Clinical Microbiology and Antimicrobial Chemotherapy. 2020; 22(3):221-230
Assessment of bacterial identification effectiveness in clinical microbiology laboratory using the MALDI-MS based system BactoSCREEN.
Bacteriological testing was done by the cultivation on Сolumbia agar with 5% of sheep blood (at 37°C for 24 hours). Colonies for identification were selected based on their growth pattern, type of hemolysis, morphology and consistency. The species identification was done by the MALDI-MS using the microbiology analyzer BactoSCREEN. Apart from MALDI-MS, we used morphology and biochemical methods for species identification when necessary. Serological tests were used for serovar and biovar identifications.
A total of 85945 bacterial identifications was performed in 2018. When compared to 2017, the throughput of the laboratory increased ten times. A total of 23252 isolates were obtained in the previously mentioned period. A single identification took 2.98–13.22 minutes including time for supporting procedures, whereas the staff time for one identification itself constituted an average of 1.55 minutes. When compared to manual methods, introduction of mass-spectrometry allowed us to achieve 3.5-fold decrease of the staff time in the average. Therefore, annual labor saving in terms of staffing corresponds to 11 full-time positions.
In view of high throughput, analysis speed, simplicity and low cost of sample preparation, MALDI-MS identification fits well into the practice of clinical microbiology laboratory, especially when large-scale screening studies of bacterial cultures are required. The use of MALDI-MS is likely to be most promising when carrying out microbiological monitoring that is traditionally associated with large number of samples and wide range of microorganisms detected.