MicrobiologyDr. Grazielle A. Millo

1. Endospores are characteristic of the genera _______.streptococcus and escherichiaclostridium and bacillusclostridium and mycobacteriumchlamydia and bacillus

B. clostridium and bacillus

CLOSTRIDIUM Gram (+) spore forming anaerobic C. botulinum food poisoning; neurotoxin causing muscle paralysis; used for botoxC. tetani tetanus; neurotoxin (tetanospasmin)C. perfringens gas gangreneC. difficile psedomembranous enterocolitis (due to overuse of abx)

BACILLUS - Gram (+)spore forming aerobicB. anthracis anthrax woolsorters disease; capsule; pneumonia-like infection; box car appearanceB. cereus food poisoning

STREPTOCOCCUS Gram (+) exotoxin producing

ALPHA HEMOLYTIC green, rdxn of Fe in Hb; partial lysis of RBCS. pneumoniaeS. viridans = Subacute Bacterial Endocarditis (SBE)

Streptococcus viridans> S. salivarius mouth, URT, dorsal of tongue> S. mutans caries> S. sanguis plaque; inhibit S. mutans; SBE> S. mitis - cheek

STREPTOCOCCUS Gram (+) exotoxin producingBETA HEMOLYTIC clear, complete rupture of RBCGroup A = S. pyogenes> pharyngitis, rheumatic fever, strep throat, scarlet fever, acute glomerulonephritisGroup B = S. agalactiae> neonatal pneumonia

ESCHERICHIA Gram ()Virulence factors: pili; exotoxin; endotoxin

E. coli diarrhea, UTI, neonatal meningitis, pneumonia

MYCOBACTERIUMAcid Fast bacilliM. leprae leprosy Hansens disease> saddle nose, leonine faces, saber shinM. tuberculosis tuberculosis

Mycobacterium tuberculosis

Resides in hilus of lungCasseous necrosisDx aids: chest xray, sputum exam, purified protein derivative skin testPrevention: BCG vaccineTx: rifampicin, isoniazid, pyrazinamide, ethambutol, streptomycin

Types of TBPrimary TB Ghon focus (nodules seen in x-ray); Ghon complex (includes lymph nodes; rosary beads)Secondary TB reactivationMiliary TB spread all over body; disseminated thru blood streamVertebral TB Potts disease

CHLAMYDIAGram (-) bacteriaC. trachomatis eyes and genitalsC. psittaci Psittacosis; atypical pneumonia

2. Negri bodies, Guarnieri bodies and molluscum bodies are examples of____ bodiesAsteroidPsammoniaC. InclusionD. Verocay

c. Inclusion

Negri bodies rabiesGuarnieri bodies small pox

3. Which of the following substances is not produced by streptococci?HemolysinCapsulesCoagulaseHyaluronidase

C. Coagulase

HEMOLYSIN cause lysis of RBC in beta-hemolytic streptococcusCAPSULES virulence factor seen in Streptococcus pyogenesCOAGULASE produced by Staphylococcus aureusHYALURONIDASE produced by streptococcus, staphylococcus and clostridium

4. The site of oxidative phosphorylation in bacterial cell is the _______.RibosomeNucleusCytoplasmCell membrane surface

D. Cell membrane surface

PROKARYOTES (Bacteria)> cell membrane surface

EUKARYOTES> inner membrane of mitochondria (ETC)

5. The rigid cell wall of gram positive bacteria is chemically characterized as ____MucopeptidePeptidoglycanGlycopeptideMureinAll of these

B. Peptidoglycan

Capsule = POLYSACCHARIDE

Cell wall = PEPTIDOGLYCAN

Cell membrane = PHOSPHOLIPID BILAYER (bound by cholesterol)

Cell Wall / Peptidoglycan layerGram (+) = teichoic acid (thick)> BLUE

Gram (-) = murein (thin) + lipopolysaccharide (endotoxin)> RED

6. Enamel matrix laid down by ameloblasts finally becomes____.None of thesePrimarily collagen80% inorganic matter96% inorganic matter

D. 96% inorganic matter

InorganicOrganicEnamel96%4%Dentin65%35%Cementum50%50%

7. The following are cutaneous viral diseases EXCEPT ______MeaslesActinomycosisHerpes zosterSmallpox

B. actinomycosisGram (+) microaerophilic bacteriaFungi-like bacteriaCausative agent: Actinomycetes israelliCauses cervico-facial abscessesSulfur granules

MEASLESaka RubeolaAn example of the Paramyxovirus family (Retrovirus)Retrovirus = needs reverse transcriptaseRNA virusKopliks spotsHisto: Warthin-Finkledy giant cellsPrevention: MMR

HERPES ZOSTERaka ShinglesVaricella ZosterDNA virusAffects one side of the bodyTrigeminal ganglionpainful

SMALLPOXPoxvirusDNA virusSpread via respiratory tractHisto: Guarnieri bodies

8. Ludwigs angina is a _____.Streptococcal infectionStaphylococcal infectionMixed infectionSpirochetal infectionViral infection

A. Streptococcal infectionThere is bilateral submental, submandibular and sublingual fascial space infection.

9. BCG vaccine consist of ______.Killed bacteriaAttenuated bacteriaToxoid substancesChemical substance

B. Attenuated bacteriaBaccilus Calmette GuerinAnti-TB vaccineVirus is alive but with weakened virulenceINACTIVATED/KILLED capsid

ATTENUATEDINACTIVATEDPolio (Sabin)Polio (Salk)Measles, mumps, rubella (MMR)CholeraChicken poxInfluenzaYellow feverPertussisH1N1TetanusBCG (anti-TB)

10. The drumstick appendage in a neutrophil is the ______.Azurophil granuleSex chromatinFifth lobe of the segmented nucleusGolgi network

B. Sex chromatin

aka Barr body Seen only in females

11. The only class of maternal immunoglobulins that can be transferred across the placenta to provide the fetus with passive immunity is: IgGIgAIgMIgE

A. IgG

IgGcan cross the placentamost abundantsmallest in sizeIgASecretory immunoglobulinIgM1st in infectionIgEFound in parasitic infections and allergic reactionsIgDLow amounts in serum

12. The morphologic characteristics of bacteria that relates to their virulence is the: NucleusCiliaCapsuleCorkscrew form

C. capsule Other virulence factors include pili and flagella

13. In the human somatic cells, there are ____ chromosomes46242848

A. 46 23 pairs = 46 chromosomes

14. Localized tissue damage of the immediate hypersensitivity type is associated with repeated injection is known as:Kochs phenomenonArthus phenomenonPrausnitz-Kustner phenomenonEhrlich phenomenon

B. Arthus phenomenon

15. The reagent used to decolorize the primary stain in Gram staining is:AcetoneBenzeneAlcoholAcid alcohol

C. alcohol

GRAM STAINACID FASTINITIAL STAINCrystal VioletGrams IodineCarbolfuschinDECOLORIZER95% Ethyl AlcoholAcid alcoholCOUNTERSTAINSafraninMethylene blue(+) due to Teichoic acidmycoside

16. The technique of the Gram stain makes use of the rxn of the dyes with a substance in the bacterial cell known as Magnesium deoxyribonucleateRibonucleic acidZinc deoxyribonucleate acidMagnesium ribonucleate

D. Magnesium ribonucleate

17. Which tissue restores functional capabilities by hypertrophy following an injury:Cardiac muscleSkinLiverCortex of adrenal

A. Cardiac muscleHYPERTROPHYFor cells not capable of mitosisSkeletal and cardiac muscle

18. To determine the relation of acidogenic bacteria and caries, the one used is:Wasserman testIsolation of Lactobacillus acidophilusSynder testIsolation of streptococci

C. Synder testSYNDER TEST test of cariesWASSERMAN TEST test for syphilis

19. The most frequent microorganism in osteomyelitis is:StaphylococcusEnterococciGonococcusstreptococcus

A. staphylococcus

OSTEOMYELITIS = S. aureus

20. Thrush is a ____.Bacterial infectionViral infectionMycotic infectionResidual infection

C. Mycotic infectionOral Thrush/ Candidiasis/ MoniliasisCausative agent: Candida albicansWhite plaques with red base that can be scraped off =PSEUDOMEMBRANOUS TYPEReddish appearance on denture px = ATROPHIC TYPE

21. _____ is the site where the poliomyelitis virus is primarily a parasiteRespiratory systemIntestinesNasal passagesCentral Nervous system

D. Central Nervous System (CNS)

22. Resistance of Staphylococcus aureus to penicillin is caused by:An enzyme that attacks penicillinLack of mycolic acid in the cell wallPresence of tough liposaccharide capsulepleomorphism

A. An enzyme that attacks penicillin

Penicillinase

23. Aseptic refers to:Inhibition of bacterial multiplicationInfectious microorganism are killedAbsence of pathogenic microorganismKilling of bacteria

C. Absence of pathogenic microorganism

ASEPSISComplete absence of pathogensBACTERICIDALKilling of pathogensBACTERIOSTATICInhibition of growth of pathogens

24. Pathognomonic sign of PsoriasisA. Lipschutz signB. Auspitz signC. Kopliks spotsD. Nikolskys sign

B. Auspitz sign

Lipschutz signHerpes Simplex VirusAuspitz signPsoriasisKopliks spotsMeaslesNikolskys signPemphigus Vulgaris

25. Resistance of the bacteria to heat is influenced by time and temperature. Another factor is the ability of the organism toAcid resistantForm sporesUndergo transformationGrows at elevated temperature

B. Form spores

26. Detergents kill bacteria by interfering with the function of the cell ___WallRibosomesCapsuleCell membrane

D. Cell membrane

DETERGENTSCell membranePHENOLSProteinALCOHOLRibosomesBETA-LACTAMSCell wall

27. Infection with gram negative bacteria is caused by RibonucleaseEndotoxinExotoxinCapsular antigen

B. Endotoxin

Lipopolysaccharide

28. In staining characteristics, yeast cells are:Gram positiveAcid fastPAS positiveGram negative

A. Gram positive

PAS = Periodic Acid Schiff = test for carbohydrates

29. Chlamydiae and rickettsia are:Facultative intracellular parasitesObligate intracellular parasitesObligate extracellular parasitesDependent intranuclear parasites

B. Obligate intracellular parasites

30. Which of the ff is correct:Viruses cannot multiply outside living cells.Viruses are able to multiply in the laboratory in blood agar.Viruses can multiply inside and outside living cells.Viruses can multiply only in anaerobic media.

A. Viruses cannot multiply outside living cells.Because they are obligate intracellular parasites

31. The neuroreceptor is the AxonNeuronNucleolusDendrite

D. Dendrite

S- sendE- efferentA- axon_________R- receiveA- afferentD- dendrite

32. Removal of capsule from an encapsulated bacteria will result inIncreased susceptibility to mutationIncreased susceptibility to phagocytosisFailure of bacteria to gram stainingLoss of viability

B. Increased susceptibility to phagocytosis

FXN OF CAPSULE:Nutrition; Virulence factor

33. Of the ff vapors and gases, which is the most effective antibacterial agent?OzoneFormaldehydeEthylene oxidePropylene

C. Ethylene oxide

34. Mycotic infxn can give rise to diseases of the oral cavity. The most common protozoa are:Entamoeba histolytica and entamoeba gingivalisTrichomonas and entamoeba coliEntamoeba gingivalis and entamoeba coliEntamoeba gingivalis and trichomonas

D. Entamoeba gingivalis and trichomonas

35. The first clinical manifestation of HSV type I infection is usuallyKeratoconjunctivitisGingivostomatitisPerlechePharyngitis

B. Gingivostomatitis