Bacteria Basics & IDs Flashcards
Gram Negative Circular Cocci:
Maltose fermenter vs. Nonfermenter?
Maltose Fermenter: N. meningitidis
Maltose Nonfermenter: N. gonorrhoeae
Gram Negative “Coccoid” Rods?
- Haemophilus influenzae (requires factors V & X)
- Pasteurella - animal bites
- Brucella - brucellosis
- Bordetella pertussis
“Italian Foods - Pasta, Bruschetta, Bordetella”
“ATE the FOOD” (H. flu)
Gram Negative Enterics, Oxidase positive, Comma-shaped:
Grows in 42 deg C vs. Alkaline Media?
42 deg C = Campylobacter jejuni
Alkaline media = Vibrio cholerae
Gram Negative Rods:
Latose fermenter - fast vs. slow?
Fast fermenters = Klebsiella, E. coli, Enterobacter
Slow fermenters = Citrobacter, Serratia
Gram Negative Rods:
Lactose Nonfermenters - Oxidase pos vs. neg?
Oxidase positive = Pseudomonas, H. pylori
Oxidase negative = Shigella, Salmonella, Proteus
Gram Positive, Branching filamentous:
Anaerobe vs. Aerobes?
Anaerobe (not acid fast) = Actinomyces
Aerobe (acid fast) = Nocardia
Gram Positive Rods (bacilli)?
- Clostridium (anaerobe)
- Corynobacterium
- Listeria
- Bacillus (aerobe)
- Mycobacterium (acid-fast)
Gram Positive Cocci – Catalase positive (clusters);
Coagulase pos vs. neg?
Coagulase positive = S. aureus
Coagulase negative =
- S. epidermidis (Novobiocin sensitive)
- S. saprophyticus (Novobiocin resistant)
Gram Positive Cocci, Catalase negative (chains):
- Optochin sensitive vs. resistant?
- Bacitracin sensitive vs. resistant?
Streptococcus
Optochin - Viridans is Resistant; Pneumoniae is Sensitive
— “OVRPS” (overpass)
Bacitracin - group B strep are Resistant; group A strep are Sensitive
— “B-BRAS”
Gram Negative Rods:
- Zoonotic organisms?
- Francisella
- Brucella
- Pasteurella
- Bartonella
Gram Negatives:
- Pleomorphic organisms?
- Rickettsiae (Giemsa)
- Chlamydiae (Giemsa)
Which bacterial organism does not Gram stain b/c it has no cell wall?
Mycoplasma
cell membrane contains sterols
Which bacterial organism has Mycolic Acid & a high Lipid content in their cell wall?
Mycobacteria
Bugs picked up by Giemsa stain?
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium
Certain Bugs Really Try my Patience
Bugs picked up by the Ziehl-Neelson (carbol fuchsin) stain?
Nocardia & Mycobacterium
acid fast organisms
Bugs picked up by the India Ink stain?
Cryptococcus neoformans
Mucicarmine can also be used to stain thick polysaccharide capsule red
Bugs picked up by Silver stain?
Legionella, Helicobacter pylori, & Fungi (e.g. Pneumocystis)
Obligate aerobes?
Nocardia, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Bacillus
“Nagging Pests Must Breathe”
Obligate anaerobes?
Clostridium, Bacterioides, Actinomyces
“anaerobes Can’t Breathe Air”
(lack catalase &/or superoxide dismutuase, thus are susceptible to oxidative damage)
Obligate intracellular organisms?
Rickettsia & Chlamydia
“stay inside b/c it’s Really Cold”
can’t make own ATP
Facultative intracellular organisms?
Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis
“Some Nasty Bugs May Live FacultativeLY”
Catalase-positive organisms?
Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S. aureus, Serratia
“you need PLACESS for your CATs”
- recurrently infect ppl w/ chronic granulomatous disease (NADPH oxidase deficiency) b/c they degrade the limited H2O2
H. influenza - Culture/media reqs?
Chocolate agar w/ Factors V (NAD+) & X (hematin)
N. gonorrhoeae & meningitidis - Culture/media reqs?
Thayer Martin (VPN) Media:
- Vancomycin (inhibits gram +’s)
- Polymyxin (inhibits gram -‘s except Neisseria)
- Nystatin (inhibits fungi)
“to connect to Neisseria, use your VPN client”
B. pertussis - Culture/media reqs?
Bordet-Gengou (potato) agar
C. diphtheriae - Culture/media reqs?
Tellurite plate, Loffler’s media
M. tuberculosis - Culture/media reqs?
Lowenstein-Jensen agar
M. pneumoniae - Culture/media reqs?
Eaton’s agar
Lactose-fermenting enterics - Culture/media reqs?
Pink colonies on MacConkey’s agar
(fermentation produces acid, turning colony pink)
E. coli is also grown on eosin-methylene blue (EMB) agar as colonies w/ green metallic sheen
Legionella - Culture/media reqs?
Charcoal yeast extract agar buffered w/ cysteine & iron
Fungi - Culture/media reqs?
Sabourad’s agar
“Sab’s a FUN GUY”
Encapsulated bacteria?
They have a positive ______ reaction.
Streptococcus pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis, E. coli, Salmonella, Klebsiella pneumoniae, Group B Strep
- Positive Quellung Reaction (capsule swells)
- Are opsonized, then cleared by spleen
Asplenics have decreased opsonizing ability & are at risk for severe infections (esp. of encapsulated bugs).
What vaccines should be given?
S. pneumoniae, H. influenzae, N. meningitidis
Urease-positive bugs?
Cryptococcus, H. pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, S. epidermidis, S. saprophyticus
“CHuck norris hates PUNKSS”
4 pigment-producing bacteria?
Actinomyces isralii - yellow “sulfur” granules composed of filaments of bacteria
(Israel has yellow sand)
S. aureus - yellow pigment
(aureus = Latin for gold)
Pseudomonas aeruginosa - blue-green pigment
(Aerugula is green)
Serratia marcescens - red pigment
(think, red maraschino cherries)
Name causative organism.
Single broad-based bud seen on KOH prep from a pulmonary infiltrate
Blastomyces dermatitidis
Gram positive organisms?
Cocci = Staph & Strep
Branching Filamentous = Actinomyces & Nocardia
Rods = Corynebacterium, Bacillus, Listeria, Clostridium, Mycobacterium
“Corny Actors Knock Back Listerine in the Closet” (+ Staph, Strep, & Mycobacterium)
Gram Negative Rods: Respiratory Organisms (aerosol transmission)?
- Haemophilus (pleomorphic)
- Legionella (silver)
- Bordetella
