One deck to rule them all Flashcards
3 solutions for acid-fast staining
- carbol fuschin stain
- 3% acid alcohol
- methylene blue
Detecting bacterial capsule (2)
Quellung/ neufeld reaction or capsule stain
Solutions for capsule stain
India ink and carbol fuschin
Detection of spore (4)
- phase contrast microscope
- zhiel neelsen
- moeller stain
- gram stain (negative stain)
What is the flagella stain?
tannic acid and aluminium potasium phosphate
What does Neisser stain detect?
presence of polar / volutin / babes-ernst granules in C; dyphteriae
Differenciating - selective culture media?
Eosin-methylene blue, only gram negative bacteria grow, differenciates w/ lactose fermentation
Volume sample blood culture adults
20-30mL / blood culture
What is streaking?
A technique to isolate a pure strain from a single species of bacteria
Aerobic bacteria (2 ex)
- p. aeruginosa
- m. tuberculosis
Parameters of culture of aerobes
37°C, 70-80% humidity, 02, 1 atm
Parameters of culture of microaerophiles
5%O2, 10% CO2, 85% N2
What does hippurate positive mean?
It means that it hydroxylyses sodium hippurate
What does CAMP test positive mean?
Increased zone of hemolysis when put with s. aureus
How long do you keep each solution on the slide for gram staining?
Crystal violet : 2 minutes
Iodine : 1 minute
Ethanol : until it’s no longer purple
Safranin : 1 minute
Neisser 1 solution
Methylene blue, glacial acetate, 96% ethanol, distilled water
Neisser 2 solution
10% crystal violet in 96% ethanol, 96% ethanol, distilled water
Chrysoidin solution
1% chrysoidin aqueous solution in distilled water
Result of neisser staining
Bacterium : yellow, granules : purple
How do we differenciate acid-fast bacteria?
Acid-fast bacteria are resistant to decolorizer (acid) due to high amount of lipoidal material in their cell wall.
How long do we keep each solution on the slide for the acid fast?
Carbol fuschin : 5 minutes (after heat)
Acid alcohol : 5 minutes
Methylene blue : 2 minutes
What type of objective is used for acid fast stain?
1000x oil immersion objective
Size of microorganisms and virus
Bacteria : 0.1-50 microM
Fungi, protozoa : 5-100 microM
Viruses : 20-400 nM
What is waterhouse friedrichen syndrome?
hemorrhage of the adrenals
What is a bacterial lawn?
sheet of bacteria that covers an agar plate used to determine antibiotic resistance of that species or for bacteriophage typing
Example of a selective medium (2)
- manitol salt agar
- chocolate agar with vancomycin for h. influenzae
Example of a differenciation medium
eosin methylene blue agar
2 microaerophilic bacteria
campylobacters, neisserias
Microaerophilic agar for C.Jejuni
skirrow campylobacter selective agar
What is anaerostate
physical method of anaerobic incubation, with N2 and CO2 instead of room air
chemical methods for anaerobic culture of bacteria
- broth
- thioglycolate bouillon
- gaspack jar
IC bacterias grown on animals
- t. pallidum grown on rabbit testis
- m. leprae on the feet of a mouse or armadillo
examples of obligate IC bacteria
- rickettsia
- coxiella
- chlamydia trachomatitis
- mycobacterium leprae
What is a biofilm?
A collection of surface associated microbial cells that is enclosed in an ECM
2 gram positive rods
- corynebacterium
- listeria
How to diferenciate gram negative rods
lactose fermentation and oxidase test
What are the obligate structures of bacteria? (5)
- cell wall
- plasma membrane
- cytoplasm
- nucleoid
- periplasmic space
Non-essential structures of bacteria (6)
- capsule
- plasmid
- spore
- fimbriae
- pili
- flagella
How are plasmids transferred?
binary fission or conjugation
Spore formation process (4)
- bacteria divides asymmetrically
- fore spore is engulfed by mother cell
- Spore is dehydrated to mature
- Endospore is released when destruction of mother cell
Arrangements of flagella (3)
- monotrichous (p. aeruginosa)
- amphitrichous
- peritrichous (e. coli)
What do streptococci ferment?
glucose
Detection of biofilm (3)
- tissue culture plate
- tube method
- congo red staining
optimum growth media for campilobacter jejuni
- 42 degrees
- skirrow media
- microaerophilic
optimum growth media for listeria monocytogenes
- 4 degrees
- facultative anaerobic
bacteria with positive urease test
klebsiella, proteus