Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Z MD1 Practical > microbiology practicals - sem 2 > Flashcards

microbiology practicals - sem 2 Flashcards

1
Q

how can bacterial meningitis cause symptoms such as severe headache, nausea and vomiting

A

strong inflammatory response –> pus –> blocks various foramina –> increased intracranial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the commonest cause of meningitis

A

viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the 3 major bacteria causing acute meningitis and what are their characteristic gram stains

A

Haemophilus influenza B - small gram negative rods Strep pneumonia - gram positive diplococci Neisseria meningitidis - grave negative cocci in pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how does the determination of protein, glucose and leucocytes help in the management of acute meningitis

A

gives you an indication whether the infection is viral or bacterial or fungal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what rapid diagnostic tests are used in the diagnosis of meningitis

A

gram stain slide agglutination with latex beads covered with Ab PCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when should a patient be started on treatment with meningitis

A

as soon as it is suspected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the antibiotic treatment for the major causes of bacterial meningitis

A

3rd generation cephalosporin such as cefitriaxone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

which organism is the fine petecial rash assocaited with

A

N. meningitidis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why is CSF inoculated into serum broth when testing for meningitis

A

patient may have been given antibiotics prior to LP - and therefore very hard to gram stain. However if just one bacterium is left it will grow overnight in serum broth and therefore can isolate the organism easier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

which common cause of meningitis is imperative that AB susceptibility testing is performed

A

Strep pneumonia - increasing prevalence to beta-lactams (by mutating beta-lactam binding protein)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the AB that is “added in” for treatment of Strep pneumonia meningitis

A

Vancomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the characteristic gram stain of Strep B aggolacti

A

gram positive cocci in long chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the current course for prevention of birth transmitted gram negative bacteria to babies (that would cause meningitis)

A

screen mother between 35-37 weeks gestation –> if positive –> give AB 4 hours before delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the commonest cause of viral meningitis

A

enterovirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what types of things can determine disease prevalence

A
  • climate/geography - vectors, reservoirs - weather - wealth of community - hygiene, sanitation, vaccination programs - length of stay - local agriculture and animal husbandary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

parasitic infections are particularly prevalent in which type of travellers

A

those returning from the tropics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how do you diagnose parasitic infection in a returned travellor

A
  • blood (thick and thin films) - blood for serology - faeces - sticky tape to perianal area - skin snips, biopsy specimens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what do you use thick and thin blood films for

A

thick - trypanosomiasis and filariasis thick and thin films for malaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the gold standard for diagnosis of eukaryotic parasites

A

visualising them micro/macroscopically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

infections in travellers fall into what 3 broad categories

A

common infections exotic infections emerging or re-emerging infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how can a hookworm infection lead to anaemia

A

hookworm attaches to intestinal wall –> bleed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

in what stage of the life cycle does hookworm infect humans

A

semi-matured hookworm that lives in soil –> penetrates bare feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

in what stage of the life cycle does hookworm make you ill

A

when it matures into adult worm and attaches to the intestinal wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how do you diagnose hookworm

A

eggs in faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what causes the abdominal discomfort associated with ascaris infection

A

blockage of viscera (due to large size)

26
Q

in what stage of the life cycle of ascaris infects humans

A

fertile eggs - ate fertile eggs from faeces

27
Q

how does infected RBCs (with malaria) lead to organ damage

A

the infected RBCs are sticky and clog up the microvasculature for the organ = organ damage

28
Q

why do you get inflammatory symptoms with malaria

A

due to cytokine response that you get when RBCs burst

29
Q

why do you get splenomegaly with malarial infection

A

due to the spleen trying to clear all the infected RBCs

30
Q

in what stage of the life cycle does malaria infect humans

A

as sporozoites

31
Q

in what stage of the life cycle does malaria make you sick

A

as merozoites that infect RBCs

32
Q

why is strongyloides particularly nasty

A

because it can cause autoinfection (can carry gut microflora into the blood when penetrating the intestinal wall) –> gram negative septicaemia

33
Q

why does salmonella typhi live in the body

A

within macrophages

34
Q

treatment of typhoid

A

quinolones 3rd generation cephalosporins macrolides

35
Q

how do STIs lead to an increased risk of HIV

A

infection brings in WBCs to the site –> HIV can more easily infect CD4 T cells

36
Q

what is the mainstay diagnostic investigations for STIs

A

serology for antigen and antibodies

37
Q

how can you tell if an infection is acute or chronic

A

type of antibody - IgM initially, converted to IgG rising antibody titre suggests acute (GOLD STANDARD) low affinity antibodies

38
Q

why is it more likely for perinatal infection with a primary infection of the mother

A

baby wont get any Ab from the mother that would be protective if the mother hasnt encountered the antigen before

39
Q

the interpretation of serology results for STIs depends on

A

infectious agent patient test specificity and sensitivity

40
Q

what is the difference between the avidity and affinity of Ab

A

avidity = the strength of Ab binding to R from a preparation of a MIXTURE of Ab affinity = the strength of Ab binding to R from a preparation of pure Ab

41
Q

what are the different things that “Ab against X are negative” mean

A
  • hasnt been infected with X before (still susceptible) - hasn’t been vaccinated against X - has been vaccinated against X but didnt convert to Ab +ve - has the infection, but still in incubation period - could be immunocompromised - assay may not be sensitive enough - lab stuffed up
42
Q

what is the difference between an Ab response to an infectious agent or a vaccine

A

vaccine = Abs only made against a specific antigen native infection = make Ab against multiple antigens

43
Q

what is the main population that has Gonorrhoea

A

men who have sex with men

44
Q

treatment for Gonorrhea

A

ceftriaxone + azithromycin

45
Q

how are the hepatitis viruses spread?

A

A and E = foecal-oral route B, C and D = parenteral route

46
Q

what is the most sensitive marker for acute hepatitis B infection

A

Hep B surface antigen (will be negative for Ab)

47
Q

what is the significance of being HepBe Ag positive

A

it means that there is active replication of the virus

48
Q

what serology results would you expect from someone who becomes a chronic carrier of HepB

A

HbsAg +ve (negative for Ab) IgG +ve (IgM for acute infection)

49
Q

what serology results would you expect from someone who clears a Hep B infection

A
  • HbsAg -ve - Hbs Ab +ve - IgM -ve - IgG +ve - HbeAg -ve - Hbe Ab +ve
50
Q

what is the treatment for acute Hep B infection

A

give hyperimmune globulin and hep B vaccine

51
Q

which ganglia does HSV 2 hide in

A

trigeminal or sacral

52
Q

treatment of HSV

A

acyclovir

53
Q

what are the three most common causes of erythematous maculopapular rash

A

rubella parvovirus enterovirus

54
Q

which viruses can lead to significant leucocytosis

A

EBC, CMV early HIV

55
Q

what test do you perform to test for EBV

A

the monospot - have Ab to sheep RBCs (EBV infected B cells will spit out there Ab - and due to the random recombination of Ab genes there will be one that reacts to sheep blood by chance)

56
Q

use of cetrimide agar

A

contains a disinfectant

57
Q

gram stains of neisseria and clostridium

A

neisseria - GNC clostridium - GPR

58
Q

how can you tell the difference between strep pyogenes and strep agolacti

A

pyogenes (group A) = bactraicin sensitive, grows on MAC

agolacti (group B) = bactraicin R, does not grow on MAC

(both beta-haemolytic)

59
Q

explain the sensitization phase of an antigen for a type 1 HS reaction

A

APC presents to Th2 –> produces IL-4,5 and CD40L –> promotes B cell differentiation and isotype switching to IgE –> IgE binds to mast cell via FceR1

60
Q

what happens during the response phase of T1HS reaction

A

allerge promotes cross linking of IgE on mast cell –> causes degranulation and exocytosis of pre-formed mediators such as histamine, TNF-alpha, leuktrienes, PGs etc

61
Q

what happens to the gut, skin, airways and blood vessels during T1HS reaction

A

gut - increased secretion and peristalsis –> diarrhoea and vomiting

skin - increased fluid secretion and vasodilation –> swelling, itching, uticaria

airways –> decreased bronchial diameter and increased mucous –> obstruction

blood vessels –> increased permeability and blood flow –> increasd fluid into tissues –> shock

Z MD1 Practical (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions