M5:Module5Exam -RequiresRespondus LockDownBrowser+Webcam
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36 minutes 96 out of 100
Scoreforthisquiz:96outof10 SubmitedAug1 at1 :24pm Thisatempto k36minutes.
Theconceptoftr
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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
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