systemic bacteriology

Question 1

how to we identify prokaryotic pathogens

Answer 1

microscopy. looking at shape, size, grouping, structures, staining

Question 2

common shapes of bacteria

Answer 2

cocci, bacilli, spiral shaped

Question 3

cocci

Answer 3

circle. diplococcus = 2 of them. streptococcus = division in 1 plain (in a line). staphylococcus = division in 3 planes (clumps)

Question 4

bacillus

Answer 4

rod shaped bacteria, chains of them are more common in Gm +ve.

Question 5

fusiform bacillus

Answer 5

long rods and species common in GI tract, mouth, head,neck

Question 6

curved rod bacillus

Answer 6

vibrio. modified structural proteins change the shape. gm -ve.

Question 7

types of spiral shaped bacteria

Answer 7

rigid spiral bacterium, spirillum. flexible. treponema

Question 8

spores

Answer 8

inert survival structure. same as seeds. Gm +ve

Question 9

sporulation

Answer 9

response to stress/starvation. spores can persist and be spread with resistance to many antimicrobial challenges. resistant to disinfectant

Question 10

gram stain

Answer 10

retention of iodine complex by gram +ve bacteria. because its membrane is thicker stain will stay more on +ve

Question 11

limitations of gram stain

Answer 11

not all organisms stain well eg mycobacterium (more complex cell wall)

Question 12

aerobic pathogen

Answer 12

grows in oxygen

Question 13

obligate aerobe pathogen

Answer 13

require oxygen to survive

Question 14

obligate anaerobic pathogen

Answer 14

killed by oxygen

Question 15

facultative anaerobes

Answer 15

tolerate oxygen

Question 16

selective media

Answer 16

media that selects for growth of specific prokaryotes. presence of specific substances permits growth on on organism over the other. therefor can help identify

Question 17

differential media

Answer 17

incorporation of chemicals produces visible colour change to help identify what your looking for

Question 18

identification of streptococci

Answer 18

has ability to kill red blood cells, most recognisable on blood agar. alpha and beta haemolysis effect blood agar in different ways