Past papers Flashcards
Eosin methylene blue
- contains eosin, methylene blue and lactose.
- lactose fermentation –> acidification –> precipitation of eosin –> staining by methylene blue –> dark blue colonies
- contains swarming inhibitor against Proteus
Pink colonies are lactose negative.
Lactose +: E.coli and klebsiella
Lance field grouping
Lancefield grouping (cell wall polysaccharide) based on the carbohydrate composition of bacterial antigens found on their cell walls.
Group A = S.Pygogenes
Groop B= S. Agalacticae
Group D = Enterococci
Zoonosis (definition + examples)
A bacterias that is transmitted from animals to humans.
Brucella, Salmonella, Campylobacter jejuni, E.coli, Shigella, Francisella Tularensis…
Special culture media for corynebacteria bacteria
Loffler (ivory color)
Clauberg - contains Tellurite, gives a dark color and garlic smell.
Morphology of Bacillus Cerus (culture, microscope)
Gram + Rod B-hemolytic Spore-forming non-capsulated Faculative anarobic
Can give diarrhea, from meat and rice that is not handled correctly after preparation or before.
Like colder temperature.
List 4 viral vaccines (what is the content, against what disease?)
HiB - hemophilius influenza ( conjugated to the B-capsule) - Given at 2 months. DPT - Diphteria, Pertussin, Tetanus -Toxoid vaccine MMR - Mups, morbilli, rubella - Live attenuated viruses given at 15 month and 11 years.
List 4 major meningitis pathogens
Streptococcus Pneumonia Nisseria meningitis Strephtococcus. Agalacticae E.coli Staphylococcus Aureus Haemophilus influenzae ( only the capsulated form)
Indol test
- Triptophane –> indole (triptophanase enzyme)
- Amylalcoholic (=organic) reagent –> idol is dissolved here after mixing –> intensive red ring on top ( because alcohol is lighter than water!)
- can be performed in ureum-indole tube.
Indole + = E.coli
Remember: Idol, people are nervous gets diarrhea (for E.coli) on the stage then get the red buzzer (for the red ring on top)
CAMP test
To check if we have St.Pygoens or Strepth agalacticae. Use staph Aureus on blood agar. If we see a butterfly shape we know that it is Strept Agalacticae.
Staphylococcus Aureus morphological features (culture, microscope)
Gram + Coccus B-hemolytic Coagulase + Capsule Golden pigment Grape-like clusters
What exotoxins do you know? (list 4)
Toxic-shock-syndrome toxin (TSST-1) Toxic-shock -syndrome-like toxin Exfoliative toxin Enterotoxin Shigalike-toxin Shiga-toxin Boutlinum- toxin Erytogenic toxin
Catalase test
To diff between strepto and staphylococcus
Microscope slide with bacteria and water. Mix them with catalase enzyme.
If you get a bubbly reaction this is positive. Remember to take one control without the bacteria.
H2O2–> CO2 + H20
Bismuth Suplhite medium
Contains: Bismuth, sulphite, lactose and brilliant green.
H2S forms black precipitate with heavy metal ions (iron, lead, bismuth) –> black colonies. (H2S producers: proteus, salmonella)
Selective medium for Salmonella
Brilliant green
Red colonies = E.coli
Colorless colonies = Salmonella typhimurium
How can we cultivate hemophilus influenzae?
On chocolate agar with factor V (NAD) and factor X (Hemin)
On blood agar with Staph Aureus in the beta hemolytic zone- gives the satellite phenomenon.
Enterovirulent E.coli strains
EPEC - enteropathogenic E.coli ETEC - enterotoxigenic E.coli EHEC - enterohaemorrhagic E.coli EIEC - enteroinvasive E.coli EAEC - enteroaggregative E.coli
remember: PATHI
Legionella
Gram - Oxidase + Grown on BCYE agar Requires Iron and cysteine to grow Can survive on water and Air condition Respiratory droplets. Give Pontiac fever and legionnaires (gives atypical pneumonia)
Psudomonas Aruginosa
Gram -
Green/blue color
Catalase +
Oxidase +
Thrives aquatic environments
Have a grape-like odor.
Encapsulated
Obligate aerobe
Toxin targets EF2.
Diseases
- Nr. 1 cause of gram - nosocomial pneumonia
and nosocomial UTI
- Osteomylelitis - IV drug users.How and when do we use optochin disc?
Use it to diff between street Viridans and strept pneumonia
Pneumonia is optochin sensitive
Viridans is optohin resistive.
Why can helicobacter pylori survive in the stomach?
- Phili
- Urease enzyme - can create basic environment around itself.
List 4 encapsulated bacterias
Psudomonas Aureus Agalacticae Pyrogenes ( Hyaluronic acid) Bacsilus Antracsis ( proteins) Salmonella
What can be the content of an active vaccine
Toxoid Antitoxin Antigens Capsular antigens inactive bacteria
Nosocomial infection ( definition + 3 important bacterias)
Hospital acquired infections Klebsiella Hemophilus influenza E.coli Epidermidis
Which bacterias can be transmitted by water? (give 4 examples)
Cholera Legionella Clostridium botolinium Campylobacter jejuni Salmonella Shigella E.coli
