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Microbiology Lab Final ExamPre-Midterm Material3-11, 3-8Deptict amphitricous Spririlum1.Morphology; Rod with 3 coming out Lophotrichous Rod2.Clinical Significance of bacterial capsule-capsule indicates virulence3.Why is heat fixing step omitted from capsule stain-because it shrinks the cell making it look positive for a capsule,4.Capsule stain list Primary, Secondary and Decolorizer-primary stain:Congo Red, DC: Water, Secondary: Mannevals5-4 Catalase5.Reagent Added-h2026.Positive or Negative result interpretation7.Observation indicates8.What are your conclusions9.Example of poor specificity15-6 Nitrate1.List Observation-Red color produced2.Conclusion-Nitrate is reduced to Nitrite3.Purpose of 0.1% Agar in this medium-yield anaerobic environment4.How might this observation change if KNO-3 omitted? -If KNO3 were omitted then NO3 wouldn’t reduce to NO2 so the color change wouldn’t be observed.2-1,2-5 Ubiquity of Organism1.Living things are composed of compounds from what fourbiochemical families? –Proteins, nucleic acids, lipids, 2.Define Ubiquitous-Grows everywhere3.Define Commensalism-one org benefits the other is 4.Given the ingredients list type of media ex. Defined or undefined?5-7 Citrate1.What inoculating Used-Needle
2.Inoculation Method-Streak no stab3.Indicator in medium-Bromthymol blue4.Result-the organism is positive5.Conclusions from this test-the organism produces citrase.Section Five- Differential Tests Ex. 5-10, 15,20, 22 & 23: BEA,DNAse,novobiocin,TaxoA,TaxoP, CAMP, BA, andCoagulaseStreptococcal pathogens and Staphylococcal pathogens.Media used for the test and ingredients that make the test possible.Indicator and the end product of interest it detects.Relevant Observation, Result and Conclusion (ORC)GPC FlowchartMRSA & VRE5-10 Bile Esculin Agar1.Selective2.Acid hydrolysis of esculin to Glucose and esculetin3.Esculetin plus iron forms a dark brown color=positive test4.Incubated at 35+- 2 degrees celcius for 24-48 hours5.Ferric Citrate added as a source of oxidized iron to indicate + test.6.Selective for gram negative enterics demonstrate tolerance to bile and members of streptococci.7.Used to differ enterococcus from other gamma streptococci.5-15 DNase Test1.Green Top2.May be used for Coagulase Negative organism.3.Substrate-DNA
4.Indicator-Methyl Green5.Plated on Minimal Media 2, 3 loops6.Don’t read until you 2+7.Positive test when the orgn. Hydrolyzes DNA so green to colorless, Halo may be small 24-48 hours.8.Differs Serratia(+) from Enterobacter, 9.Moraxella catarrhalis (+) from Neisseria species and 10.Staphylococcus aureus (+) from staphylococcus species11.Forms Fragments12.Dnsae from staphylococcus hydrolyzes DNA at the bond between the 5’ carbon and the phosphate, therbty producing fragments with a free 3 prime phosphate.