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Flashcards in The bacteria basics Deck (50):
1

Peptidoglycan

repeating disaccharide base w aa side chains that are cross linked by the enzyme Transpeptidase (blocked by PCN)
-Transpeptidase = "PCN-binding-protein"
-Peptidoglycan cell walls allow bacteria to survive osmotic stres! Give PCNs, cephalosporins, or Vanco to take away this defense - bacteria would disintegrate in hypotonic solution.

2

Catalase+

You need PLACESS for your CATs

Pseudomonas
Listeria
Aspergillus
Candida
E.coli
Staph
Serratia

3

Obligate aerobes

Nagging Pests Must Breathe

Nocardia
Pseudomonas aeruginosa
Mycobacterium
Bacillus

4

Aerobe in burns wounds, diabetes, nosocomial pneumonia, Pneumonia in CF

Pseudomonas Aeruginosa
(obligate aerobe)

5

Capsule of D-glutamate (i.e. made of aa residues)

Bacillus anthracis
(unique. Other capsules are made of sugar)

6

Periplasm enzyme

Beta-lactamases

7

LPS

Gram-negative outer membrane
more inside: Lipid A (induces TNF and IL-1)
Outer: O-polysaccharide (antigen)

8

Gram + cell wall

Peptidoglycan (support) + Lipotechoic acid (induces TNF and IL-1)

9

Pilus/fimbria

Mediates adherence of bacteria to cell surface
Sex pilus: connect bacteria during conjugation
-Made of glycoprotein
-E.g. Meningococcal pili - responsible for epithelial attachment to nasopharynx**

10

Flagella

Motility
-made of protein

11

Spore

Resistant to dehydration, HEAT, chemicals
-Keratin-like coat*, dipicolinic acid, peptidoglycan
-Spores form when shortage of nutrients --> lie dormant for years
-Kill w STEAM

Bacillus (aer) and Clostridium (anaer)
found in soil

12

Plasmid

DNA
contains genes for antibiotic resistance, enzymes, toxins

13

Glycoclayx

Mediates adherence to surface (like pilus) esp foreign ones (catheters!!!)
-made of polysaccharide (like pilus)

14

Obligate Anaerobes

Can't Breathe Air

Clostridium
Bacteroides
Actinomyces

15

Do not gram stain well

These Rascals May Microscopically Lack Color

Treponema (too thin)
Rickettisa (intracellular)
Mycobacteria (high lipid)
Mycoplasma (no cell wall)
Legionella pneumophila (intracellular)
Chlamydia (intracellular, lacks muramic acid in cell wall)

16

Silver stain

Legionella, Helicobacter pyloria, Fugni (e.g. Pneumoncystis)

17

Dark-field microscopy and fluorescent AB staining

Treponema

18

Giemsa stain

Certain Bugs Really Try my Patience

Chlamydia
Borrelia
Rickettsia
Trypanosomes
Plasmodium

19

PAS stain (periodic acid-schiff)

PASs the SUGAR (glycogen)

Stain glycogen, mucopolysaccharides
-Use to diagnose Whipples (Tropheryma whipplei)

20

Ziehl-Neelsen (carbolfuchsin**) stain

Acid fast organisms (Nocardia, Mycobacterium)- stains mycolic acid

21

India ink stain

Capsule not taken up by stain --> see translucent halo around the cell. Used primarily to identify:
Cryptococcus neoformans

India --> mother theresa --> halo --> capsule --> Crypto

22

Chocolate agar w factors V (NAD+) and X (Hematin)

H. influenzae

When child has the "flu" mom goes to V/five and X/dime store to get CHOCOLATE

23

Thayer-martin (or VPN) SELECTIVE media: Vnacomycin, Polymyxin, Nystatin

N. gonorrhoeae

24

Bordet-Gengou (potato) agar

B. pertussis

Bordet for BORDETella

25

Tellurite plate, Loffler's media

C. diptheriae

Loffffffffler (something stuck in your throat... like a pseudomembrane)

26

Lowenstein-Jensen agar

M. tuberculosis

27

Eaton's agar

M. pneumoniae

Mycoplasma like us: We like to EAT, have no cell wall, have cholesterol in our membranes

28

Pink colonies on MacConkey's agar

Lactose-fermenting enterics (e.g. E. coli)

29

Eosin-methylene blue (EMB) agar. Colons w metallic green sheen

E. coli

30

Charcoal yeast extract agar buffered w cysteine and iron

Legionella

31

Sabouraud's agar

Fungi

Sab's a FUN GUY!

32

Obligate intracellular

Stay inside when it's Really Cold
(steal ATP from the host cell)

Rickettsia
Chlamydia

33

Facultative Intracellular

Some Nasty Bugs May Live FacultativeLY

Salmonella
Neisseria
Brucella
Mycobacterium
Listeria
Francisella
Legionella
Yersinia pestis

34

Encapsulated organisms
positive Quelleng rxns (capsular "swelling")

SHiNE SKiS
**The capsule prevents phagocytosis

Strep pneumo
H. influenza Type B
Neisseria meningitidies
E. coli

Salmonella
Klebsiella
Group B Strep

35

Gram + Rods

Crappy Bacteria Can Make Logs

Clostridium
Bacillus
Corynebacterium
Mycobacterium* (acid fast)
Listeria

36

Gram + Branching filamentous

+ brANchers

Actinomyces
Nocardia (weakly acid fast)

37

Urease + bugs

CHuck norris hates PUNKSS

Cryptococcus
H. pylori
Proteus
Ureaplasma
Nocardia
Klebsiella
S. epidermidis
S. saprophyticus

38

Pigment producing: yellow "sulfur" granules
composed of filaments of bacteria

Actinomyces israelii

(yellow sand in israel)

39

Pigment producing: yellow pigment

S. aureus
aureus = gold

40

Pigment producing: blue-green pigment (pyocyanin)

Pseudomonas aeruginosa
(aerug- is green)

41

Pigment producing: red pigment

Serratia marcescens

(thing red maraschino cherries

42

Protein A

Binds Fc portion of IgG - prevents opsonization and phagocytosis <-- prevents complement activation
S. aureus

43

IgA protease

Enzyme cleaves IgA - allows colonization of respiratory mucosa

(SHiN): Strep pneumo, H. influenza type b, Neisseria (both mening and gonoc)

44

M protein

Helps prevent phagocytosis and complement activation
-mediates bacterial adherence
-Is the target for type-specific humoral-immunity
-Group A streptococci

45

ENDOTOXIN

Edema
Nitrous Oxide
DIC (activate tissue factor)
Outer membrane (LPS)
TNF --> hypotension, fever
O-antigen (on the outer part)
eXtremely heat stable (100C for 1 hr)
IL-1 --> fever
Neutrophil chemotaxis <-- C5b

46

Lysogenic phage carries genes for these 5 bacterial toxins:

ABCDE

shigA like toxin
Botulinum toxin (certain strains)
Cholera toxin
Diptheria toxin
Erythrogenic toxin of Strep pyogenes

47

Guidelines for prevention of catheter infxn

-1) Proper hand washing
-2) full barrier precautions during insertion of a central line
-3) Chlorhexidine for skin disinfection
-4) Avoidance of femoral insertion site
-5) Removal of catheter(s) when no longer needed

Most common pathogens: Coag neg staph, Staph aureus

48

Transformation

Ability to take up naked DNA and incorporate into your own. A feature of many bacteria, but esp S. pneumo, H. flu type b, Neisseria (SHiN).

49

Transduction

Transfer of genetic information between organisms by viral phages
-Generalized: a packaging event - parts of the bacterial chr may be accidentally packed in with the viral phage
-Specialized: an excision event. the phage gets incorporated into bacteria, but then poorly excised out such that some of the bacterial genome is take with the viral phage.

50

Transposition

DNA pieces w legs! can "jump" from one location to another and transfer genes from plasmid to chr and vice versa. no DNA homoogy necessary for insertion of transposon (can happen btwn different speices).