Clinical Mycology Techniques

Questions and Answers

What is a disadvantage of using swabs for specimen sampling?

Swabs can collect more specimens than other methods.

Swabs effectively transfer bacteria to culture plates.

Swabs can desiccate the specimen and trap bacteria. (correct)

Swabs maintain a sterile environment during transport.

What is the minimum volume of water sample that should be collected?

250 ml

150 ml

200 ml (correct)

100 ml

If a water sample cannot be tested within 3 hours, what is the appropriate action?

Test it immediately without refrigerating.

Refrigerate the sample and test within 24 hours. (correct)

Pack the sample on ice and test within 48 hours.

Allow the sample to come to room temperature before testing.

What type of bottle is recommended for water sample collection?

Sterile glass or autoclavable plastic bottles Signup and view all the answers

What can happen if there is a sudden removal of fluid?

It may draw down the cerebellum into the Foramen magnum. Signup and view all the answers

What temperature should stool, cerebrospinal fluid, and sputum samples be transported at?

Room temperature Signup and view all the answers

When collecting hair samples for mycology, what is the recommended method?

Pluck involved hairs from the edges of the patches using forceps. Signup and view all the answers

What should be done if there is a delay in transportation of CSF specimens?

Leave the specimens at room temperature. Signup and view all the answers

What type of specimen is considered ideal for submission from wounds?

Pus or exudates. Signup and view all the answers

What is the recommended cleaning agent for the site before collecting mycology samples?

70% ethanol. Signup and view all the answers

What is a key reason for collecting samples before administering antimicrobial agents?

To prevent contamination from indigenous microbiota Signup and view all the answers

Which of the following is essential to ensure the proper quality of a sample?

Utilizing appropriate collection devices and sterile equipment Signup and view all the answers

What precaution should always be taken when handling biological samples?

Treating all specimens as potentially biohazardous Signup and view all the answers

Which statement about sample transportation is correct?

Use sturdy, sterile, screw-cap containers to prevent leaks. Signup and view all the answers

What should be included when labeling a specimen container?

The patient’s name, identification number, date and time of collection Signup and view all the answers

Inadequate amounts of a specimen during collection can lead to which outcome?

False-negative results Signup and view all the answers

What is the purpose of using aseptic technique during specimen collection?

To prevent the introduction of microorganisms during collection Signup and view all the answers

Which is NOT a part of the sample safety considerations?

Ignoring potential sample contamination Signup and view all the answers

Which specimen requires proper labeling and immediate transport to prevent contamination?

Urine Signup and view all the answers

What is the minimum volume required for a solid stool sample collection?

5 grams Signup and view all the answers

What factor would NOT be considered a rejection criterion for specimen transport?

Excessive volume Signup and view all the answers

Before collecting a blood sample, which action is essential to prevent contamination?

Apply disinfectant Signup and view all the answers

What transport medium is recommended for stool specimens suspected of gonococcal infection?

Amie's transport medium Signup and view all the answers

What is the maximum allowable contamination level in urine samples indicated by CFU/ml?

10000-100000 cfu/ml Signup and view all the answers

What should be preserved at 4-6 degrees centigrade if there is a delay in transporting urine samples?

Urine Signup and view all the answers

What is the preferred method for collecting sputum samples suspected of containing TB?

Deep coughing after gargling saline Signup and view all the answers

How should a rectal swab specimen be collected properly?

Rotate for 10 seconds avoiding skin contact Signup and view all the answers

What is a proper action to take if a specimen cannot be transported immediately?

Preserve in 10% formalin for stool Signup and view all the answers

Study Notes

General Considerations for Sample Collection

Proper guidelines must be established by laboratories for accurate sample collection.
Diagnostic outcomes rely heavily on the quality of received samples.
Poor collection, transport, or media can lead to erroneous results.
Collect samples prior to antibiotic therapy when feasible.
Use sterile equipment and aseptic techniques to avoid contamination.
Clearly label containers with the patient’s information, date, and initials.
Ensure adequate specimen volume to prevent false negatives.
Correctly identify the specimen source to choose appropriate culture media.
Use leak-proof, sturdy containers that do not aerosolize upon opening.
Prepare the collection area with disinfectants like spirit and povidone iodine.

Sample Safety Considerations

Adhere to universal precautions; treat all specimens as potential biohazards.
Utilize protective barriers like gloves and lab coats during handling.
In cases of potential splashing, additional protective gear may be necessary.
Prevent contamination of collection containers and paperwork.
Minimize direct handling during specimen transport.
Use plastic sealable bags with separate compartments for requisition orders.
Label high-risk specimens, such as sputum from tuberculosis patients, and fecal samples from cholera or typhoid suspects.

Rejection Criteria for Samples

Containers that are leaking or broken.
Insufficient specimen size.
Improper labeling of samples.
Extended time between collection and transport.
Inappropriate transport media or temperature.
Hemolyzed samples.

Important Questions Before Collection

Is there a suspicion of infection? If so, determine its nature (bacterial, viral, etc.).
Identify priority tests and the optimal timing for specimen collection.
Ensure the correct container type is chosen for collection.
Understand the importance of prompt specimen delivery; consider preservation methods if delays exist.
Complete request forms including patient information, urgency, and type of specimen needed.

When to Request Transport Medium

Request medium when tests can't be performed at the collection site or if transport distance is significant.
Common transport media include Amie's transport medium for gonococcal infections, Carry Blair medium for stool, and V.R medium for stool.

Collection of Various Samples

Blood: Use sterile needles, collect 5-10 ml (or 2-5 ml for children), and infuse into BHI after disinfection.
Urine: For females, perform midstream clean catch; for males, retract prepuce or use catheterization if needed. Preserve contaminated samples at 4-6°C.
Stool: Collect in clean, leak-proof containers, avoiding contamination with urine. In case of difficulty, rectal swabs may be used.
Rectal Swab: Use a sterile swab, avoid contact with skin, and seal immediately.
Sputum: Collect two samples, ensuring the first is at the spot and second in the morning for accurate results. Ask the patient to gargle before collection.
CSF: Collect 3-5 ml gently, labeling the container. Avoid rapid fluid removal to prevent headaches.
Mycology Samples: Collect skin scrapings, nail scrapings, and hair according to aseptic techniques and in sufficient quantities.
Wound Samples: Prefer pus or exudates over swabs, using sterile containers to avoid desiccation.

Water Sampling for Bacteriology

Collect samples at a depth of at least 20 cm from water bodies; avoid bottle contact with well sides.
Use sterile glass or autoclavable plastic bottles with secure lids, avoiding bacterial contamination.
Test water samples within 3 hours; if delayed, preserve them in ice and test within 24 hours.

Transportation Guidelines for Samples

Transport stool, CSF, and sputum at room temperature; refrigeration is not appropriate.
Urine, swabs, skin samples, and food/water samples should also be transported ASAP at room temperature but can be refrigerated when delays occur.

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Description

This quiz explores essential techniques in clinical mycology, focusing on specimen handling and transportation for laboratory analysis. It highlights the importance of preserving cerebrospinal fluid and the correct preparation of mycology samples. Understanding these practices is crucial for accurate diagnosis and effective treatment.