Brainscape's Knowledge GenomeTM

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


See full index

Medicine Unit 6 > Microbiology of meningitis > Flashcards

Microbiology of meningitis Flashcards

1
Q

meningitis definition

A

inflammation of the meninges
can be caused by bacteria, viruses and protozoa

other causes: cancer, inflammatory diseases and drugs

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

encephalitis definition

A

inflammation of the Brian and severity is variable
causes are HSV, parasites, autoimmune diseases, certain medications

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

what is the CNS composed of

A

brain and spinal column

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

cerebra-spinal fluid

A

clear fluid
occupies subarachnoid space and ventricular system
around and inside brain and spinal cord
cushions brain

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

infections of the CNS

A

normally sterile and well protected
has poor immune function
infections generally originate from the bloodstream
severe trauma may result in CNS infection

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

meninges definition

A

system of protective membranes enveloping CNS

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

label the image

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

what is the blood brain barrier

A

separation of circulating blood and the CSF in the central nervous syste m

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

vasogenic brain oedema cause

A

BBB injury
with association alteration in albumin transcytosis
in many forms of CNS infections

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

tight junctions

A

zonula occludens
closely associated areas of 2 cells whose membranes join together forming virtually impermeable barrier to fluid

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

meningitis with antibiotics

A

risk of neurological disorders

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

meningitis without antibiotics

A

high mortality rate

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

symptoms of meningitis

A

fever
photophobia
nuchal rigidity
altered mental status
purpuric rash
headache

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

common meningitis pathogens in neonates

A

E coli
group B streptococci
listeria monocytogenes

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

common meningitis pathogens in infants/children and adults

A

Neisseria meningitidis
strep pneumoniae
haemophilus influenza

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

common meningitis pathogens in immunosuppressed patients

A

cryptococcus neofromans
l. monocytogenes

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

Nuchal rigidity

A

stiff neck
sign of meningeal irritation
present when the neck resists passive flexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Kernigs sign

A

elicited with patient in supine position
thigh is flexed on abdomen with knee flex
elicit pain when knee extends

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

Brudzinskis sign

A

elicited with the patient in the supine position
positive when passive flexion of the neck results in spontaneous flexion of the hips and knees

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

Glass test

A

purpuric rash that doesnt fade under pressure
sign of meningococcal septicaemia

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

what are the common meningitis pathogens

A

streptococcus pneumoniae
group B streptococcus
neisseria meningitidis
haemophilus influenzae
listeria monocytogenes
escherichia coli

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

label the image to display Neisseria meningitidis interaction with the BBB

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

label the image of pathophysiology of meningitis

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
A
26
Q

neisseria meningitidis

A

gram negative diplococcus, intracellular

27
Q

what is in the image

A

Neisseria meningitidis

28
Q

pathogenicity factors of meisseria meningitidis

A

type IV pilus involvedi n mucosal colonisation
polysaccharide capsule helps avoid phagocytosis
major toxin: lips-oligosaccharide endotoxin

29
Q

what are the 6 serotypes of N.meningitidis

A

A
B
C
W
X
Y

30
Q

type IV pilus in mucosal colonisation

A

main means of meningococcal adhesion onto host cells

31
Q

pilus-mediated adhesion

A

induces formation of microvilli-like structures at the site of interaction
trigger bacterial internalisation

32
Q

consequence of pill-induced signalling

A

reorganisation of actin cytoskeleton
leads to formation of membrane protrusions
engulfing bacterial pathogens into intracellular vacuoles
polysaccharide capsule helps avoid phagocytosis

33
Q

major toxin

A

lips-oligosaccharide endotoxin

34
Q

NMEC

A

neonatal meningitis E coli
type of extra intestinal E coli
commonly inhabits in GI tract, perinatal transfer form mother
most frequent cause of gram-negative meningitis in neonates

35
Q

NMEC important factors in pathophysiology

A

K1 capsule
OMPA and type 1 pili for adhesion and invasion
CNF-1 and IbeA for invasion

36
Q

attachment of NMEC

A

mediated by type 1 pili binding to CD48 and OmpA (outer-membrane protein A) binding to ECGP96

37
Q

NMEC invasion

A

involves cytotoxic necrotizing factor 1 (CNF1) binding to 67 kDa laminin receptor (67LR; also known as RPSA) as well as type1 pili and OmpA binding their receptors.

38
Q
A
39
Q

why is NMEC protected from the host immune response

A

by its K1 capsule
invasion into macrophages may provide replicative niche
for high bacteraemia
allows generation of sufficient bacteria to cross BBB

40
Q

categories of NMEC pathogenicity factors

A

adhesions
immune evasion
iron acquisition
invasion factors
toxins

41
Q

NMEC adhesins

A

OmpA
S-fimbriae- bind sialic acid of human cell surface glycoproteins (type 1 pili)

42
Q

NMEC immune evasion

A

K1 capsule, antiphagocytic

43
Q

iron acqusition NMEC

A

enterobactin

44
Q

NMEC innvasion factors

A

IbeA receptor binding

45
Q

NMEC toxins

A

cytotoxic necrotising factor
CNF1

46
Q

processing of lumbar puncture

A

appearance
cell count
centrifugation
gram stain
culture
further tests

47
Q

CSF appearance: clear/colourless

A

normal

48
Q

CSF appearance: turbidity

A

WBC’s
possibly other cells seen in microscopy

49
Q

CSF appearance: red staining

A

RBC’s present
stroke/ haemorrhage

50
Q

hallmarks of bacterial meningitis in CSF count

A

recruitment of leukocytes into CSF
WBC’s are polymorphonucleus, lymphocytes
bacterial meningitis has high WBC count
viral and TB meningitis has lower WBC count

51
Q

in case of some WBC’s increase but bacteria isn’t visible

A

patient has meningitis but the bacteria killed by antibiotics
early stage meningitis
need to do antigen detection, capsule is highly antigenic e.g. latex bead assays
PCR testing for rapid diagnosis

52
Q

PCR testing for rapid diagnosis

A

alternative to antigen testing
confirmation of gram staining
specific primers
broad-range/ universal primers

53
Q

typical approach for fungi and parasites

A

microscopy
culture
antigen detection
PCR

54
Q

treatment of bacterial meningitis

A

commence ASAP before microbiological diagnosis
high dose intramuscular or IV benzylpenicillin given at earliest opportunity
high does IV 3rd generation cephalosporin
antibiotic susceptibility may modify treatment
household contacts may be given prophylactic antibiotics

55
Q

TB meningitis treatment

A

long term treatment with specialised anti-tubercular/ antifungal agents

56
Q

3rd generation cephalosporins in meningitis

A

ceftriaxone or cefotaxime or broad spectrum activity vs gram positives and gram negatives
penetrate well into CSF

57
Q

different meningitis vaccines

A

meningitis B
6 in 1
pneumococcal
Hib/Men C
meningitis ACWY

58
Q

6 in 1 vaccine

A

also known as the DTaP/IPV/Hib/Hep Bvaccine, offers protection againstdiphtheria,tetanus,whooping cough,hepatitis B,polioandHaemophilus influenzae type b (Hib).

59
Q

common causes viral meningitis

A

enteroviruses
HSV-2
HIV
LCMV
arbovirus
mumps

60
Q

less common causes of viral meningitis

A

HSV-1
CMV
EBV
VZV
adenovirus
measles
rubella

61
Q

rare causes of viral meningitis

A

influenza
parainfluenza
rotavirus
vaccinia
encephalomyocarditis virus

62
Q

treatment of acute viral meningitis

A

primarily symptomatic and includes use of analgesics, antipyretics and antiemetics
oral or IV acyclovir for HSV-1 or 2 and severe EBV or VZV

Medicine Unit 6 (23 decks)

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