Flashcards in Micro - Basic Bacteriology (Bacterial Identification) Deck (27):
What are the Gram-positive versus Gram-negative cocci?
GRAM-POSITIVE COCCI = Staphylococcus, Streptococcus; GRAM-NEGATIVE (diplo)COCCI = Neisseria
What are the Gram-positive rods (bacilli)? Which 2 have special qualities related to classification, and what are those qualities?
(1) Clostridium (2) Bacillus (3) Corynebacterium (4) Listeria (5) Mycobacterium (6) Gardnerella; Mycobacterium = acid-fast; Gardnerella = Gram variable
What are the categories of Gram-negative rods, and what bacteria within each category?
ENTERICS - Klebsiella, E. coli, Enterobacter, Serratia, Shigella, Salmonella, Proteus, Yersinia, Helicobacter, Pseudomonas, Bacteroides, Vibrio, Campylobacter; RESPIRATORY - Haemophilus (pleomorphic), Legionella (silver), Bordetella; ZOONOTIC - Francisella, Brucella, Pasteurella, Bartonella
Again, what are Gram-negative rods known for respiratory infections? Which 2 have special qualities related to classification, and what are those qualities?
Haemophilus (pleomorphic), Legionella (silver stain), Bordetella
What are the branching filaments bacteria? Which is weakly acid fast? What kind of gram stain do both have?
(1) Actinomyces (2) Nocardia (weakly acid fast); Gram-positive
What are the pleomorphic bacteria? How are they stained? Under what Gram stain are they (theoretically) classified?
Rickettsiae, Chlamydiae; Giemsa; Gram-negative
What are the spiral bacteria? Which Gram stain are they? Which one can be stained well with Giemsa?
Spirochetes: Leptospira, Borrelia (Giemsa), Treponema; Gram-negative
Which bacteria has no cell wall? What kind of Gram stain does it have?
Mycoplasma; Does not Gram stain
What is unusual about the cell membrane/wall of Mycoplasma?
Contain sterols (in cell membrane) and have NO cell wall
What is unusual about the cell membrane/wall of Mycobacteria?
Contain mycolic acid and high lipid content
Which bugs do not Gram stain well, and why?
(1) Treponema (too thin to be visualized - use dark-field microscopy & fluorescent antibody staining) (2) Rickettsia (intracellular parasite) (3) Mycobacteria (high lipid content in cell wall detected by carbolfuchsin in acid-fast stain) (4) Mycoplasm (no cell wall) (5) Legionella pneumophila (primarily intracellular - use silver stain) (6) Chlamydia (intracellular parasite; lacks muramic acid in cell wall); Think: These Rascals May Microscopically Lack Color
What is used to stain Treponema? What about Legionella pneumophila?
Dark-field microscopy and fluorescent antibody staining; Silver stain
Which bugs work best with Giemsa stain?
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium; Think: Certain Bugs Really Try my Patience
What does PAS stand for? What kind of molecules does it stain? Which disease is it used to diagnose, and what microbe causes that?
Periodic acid-Schiff; Stains glycogen, mucopolysaccharides; Think: PASs the sugar; Used to diagnose Whipple's disease (Tropheryma whipplei)
What is another name for Ziehl-Neelsen stain? What kind of organisms does it stain? What are 2 specific examples?
Carbol fuchsin; Acid-fast organisms; Nocardia, Mycobacterium
What organism is India ink known for staining? What is another staining method that can be used on this organism, and why/how?
Crytococcus neoformans; Mucicarmine can also be used to stain thick polysaccharide capsule red
What 3 organisms is Silver stain known for staining?
(1) Fungi (e.g., Pneumocystis) (2) Legionella (3) Helicobacter pylori
What media is used for isolation of H. influenzae? Include names of specific factors in this agar.
Chocolate agar with factors V (NAD+) and X (hematin)
What media is used for isolation of N. gonorrhoeae and/or N. meningitidis? Include specific components of this agar and their purposes.
Thayer-Martin (or VPN) media - Vancomycin (inhibits gram-positive organism), Polymyxin (inhibits gram-negative organisms except Neisseria), and Nystatin (inhibits fungi); Think: "To connect to Neisseria, please use your VPN client"
What media is used for isolation of B. pertussis?
Bordet-Gengou (potato) agar; Think: Bordet for Bordetella
What media is/are used for isolation of C. diphtheriae?
(1) Tellurite plate (2) Loffler's media
What media is used for isolation of M. tuberculosis?
What media is used for isolation of M. pneumoniae? What is required for their growth?
Eaton's agar, requires cholesterol
What media is used for isolation of Lactose-fermenting enterics? How are they distinguished in this media?
Pink colonies on MacConkey's agar (fermentation produces acid, turning colony pink colony;
What media is used for isolation of E. coli? How does it appear on this media?
(In addition to MacConkey's agar) E. Coli is also grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen
What media is used for isolation of Legionella? Include the specific components in this agar.
Charcoal yeast extract agar buffered with cysteine and iron