1、名校醫(yī)學(xué)微生物學(xué)28名校醫(yī)學(xué)微生物學(xué)28Objective of Experiment To master basic principle and method,which use to isolate and identify pyogenic cocci from clinical specimens.To diagnose clinical disease and guide doctors to select proper medicines .Objective of Experiment To masSpecimens (Gram-stain) Morphological char

2、acteristics (Microscopic examination) Isolation culture Smears (blood agar plate) Colonial characteristics Hemolytic reaction Pigmentation PROCEDURE morphology observation colonial typical colonies stained and observe Pure culture Antibiotic susceptibility test Direct identificationSpecimens (Gram-s

3、tain) MorpholIdentified method for StaphylococciGram-stain Isolation and culture Pure culture Direct identificationIdentified method for StaphyloStaphylococci are Gram-positive cocci, typically arranged in clumps or Grape-like clustersStaphylococci are Gram-positiv名校醫(yī)學(xué)微生物學(xué)28Direct identificationThe

4、mannitol fermentation test. The Coagulase Test The Dnase Test The phage typing test Animal ExperimentDirect identificationThe manniThe mannitol fermentation test. Inoculate the bacteria into a mannitol micro-tube,incubate at 370C for 18h.S.aureus will ferment mannitol to produce acid,which causes th

5、e medium to turn yellow. The mannitol fermentation testTest of Microbiological experiment While a patient is infected by pathogenic enterobacteria (Salmonella),how to diagnose with microbiological methods in lab? (simple procedure)While a patient is infected by pyogenic cocci,how to diagnose with mi

6、crobiological methods in lab?(simple procedure)While a patient is infected by influenza virus,how to diagnose with microbiological methods in lab?(simple procedure)Test of Microbiological experiThe Coagulase TestCoagulase is an enzyme converting fibrinogen into fibrin promoting blood clotting. It mi

7、ght be a virulence factor with the coagulated blood around the bacteria protecting them from the immune system. Coagulase-negative strains are often as pathogenic as coagulase-positive strains.The Coagulase TestCoagulase isThe Slide Coagulase TestThe Slide Coagulase TestThe Tube coagulase TestLeft t

8、ube coagulase positive Right tube coagulase negative The Tube coagulase TestLeft tThe Dnase TestInoculate Dnase agar plates with a loop so that the growth is in plaques about 1 cm in diameter.Incubate at 370C overnight.Flood the plate with 1 N hydrochloric acid.Clearing around the colonies indicates

9、 Dnase activity.The hydrochloric acid reacts with unchanged deoxyribonucleic acid to give a cloudy precipitate.A few other bacteria,e.g. Serratia,may give a positive reaction. The Dnase TestInoculate DnaseThe phage typing testThis test is used to trace the infective agent in epidemiology if necessar

10、y.It is usually not done for routine clinical purpose. The phage typing testThis tesAnimal Experimentvomitexcrementremaindered foodIsolation and identification of bacteriaMeat soup mediafilterinjection68w catobservationFood poisoningAnimal ExperimentvomitexcremenThe antibiotic susceptibility testThi

11、s test is helpful for the treatment of S.aureus infection.materialsStaphaureus（isolated from the pus of a patient）. Several kinds of filter paper （each contains different kinds of antibiotics）Nutrient agar plateThe antibiotic susceptibility The antibiotic susceptibility testStreaking the staphaureus

12、 on agar plate (thoroughly covered the plate)Put 4 kinds of paper contained different antibiotics on the plate (each paper are far away about 2 cm) Incubate at 370C for 18-24 hours. Observe the results the plates The sensitivity of the organism is indicated by the diameter of the zone of growth inhi

13、bition.The antibiotic susceptibility 名校醫(yī)學(xué)微生物學(xué)28Laboratory Diagnosis of Pathogenic Enterobacterial InfectionLaboratory Diagnosis of PathogDimidiation of the enterobacteria according to the fermentation of lactose Lactase fermenters: saprophytic and commensal Escherichia Klebsiella Citrobater Enteroba

14、cterNon lactase fermenters: pathogens Salmonella Shigella some Citrobacter Proteus Serratia Dimidiation of the enterobact名校醫(yī)學(xué)微生物學(xué)28 Colonial characteristic observationSpecimens isolation Gram Staining (SS/EMB plate) Serological identification TSI Biochemical reaction Procedure SpecimensDifferent spe

15、cimens should be taken depending on the kind and the process of the disease. blood bone marrow Urine stoolSpecimensDifferent specimens sIsolationCulture medium: S.S agar Method: streak plateResult: Pathogenetic colonies: middle size, red Suspect colonies: colorless, small, opaque IsolationCulture me

16、dium: S.S aBiochemical reactions of Salmonella, etc Species bottom slope H2S motility E.coli AG AG - + Salmonella A - +/- + Other Salmonella AG - +/- + Shigella A - +/- - bottom: ferment dextrose slope: lactose A:acid AG: acid and gas Biochemical reactions of SalmoAntigens of salmonellaO antigen pol

17、ysaccharide of LPS somatic antigen used to divide Salmonella to 42 groups A-Z groups are pathogenic stable to heat (remains activity at 100 )H antigen flagella antigen divide Salmonella tow phase: special no specialVi antigen related to the virulence of Salmonella sensitive to heat ( lose activity at 60 )Antigens of salmonellaO antige名校醫(yī)學(xué)微生物學(xué)28Salmonella Salmonella Serological Identification of SalmonellaSelect the specimenReact with A-Z polyvalent antiserumReact with several individual types of anti-O an