Brainscape's Knowledge GenomeTM

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


See full index

micro 187 maddie > LO7, 7.1-7.5 > Flashcards

LO7, 7.1-7.5 Flashcards

1
Q

upper vs lower urinary conssts of what

A

upper kidney and ureter
lower bladder and urethra

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

urine is always consdered sterile above

A

urethra

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

UTIs are dependant on factors such as:

A
  • Age
  • Sex (male vs. female)
  • Hormonal change
  • Diabetes
  • Renal failure
  • Neurological and structural abnormalities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

most common gram negative bcsillus causing UTI

A

Escherichia coli

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

most common Gram positive coccus causing UTI)

A

Enterococcus sp.

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

7.2

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

what are the used preservative that is used to ship urine

A

boric acid, sodium formate or glycerol preservative in urine transport containers

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

7.3: Culture urinary tract specimens

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

what are callibrated loops and their use

A

urine spec are inoculated using a calibrated loop that have an exact volume
routine: 1 uL
sterule: 10 uL

used for a quantitative technique for culturing urine

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

The following is the calibrated loop method of culturing

A
  1. The sample is mixed by swirling and then the lid is removed.
  2. The loop is inserted vertically into the urine in the container and then removed (check for
    bubbles). If the loop is not inserted vertically, the volume of urine picked up may be too
    large and subsequent colony counts will be erroneously high.
  3. The loop is then touched to the center of the agar plate and spread back and forth in a line
    across the diameter of the plate.
  4. The loop is drawn back and forth across the entire surface of the plate, going through the
    original streak line several times
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The plate media that are most often used for culturing urine are 4

A

BA, CLED, MAC, chromogenic
incubated at 35-37

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

7.4 : how to get CFU/ L

A

if in the 1uL you have 4 colonies then in a liter it should equal to = 4 x 10^6

ratio it out

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

first lab Learning Step 7.5: Identify the clinically significant bacteria:
Streptococcus sp. and Enterococcus sp.

2 genera and 8 species

A

Streptococcus
Enterococcus

Streptococcus pyogenes (Group A Streptococcus)
Streptococcus agalactiae (Group B Streptococcus)
Group C Streptococcus
Group D Streptococcus - Enterococcus sp.
- Non-Enterococcus
Group F Streptococcus
Group G Streptococcus
Viridans Streptococcus Group
Streptococcus pneumoniae (Learning Outcome 8, Learning Step 8.2)

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

The identification of β hemolytic streptococci is based on detection of specific

A

carbohydrate or “C” antigens in the cell wall.

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

Streptococcaceae: commone characteristiscs

A

-Gram positive cocci in pairs and/or chains
- Grey (sometimes grey-white) on BA
- catalase negative
- *facultative anaerobes
- *mesophiles
- require enriched media for growth (e.g. 5% sheep blood)
- genus Streptococcus is divided on the basis of the hemolysis reaction on blood agar (∝, ß, ϒ)

 BA: small grey or grey-white, translucent; alpha-, beta-, or gamma-hemolytic
 CLED: can be LF or NLF
 MAC: no growth
 PEA: small grey or grey-white

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

which specific test sis used to increse specification

A

PYR

17
Q

Streptococcus pyogenes (βH)

A

Latex Group “A”
PYR – positive

 Always considered a pathogen
 Can be colonized in URT, skin and anal mucosa but not considered NF
 Spread by direct contact or droplet
 Has many virulence factors (toxins, hemolysins)
 Localized Group A infections:
 Acute pharyngitis (strep throat)
 Skin infections (impetigo,
erysipelas)
 Note: rarely seen in UTI
 Streptococcal Pyrogenic Exotoxin causes:
 Scarlet fever
 Streptococcal TSS (toxic shock syndrome)
 Systemic Group A infection travels to deeper tissues (necrotizing fasciitis)

18
Q

POST-STREPTOCOCCAL DISEASES

A

Toxin production can cause secondary disease (sequelae) from localized infection:

Rheumatic Fever:
* Following respiratory infection
* May be mediated by antibodies against Group A that react with heart tissue
* Fever, carditis, subcutaneous nodules, polyarthritis

Acute glomerulonephritis
* Following respiratory or cutaneous infection
* Mediated by antigen-antibody complexes that deposit in the glomeruli
* Edema, hypertension, hematuria, proteinuria

19
Q

2 hemolosys: Streptolysin S and O?

A

S is beta hemolysis and oxygen stable*, Inactivated by acid from
fermentation of glucose (use a low-carb BA)

O is mainly in Group A, needs to be incubated anaerobically*/ oxygen liable : AB would indicate infection

20
Q

STREPTOCOCCUS AGALACTIAE

A

 NF of female GT and lower GIT (sometimes also URT)
 Can cause UTI
 Transferred to baby in utero or during birth (leading cause of neonatal
sepsis)
 Post-partum pelvic abscess and septic shock

21
Q

GROUPS C, F, AND G STREPTOCOCCUS

A

 NF of skin, nasopharynx, GIT, and GT
 Not commonly found in UTI but significant in other types of infections

22
Q

ENTEROCOCCUS SP./ Group D

A

 Group D Streptococcus is divided into Enterococcus sp. and non-Enterococcus sp.
 Enterococcus sp. can be gamma or alpha hemolytic
 NF of the lower GIT and female GT
 Most common Gram positive cause of UTI
 Prominent cause of nosocomial infections: bacteremia, UTI, abdominal, pelvic and
wound infections
 VRE – vancomycin-resistant Enterococcus sp.

23
Q

NON-ENTEROCOCCAL GROUP D STREPTOCOCCUS SP

A

 Usually considered normal flora
 Not considered a cause of UTI

24
Q

VIRIDANS GROUP STREPTOCOCCUS

A

 NF of human oral cavity, GIT, female GT
 Opportunistic, low virulence
 Infections usually from endogenous strains getting access to normally sterile sites

like teeth during surgery

25
Q

BIOCHEMICAL TESTS FOR STREPTOCOCCACEAE
6

A

Catalase
PathoDx
PYR
Bile Esculin
6.5% NaCl
CAMP

26
Q

the catalase test

A

 Catalase is an enzyme present in an organism
 Catalase breaks down hydrogen peroxide into water and O2, therby producing bubbles

 Positive: rapid production of bubbles (Staphylococcaceae)
 Negative: minimal or no bubbles (Streptococcaceae)

27
Q

CATALASE TEST
false +
false -

A

false +
* RBCs from BA – don’t gauge agar,
don’t add reagent to plate
* Pseudoperoxidase that slowly
catalyzes breakdown of peroxide
(considered to be negative but may
be recorded as “weak positive” (i.e.
Enterococcus sp.)
* Platinum loops

false -
* Medium should be “low carb” – carb
utilization results in an acid pH
which can interfere with test

28
Q

AGGLUTINATION TESTING/ pato

A

 Beta-hemolytic streptococci are often identified by antigen (agglutination) testing
 Testing detects the specific “C” antigens in the cell wall
 The antigen is extracted with an acid or enzyme
 We test the antigen against antibodies for Lancefield Groups A, B, C, F, and G

antibodies bound to latex beads are mixed with colonies and your trying to see clumps

29
Q

STREPTOCOCCUS GROUPS

A

 Group A: Streptococcus pyogenes
 Group B: Streptococcus agalactiae
 Group C, F, G: referred to as Group “C” or “F” or “G” Streptococcus

30
Q

PYR TEST

A

 Looking for enzyme PYRase
 PYRase can hydrolyze L-pyrrolidonyl-𝜷-napthylamide to 𝜷-napthylamine
 𝜷-napthylamine can be detected by N, N-methylaminocinnameldehyde (PYR reagent)
 Positive: Streptococcus pyogenes, Enterococcus sp.
 Negative: all other streptococci

 Positive: bright red/pink colour
 Negative: no colour change

31
Q

BILE ESCULIN TEST

A

 Nutrient agar slant containing 40% bile (4% bile salts), esculin, ferric ammonium
citrate (ferric salts)
 Group D Streptococcus (incl. Enterococcus sp.) can grow in the presence of bile
while other Gram pos. cannot
 Group D Streptococcus (incl. Enterococcus sp.) can hydrolyze esculin to esculetin
 Esculetin combines with ferric salts to make a phenolic iron complex (black/brown)

 Positive: black/brown (Enterococcus sp.)
 Negative: no colour change

32
Q

6.5% SODIUM CHLORIDE TEST

A

 Broth contains base infusion and 6.5% NaCl
 Some organisms can grow in the presence of increased salt, while others cannot
 Inoculate 1-2 colonies and incubate for 24-48 hours at 35-37°C

 Positive: visible turbidity (Enterococcus sp.)
 Negative: no turbidity (non-enterococcal Group D Streptococcus)

33
Q

CAMP TEST

A

 Detects CAMP factor (extracellular protein) which acts synergistically with
the beta-lysin of Staphylococcus aureus causing enhanced lysis of RBCs
 CAMP factor is produced by Streptococcus agalactiae (Group B)

streak a BA plate with a BH auerus and incubate trying to see some thicker hemolysis ? we didint do it

34
Q

I only did madies slide for this ill just read the notecs forwards

A

micro 187 maddie (10 decks)

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