Classification of medically important organisms

Question 1

how do you write the genus and the species?

Answer 1

the Genus is in capital letter, species is lowercase, and all is italic

Question 2

what colour is gram positive bacteria?

Answer 2

purple

Question 3

the bacteria genus, Bacillus, how would you describe them?

Answer 3

they are gram positive, they are rod shaped, live everywhere - air, soil, water, they’re quite large compared to other bacteria. they are aerobes and they form spores.

Question 4

why are spores needed in Bacillus?

Answer 4

they are important in terms of survival. when the food isnt good / temp isnt suitable, then these bacteria will sporillate and become inactive but still alive

Question 5

give examples of Bacillus bacteria and what they cause

Answer 5

B. anthracis - causes anthrax
B. stearothermophilus - highly resistant to heat
B. cereus - food poisoning bacteria

Question 6

name some genus of gram positive rod shaped bacteria

Answer 6

Bacillus, clostridium, listeria

Question 7

describe the gram positive rod shaped bacteria, Clostridium

Answer 7

it lives in soil and water and is anaerobic, it forms spores, produce gas (they stink)

Question 8

examples of clostridium bacteria and what they cause

Answer 8

C. perfringens - causes gas gangrene
C. tetani - causes tetanus
C. botulinum - serious food poisoning, used to produce botox

Question 9

where do Listeria grow?

Answer 9

they are common in the environment, can grow at fridge temp

Question 10

what is the main species of Listeria? and what does it cause?

Answer 10

L. monocytogenes - it causes listeriosis (Rare), it can cross the placenta, can cause spontaneous abortion

Question 11

which 2 gram positive bacteria form spores?

Answer 11

Bacillius and Clostridium

Question 12

describe Corynebacterium

Answer 12

they are gram poisitive, irregular shaped rods, they live in the air, water and skin, they are aerobic

Question 13

give 2 examples of corynebacterium and what they are used for

Answer 13

C. glutamicum, - used to make glutamic acid (MSG).

C. diphtheriae - causes diphtheria, produce exotoxins

Question 14

give examples of gram positive cocci genus

Answer 14

staphylococcus, pseudomonas, streptococcus

Question 15

describe staphylococcus

Answer 15

they are gram positive, cocci shaped bacteria. they live in the air, soil, skin, it is a facultative anaerobe and an opportunistic pathogen

Question 16

give examples of staphylococcus bacteria and what they cause

Answer 16

S. aureus - causes boils , TSS, endocarditis, antibiotic resistance
- S. epidermidis - medical device infection

Question 17

describe streptococcus

Answer 17

they live in air, soil and the throat
they are a facultative anaerobe
- opportunistic pathogen

Question 18

give examples of streptococcus bacteria and what they cause

Answer 18

S. pneumoniae - can cause bacterial pneumonia, produces a capsule
S.pyogenes - causes sore throats and scarlet fever

Question 19

give examples of gram negative bacteria genus

Answer 19

Pseudomonas, escherichia, neisseria

Question 20

describe Pseudomonas

Answer 20

it is a gram negative rod, it is ubiquitous, aerobe, opportunistic pathogen, antibiotic resistant bc of the slime, biochemically versatile - can metabolisme many different things,
they produce slime

Question 21

give examples of 2 gram negative rod shaped genus bacteria

Answer 21

Pseudomonas, escherichia

Question 22

give examples of a gram negative cocci shaped genus bacteria

Answer 22

neisseria

Question 23

give an example of Pseudomonas bacteria and what does it cause

Answer 23

P. aeruginosa, causes 50% of gram negative infections, cystic fibrosis, conjunctivitis, contact lens contamination, secondary infection of wounds, burns etc

Question 24

describe Escherichia

Answer 24

it’s E.coli, comes only from our gut, can survive in soil, water and vegetation.
it is a facultative aerobe, its enteric

Question 25

where does E.coli come from/?

Answer 25

strictly only our gut

Question 26

what does enteric mean?

Answer 26

it lives in the gut

Question 27

give an example of Escherichia

Answer 27

E.coli - some strains are pathogens, causes 80% of UTIs, infant enteritis and cystitis

Question 28

describe Neisseria

Answer 28

a gram negative cocci shaped bacteria
they live in throats and air
facultative anaerobe
diplococci - hang around in pairs

Question 29

give example of Neisseria and what they cause

Answer 29

N.meningitidis - causes bacterial meningitis which has a 100% mortality rate if untreated and less than 15% mortality rate if treated .
-N. gonorrhoeae, causes gonnoria and it has to live in humans, cant live in soil

Question 30

which bacteria are neither gram positive or gram negative?

Answer 30

Mycoplasmas and mycobacteria, and the obligate intracellular bacteria, they HAVE to live inside cells - difficult to grow in lab

Question 31

what is the structure of mycoplasmas?

Answer 31

they are the smallest free living organisms, they have no cell wall therefore they cant be gram stained, they have a very small genome

Question 32

why cant mycoplasmas be gram stained?

Answer 32

they have no cell wall

Question 33

give 2 examples of mycoplasmas

Answer 33

M.pneumoniae, M.genitalium

Question 34

features of mycobacteria:

Answer 34

very slow growing - takes 12 days, this is bc it has very unusual cell wall structure - waxy due to mycolic acid, can be stained using Ziel-Nielson stain

Question 35

give 2 examples of mycobacteria:

Answer 35

M.tuberculosis, M.leprae

Question 36

list some obligately intracellular bacteria and what do they cause?

Answer 36

• Chlamydia eg C.trachomatis causes pelvic inflammatory disease, linked to ectopic pregnancy (grow outside the body)
  2. Rickettsia - causes typhus spread by arthropods.

3.Coxiella - causes Q fever

Question 37

how can you go grow obligately intracellular bacteria in the lab?

Answer 37

must be cultivated in living tissue, this hinders research