Laboratoary identification of anaerobic bacteria isolated from clinical specimens by maldi-TOF MS and conventional methods and determination of their antibiotic susceptibilities

In this study, it was aimed to isolate and identify the anaerobic bacteria from different clinical specimens (n: 359) submitted to our laboratory when an anaerobic infection was suspected in patiens. In addition, the determination of antimicrobial susceptibilities of isolated organisms was also planned. Of 359 clinical samples, the 2 samples were rejected when rejection criteria were applied. A total of 95 anaerobic bacteria was isolated from the samples (n: 357) handled. Of these 95 isolates, 94 were identified to genus or species level. The identity of the remaining isolate (n: 1) was limited to their Gram stained characteristic and they were reported to the related clinic only with this information. In identification process, both macroscopic and microscopic examinations along with the use of a identification discs and MALDI-TOF MS (Matrix assisted laser desorption mass spectrometry) system, were performed. Of the 95 anaerobic bacteria, 36 were not reproduced during the passage and antimicrobial susceptibility testing phase. Thus, the antimicrobial susceptibility testing was made for the remaining 59 anaerop bacteria. E-test method was used to determine antimicrobial susceptibilities of isolates, antibiogram results were evaluated according to CLSI for cefoxitin and EUCAST for other antibiotics. Statistical analysis could not be performed due to low rate of isolation. Key Words: Anaerobe, E-test, MIC, MALDI-TOF MS, Conventional