedthrough vacination. True Thereisnocurefortetanus.However,tetanusisentirelypreventablethroughvacination. False Identifythemedicalconditioncharacterizedbyrobustcarbohydratefermentationunder anaerobicconditions,swelingoftheinfectedareasandfever. YourAnswer: Themedicalconditionwouldbeclostridium perfinges(gasgangrene).Gasgangrene presentswithmuscleneocrosis,swelingoftheinfectedareas,andfever.Treatment optionsincluderemovaloftheinfectedareasandamputation. Gasgangrene.Thekeyidentifierhereistherobustcarbohydratefermentation, whichmanifestsasintensegasproductionandsweling—bothtrademark conditionsofgasgangrene. Whydoesthealphatoxin(perfringolysin)producedduringaninfectionofgasgangrene causeceldeath? YourAnswer: Thealphatoxincausesceldeathbecausethetoxinperforatesthemembrane.Itforms poresintheplasmamembraneofthehostcels. Thetoxinperforatesthemembrane.Itformsporesintheplasmamembraneof hostcelsresultinginuncontroledionfluxesandeventualycelysisanddeath. Youdevelopafever,chils,andpneumoniaafterecentlyreturningfrom agetaway we kendwhereyousatinahotub.Whatbacterialdiseasewouldadoctorsuspectis causingyoursymptoms?Wouldthedoctorsuspectyoucontracteditfrom another person? YourAnswer: Legionarres.Youcan otcontractLegionaresfrom directcontractwithanotherperson. Itistransmitedthroughdropletssmalenoughtobeinhaled. Legion aires.No—legionelacan otbespreadsimplybydirectcontactbetwe n people.Legionelacanonlybetransmitedthroughdropletssmalenoughtobe breathedin. TrueorFalse.Bubonicplagueisoftencharacterizedbypainfulyswolenlymphnodes. True False Whichform oftheplagueisthemostrare?Whatdoesitarget? YourAnswer: Themostraretypeofplagueissepticmetic,whichtargetstheblo dsystem. Septicemicplagueisthemostrareanditargetstheblo dsystem. Identifythefolowingdisease: Tetanus Scalded-skinsyndrome Gasgangrene Lymedisease Lymedisease.Thetrademark‘buls-eye’rashisaclearindicator. Syphilisiscausedby: Diplococicbacteria RNAvirus Staphylococusbacteria Diplococicbacteria. Gram-Negativespirochete TrueorFalse.Chlyamidaisanobligateparasiteandassuchcanbegrownonagar platesalone. True False Anobligateparasiterequiresahost(viablecels)tobepresentforitsgrowth. Matchthefolowingdiseaseswiththeirespectivesymptomsifleftuntreated: 1. Gonorrhea A. Paralysis, blindness and dementia 2. Syphilis B. Painfully swollen lymph nodes 3. Chlamydia C. Cardiac and neurological complications D. Respiratory failure associated with lock-jaw E. Infertility and pelvic inflammatory disease. F. Sore throat, ocular discharge and fever 1 2 3 OtherIncorrectMatchOptions: • D • F • B QuizScore:96outof10 [Show More]

Last updated: 2 years ago

Preview 1 out of 14 pages