Culture, Bacterial, Anal/Genital, Ear, Eye, Skin, and Wound

Culture, Bacterial, Anal/Genital, Ear, Eye, Skin, and Wound

Synonym/acronym: N/A.

Common use

To identify pathogenic bacterial organisms as an indicator for appropriate therapeutic interventions for multiple sites of infection.

Specimen

Sterile fluid or swab from affected area placed in transport media tube provided by laboratory.

Normal findings

(Method: Culture aerobic and/or anaerobic on selected media; cell culture followed by use of direct immunofluorescence, nucleic acid amplification and DNA probe assays [e.g., Gen-Probe] are available for identification of Neisseria gonorrhoeae and Chlamydia trachomatis.) Negative: no growth of pathogens.

Description

When indicated by patient history, anal and genital cultures may be performed to isolate the organism responsible for sexually transmitted disease. Group B streptococcus (GBS) is a significant and serious neonatal infection.The Centers for Disease Control and Prevention (CDC) recommends universal GBS screening for all pregnant women at 35 to 37 wk gestation. Rapid GBS test kits can provide results within minutes on vaginal or rectal fluid swab specimens submitted in a sterile red-top tube.

Ear and eye cultures are performed to isolate the organism responsible for chronic or acute infectious disease of the ear and eye.

Skin and soft tissue samples from infected sites must be collected carefully to avoid contamination from the surrounding normal skin flora. Skin and tissue infections may be caused by both aerobic and anaerobic organisms. Therefore, a portion of the sample should be placed in aerobic and a portion in anaerobic transport media. Care must be taken to use transport media that are approved by the laboratory performing the testing.

Sterile fluids can be collected from the affected site. Refer to related body fluid monographs (i.e., amniotic fluid, cerebrospinal fluid, pericardial fluid, peritoneal fluid, pleural fluid, synovial fluid) for specimen collection.

A wound culture involves collecting a specimen of exudates, drainage, or tissue so that the causative organism can be isolated and pathogens identified. Specimens can be obtained from superficial and deep wounds.

Optimally, specimens should be obtained before antibiotic use. The method used to culture and grow the organism depends on the suspected infectious organism.There are transport media specifically for bacterial agents. The laboratory will select the appropriate media for suspect organisms and will initiate antibiotic sensitivity testing if indicated by test results. Sensitivity testing identifies the antibiotics to which organisms are susceptible to ensure an effective treatment plan.

This procedure is contraindicated for

    N/A

Indications

    Anal/Genital

  • Assist in the diagnosis of sexually transmitted diseases.
  • Determine the cause of genital itching or purulent drainage.
  • Determine effective antimicrobial therapy specific to the identified pathogen.
  • Routine prenatal screening for vaginal and rectal GBS colonization.
  • Ear

  • Isolate and identify organisms responsible for ear pain, drainage, or changes in hearing.
  • Isolate and identify organisms responsible for outer-, middle-, or inner-ear infection.
  • Determine effective antimicrobial therapy specific to the identified pathogen.
  • Eye

  • Isolate and identify pathogenic microorganisms responsible for infection of the eye.
  • Determine effective antimicrobial therapy specific to identified pathogen.
  • Skin

  • Isolate and identify organisms responsible for skin eruptions, drainage, or other evidence of infection.
  • Determine effective antimicrobial therapy specific to the identified pathogen.
  • Sterile Fluids

  • Isolate and identify organisms before surrounding tissue becomes infected.
  • Determine effective antimicrobial therapy specific to the identified pathogen.
  • Wound

  • Detect abscess or deep-wound infectious process.
  • Determine if an infectious agent is the cause of wound redness, warmth, or edema with drainage at a site.
  • Determine presence of infectious agents in a stage 3 and stage 4 decubitus ulcer.
  • Isolate and identify organisms responsible for the presence of pus or other exudate in an open wound.
  • Determine effective antimicrobial therapy specific to the identified pathogen.

Potential diagnosis

Positive findings in:

    Anal/Endocervical/Genital

    Infections or carrier states are caused by the following organisms: C. trachomatis, obligate intra-cellular bacteria without a cell wall, gram variable Gardnerella vaginalis, gram negative N. gonorrhoeae,Treponema pallidum, and toxin-producing strains of gram positive Staphylococcus aureus, and gram positive GBS.

    Ear

    Commonly identified gram negative organisms include Escherichia coli,Proteus spp., Pseudomonas aeruginosa, gram positive S. aureus, and β-hemolytic streptococci.

    Eye

    Commonly identified organisms include C. trachomatis (transmitted to newborns from infected mothers), gram negative Haemophilus influenzae (transmitted to newborns from infected mothers), H. aegyptius, N. gonorrhoeae (transmitted to newborns from infected mothers), P. aeruginosa, gram positive S. aureus, and Streptococcus pneumoniae.

    Skin

    Commonly identified gram negative organisms include Bacteroides, Pseudomonas, gram positive Clostridium,Corynebacterium, staphylococci, and group A streptococci.

    Sterile Fluids

    Commonly identified pathogens include gram negative Bacteroides,E. coli,P. aeruginosa, gram positive Enterococcus spp., and Peptostreptococcus spp.

    Wound

    Aerobic and anaerobic microorganisms can be identified in wound culture specimens. Commonly identified gram negative organisms include Klebsiella,Proteus,Pseudomonas,gram-positiveClostridium perfringens,S. aureus, and group A streptococci.

Critical findings

  • Listeria in genital cultures; listeriosis in pregnant women may result in premature birth, miscarriage, or stillbirth. The earlier in pregnancy the infection occurs, the more likely that it will lead to miscarriage or fetal death. After 20 weeks gestation, listeriosis is more likely to cause premature labor and birth.
  • Methicillin-resistant S. aureus (MRSA) in skin or wound cultures
  • 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

  • Failure to collect adequate specimen, improper collection or storage technique, and failure to transport specimen in a timely fashion are causes for specimen rejection.
  • Pretest antimicrobial therapy will delay or inhibit the growth of pathogens.
  • Testing specimens more than 1 hr after collection may result in decreased growth or no growth of organisms.

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 that 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, as appropriate, a history of sexual activity.
  • 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. Instruct female patients not to douche for 24 hr before a cervical or vaginal specimen is to be obtained.
  • 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
  • Ensure that the patient has complied with medication restrictions prior to the procedure.
  • 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. Positively identify the patient, and label the appropriate specimen containers with the corresponding patient demographics, specify the exact specimen source/origin (e.g., vaginal lesion or ear, left or right, as appropriate), patient age and gender, date and time of collection, and any medication the patient is taking that may interfere with the test results (e.g., antibiotics). Do not freeze the specimen or allow it to dry. Chlamydia is an intracellular obligate pathogen. Culture of infected epithelial cells is considered the gold standard for the identification of chlamydia because of the higher sensitivity of nucleic acid amplification or DNA probe assays relative to antibody assays. Therefore, culture should always be the test of choice in cases of suspected or known child abuse.
  • Anal

  • Place the patient in a lithotomy or side-lying position and drape for privacy. Insert the swab 1 in. into the anal canal and rotate, moving it from side to side to allow it to come into contact with the microorganisms. Remove the swab. Place the swab in the Culturette tube, and squeeze the bottom of the tube to release the transport medium. Ensure that the end of the swab is immersed in the medium. Repeat with a clean swab if the swab is pushed into feces.
  • Genital

  • Female Patient
  • Position the patient on the gynecological examination table with the feet up in stirrups. Drape the patient’s legs to provide privacy and reduce chilling.
  • Cleanse the external genitalia and perineum from front to back with towelettes provided in culture kit. Using a Culturette swab, obtain a sample of the lesion or discharge from the urethra or vulva. Place the swab in the Culturette tube, and squeeze the bottom of the tube to release the transport medium. Ensure that the end of the swab is immersed in the medium.
  • To obtain a vaginal and endocervical culture, insert a water-lubricated vaginal speculum. Insert the swab into the cervical orifice and rotate the swab to collect the secretions containing the microorganisms. Remove and place in the appropriate culture medium or Gen-Probe transport tube. Material from the vagina can be collected by moving a swab along the sides of the vaginal mucosa. The swab is removed and then placed in a tube of saline medium.
  • Male Patient
  • To obtain a urethral culture, cleanse the penis (retracting the foreskin), have the patient milk the penis to express discharge from the urethra. Insert a swab into the urethral orifice and rotate the swab to obtain a sample of the discharge. Place the swab in the Culturette or Gen-Probe transport tube, and squeeze the bottom of the tube to release the transport medium. Ensure that the end of the swab is immersed in the medium.
  • Ear

  • Cleanse the area surrounding the site with a swab containing cleaning solution to remove any contaminating material or flora that have collected in the ear canal. If needed, assist the appropriate HCP in removing any cerumen that has collected.
  • Insert a Culturette swab approximately 1/4 in. into the external ear canal. Rotate the swab in the area containing the exudate. Carefully remove the swab, ensuring that it does not touch the side or opening of the ear canal.
  • Place the swab in the Culturette tube, and squeeze the bottom of the tube to release the transport medium. Ensure that the end of the swab is immersed in the medium.
  • Eye

  • Pass a moistened swab over the appropriate site, avoiding eyelid and eyelashes unless those areas are selected for study. Collect any visible pus or other exudate. Place the swab in the Culturette or Gen-Probe transport tube, and squeeze the bottom of the tube to release the transport medium. Ensure that the end of the swab is immersed in the medium.
  • An appropriate HCP should perform procedures requiring eye culture.
  • Skin

  • Assist the appropriate HCP in obtaining a skin sample from several areas of the affected site. If indicated, the dark, moist areas of the folds of the skin and outer growing edges of the infection where microorganisms are most likely to flourish should be selected. Place the scrapings in a collection container or spread on a slide. Aspirate any fluid from a pustule or vesicle using a sterile needle and tuberculin syringe. The exudate will be flushed into a sterile collection tube. If the lesion is not fluid filled, open the lesion with a scalpel and swab the area with a sterile cotton-tipped swab. Place the swab in the Culturette tube, and squeeze the bottom of the tube to release the transport medium. Ensure that the end of the swab is immersed in the medium.
  • Sterile Fluid

  • Refer to related body fluid monographs (i.e., amniotic fluid, cerebrospinal fluid, pericardial fluid, peritoneal fluid, pleural fluid, synovial fluid) for specimen collection.
  • Wound

  • Place the patient in a comfortable position, and drape the site to be cultured. Cleanse the area around the wound to remove flora indigenous to the skin.
  • Place a Culturette swab in a superficial wound where the exudate is the most excessive without touching the wound edges. Place the swab in the Culturette tube, and squeeze the bottom of the tube to release the transport medium. Ensure that the end of the swab is immersed in the medium. Use more than one swab and Culturette tube to obtain specimens from other areas of the wound.
  • To obtain a deep wound specimen, insert a sterile syringe and needle into the wound and aspirate the drainage. Following aspiration, inject the material into a tube containing an anaerobic culture medium.
  • General

  • Promptly transport the specimen to the laboratory for processing and analysis.

Post-Test

  • Instruct the patient to resume usual medication as directed by the HCP.
  • Instruct the patient to report symptoms such as pain related to tissue inflammation or irritation.
  • Instruct the patient to begin antibiotic therapy, as prescribed. Instruct the patient in the importance of completing the entire course of antibiotic therapy even if no symptoms are present.
  • Inform the patient that a repeat culture may be needed in 1 wk after completion of the antimicrobial regimen.
  • Advise the patient that final test results may take 24 to 72 hr depending on the organism suspected but that antibiotic therapy may be started immediately.
  • Anal/Endocervical/Genital
  • Inform the patient that final results may take from 24 hr to 4 wk, depending on the test performed.
  • Advise the patient to avoid sexual contact until test results are available.
  • Instruct the patient in vaginal suppository and medicated cream installation and administration of topical medication to treat specific conditions, as indicated.
  • Inform infected patients that all sexual partners must be tested for the microorganism.
  • Inform the patient that positive culture findings for certain organisms must be reported to a local health department official, who will question him or her regarding sexual partners.
  • Social and Cultural Considerations: Offer support, as appropriate, to patients who may be the victims of rape or sexual assault. Educate the patient regarding access to counseling services. Provide a nonjudgmental, nonthreatening atmosphere for discussing the risks of sexually transmitted diseases. It is also important to address problems the patient may experience (e.g., guilt, depression, anger).
  • Wound
  • Instruct the patient in wound care and nutritional requirements (e.g., protein, vitamin C) to promote wound healing.
  • General
  • 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.
  • 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. Provide information regarding vaccine-preventable diseases where indicated (e.g., cervical cancer, hepatitis A and B, human papillomavirus). Provide contact information, if desired, for the CDC (www.cdc.gov/vaccines/vpd-vac). Answer any questions or address any concerns voiced by the patient or family.
  • Instruct the patient in the use of any ordered medications (oral, topical, drops). Instruct the patient in the proper use of sterile technique for cleansing the affected site and application of dressings, as directed. Explain the importance of adhering to the therapy regimen. As appropriate, instruct the patient in significant side effects and systemic reactions associated with the prescribed medication. Encourage him or her to review corresponding literature provided by a pharmacist.
  • 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 amniotic fluid analysis, antimicrobial drugs, audiometry hearing loss, biopsy site, CSF analysis, culture viral, Gram stain, otoscopy, pericardial fluid analysis, Pap smear, peritoneal fluid analysis, pleural fluid analysis, procalcitonin, spondee speech reception threshold, synovial fluid analysis, syphilis serology, tuning fork tests, vitamin C, and zinc.
  • Refer to the Immune System table at the end of the book for related tests by body system.
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