5310. Bacterial culture. Sputum. Antimicrobial resistance profile with MIC (if microflora is detected)

A sputum culture is a bacteriological test that allows the detection of pathogens causing lower respiratory tract infections (bronchitis, pneumonia, lung abscess), as well as determining their quantity and sensitivity to antibacterial drugs.

Performing an antibiotic susceptibility test with MIC (minimal inhibitory concentration) helps the doctor choose the most effective antibacterial therapy for the patient.

Automated identification of microorganisms is performed using MALDI-TOF mass spectrometry on the MALDI Biotyper sirius IVD System analyzer (Bruker, Germany).

This bacteriological test is performed to assess the qualitative and quantitative composition of the microflora, as well as to determine its clinical significance.

Normally, the lower respiratory tract is sterile; however, in cases of bronchitis, pneumonia, lung abscess, bronchiectasis, or other infectious diseases, pathogenic bacteria may be detected in the sputum, which indicates inflammation. Inflammation may also be caused by excessive growth of conditionally pathogenic microorganisms. Identification of the pathogen helps not only to confirm the diagnosis but also to select effective treatment.

The presence of microorganisms in a titer of 10⁵ CFU/ml or higher is considered etiologically significant, indicating a bacterial origin of the inflammatory process. If no clinically significant bacterial growth is detected during culture, but symptoms suggest infection, additional tests (such as PCR or tests for atypical pathogens) are recommended.

After inoculating the material onto nutrient media, bacterial identification and an antibiotic susceptibility test with MIC determination are performed. Interpretation of results is carried out according to international EUCAST and CLSI standards.

Important!

• The test should be performed before starting antibiotic therapy, in the morning, after thoroughly rinsing the mouth with boiled water to avoid contamination from the oral cavity.
• Failure to follow sample collection or transportation rules, as well as taking antibiotics, may affect the reliability of results.
• If necessary, additional tests for anaerobic microflora and active or latent tuberculosis (LTBI) are recommended.

The results of the bacteriological test must be interpreted only by a physician, taking into account the clinical picture and individual characteristics of the patient (allergies, comorbidities, pregnancy, etc.). They are not a sufficient basis for self-prescription or adjustment of treatment.

• For cough with sputum production lasting more than 2 weeks.
• In case of suspected pneumonia, bronchitis, lung abscess, or other bacterial respiratory infections.
• In the presence of radiological changes in the lungs or symptoms of intoxication (fever, weakness, chest pain, shortness of breath).
• In cases of ineffective or recurrent infections after antibiotic therapy.
• In patients with weakened immunity, chronic obstructive pulmonary disease (COPD), diabetes mellitus, or after prolonged hospitalization.

• Various types of speciamen depending on the test