(P) Lec 5: Collection, Handling, and Processing Of Specimen

Question 1

All parts of the body exposed to the outside environment is inhabited by the
____ and specimens coming from these parts are considered ____.

Answer 1

Normal Microbiota
Non-sterile

Question 2

Consists of non-pathogenic organisms but can be pathogenic once placed outside their normal habitat

Answer 2

Normal Micriobiota

Formerly known as normal flora

Question 3

Specimens coming from body parts not exposed to the outside environment

Answer 3

Sterile Specimens

Question 4

Sterile or Non-sterile Specimen?

✦ Cerebrospinal Fluid (CSF)
✦ Peritoneal Fluid
✦ Pericardial Fluid
✦ Pleural Fluid
✦ Blood
✦ Suprapubic Aspirate (SPA)

Answer 4

Sterile

Question 5

Sterile Specimens

When cultured under normal conditions, there should be ____

Answer 5

no growth of microorganisms (absolutely negative)

Question 6

Specimens coming from body parts exposed to the outside environment

Answer 6

Non-sterile Specimen

Question 7

Sterile or Non-sterile Specimen?

✦ Urine
✦ Stool
✦ Sputum

Answer 7

Non-sterile

Question 8

Normally, urine is ____ in the bladder

Answer 8

sterile

Question 9

Collection via ____ is critical because there might be a possibility of contamination when performed incorrectly

Answer 9

midstream clean-catch

Question 10

When is urine considered sterile?

Answer 10

When collected via suprapubic aspiration

Question 11

What do MDs usually request prior to antibiotic therapy?

Answer 11

Culture & Sensitivity

Unless the objective is to monitor the treatment

Question 12

Why is sepsis and exception to requesting C&S prior to antibiotic therapy?

Answer 12

Because administration of first line antimicrobials cannot be delayed

Question 13

In automated blood culture machines, they have?

Answer 13

Antimicrobial Removing Device (ARD)

Blood C&S with ARD (antibiotic is already given but C&S is still requested)

Question 14

In aseptic collections and sterile containers, there should be no ____

Answer 14

Contaminants

Question 15

In microbiology, ____ will do except for blood culture

Answer 15

minimal amounts

Question 16

In microbiology, minimal amounts will do except for ____

Answer 16

blood culture

Question 17

This is to obtain a higher yield of isolates

Answer 17

Acute Stage of the Disease Process

Question 18

Ideal TAT

Answer 18

Processed immediately after collection

Question 19

Ideal TAT for critical specimens (coming from sterile site)

Answer 19

Within 15 mins after collection

Question 20

Ideal TAT for non-critical (other) specimens

Answer 20

within 2 hours after collection

Question 21

When processing, we should prioritize what type of specimen?

Answer 21

Critical

Question 22

What should you process first?

Stool vs. Urine vs. Blood vs. CSF

Answer 22

Blood then CSF

Question 23

If you are considering that the sample contains
microorganisms that are sensitive to drying, you should process them ____

Answer 23

immediately

Question 24

Collection Methods

Suitable and done ONLY for aerobic organisms

Because the collection method is already exposed to oxygen

Answer 24

Cotton Swab (Swab Technique)

Question 25

Advantage of cotton swab technique?

Answer 25

Common, easily available, easy to perform

Question 26

Disadvantage of cotton swab technique?

Answer 26

Toxic to other organisms

Question 27

If you are suspecting that the isolate is ____ (also sensitive to drying), note that cotton contains fatty acids that are toxic to the organism

Answer 27

Neisseria gonorrhoea

Question 28

If there is no other choice besides cotton, what can you do when the isolate is Neisseria gonorrhoea?

Answer 28

Add charcoal so as to neutralize the toxic fatty acids present in the cotton

Question 29

✦ Made of synthetic fiber, not cotton ✦ Highly absorbent, so the sample will not easily dry out

Answer 29

Rayon and Dacron Technique

Question 30

Disadvantage of Rayon and Dacron?

Answer 30

Expensive and may not be readily available

Question 31

◦ Any extraction can support the growth of aerobic and anaerobic culture, simply because the method does not allow exposure of the specimen to oxygen ◦ Aerobic and anaerobic culture ◦ Ex: Peritoneal fluid, urine via SPA, wound exudate, blood

Answer 31

Needle Aspiration/Extraction

Question 32

Done by aspirating from a catheter tube

Answer 32

Catheterization

Question 33

Diagnostic Purpose of Blood Specimen

Answer 33

To determine bloodstream infection (bacteremia)

Question 34

What can be determined during blood culture?

Answer 34

Presence of bacteria, not the toxin

Question 35

Usual order of blood specimen

Answer 35

2 sets of blood culture (1 for aerobic bottle and 1 for anaerobic bottle)

Question 36

Why do they order 2 sets of blood culture?

Answer 36

To distinguish TRUE pathogen

Question 37

Media for manual blood culture

Answer 37

Brain-Heart Infusion Broth (BHIB) with 0.025% Sodium Polyanethole Sulfonate (SPS) (+/- 1% Gelatin)

Question 38

Best anticoagulant for blood culture despite it being able inhibit some microorganisms

Answer 38

SPS

Question 39

Why SPS regarded as the best anticoagulant for blood culture?

Answer 39

because of its anticomplement and antiphagocytic properties; it also neutralizes aminoglycosides

Question 40

Anticoagulant-to-Blood Ratio for Adults

Answer 40

1:10

Question 41

Anticoagulant-to-Blood Ratio for Children

Answer 41

1:5

Question 42

Positive result indicators for manual blood culture

Answer 42

Hemolysis, Turbidity, Pellicle Formation, Bubble Formation

Question 43

Preliminary / Initial Reporting of Results

Answer 43

after 24 hrs, 48 hrs, 72 hrs, 5 days, 7 days

Question 44

When the spx tested negative after 24 hours,

Answer 44

the initial report would be **negative**

Question 45

When the spx tested positive after 48 hours,

Answer 45

subculture is performed

Question 46

Official report on the isolate is released usually ___

Answer 46

after another 3 days (5th day)

Question 47

The final result would be released at the ___

Answer 47

7th day

Question 48

T or F: When spx tested positive in a time frame, you do not have to perform a subculture

Answer 48

F (you have to)

Question 49

If you see this, study how to do the subculture hehe

Answer 49

Go bebi !!

Question 50

TAT for Typhoid Fever

Answer 50

7 days

Question 51

TAT for Brucellosis and Endocarditis secondary to HACEK species

Answer 51

21 days

Question 52

What are the HACEK species?

Answer 52

Haemophilus Aggregatobacter Cardiobacter Eikenella Kingella kingae

Question 53

These organisms associated with bacterial endocarditis are slow-growers

Answer 53

HACEK

Question 54

Principle of Automated Blood Culture

Answer 54

Fluorescence-based

Question 55

TAT of Automated Blood Culture

Answer 55

5 days

Question 56

* Normally sterile (inside the bladder) * Depending on how it is collected, it can be sterile or nonsterile

Answer 56

Urine Specimen

Question 57

Collection Methods for urine specimens

Answer 57

Midstream Clean-Catch Catheterized Suprapubic Aspiration

Question 58

Diagnostic Purpose of urine specimen

Answer 58

Diagnosis of UTI

Question 59

T or F: Only in urine culture that we perform quantitation

Answer 59

T

Question 60

Give the formula of CFU

Answer 60

CFU = # of Colonies x Loop Factor (calibrated wire loop) ## Footnote **Loop Factors** ▪︎ 0.1 mL - 10 ▪︎ 0.01 mL - 100 ▪︎ 0.001 mL - 1000

Question 61

# Urine Specimen When is the interpretation for **>100,000 CFU/mL**?

Answer 61

Significant

Question 62

# Urine Specimen When is the interpretation for **< 50,000 CFU/mL?**

Answer 62

Negative

Question 63

# Urine Specimen When is the interpretation for **Between 50,000 and 100,000 CFU/mL**?

Answer 63

Borderline or Indeterminate

Question 64

What happens when the urine specimen falls as borderline or indeterminate?

Answer 64

You will need to repeat urine culture

Question 65

Critical and sterile Specimen and collected via Lumbar Puncture

Answer 65

CSF Specimen

Question 66

Diagnostic Purpose for CSF specimen

Answer 66

For the diagnosis of Bacterial Meningitis

Question 67

Media for CSF specimens

Answer 67

BAP, CAP, MAC

Question 68

CSF is incubated at what temperature?

Answer 68

Room Temperature or Body Temperature

Question 69

* Polymicrobial in nature; allows isolation of several microorganisms * Collected through swabs or aspirations * Emits foul odor due to Anaerobes and Facultative Anaerobes (most pathogenic organisms)

Answer 69

Wound discharge/abscess specimen

Question 70

Media for Wound discharge/abscess specimens

Answer 70

◦ Plating through MAC and BAP ◦ Thioglycollate (Liquid Media)

Question 71

# Which media of wound discharge/abscess specimen is this? ✦ Enrichment Broth ✦ Allows the growth of Obligate Aerobes, Facultative Anaerobes, and Microaerophilics

Answer 71

Thioglycollate (Liquid Media)

Question 72

* Contain many enteric organisms (contaminated with normal microbiota) * Gram stain is NOT usually done (very seldom, simply because the fecal matter is full of gramnegative organisms)

Answer 72

Stool specimen

Question 73

What selective and differential media are being used for stool specimen?

Answer 73

✦ MAC - MacConkey Agar ✦ HEA - Hektoen Enteric Agar ✦ EMB - Eosin-Methylene Blue Agar

Question 74

Differential selective media for isolation of Salmonella spp.

Answer 74

SSA (Salmonella-Shigella Agar), Selenite F Broth

Question 75

Differential selective media for isolation of Vibrio spp.

Answer 75

TCBS (Thiosulfate-Citrate-Bile Salts-Sucrose Agar) and Peptone Water

Question 77

Includes nasopharyngeal swabs, sputum, bronchial and tracheal aspirate, and nasopharyngeal aspirates

Answer 77

Respiratory specimens

Question 78

# Respiratory specimens Gold standard for decontamination

Answer 78

Sodium hydroxide

Question 79

# Respiratory specimen Gold standard for digestion

Answer 79

N-acteyllcysteine (NaLC)

Question 80

Plating media for respiratory specimens

Answer 80

BAP, MAC, CAP

Question 81

Diagnostic purpose for throat swabs

Answer 81

Strep Throat, Diptheria, Neisseria infection

Question 82

Plating media for throat swabs

Answer 82

BAP, CAP

Question 83

Plating media for Neisseria spp.

Answer 83

Modified Thayer Martin Media

Question 84

* Do Gram Stain (to check for the intracellular presence of Gram-negative coccobacilli)

Answer 84

Vaginal, Urethral & Rectal Swabs

Question 85

Media for Vaginal, Urethral & Rectal Swabs

Answer 85

CAP BAP MTMM (if infection with Neisseria gonorrhoeae is suspected)

Question 86

How many sputum specimen is required for TB culture?

Answer 86

Three *(1 for culture, 2 for acid-fast staining)*

Question 87

Gold standard for TB Culture

Answer 87

NaOH (decontamination) and NaLC (digestion)

Question 88

Media for TB Culture

Answer 88

◦ Löwenstein-Jensen (LJ) Medium ◦ Middlebrook 7H11/7H10 ◦ BACTEC ◦ Gene Xpert

Question 89

This can detect the presence of Mycobacterium tuberculosis in the specimen and determine whether the isolate is Multidrug Resistant

Answer 89

Gene Xpert

Question 90

Check niyo table summary ni Wakin and tell him thank you <3

Answer 90

Kaldagan niyo na rin hehe