Microbiology

Question 1

what colour do gram negative bacteria stain

Answer 1

pi’N’k (‘N’egative)

Question 2

what colour do gram positive bacteria stain

Answer 2

‘P’urple(‘P’ositive)

Question 3

what different shapes can bacteria be

Answer 3

spiral, cocci(spheres) or bacilli(rods)

Question 4

what do bacteria replicate by and under what conditions can they replicate

Answer 4

by binary fusion

in aerobic, anaerobic or microaerophilic conditions

Question 5

what is an endotoxin and where is it found

Answer 5

it is a toxin found in gram negative bacterial cell wall

eNdo = Negative

Question 6

what is an exotoxin and where is it found

Answer 6

toxin found in gram positive bacteria, produced inside cell and exported out of it

Question 7

what does commensal mean

Answer 7

part of the normal flora

Question 8

what does opportunistic pathogen mean

Answer 8

usually causes problems in immunocompromised patients

Question 9

what is pathogenicity

Answer 9

ability of an organism to cause disease/infect host

Question 10

what is virulence

Answer 10

degree of pathogenicity/severity of disease in host

Question 11

what is the coagulase test used for

Answer 11

to determine between coagulase +ve staph aureus(appears golden) and coagulase -ve staphylococcus( eg staph epidermis)

Question 12

what is partial haemolysis caused by

Answer 12

caused by enzymes denaturing haemoglobin inside RBCs

Question 13

what is complete haemolysis caused by

Answer 13

caused by enzymes that lyse RBCs

Question 14

describe alpha haemolysis

Answer 14

partial haemolysis
appears as greening of colonies
eg Strep viridans and Strep pneumonia

Question 15

describe beta haemolysis

Answer 15

complete haemolysis

appears yellow and transparent

Question 16

describe gamma haemolysis

Answer 16

no haemolysis

eg Enterococcus