Gram Stain by Sputum

Bacterial/ Viral

Report in 12Hrs

At Home

No Fasting Required

Details

Microscopic bacterial staining.

₹192₹275

30% OFF

Gram Stain by Sputum - Comprehensive Medical Test Guide

Why is it done?
- Test Description: A microscopic examination of sputum (phlegm/mucus coughed up from the respiratory tract) using Gram staining to identify and differentiate bacterial organisms based on their cell wall composition and staining characteristics.
- Primary Indications: Suspected bacterial respiratory infections including pneumonia, bronchitis, and other lower respiratory tract infections
- Clinical Reasons for Ordering: Persistent cough lasting more than 2-3 weeks, productive cough with purulent sputum, fever with respiratory symptoms, immunocompromised patients with respiratory symptoms, tuberculosis screening, cystic fibrosis monitoring, or when rapid identification of causative organisms is needed to guide empiric antibiotic therapy
- Typical Timing: Performed urgently in acute respiratory infections, during initial presentation of respiratory symptoms, or as part of routine workup for hospitalized patients with suspected pneumonia
Normal Range
- Normal Result: Negative or No organisms identified
- Normal Findings Include: Abundant squamous epithelial cells (>10 per low power field), minimal or no polymorphonuclear leukocytes (PMNs), rare or absent bacteria, presence of normal flora only
- Reference Range Interpretation: Negative = No pathogenic bacteria detected; Not representative = Contaminated sample with saliva/normal flora (too many squamous epithelial cells); Positive = Specific bacteria identified with Gram characteristics noted
- Quality Assessment Criteria: Good quality sputum sample = <10 squamous epithelial cells and >25 polymorphonuclear leukocytes per low power field; Poor quality = >10 squamous epithelial cells (indicates saliva contamination) and should be rejected or recollected
- Units of Measurement: Microscopic assessment reported as semi-quantitative (rare, few, moderate, many) or as reported/not reported; organisms identified by morphology and Gram characteristics (Gram-positive cocci, Gram-negative rods, etc.)
Interpretation
- Gram-Positive Cocci in Pairs/Chains: Suggestive of Streptococcus species (S. pneumoniae, S. pyogenes); common cause of community-acquired pneumonia; typically indicates need for antibiotics covering streptococci
- Gram-Positive Cocci in Clusters: Characteristic of Staphylococcus aureus; associated with aspiration pneumonia, healthcare-associated infections, and post-influenza pneumonia; may indicate methicillin-resistant S. aureus (MRSA) in appropriate clinical context
- Gram-Negative Rods: May include Enterobacteriaceae (E. coli, Klebsiella), Pseudomonas aeruginosa, or Haemophilus influenzae; associated with hospital-acquired pneumonia, chronic respiratory disease, and immunocompromised patients; requires broader spectrum antibiotic coverage
- Pleomorphic Gram-Negative Coccobacilli: Suggestive of Haemophilus influenzae; common respiratory pathogen; important in COPD exacerbations and communityacquired pneumonia
- Acid-Fast Positive Organisms: Mycobacterium tuberculosis or nontuberculous mycobacteria; requires immediate notification and infection control measures; indicates tuberculosis or atypical mycobacterial infection
- Mixed Flora: Multiple organism types suggest aspiration pneumonia or anaerobic infection; commonly seen with oral anaerobes in patients with impaired swallowing or altered consciousness
- Factors Affecting Results: Prior antibiotic therapy may reduce organism visibility; sample timing (early vs late in infection); specimen quality and contamination; age of sample before processing; improper collection technique or contamination with saliva; presence of comorbid conditions; immune status of patient; environmental factors in hospitalized patients
- Clinical Significance: Positive Gram stain provides presumptive rapid identification allowing earlier targeted antibiotic therapy; negative result does not exclude infection as organisms may be slow-growing or require special stains; results guide empiric therapy while culture results are pending; essential for infection control decisions in suspected tuberculosis
Associated Organs
- Primary Organ System: Lower respiratory tract including lungs, bronchi, and trachea
- Associated Diseases and Conditions: Community-acquired pneumonia (CAP), hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), acute exacerbation of chronic bronchitis, cystic fibrosis, tuberculosis, bronchiectasis, lung abscess, empyema, aspiration pneumonia, acute respiratory distress syndrome (ARDS)
- Commonly Diagnosed Pathogens: Streptococcus pneumoniae (most common in CAP), Staphylococcus aureus (particularly MRSA in hospitalized patients), Haemophilus influenzae, Gram-negative Enterobacteriaceae, Pseudomonas aeruginosa (in immunocompromised and chronically ill patients), Mycobacterium tuberculosis, anaerobes in aspiration cases
- Complications of Abnormal Results: Sepsis and septic shock if untreated, respiratory failure requiring mechanical ventilation, pleural effusion or empyema, lung abscess formation, systemic inflammatory response syndrome (SIRS), bacteremia/bloodstream infection, acute respiratory distress syndrome, pneumothorax, death if severe infection untreated, chronic lung damage from recurrent infections
- At-Risk Populations: Elderly patients, immunocompromised individuals (HIV/AIDS, chemotherapy patients), chronic smokers, patients with COPD, diabetics, patients on mechanical ventilation, post-surgical patients, aspiration-prone individuals
Follow-up Tests
- Sputum Culture: Definitive identification and antibiotic susceptibility testing (AST); recommended for all positive Gram stains or clinically suspected infection; results available in 48-72 hours typically
- Acid-Fast Bacilli (AFB) Stain and Culture: If tuberculosis suspected; includes sputum smear microscopy and TB culture; may require multiple specimens collected on separate days
- Blood Culture: If patient febrile or clinically septic; detects bacteremia associated with severe pneumonia; obtained before antibiotic administration
- Chest X-ray: Confirm pneumonia, assess extent of infection, identify complications such as pleural effusion, lung abscess, or empyema; helps guide clinical management
- Complete Blood Count (CBC): Assess white blood cell count elevation, anemia, thrombocytopenia; helps determine severity of infection and immune response
- Procalcitonin and C-Reactive Protein (CRP): Inflammatory markers to assess infection severity and monitor response to treatment
- Respiratory Viral Panel PCR: If viral etiology suspected (influenza, COVID-19, RSV, parainfluenza); guides antiviral therapy decisions
- Legionella and Mycoplasma Testing: If atypical pneumonia suspected; these organisms don't Gram stain well and require special testing or serology
- Imaging Studies: CT chest if pneumonia complicated or disease course atypical; ultrasound if pleural effusion suspected
- Monitoring Frequency: Repeat Gram stain not typically needed unless clinical deterioration; follow culture results within 48-72 hours; reassess patient clinically at 48-72 hours for treatment response; repeat chest imaging if clinical improvement not evident after 48-72 hours of appropriate therapy
Fasting Required?
- Fasting: NO - Fasting is not required for sputum collection or Gram stain testing
- Patient Preparation: Patient may eat and drink normally; rinse mouth with water before collection (but do not use mouthwash) to reduce contamination with saliva and normal oral flora; drink water or warm beverage 15-30 minutes before collection to promote sputum production; collection best performed early morning when sputum volume highest
- Pre-Collection Instructions: Avoid tobacco use 30 minutes prior to collection; remove dentures if possible to improve specimen quality; rinse mouth thoroughly with water only; do not use antiseptic mouthwash; place specimen directly into sterile container provided; collect early morning specimen if possible
- Collection Technique: Deep cough to produce sputum from lower respiratory tract (not saliva from mouth); expel directly into sterile container; minimum 2-5 mL needed for analysis; ensure specimen is sputum and not saliva by appearance (thicker, yellowish or greenish, more opaque)
- Specimen Handling: Transport to laboratory immediately (within 1-2 hours); do not refrigerate sputum specimen; if immediate transport impossible, refrigerate at 4°C; label container clearly with patient name, date, time of collection, and specimen type; avoid contamination of outside of container
- Medications: No medications need to be held for specimen collection; sputum can be collected while on antibiotics (though organism recovery may be reduced if on therapy for prolonged period); continue all prescribed medications unless otherwise directed by physician
- Special Considerations: For non-productive patients, ultrasonic nebulizer with normal saline may be used to induce sputum production; chest physiotherapy may help mobilize secretions; position patient upright during collection; use infection control precautions if tuberculosis suspected (droplet precautions); specimen collection should occur before antibiotic administration if possible for optimal organism recovery

How our test process works!