Related Experiment Video
Updated: Jul 6, 2026
Visualization of Pseudomonas aeruginosa within the Sputum of Cystic Fibrosis Patients
Published on: July 16, 2020
[Stability for long-term storage and reproducibility of positivity in the panel test slide prepared with the
Hiroyuki Yamada1, Hiroko Matsumoto, Satoshi Mitarai
1Bacteriology Division, Mycobacterium Reference Center, Research Institute of Tuberculosis, JATA, Tokyo, Japan. hyamada@jata.or.jp
Objective:
A novel artificial sputum has been developed using polyacrylamide, cultured THP-1 cell and BCG-Pasteur. Smears prepared with this artificial sputum are similar to actual sputum and has feasibility to set any positivity grades. Long-term storage and reproducibility of the positivity was examined to support further availability.
Method:
The artificial sputa were stored for up to 9 months at room temperature, 4 degrees C and -20 degrees C. Then, smears were prepared and their macroscopic and microscopic appearance were examined compared with smears from freshly prepared artificial sputum. Furthermore, smears with different positivities (+/-, 1 +, 2 + and 3 +) were prepared and examined by several trained technicians, and the reproducibility of the original sputum positivity was determined.
Results:
Macroscopic and microscopic appearance of smears prepared from long-term stored artificial sputum showed little changes compared with smears of freshly prepared artificial sputum. The positivity of these smears fell in their original grade. A total of 91 smears were prepared from artificial sputum with different positivity and examined by trained technicians. Although 3 out of 36 +/- smears were determined as negative, all of the remaining smears were evaluated correctly.
Discussion:
This study confirmed that the artificial sputum and the smears have long-term storage stability and reproducibility in the positivity. These results suggest that the artificial sputum can be widely used to perform external quality assessment in many countries, including high prevalence countries.
Related Concept Videos
01:26Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
01:20Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...