microbiology

Question 1

What is virulence?

Answer 1

the degree to which a pathogen is pathogenic

Question 2

What shape are cocci?

Answer 2

spheres

Question 3

What shape are bacilli?

Answer 3

rods

Question 4

what are the different types of agar?

Answer 4

blood
chocolate (cooked blood)
MacConkey
XLD agar

Question 5

What colour do gram positive bacteria stain?

Answer 5

purple

Question 6

what is the sequence for gram staining?

Answer 6

Come In And Stain
crystal violet
iodine
alcohol
safranin

Question 7

What environments do gram positive bacteria prefer?

Answer 7

dry/dusty - skin colonisers

Question 8

What environments do gram negative bacteria prefer?

Answer 8

wet/damp - mucous membranes

Question 9

What test is used on gam positive cocci to differentiate staph from strep?

Answer 9

catalase test (staph=+, strep=–

Question 10

What test is used to differentiate S. aureus from other staphs?

Answer 10

coagulase test (S. aureus = +)

Question 11

What two groups are strep initially differentiated into?

Answer 11

alpha and beta haemolytic streps

Question 12

What test is used to differentiate the alpha haemolytic steps?

Answer 12

optochin test

Question 13

Which alpha haemolytic strep is optochin susceptible?

Answer 13

S. pneumoniae
(other streps - viridans are resistant)

Question 14

What grouping is used to differentiate beta haemolytic streps?

Answer 14

lancefield grouping

Question 15

What bacteria is group A lancefield?

Answer 15

S. pyogenes

Question 16

What is the usual pathogen to cause CAP?

Answer 16

S. pneumoniae

Question 17

What is the first line treatment for CAP?

Answer 17

oral amoxicillin

Question 18

What are the most common pathogens to cause HAP?

Answer 18

E. coli, K. pneumoniae

Question 19

What is the 1st line treatment for hospital acquired pneumonia?

Answer 19

IV co-amoxiclav and gentamicin

Question 20

What type of gram positive rods are strict anaerobes?

Answer 20

clostridium spp - C. difficile

Question 21

What are the 4 C’s associated with C. difficile infection?

Answer 21

clindomycin
cephalopsorins
co-amoxiclav
ciprofloxacin

Question 22

What is the treatment for C. difficile?

Answer 22

stop inciting agent and start fidaxomicin or vancomycin

Question 23

What is the usual pathogen to cause meningitis?

Answer 23

S. pneumoniae

Question 24

How is meningitis treated?

Answer 24

IV cefotaxime or ceftriaxone (cephalosporins)

Question 25

How is meningococcal septicaemia treated in the community?

Answer 25

IM benxylpenicillin

Question 26

what test is used to split gram negative rods into two groups?

Answer 26

oxidase test (determines if bacteria produce certain cytochrome C oxidases

Question 27

What test is used do differentiate the oxidase positive gram negative rods?

Answer 27

indole test

Question 28

What gram negative bacteria is oxidase positive and indole negative?

Answer 28

pseudomonas aeruginosa

Question 29

What gram negative bacteria is oxidase positive and indole positive?

Answer 29

haemophilus influenzae

Question 30

What test is used to split the gram negative, oxidase negative bacteria into two groups?

Answer 30

lactose fermentation test

Question 31

What are the non lactose fermenting gram negative bacteria?

Answer 31

proteus mirabilis shigella spp salmonella spp

Question 32

What further test is done on the lactose fermenting gram negative bacteria?

Answer 32

indole test

Question 33

Give an example of a lactose fermenting, indole positive bacteria

Answer 33

E.coli

Question 34

Give an example of a lactose fermenting, indole negative bacteria?

Answer 34

klebsiella pneumoniae

Question 35

What organism causes 90% of UTIs?

Answer 35

E. coli

Question 36

What are the antibiotics used to treat UTI?

Answer 36

nitrofurantoin or trimethoprim

Question 37

What type of antibiotics inhibit cell wall synthesis?

Answer 37

glycopeptides beta lactams: - penicillins - cephalosporins - carbapenems (usufell to treat gram +ve bacteria as they have thick cell wall)

Question 38

Give an example of a glycopeptide

Answer 38

vancomycine teicoplanin

Question 39

Give an example of a penicillin

Answer 39

benzylpenicillin amoxicillin flucloxacillin

Question 40

give and example of a cephalosporin

Answer 40

cephalexin cefotaxime ceftriaxone

Question 41

Give an example of a carbapenem

Answer 41

imipenem estapenem

Question 42

What groups of antibiotics inhibit protein synthesis?

Answer 42

chloraramphenicol macrolides tetracyclines aminoglycosides

Question 43

Give and example of a macrolide

Answer 43

clarithromycin erythromycin (used instead of penicillins if allergic)

Question 44

Give an example of a tetracycline

Answer 44

doxycycline

Question 45

Give an example of an aminoglycoside

Answer 45

gentamicin streptomycin

Question 46

What groups of antibiotics inhibit nucleic acid synthesis?

Answer 46

trimethoprim (inhibits folate) sulphonadmides fluroquinolones rifampicin metronidazole

Question 47

Give an example of a sulphonamide

Answer 47

sulphamethoxazole (inhibits folate synthesis)

Question 48

Give an example of a fluroquinolone

Answer 48

ciprofloxacin (inhibits DNA gyrase)

Question 49

What is the action of rifampicin?

Answer 49

binds to DNA polymerase

Question 50

What is the action of metronidazole?

Answer 50

DNA strand breaks

Question 51

What group of people should you never give trimethoprim to?

Answer 51

pregnant women

Question 52

Name three antibiotic resistance mechanisms

Answer 52

beta-lactamase producing bacteria (resistant to penicillin derived antibiotics) MRSA - mecA gene - unique transpeptidase not inhibited by B-lactam abx efflux pump resistance mechanism

Question 53

What are the symptoms of TB?

Answer 53

night sweats, cough, haemoptysis, weight loss, malaise

Question 54

What is the treatment for TB?

Answer 54

isoniazid rifampicin ethambutamol pyrazinamide

Question 55

What test is used for TB?

Answer 55

histology with Ziehl-Neelson stain

Question 56

What test is used for TB?

Answer 56

histology with Ziehl-Neelsen stain

Question 57

What is the process of the Ziehl-Neelsen stain?

Answer 57

heat sample with carbol fuchsin dye (heat makes it resistant to decolourisation with acid) acid wash methylene blue counterstain

Question 58

Give an example of an anti fungal drug

Answer 58

clotrimazole (-azole)

Question 59

Give an example of fungal infections

Answer 59

candida albicans (vaginal/oral infections, catheter/line infections aspergillus fumigatus (lung infections)

Question 60

What test is used to confirm active HBV infection?

Answer 60

HBsAg test - positive will mean active infection

Question 61

Which cells does HIV effect?

Answer 61

CD4+

Question 62

What are the symptoms of HIV?

Answer 62

non-specific malaise, recurrent infection

Question 63

Give an example of a pathogenic protozoa

Answer 63

malaria, giardia lambia, toxiplasmosis

Question 64

What does malaria effect?

Answer 64

liver and RBCs

Question 65

What are the symptoms of malaria?

Answer 65

fever, chills, sweats, headaches, myalgia

Question 66

What test is done to check for malaria?

Answer 66

Giemsa stained thin and thick blood film

Question 67

Which is the most common pathogen to cause malaria?

Answer 67

plasmodium falciparum

Question 68

What two species can cause dormant malaria?

Answer 68

P. ovale and P. vivax

Question 69

What is the treatment for simple malaria?

Answer 69

hydroxycholoroquine

Question 70

What is the treatment for complicated malaria?

Answer 70

IV artusenate

Question 71

What medication can be given for dormant malaria?

Answer 71

primaquine