Gram Stain

Synonym/Acronym

N/A

Rationale

To provide a quick identification of gram-negative or gram-positive organisms to assist in medical management.

Patient Preparation

There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings

N/A

Critical Findings and Potential Interventions ⬆ ⬇

Any positive results in blood, cerebrospinal fluid, or any body cavity fluid.
Specific infectious organisms are required to be reported to local, state, and national departments of health. Lists of specific organisms may vary among facilities. State health departments provide information regarding reportable diseases, which can be accessed at each state health department website. The Centers for Disease Control and Prevention provides information regarding national notifiable diseases at https://ndc.services.cdc.gov/search-results-year/.

Timely notification to the requesting health-care provider (HCP) of any critical findings and related symptoms is a role expectation of the professional nurse. A listing of these findings varies among facilities.

Overview ⬆ ⬇

(Study type: Blood, biopsy specimen, or body fluid as collected for culture; related body system: Immune and multisystem.)

Gram stain is a technique commonly used to identify bacterial organisms on the basis of their specific staining characteristics. The method involves smearing a small amount of specimen on a slide, and then exposing it to gentian or crystal violet, iodine, alcohol, and safranin O. Gram-positive bacteria retain the gentian or crystal violet and iodine stain complex after a decolorization step and appear purple-blue in color. Gram-negative bacteria do not retain the stain after decolorization but can pick up the pink color of the safranin O counterstain.

Gram stains provide information regarding the adequacy of a sample. For example, a sputum Gram stain showing greater than 25 squamous epithelial cells per low-power field, regardless of the number of polymorphonuclear white blood cells, indicates contamination of the specimen with saliva, and the specimen should be rejected for subsequent culture. Gram stains are reviewed over a number of fields for an impression of the quantity of organisms present, which reflects the extent of infection. For example, a Gram stain of unspun urine showing the occasional presence of bacteria per low-power field suggests a correlating colony count of 10,000 bacteria/mL, while the presence of bacteria in most fields is clinically significant and suggests greater than 100,000 bacteria/mL of urine. Gram stain results should be correlated with culture and sensitivity results to interpret the significance of isolated organisms and to select appropriate antibiotic therapy.

Indications ⬆ ⬇

Provide a rapid determination of the acceptability of the specimen for further analysis.
Provide rapid, presumptive information about the type of potential pathogen present in the specimen (i.e., gram-positive bacteria, gram-negative bacteria, or yeast).

Interfering Factors ⬆ ⬇

Very young, very old, or dead cultures may react atypically to the Gram stain technique.

Potential Medical Diagnosis: Clinical Significance of Results ⬆ ⬇

Gram Positive
Actinomadura	Actinomyces	Bacillus	Clostridium, Clostridioides	Corynebacterium
Enterococcus	Erysipelothrix	Lactobacillus	Listeria	Micrococcus
Mycobacterium (gram variable)	Peptostreptococcus	Propionibacterium	Rhodococcus	Staphylococcus
Streptococcus

Gram Negative
Acinetobacter	Aeromonas	Alcaligenes	Bacteroides	Bordetella
Borrelia	Brucella	Campylobacter	Citrobacter	Chlamydia
Enterobacter	Escherichia	Flavobacterium	Francisella	Fusobacterium
Gardnerella	Haemophilus	Helicobacter	Klebsiella	Legionella
Leptospira	Moraxella	Neisseria	Pasteurella	Plesiomonas
Porphyromonas	Prevotella	Proteus	Pseudomonas	Rickettsia
Salmonella	Serratia	Shigella	Vibrio	Xanthomonas
Yersinia

Acid Fast or Partial Acid Fast
Nocardia		Mycobacterium

Note:Treponema species are classified as gram- negative spirochetes, but they are most often visualized using dark-field or silver-staining techniques.

Nursing Implications ⬆

Before the Study: Planning and Implementation

Teaching the Patient What to Expect

Review the procedure with the patient.
Discuss how this test can assist in identifying the presence of pathogenic organisms.
Explain that the time it takes to collect a proper specimen varies according to the patient’s level of cooperation as well as the specimen collection site. Specific collection instructions are found in the associated culture studies.
Explain that there may be some discomfort during the procedure.

After the Study: Implementation & Evaluation Potential Nursing Actions

Treatment Considerations

Interventions/actions include the following: Administer ordered antibiotics. Instruct the patient in the importance of completing the entire course of antibiotic therapy even if no symptoms are present. Address concerns about pain or fever and interventional options to address each issue.

Clinical Judgement

Consider how to emphasize the importance of adhering to the therapeutic regime to maintain health.

Follow-Up Evaluation and Desired Outcomes

Recognizes the importance of strict adherence to the HCP’s therapeutic regime in order to resolve any identified infectious process.