micro-classification and identification fo bacteria of medical importance

Question 1

why do we need to learn medical microbiology

Answer 1

to study microbes that cause disease

help with diagnosis prevention and treatment

Question 2

what is the germ theory of disease

Answer 2

Changed peoples perception of microbes and the aetiology agents of disease
discovered by louis pasteur

Question 3

what are the three main types of organisms

Answer 3

eukaryotes
prokaryotes
viruses

Question 4

give examples of eukaryotes

Answer 4

fungi and protozoa

Question 5

give examples of prokaryotes

Answer 5

eubacteria

Question 6

describe viruses

Answer 6

non cellular

50-100 mm in length

Question 7

what are bacteria divided into

Answer 7

gram +ve and gram -ve

Question 8

describe gram negative bacteria

Answer 8

have a thinner cell wall by a phospholipid membrane with LPS molecules attached

Question 9

what shape are cocci bacteria

Answer 9

circular

Question 10

what shape are rod/bacilli bacteria

Answer 10

long straight noodle shape

Question 11

what shape are coccobacilli

Answer 11

stretched out oval

Question 12

what shape a vibrio

Answer 12

curved C shape

Question 13

what shape are spirilla

Answer 13

wiggle shaped

Question 14

how do we identify bacteria in the lab

Answer 14

they need to be isolated and in pure culture

then cultivated on columbia blood agar

Question 15

how many bacteria can we currently cultivate

Answer 15

around 700 app

Question 16

why can we not cultivate all bacteria

Answer 16

due to the fact we cannot correctly simulate all the conditions needed to grow certain bacteria

Question 17

what are the types of differential characteristics

Answer 17

colony morphology

cell morphology

Question 18

what is colony morphology

Answer 18

a change in shape haemolysis and pigment

Question 19

what is cell morphology

Answer 19

shape spores and gram staining

Question 20

describe the different types of haemolysis

Answer 20

a - species produce enzymes that cause oxidation of the iron in the haemoglobin molecule and that leads to a yellow green shine around these species
b - enzymes that causes complete rupture of the haemoglobin cells
gamma - no haemolytic enzymes produced

Question 21

what is the procedure of gram staining

Answer 21

fixation 
WASH 
crystal violet 
WASH 
iodine 
WASH 
decolorisation using alcohol 
WASH 
counter stain 
WASH

Question 22

describe +ve bacteria

Answer 22

+ bacteria have a thick peptidoglycan outer wall and therefore the cell wall absorbs the violet and binds to the iodine

Question 23

describe gram -ve bacteria

Answer 23

bacteria have a thin outer membrane wall and therefore cannot retain the crystal violet and iodine colour

Question 24

what colour does gram +ve bacteria change to

Answer 24

purple

Question 25

what colour does gram -ve bacteria change to

Answer 25

pink

Question 26

what are some other differential characteristics

Answer 26

metabolic activity antigens cellular composition DNA

Question 27

example of another stain test

Answer 27

ziehl neelsen test

Question 28

describe the ziehl neelsen test

Answer 28

adapted version of the gram stain

Question 29

what are the steps to the ziehl neelsen test

Answer 29

carbol function decolorisation methylene blue

Question 30

describe the catalase test

Answer 30

determines whether a sample of bacteria is capable of producing the catalase enzyme using H202 and if the catalase is present then H202--> water and O2

Question 31

describe the coagulase test

Answer 31

test the bacteria ia capable of producing a coagulase enzyme soluble fibrinogen into insoluble fibrin

Question 32

which bacteria is coagulase positive

Answer 32

s aureus

Question 33

describe the oxidase test

Answer 33

testing for Cytochrome C oxidase | reagent turns dark blue when oxidised and colourless when negative

Question 34

give examples for which bacteria we can use the oxidase test for

Answer 34

nicerella campylobacter and pasteurella sp

Question 35

give examples of gram +ve bacilli

Answer 35

Mycobacterium tuberculosis Mycobacterium leprae- Leprosy Mycobacterium avium

Question 36

give examples of spore producing gram +ve bacilli

Answer 36

``` bacillus anthracis bacillus cerus clostridium spp clostridium perferingens c tentani c botulinum ```

Question 37

give examples of motile and non sporing bacilli

Answer 37

listeria spp corynebacteria- c diphtheria propionibacteria- p acnes

Question 38

what does clostridium perfringens cause

Answer 38

gas gangrene

Question 39

what does c tetani cause

Answer 39

tetanus

Question 40

describe listeria spp

Answer 40

major human pathogen is listeria monocytogenes causing listeriosis not advised in pregnancy babies who can this can suffer from meningitis or septicaemia

Question 41

what is listeria monocytogenes found

Answer 41

in cheese and pates

Question 42

describe diphtheria

Answer 42

mucosal disease of the throat and nose. prevented by vaccine. If untreated it can cause damage of kidneys and the heart

Question 43

which bacterias are cala tase negative

Answer 43

streptococci | strep pneumoniae

Question 44

which bacteria is catalase positive

Answer 44

staphylococci aureus

Question 45

give examples of gram -ve cocci bacteria

Answer 45

veillonella spp parvobacteria acinobacters neisseria spp

Question 46

describe veillonella spp

Answer 46

obligately anaerobic meaning no oxygen for growth important members of the human oral microbiota isolated in dental plaque

Question 47

describe parvobacteria and acinobacters

Answer 47

opportunistic bacteria causing infection in compromised pt

Question 48

describe neisseria spp

Answer 48

neisseria meningitis causing meningoccal meningitis | n gonorrhoea causing gonorrhoea

Question 49

give examples of gram -ve bacilli bacteria

Answer 49

``` haemophilus spp h influenza legionella app l pneumophilia bordetella spp ```

Question 50

describe h influenza

Answer 50

associated with respiratory infections | may cause epiglossitis

Question 51

describe legionella spp

Answer 51

L penumophilia caking legionaries disease

Question 52

describe bordetella spp

Answer 52

bordetella pertussis causing whooping cough

Question 53

which species are part of of the enterobacteriacaeae oxidase negative

Answer 53

``` E coli Y pestis S dysenteriae salmonella spp providencia spp ```

Question 54

describe e coli

Answer 54

member of the commensal gut bacteria

Question 55

describe y pestis

Answer 55

caused the plague

Question 56

describe s dysenteriae

Answer 56

causes bacterial dysentery

Question 57

describe salmonella

Answer 57

salmonella enterica causes gastroenteritis | salmonella typhi causes typhoid fever

Question 58

describe providencia spp

Answer 58

causes UTI in people with catheters

Question 59

give examples of gram -ve bacilli which are oxidase positive

Answer 59

``` campylobacter spp vibrio spp brucella spp flavobacterium spp pseudomonas spp ```