spring term practical MCQ Flashcards Preview

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Flashcards in spring term practical MCQ Deck (57):
1

what is the proper term for throat and ear infections

upper respiratory infections

2

common bacteria to find in ENT samples

staphylococcus
haemophillis influenzae
Ps. aeroningasa
neisera sp
haemolytic strotococcu
coryneforms

3

common bacteria in blood: aerobic

streptococci
staph aureus
s.peumoniae
enterococci
haemophillis influenzae
psuedomonas aeroginosa
neiseria mingitidius

4

common anaerobic bacteria in blood samples

bacteriodies spp
clostridium spp.
stroptococci

5

where should genital swabs be plated?

on blood
aerobic and anaerobic
chcolate agars
gram stainedo

6

pathogens in genital swabs

n. gonorrhea
canida albicans
streptococcus spp.

7

how should CSF be handled?

centrifuged for 10mins at full speed
resuspeneded sediment in 0.5ml of supernantant fluid
gram film this on blood and chocolate

8

common CSF pathogens

Haemophilis infulenzae
streptococcus pygones
nieseria menignitis
mycobacterium tuberciosis

9

how should sputum samples be dealt with

plated on blood, choc, maconkeys and choc under 10% CO2
Optochocin disk on blood plate

10

optochochin on blood plate of sputum samples use

aids in differntiation between streptococcus pneominiae and other alpha-haemolotic streptococci

11

how should a faecal sample be dealt with?

emulsified in sterile saline and inncolulated into selenite broth, maconkeys agar or DCA or prestons agar

12

prestons agar results with faecal sample

small transparent colonies might be seen and should be gram stained and tested
this only occurs if no lactse fermenters found on macconkeys agar

13

acintomycotis

pus and would exudates
granules indiactes this

14

whats the selective agent in macconkeys agar?

bile salt
sodium tauroglycholate

15

whats the differntiate agent in macconkeys agar?

lactose with bromo-cresol purple

16

why is sorbitol macconkeys used?

E.coli 0157:H7

17

selective agent in desoxycholate citrate agar

sodium dexoycholate and citrate

18

why do salmonella on desoxycholate citrate agar have a central black dot?

production of Fes

19

oxidase test

detects presence of cytochome oxidase
purple colour indictes positive reaction

20

catalase test

produced by aerobic bacteria to protect from toxic oxygen byproduct of peroxidase

21

OF test

oxidatative fermemtation
ability of bacteria to ferment specific sugars eg gucose maltoe lactose
acid detected through color change

22

whats the two options of the result of the OF test

bacteria either degrate the sugrs using embden=meyerhof pathway to pyruvate
OR
mixed acid fermenters producing acid
OR
budanedoil fememnters

23

what is VITEK

better version of API strip
faster and accurate
automated machine

24

how can LSP be used in sub-typing?

reagents can recognise O antigen side chain on LPS and the different ones of this recognise sub types within the genus of salmonella and E.coli
each sugar can be detected by specific antibody conferring the serotype specificity

25

what media does haemophilus onfluenzae require?

grows well on choclate
requires factors X (haemin) and V (NAD) to grow

26

red colonies on chomogenic UTI agar

cleaved by beta-galactoside
ECOLI

27

blue colonies on chromochenic UTI agar

cleaved by beta-glucosidase
enterococci

28

purple colonies on chromogenic UTI agar

cleaves both
indicates other coliforms

29

what should stool samples be cultured for?

campylobacter
ecoli
shigella and salmoella

30

media for campylobacter

modified CCDA

31

media for Ecoli

sorbitol macconkeys

32

media for shigella and salmonella

XLD or DCA after preenrichement in selenite broth

33

basic process of MALDI-TOF

bacteria loaded onto target plate
matrix added
bacterial co-crystalises and becomes cloud of protons
ions travel through magnetic field
separate on mass and charge
detections of this and print out of mass spectra

34

streptococcus serotyping

uses latex beads coated with ab against serotype A carbohydrate
they aggultinate as the bind to surface of serotyped bacteria

35

phagovar

bacterium with sensitivity to certain collections of phage types

36

bacteriophage typing

lawn on bacteria on agar
add phage in refrence grid
plaques of lysis show sensitvity to the phage

37

why is subtyping important

track down source of infections
identifying a pathogenic subtype can be important also

38

what is In situ hybridisation used for?

uses a tissue section
can detect virus infections in cells

39

how does In situ hybridisation work?

DNA probe used of a few nucleotides, its labelled /tagged
sample heated and cooledallowing DNA to denature and probe hybridses

40

how is PCR used to subtyping?

rapidly amplifies known sequence of DNA and can detect the microbe when its hard to grow
very sesnsitie to low levels

41

another name of PCR

NAA
nucleic acid amplification

42

mecA gene

NAA
identifieds methicillin restiatnce in staph aureues

43

siaD

NAA
synthesis of capsular sialic acid in neiseria meningitis

44

RFLP

restriction fragment length polymorphism

45

catalse test priniciple

catalase decomposes hydrogen peroxide with oxygen

46

use of catalase test

differentiation of staphylococcus from streptococcus and bacillus from clostridium

47

coagulase test principle

coagulase reacts with prothombin factor plasma creating a complex which reacts with fibrin producing fibrin forming a clot

48

citrate test

citrate may be usedas sole source of carbon
pH value of medium raised

49

coagulase test used for

staphylococci
takes hours

50

oxidase test principle

reaction detects cytochome oxidase activity
purple is pos

51

OF test

to determine if bacteri is oxidative or fermetative or both in using carbs
pink in closed tube: ferment
pink in closed tube: oxiative
pink in both: both pathways

52

phospate test

distunguising between pathogenic and non-pathogenic staphylococci and between enterobcter and serratia

53

salmonella serotyping

antisera reacting to cell surface (O) or flagella (H) antigens

54

urease test

observing pH increase when urease splits to urea,
pos: pink colour

55

what does the urease test differntiate?

identification of Proteus

56

number of baccteria in male urine normally bacteruria

3,000

57

bacteruria in female urine normally

10,000