Culture, Fungal

Culture, Fungal

Synonym/acronym: N/A.

Common use

To identify the pathogenic fungal organisms causing infection.

Specimen

Hair, skin, nail, pus, sterile fluids, blood, bone marrow, stool, bronchial washings, sputum, or tissue samples collected in a sterile plastic, tightly capped container.

Normal findings

(Method: Culture on selective media; macroscopic and microscopic examination) No presence of fungi.

Description

Fungi, organisms that normally live in soil, can be introduced into humans through the accidental inhalation of spores or inoculation of spores into tissue through trauma. Individuals most susceptible to fungal infection usually are debilitated by chronic disease, are receiving prolonged antibiotic therapy, or have impaired immune systems. Fungal diseases may be classified according to the involved tissue type: dermatophytoses involve superficial and cutaneous tissue; there are also subcutaneous and systemic mycoses.

This procedure is contraindicated for

    N/A

Indications

  • Determine antimicrobial sensitivity of the organism
  • Isolate and identify organisms responsible for neonatal thrush
  • Isolate and identify organisms responsible for nail infections or abnormalities
  • Isolate and identify organisms responsible for skin eruptions, drainage, or other evidence of infection

Potential diagnosis

Positive findings in:

  • Blood
    • Candida albicans
    • Histoplasma capsulatum
  • Cerebrospinal fluid
    • Coccidioides immitis
    • Cryptococcus neoformans
    • Members of the order Mucorales
    • Paracoccidioides brasiliensis
    • Sporothrix schenckii
  • Hair
    • Epidermophyton
    • Microsporum
    • Trichophyton
  • Nails
    • C. albicans
    • Cephalosporium
    • Epidermophyton
    • Trichophyton
  • Skin
    • Actinomyces israelii
    • C. albicans
    • C. immitis
    • Epidermophyton
    • Microsporum
    • Trichophyton
  • Tissue
    • A. israelii
    • Aspergillus
    • C. albicans
    • Nocardia
    • P. brasiliensis

Critical findings

  • Positive findings in any sterile body fluid such as blood or cerebrospinal fluid.

  • Note and immediately report to the health-care provider (HCP) positive results and related symptoms.

  • It is essential that a critical finding be communicated immediately to the requesting health-care provider (HCP). Lists of specific organisms may vary among facilities; specific organisms are required to be reported to local, state, and national departments of health.

  • Timely notification of a critical finding for lab or diagnostic studies is a role expectation of the professional nurse. Notification processes will vary among facilities. Upon receipt of the critical value the information should be read back to the caller to verify accuracy. Most policies require immediate notification of the primary HCP, Hospitalist, or on-call HCP. Reported information includes the patient’s name, unique identifiers, critical value, name of the person giving the report, and name of the person receiving the report. Documentation of notification should be made in the medical record with the name of the HCP notified, time and date of notification, and any orders received. Any delay in a timely report of a critical finding may require completion of a notification form with review by Risk Management.

Interfering factors

  • Prompt and proper specimen processing, storage, and analysis are important to achieve accurate results.

Nursing Implications and Procedure

Pretest

  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this test can assist in identification of the organism causing infection.
  • Obtain a history of the patient’s complaints, including a list of known allergens.
  • Obtain a history of the patient’s immune system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Note any recent medications that can interfere with test results.
  • Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 min. Address concerns about pain and explain that there may be some discomfort during the specimen collection.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Note that there are no food or fluid restrictions unless by medical direction.

Intratest

  • Potential complications: N/A
  • Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Instructions regarding the appropriate transport materials for blood, bone marrow, bronchial washings, sputum, sterile fluids, stool, and tissue samples should be obtained from the laboratory. Positively identify the patient, and label the appropriate collection containers with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection.
  • Promptly transport the specimen to the laboratory for processing and analysis.

    • Skin

  • Clean the collection site with 70% alcohol. Scrape the peripheral margin of the collection site with a sterile scalpel or wooden spatula. Place the scrapings in a sterile collection container.

    • Hair

  • Fungi usually grow at the base of the hair shaft. Infected hairs can be identified by using a Wood’s lamp in a darkened room. A Wood’s lamp provides rays of ultraviolet light at a wavelength of 366 nm, or 3,660 Å. Infected hairs fluoresce a bright yellow-green when exposed to light from the Wood’s lamp. Using tweezers, pluck hair from skin.

    • Nails

  • Ideally, softened material from the nailbed is sampled from beneath the nail plate. Alternatively, shavings from the deeper portions of the nail itself can be collected.
  • Results of a conventional fungal culture may take up to 4 wk. Results of fungal antibody tests are available within a few days of collection and may be ordered when there is a strong suspicion of a particular pathogen. Most often, results indicating the presence or absence of fungi can be obtained in moments by looking at small amounts of the specimen under a microscope. A portion of the sample or swab is placed in sterile saline, and a drop from the diluted sample is placed on a glass slide, also called a wet prep. Another portion of the sample or a second swab is mixed with 15% potassium hydroxide (KOH), and a drop from the KOH sample is placed on a glass slide. A coverslip is placed over each specimen on the slide. The slides are examined under a microscope for the presence of fungal elements: mycelium, mycelial fragments, spores, or budding yeast cells. The KOH test is used in conjunction with the wet prep because the KOH destroys bacterial and epithelial cells while leaving fungal elements clearly visible, if present.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
  • Instruct patient to begin antifungal therapy, as prescribed. Instruct the patient in the importance of completing the entire course of antifungal therapy even if no symptoms are present.
  • Recognize anxiety related to test results. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Emphasize the importance of reporting continued signs and symptoms of the infection. Answer any questions or address any concerns voiced by the patient or family. Educate the adult patient regarding good oral and personal hygiene. Educate the parents or caregivers of infants or children with thrush (oral Candida infection) regarding the mechanism for transmission of the infection; stress the importance of keeping bottle-feeding equipment (especially nipples), pacifiers, and toys, cleaned and disinfected or sterilized, as appropriate, on a regular basis. Stress the importance of good hand hygiene for all who come in contact with the infant/child whose immune system is still developing and may be at higher risk for infection. Diaper rash or diaper Candidiasis may be instigated by changes in diet or frequent stools that affect the integrity of the infant or child’s delicate skin and allow an opportunity for infection to occur. Discuss the importance of frequent diaper changes and proper cleansing of the genital area with the parents or caregivers of infants or children with diaper rash.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include relevant biopsies (lung, lymph node, skin), bronchoscopy, cultures (blood, mycobacteria, throat, sputum, viral), CSF analysis, gallium scan, HIV-1/2 antibodies, pulmonary function tests, and TB tests.
  • Refer to the Immune System table at the end of the book for related tests by body system.