3.1.2 Bacterial Pathogens Flashcards Preview

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Flashcards in 3.1.2 Bacterial Pathogens Deck (32)
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1

Explain the significance of Koch’s postulates as they relate to bacterial pathogenesis

2

What are some of the various types of virulence factors?

Motility, adhesins, invasins, exotoxins, endotoxins (LPS), degradative enzymes, caspsules, siderophores, resistance to antibiotics

3

What is a virulence factor?

Help bacteria to invade the host, cause disease, and evade host defenses

4

What are some different forms of adhesion virulence factors?

Pili (fibriae): Type I pili adhere to receptors containing mannose; P pili attach to receptors containing Gal-Gal

Protein adhesins

Biofilms (e.g. plaque)

5

What are some of the different types of growth associated with invasion and spread?

Extacellularly

Intracellularly (obligate or facultative)

6

Give three types of invasion of intracellular pathogens

Passive uptake, active invasion, transcytosis

7

What is the difference b/t exotoxins and endotoxins?

Bacteria-mediated = exotoxins

Host-mediated pathogenesis = endotoxin (LPS, gram - only)

8

Give four examples of exotoxins

Enzymes, A-B type toxins, membrane damaging toxins, superantigens

9

What is the role of the different portions of A-B toxins?

B: Binds cell surface receptor

A: ezymatically active and is transported to the cell interior

10

What are some of the targets of A subunits in A-B toxins?

11

How do superantigens illicit a response?

12

What type of toxin is LPS?

Endotoxin

13

What are three methods to evade the host immune response?

Defensive, offensive, stealth

14

What are some of the different sample collection methods?

15

What are the different types of hemolysis seen in blood agar?

16

What bacteria are associated with pigment formation?

Yellow: Staph aureus

Blue-green: Pseudomonas aeruginosa

Red: Serratia marcescens

17

What are three different enzymatic tests that can be performed?

Catalase, coagulase, oxidase

18

What type of microscopy is required to detect spirochetes?

Darkfield microscopy

19

 Describe staining techniques for microscopic examination of bacteria.

Gram stain: most common stain

Acid-fast stain (Ziehl-Neelsen): mycobacteria and other acid-fast microorganisms

Wright-Giemsa stain: chlamydial inclusion bodies, spriochetes, and Rickettsiae

20

How is a gram stain performed?

21

How is an acid-fast stain performed?

22

What are some of the different serology diagnostic techniques?

Immunodiffusion

Latex agglutination

Enzyme-linked Immunosorbent Assay (ELISA)

Western immunoblot

23

What is ELISA?

24

How is Western immunoblot performed?

25

 Describe how antibiotic susceptibility testing is performed and interpreted.

26

What is the dilution test for MIC?

MIC = minimal inhibitory concentration

27

What are some molecular diagnostic techniques?

28

What type blot is performed when nucleic acid probes target DNA? RNA?

DNA: Southern blot

RNA: Nothern blot

29

What is the process of nucleic acid hybridization?

30

What are the steps of PFGE?