Bacteria

Question 0

What color stain does gram - bacteria appear?

Answer 0

Pink or red

Colorless until stained with safranin

Question 1

Gram stain + organisms appear what color under the microscopic

Answer 1

Dark violet, purple or blue.

Gram + bacteria

Question 2

What is the purpose of gram staining?

Answer 2

To determine type of media to used for culture

Gram stain reaction, cell shape and arrangement

Question 3

What color does acid fast organisms stain?

Answer 3

Retain carbolfuchsin
Turn red
Used for mycobacterium

Question 4

What is the zone of inhibition?

Answer 4

Disks are impregnates with antibiotics and put on the plate which has bacteria on it. If the bacteria grows up to the disk the antibiotic is resistant. If growth is inhibited, the abx is sensitive.

Question 5

What bacteria could be resistant to b Lactamase?

Answer 5

Hemophilia influenza, news seeks gonorrhoeae, staph coccyx, Pseudomonas.

Question 6

What is wet mount diagnostic test used for?

Answer 6

Fresh clinical specimens
Sputum for fungus
Stool for larvae
CSF a for cryptococcosis 
Vaginal - trichomonas

Question 7

Aerobic bacteria

Answer 7

Must have oxygen

Question 8

Obligate anaerobes

Answer 8

Grow without oxygen

Killed or inhibited in presence of oxygen

Question 9

Facultative anaerobes

Answer 9

Can grown with or without presence of oxygen

Question 10

Microserophilic bacteria

Answer 10

Require 2-10 % oxygen and may require increased carbon dioxide.

Question 11

Lab testing disk diffusion

Answer 11

Kirby of our paper disks impregnated with antimicrobial them placed on Ager plate with growth of organisms measures the zone of inhibition around the disk
Used to Measure as susceptible and intermediate or resistant

Question 12

What is the e test

Answer 12

And impregnated plastic strip is placed on agar plate.

Used for VRE confirmation

Question 13

What is disk approximation test

Answer 13

The disc approximation to shows inducible Clindamycin resistance

Question 14

What is broth dilution

Answer 14

Herman’s the minimum inhibitory concentration MIC

Question 15

3 methods for detecting viruses

Answer 15

Direct detection methods (hep b, RSV, HIV)
Antibody assay checks for immunoglobinsqqq
Viral culture

Question 16

Fungi determination

Answer 16

Skin scrapping - identified directly from the specimen
Some yeasts Grow on routine agar
Germ tube and sugar assimilation tests
Incubated for weeks at room temperature
Direct antigen detection methods

Question 17

How to identify viruses

Answer 17

Direct detection method ELISA, PCR, microscopy
Antibody assay for serum- immunoglobin presence or absence
Viral culture- special media

Question 18

Mycobacterium

Answer 18

Special culture techniques
Must kill bacteria first
Incubated for 4-6 weeks
PCR, DNA probes

Question 19

How are parasites detected

Answer 19

Microscopy - morphological appearance

Serological methods by reference labs

Question 20

How is mycoplasma tested for?

Answer 20

Culture rarely attempted, fastidious growth requirements

Serological testing used to diagnose infection

Question 21

Identification of Chlamydiae

Answer 21

Requires tissue culture - not done in most labs

Direct direction method fluorescent staining and ELISA technique

Question 22

What type of cell wall does gram + bacteria have

Answer 22

Peptidoglycans cell wall doesn’t allow the crystal violet to wash away

Gram neg cells have a thin peptidoglycans layer and stain red to pink
gram positivity have a thick peptidoglycan layer and stain blue or purple

Question 23

Gram - bacterial cell wall is composed of?

Answer 23

Lipopolysaccharide

Gram negative are colorless when going a gram stain until counter stained with safranin.

Question 24

Specimens not appropriate for anaerobic cultures include

Answer 24

Sputum
Rectal swab
Nasal or throat swab
Urethral swab
Voided urine