Brainscape's Knowledge GenomeTM

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


See full index

CELL MICRO S1 > Mycoplasma and Streptococcus > Flashcards

Mycoplasma and Streptococcus Flashcards

1
Q

what are the 5 types of Mycoplasma? describe each : where are they found, oxygen req etc

A

1 Mycoplasma- parasites of animal mucous membranes
- >60 species
2 Ureaplasma- (T strain mycoplasmas).
-Microaerophilic.
-Req cholesterol and urea to grow
-Associated with nongonococcal urethritis
3 Acholeplasma- widely an animal parasite
-Can grow w/out sterols
- common contaminants of cell lines in tissue culture
4 Anaeroplasma
- strictly anaerobic
- inhabit bovine/ovine rumen
5 Spiroplasma
-helical, motile
-parasites of arthropods and plants (citrus stubborn disease and corn stunt disease)
- few cause disease in animals

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

describe the structure of Mycoplasma/Mollicutes

A
  • lack cell wall (only memb) O sensitive to osmotic lysis
  • plasma memb strengthened by STEROLS
  • pleomorphic
  • very small (smallest living cells)
  • low GC content
  • contaminate tissue cultures
  • can be grown in lab media
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the appearance of Mycoplasma on solid agar media?

A

fried egg shape

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

describe genome of Mycoplasma

A

SMALLEST GENOME of any self replicating organism- encodes 472 genes

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

which Mycoplasmas are human pathogens? How are they diagnosed? What do they cause? How are they treated?

A

1) M. pneumonia- causes resp tract inf—> results in PRIMARY ATYPICAL PNEUMONIA (walking pneumonia- milder)
Diagnosis- patchy diffuse X-ray, serological tests, culture
Treatment- ABs that don’t target cell wall (Erythromycin , doxycycline, azithromycin)

2) GENITAL MYCOPLASMAS- M.genitalium, M.hominis, Ureaplasma urealyticum. Causes non-gonococcal (non-chlamydial) urethritis (NGU).
Men-infertility
Women- cercitis, endometriosis, tubal factor infertility
Diagnosis- PCR- it is difficult to culture
Treatment- doxycycline/erythromycin or azithromycin

3) M.penetrans- infects UROGENITAL and RESP tracts
Pathogenesis- penetrates into human cells, intracellular replication and persistence for months/years.
Associated w/ HIV

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

describe lactic acid bacteria

  • how do they obtain energy
  • growing media/cond
A
  • prod lactic acid as a prod of fermentation
  • non spore forming
  • non motile
  • lack cytochromes, use sub level phosphorylation NOT ETC
  • obtain energy from sugars
  • req many vitamins, aa and purines and pyrimidines
  • aerotolerant (growth not affected by air)
  • grown on media cont yeast , peptone, supplemented by fermentable carbohydrate. colonies are small, barely pigmented
  • ACID TOLERANT- many cannot grow at pH 6 . SELECTIVE VALUE-eliminate competition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the shape of streptococci?

A

chains (divides in one plane)

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

what is the shape of lacobacillus?

A

rods

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

what is the shape of pediococcus?

A

pairs or tetrads

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

what is the shape of leuconostoc?

A

spheres in chains

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

what is the meaning of homofermentative? give an example

A

only prod LACTIC ACID as the product of fermentation

eg Strep, Enterococcus

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

what is the meaning of heterofermentative? give an example

A

produces LACTIC ACID and other products, such as CO2 and ETHANOL
eg Leuconostoc

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

describe Streptococci
shape
media for growth
catalase?

A
  • spherical cells
  • chains
  • req complex media (blood agar)
  • unable to make haem group for cytochromes or catalase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how can haemolysis be used to group streptococci

A

if COMPLETE haemolysis (clear zone)—> BETA haemolytic

if PARTIAL haemolysis (greenish-brown zone) —> ALPHA haemolytic

if NO haemolysis —> GAMMA haemolytic

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

how can antigen/serologic methods be used to group streptococci

A

use LANCEFIELD GROUPS OF BETA-HAEMOLYTIC STREPS:

  • heat up the Streps to 150°C
  • identify the carbohydrate antigen attached to it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are Group A Streptococci?

A

S.pyogenes

17
Q

Group B Streptococci

who doe sit affect?

A

S. agalactia

cattle and humans

18
Q

what does Group A Strep caused by? what does it cause?
where is it found?
how can you test for Group A Strep?

A

caused by S.pyogenes
- antigenicity of M-PROTEINS in cell wall—> grouping
- main Streptococcus diseases in humans
Found: 5-30% of people are healthy carriers in throat and nasopharynx
Test: Bacitracin sensitivity test—> zone of inhibition

19
Q

where are Group D Streptococci found?

A

intestinal tract of man and animals

hence name ENTEROCOCCI

20
Q

what does Group A Strep cause?

A
  • strep throat (treat w/ ABs)
    (inflammaton of uvula, tonsils have white exudate)
  • impetigo skin infection
    (mostly young children, small vesicles on skin form a thin amber crust)
  • Scarlet fever
    Symptoms: fever, susceptibility to ENDOTOXIC shock, ERYTHEMATOUS rash
    (caused by S.pyogenes strain carrying a bacteriophage (virus that infects bacteria) that produces either A,B or C TOXIN.
    -Cellulitis (inf of deep layers of skin)
  • Necrotizing fasciitis (invasive, toxigenic, infection of soft tissues and fascia)

Non supporative

- Rheumatic fever 
2/3 weeks after untreated pharyngeal 
Joints and heart affected
Maybe immunological reaction 
-Glomerulonephritis 
After initial Strep infection
Strep directed antibody reacts with glomerular basement membrane/ antibody-antigen complexes deposited onto basement membrane. 
Results in loss of protein via kidneys---> kidney failure
21
Q

where is group B Strep found?
who do group B Strep infections affect the most &what do they cause?
how is it diagnosed?

A

-vaginal flora of 25% of women
- affects NEWBORNS- pneumonia, septicaemia, meningitis
Diagnosis: hippurate test (hydrolyse sodium hippurate forming purple colour)

22
Q

where is group D Strep found?
what do they cause?
why is it of high concern?

A
  • found in fecal flora
  • cause UTI and wound infections
  • high concern due to V high VANCOMYCIN resistance
    (could it pass resistance to other bac??)
23
Q

what is the major group within the alpha haemolytic Strep?

what can they cause?

A

the Viridans (not a species, but a GROUP)
S.Viridans
Can cause BACTERIAL ENDOCARDITIS-inf of HEART VALVE—> fatal if not treated

24
Q

where does the Viridans group inhabit?

A

throat and nasopharynx

25
Q

give an example of a member of the Viridans. what does it cause

A

S.mutans

causes dental CARIES/CAVITIES

26
Q

what is the shape of Strep. pneumoniae?
outer structure?
habitat?

A
  • lancet shaped, arranged in pairs
  • ENCAPSULATED- can resist phagocytosis
  • habitat=normal commensal of upper resp tract
27
Q

what can Strep. pneumoniae cause?

what are mortality rates like?

A
  • acute lung inflammation
    -chills, fever and pleural pain
  • alveoli fill with exudate
  • may cause BACTEREMIA (25%)
  • pneumococci may invade other tissues (sinuses, middle ear and meninges)
    MORTALITY- 10-20% (1M deaths p/a)
    2nd most common cause of meningitis in adults
28
Q

how is Strep. pneumoniae diagnosed?

A
  • sputum smears examined for G+ve bacteria that are encapsulated
  • Quellung test: specific antibody for bacteria w/ bacteria. Causes capsule to swell O more visible & refractile due to antibody attachment
  • Optochin (AB) disks- disk diffusion assay, zone of inhibition suggests Strep.pneumoniae
  • Bile solubility test
29
Q

how is Strep. pneumoniae treated?

why are there concerns about treatment?

A 
penicillin G (except meningitis- treated with chloramphenicol)
concerns due to HIGH AB resistance O treated w/ Vancomycin, but resistance could spread from enterococci.
30
Q

how is Strep. pneumoniae prevented?

A

VACCINE- cont polysaccharide from 23 most prevalent types

31
Q

who is Strep. pneumoniae vaccine given to?

A

high risk groups (chronic resp disease)

all children in UK

32
Q

is mycoplasma a low or high GC content bacteria?

A

low (firmicute)

33
Q

is mycoplasma a lactic acid producing bacteria?

A

yes

34
Q

is Strep a low or high GC content bacteria?

A

low (firmicute)

35
Q

is Strep a lactic acid producing bacteria?

A

yes

36
Q

how does M.pneumoniae cause disease?

A
  • settles and binds on respiratory epi cell
  • using P1 adhesion proteins, adherence accessory proteins and interactive proteins
  • results in: colonisation of mucous memb and eukaryotic cell surfaces
37
Q

how does M.pneumoniae cause cell disruption?

A

produces hydrogen peroxide

38
Q

what vector is used by Spiroplasma?

A

leafhopper

CELL MICRO S1 (16 decks)

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