Karteikarten
Practical 3
Karten in diesem Stapel (29)
- 1Sabouraud Dextrose agars a 1. What does it grow? 2. Give species example. 3. What samples is it used for? 4. What colour is a positive result?1. Grows fungi + fungi (unicellular aka. yeasts)
2. Candida albicance
3. Vaginal samples, fungal infections
4. Creamy colour = fungal growth - 2MacConkey Agar 1. What does it grow? 2. Give species example. 3. What samples is it used for? 4. What colour is a positive result?1. Grows gram-negative, rod shaped bacteria
2. Most are enteric
2/4. E. coli = dark red
3. Feacal, urine
4. Other enteric = clear to brown - 3SS agar (salmonella-shigella) 1. Give species example. 3. What samples is it used for? 4. What colour is a positive result?1. Selectively salmonella and shigella
3. Food, faecal sample, urine sample
4. Salmonella = black; Shigella =clear - 4Vogal Johnson Agar 1. What does it grow? 2. Give species example. 3. What samples is it used for? 4. What colour is a positive result?1. Pathogenic Staphylococci
2. S. aureus
3. Foods, skin infection
4. Further tests needed - 5Clostridium agar 1. What does it grow? 2. Give species example. 3. What samples is it used for?1. Anaerobic, gram positive, rod-shaped bacteria
2. Clostridium (bacillius)
3. foods, wounds, skin samples - 6Pseudomonas-isolation group 1. What does it grow? 2. Give species example. 3. What samples is it used for? 4. What colour is a positive result?1. Pseudomonas
2. P. aeruginosa
3. Skin samples, wounds, burns, ear infections
4. P. aeruginosa light green to brown colonies - 7Blood agar1. majority of know bacteria
2. isolation of pathogenic bacteria
3. bacteria produce haemolysin - 8What is: 1. Enriched media 2. Selective media: 3. Fastidious: 4. Differential:1. Specific growth factors for fastidious microbes
2. Media that has factors that reduce other microbes such as MacConkey has bile salts which inhibits non-enteric microbes
3. Microbes with special requirements
4. Differential media is used to differentiate between 2 similar species such as SS agar. - 9What are three factors used to determine if an out break has occurred.1. Isolates represent the outbreak strain are from a recent progeny of a common precursor.
2. such isolates have the same genotype
3. Non-related have a different genotype - 10While investigating an outbreak what assumptions should apply to isolates?1. Isolate was obtained from patients, fomites and env. sources related to outbreak.
2. Isolates should be taken while outbreak was current.
3. And within physical proximity to where the outbreak is occurring. - 11List five phenotypic tests for fingerprinting1. biotyping
2. bacteriophage typing
3. biochemical fingerprinting
4. antibiotic susceptibility patterns
5. electrophoretic protein typing - 12List 5 genotypic or DNA based methods for fingerprinting1. PCR typing
2. Plasmid profile analysis
3. Ribotyping
4. Pulsed field electrophoresis
5. Restriction endonuclease analysis (of DNA) - 13List the three essential properties of typing analysis.1. Typeability: ability to determine positive, clear cut results.
2. Reproducibility: method can yield same results on numerous occasions.
3. Discriminatory Power: ability of method to determine unrelated strains - 14What are the main differences between biotyping and biochemical fingerprinting?Biotyping relies on picking up differences in biochemical reactions.
- 15Why should inoculated agar plates put upside down.1. So that any condensation does not fall on bacteria from the lid if the agar plat is stored the right way up.
2. Prevent airborne particles within the disk falling onto the bacteria (rather particles fall on the lid when upside down).
3. Prevent scientist from dropping agar plate (if it is picked up by the lid when right way up)
4. Upside down storage allows moisture to dry off in incubator. - 16List the 5 desirable properties of a typing method.1. Typeability
2. Reproducibility
3. Discriminatory Power
4. Ease of performance
5. Ease of interpretation - 17What agar is used for most Kirby-Bauer tests?Muller-Hinton with pH of 7.2-7.4
- 18Describe how the zone of inhibition is formed.Agent from the antibiotic disk diffuses into the surrounding agar. If the microbes inoculated onto the agar plate is sensitive, a zone of no microbial growth surrounding the disk results. Until the microbe can withstand the concentration of antibiotic diffused into the agar, where growth is evident. This results in a zone of inhibition.
- 19How might a gram reaction be useful in prescribing antibiotic treatments?To determine its sensitivity to the antibiotic correlates with cell wall type.
- 20Is the disk-diffusion technique measuring bacteriostatic or bactericidal activity?Bacteriostatic. If a zone of inhibition occurs, growth has been stopped. A sub-culture would be necessary to determine if the antibiotic was bacteriocidal.
- 21In which growth phase is an organism most sensitive to an antibiotic?During exponential growth when microbes are highly metabolically active.
- 22Why is the disk diffusion technique not a perfect indication of how the drug will perform in vivo?Because the in vivo environment is not as perfectly controlled/optimised as the disk diffusion environment. Factor such as drug administration, concentration, absorption through tissue, pH, and bodily temperature all effect drug usefulness.
- 23What other factors are considered before using the chemotherapeutic agent in vivo?How drug is metabolized, excreted, illness of the patient, effectivity of the drug and any side effects possible.
- 24List the advantages and disadvantage of using the pattern of antibiotic susceptibility testing for tracing the source of bacterial infection in clinical setting.Advantages: tests is easy to complete, cost effective.
Disadvantages: increased amount of microbes that have antibiotic resistance. Dish diffusion method is not comprehensive for microbial identification and should be used in conjunction with other tests. - 25Define an isolatePure culture of bacteria obtained from a subculture of a single colony. From a single oraganism.
- 26Define epidomiologically related isolatesIsolates that are culture from samples taken from patients, fomites and environment during the outbreak.
- 27Define strainIsolate that can be separated from other same species and genus by phenotypic and genotypic characteristics.
- 28Define outbreak strainIsolates from the same species that are epidemiologically and genetically related.
- 29Define endemic strainsIsolates that are frequently found from infected patients in a close location that are closely related for which no epidemiologic linkage can be found.
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- Beschreibung
- University Medical Microbiology Karteikarten am Practical 3, erstellt von Leah MacDonald am 11/10/2014.
- Erstellt von
- Leah MacDonald
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- 62
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