Gram Stain

CPT Code(s):
87205

Turnaround Time:
1 day

Specimen Requirements

Preferred Specimen:
Wounds, Abscess, Aspirates or Drainage

Minimum Volume:
0.5 mL (or 1 swab)

Transport Container:
BBL CultureSwab or ESwab; Sterile Cup

Transport Temperature:
Room Temperature

Collection Instructions:
Swab the infected area or exudates using proper collection technique. Do not send syringe with needle.

Rejection Criteria:
Improper labeling; specimen received in grossly leaking transport container; specimen received in expired transport media; specimen received after prolonged delay (usually more than 48 hours)

Stability Criteria

Room Temperature:
48 hours

Refrigerated:
7 days

Frozen:
Unacceptable

Clinical Significance

Gram Stain holds specific clinical significance and diagnostic use in the identification and classification of bacteria based on their cell wall structure. It is a fundamental and widely used laboratory test in microbiology.

The specific clinical significance and diagnostic use of Gram Stain include:

1. Bacterial Identification: Gram Stain allows for the initial identification and classification of bacteria into two broad categories: Gram-positive and Gram-negative. This information provides valuable insights into the bacterial characteristics and helps guide further laboratory testing and treatment decisions.

2. Preliminary Diagnosis: Gram Stain provides rapid results, making it a valuable tool in the early stages of diagnosing bacterial infections. By staining and observing bacterial cells under a microscope, healthcare providers can identify the presence of bacteria in clinical samples such as blood, urine, sputum, or wound specimens. This aids in making preliminary diagnoses and initiating appropriate antibiotic treatment while awaiting more specific culture or molecular test results.

3. Antibiotic Selection: Gram Stain plays a critical role in guiding antibiotic therapy. Gram-positive and Gram-negative bacteria have different susceptibilities to various classes of antibiotics. By determining the Gram stain result, healthcare providers can make informed decisions about the choice of initial empiric antibiotic therapy, optimizing the selection of antibiotics that are most likely to be effective against the identified bacteria.

4. Infection Control Measures: Gram Stain aids in infection control measures, particularly in hospital settings. Rapid identification of Gram-negative bacteria, including those that may be resistant to multiple antibiotics, allows healthcare providers to implement appropriate isolation precautions, minimizing the risk of cross-transmission and controlling the spread of multidrug-resistant organisms.

5. Follow-up Monitoring: Gram Stain is valuable for monitoring the progress and effectiveness of antibiotic treatment. Repeat Gram Stain tests can be performed on clinical samples to assess the clearance of bacteria or the presence of persisting or recurrent infection. These results guide adjustments to antibiotic therapy and help ensure appropriate management of bacterial infections.

6. Research and Surveillance: Gram Stain is utilized in research studies and surveillance programs to monitor the prevalence and trends of different bacterial pathogens in specific populations or geographic regions. By classifying bacteria into Gram-positive or Gram-negative groups, this test provides valuable data for epidemiological studies and informs public health interventions.

It is important to note that Gram Stain has limitations and is not sufficient for definitive identification of specific bacterial species. Further culture-based techniques or molecular testing may be necessary to identify the exact bacterial species and determine antibiotic susceptibility patterns.

In summary, Gram Stain has specific clinical significance in bacterial identification, preliminary diagnosis of infections, guiding antibiotic selection, infection control measures, follow-up monitoring of treatment, and contributing to research and surveillance. By providing rapid and initial information about bacterial cell wall characteristics, this test plays a critical role in guiding clinical decision-making, optimizing antibiotic therapy, and improving patient care outcomes related to bacterial infections.