Accelerated Techniques of Pathogen Identification from Positive Blood Cultures by MALDI-TOF Mass Spectrometry

Clinical Microbiology and Antimicrobial Chemotherapy. 2016; 18(4):296-307

​ Popov D.A., Nadtochey E.A., Vostrikova T.Yu., Ovseenko S.T.
bacteremia blood culture rapid identification MALDI-TOF mass spectrometry
Section
Personal Experience
Type
Journal article
Publication
Clinical Microbiology and Antimicrobial Chemotherapy. 2016; 18(4):296-307

Objective.

To assess pathogen identification from positive blood cultures by MALDI-TOF mass spectrometry.

Materials and Methods.

At the first stage, an in vitro study using MALDI-TOF MS and including 11 pathogen species (K. pneumoniae, E. coli, P. aeruginosa, A. baumannii, S. aureus, S. epidermidis, S. haemolyticus, E. faecalis, E. faecium, C. albicans, C. parapsilosis) was performed. This study involved hourly attempts to identify the above listed pathogens by MALDI-TOF MS (Vitek MS, bioMerieux) during incubation until their correct identification. At the second (clinical) stage, a total of 360 positive blood cultures obtained from 187 patients undergoing cardiac surgery were tested. Two accelerated techniques of pathogen identification from the positive blood cultures were studied concurrently with the routine method (MALDI-TOF MS assay following 24-hour incubation). A total of 300 blood samples (284 single cultures) were tested by the short-term incubation technique. A total of 211 blood samples (201 single cultures) were tested by the direct identification technique (with no culture on a solid medium). A total of 151 blood samples were tested by these two identification techniques concurrently.

Results.

At the first stage, the incubation time (on blood agar) required to complete identification was no more than 5 hours and 6 hours for vials with polymer granules and vials with active charcoal, respectively. The incubation times for Candida spp. were 10 to 22 hours. The identification by MALDI-TOF MS following short-term incubation on blood agar was successful for 259⁄284 (91.2%) of pathogens, including 97%, 94.5%, and 43.5% of Gram-negative rods, Gram-positive cocci, and Candida spp., respectively; the mean incubation times were 2.7, 3.9 and 5 hours, respectively. The results of successful pathogen identification coincided with those obtained by the routine method in all cases. The identification to species level by the direct MALDI-TOF MS assay was correct for 163⁄201 (81.1%) of pathogens, including 94%, 75.2%, and 40% of Gram-negative rods, Gram-positive cocci, and Candida spp., respectively. A turnaround time for this technique, including sample preparation, was no more than 1 hour. The concurrent use of the both accelerated techniques provided the overall successful identification in 95% of cases, including 98.4%, 96%, and 50% of Gram-negative rods, Gram-positive cocci, and Candida spp., respectively (Cohen’s kappa for comparison with the routine method was 0.92).

Conclusions.

The accelerated techniques of pathogen identification from blood cultures by MALDI-TOF MS provide rapid and reliable identification of microorganisms causing bacteremia, which in combination with local microbiological monitoring data may contribute to early appropriate antimicrobial therapy.

Dmitriy A. Popov

A.N. Bakoulev Scientific Center for Cardiovascular Surgery, Moscow, Russia

Nadtochey E.A.

A.N. Bakoulev Scientific Center for Cardiovascular Surgery, Moscow, Russia

Vostrikova T.Yu.

A.N. Bakoulev Scientific Center for Cardiovascular Surgery, Moscow, Russia

Ovseenko S.T.

A.N. Bakoulev Scientific Center for Cardiovascular Surgery, Moscow, Russia

  • 1. Magill S.S., Edwards J.R., Bamberg W., et al. Multistate Point-Prevalence Survey of Health Care-Associated Infections. New Engl J Med 2014; 370:1198-208.
  • 2. Vincent J.L., Rello J., Marshall J. and EPIC II Group of Investigators. International study of the prevalence and outcomes of infection in intensive care units. JAMA 2009; 302(21): 2323-9.
  • 3. Руднов В.А., Бельский Д.В., Дехнич А.В., исследовательская группа РИОРИТа. Инфекции в ОРИТ России: результаты национального многоцентрового исследования. Клин микробиол антимикроб химиотер 2011; 4:294-303.
  • 4. Kumar A., Roberts D., Wood K.E., et al. Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in human septic shock. J Crit Care Med 2006; 34 (6):1589-96.
  • 5. Попов Д.А., Овсеенко С.Т., Вострикова Т.Ю. Экспрессидентификация положительных гемокультур с помощью метода прямой MALDI-TоF масс-спектрометрии. Анестезиология и реаниматология 2015; 5:71-5.
  • 6. Попов Д.А., Вострикова Т.Ю. Первый опыт применения метода ПЦР в режиме реального времени для диагностики бактериемии в послеоперационном периоде у кардиохирургических больных. Клиническая лабораторная диагностика 2011; 8:49-52.
  • 7. Костюк С.А., Кулага О.К., Хворик Д.Ф. Новые аспекты клинического применения полимеразной цепной реакции. Медицинские новости 2006; 5:14-1
  • 8. Price C., Douglas I., Tuttle E., et al. Rapid identification and antimicrobial susceptibility testing of bacteria in bloodstream infections using the Accelerate ID/AST technology. ECCMID 2015; EV0493.
  • 9. Pfaller M.A., Wolk D.M., Lowery T.J. T2MR and T2Candida: novel technology for the rapid diagnosis of candidemia and invasive candidiasis. Future Microbiology 2016; 11(1):103-17.
  • 10. Попов Д.А., Овсеенко С.Т., Осипов Г.А., Вострикова Т.Ю. Ускоренный способ идентификации возбудителей бактериемий с применением метода газовой хромато-масс-спектрометрии. Клиническая лабораторная диагностика 2013;5: 54-8.
  • 11. Lagacé-Wiens P.R., Adam H.J., Karlowsky J.A., et al. Identification of blood culture isolates directly from positive blood cultures by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry and a commercial extraction system: analysis of performance, cost, and turnaround time. J Сlin Microbiol 2012; 50:3324-8.
  • 12. Patel R. Matrix-assisted laser desorption ionization-time of flight mass-spectrometry in clinical microbiology. J Clin Infect Dis 2013; 57: 564-72.
  • 13. Wieser A., Schneider L., Jung J., Schubert S. MALDITоF MS in microbiological diagnostics – identification of microorganisms and beyond (mini review). J Appl Microbiol Biotechnol 2012; 93:965-74.
  • 14. Idelevich E.A., Schule I., Grunastel B., Wullenweber J., Peters G., Becker K. Rapid identification of microorganisms from positive blood cultures by MALDITOF mass spectrometry subsequent to very short-term incubation on solid medium. J Clin Microbiol Infect 2014; 20(10):1001-6.
  • 15. Kohlmann R., Hoffmann A., Geis G., Gatermann S. MALDI-TOF mass spectrometry following short incubation on a solid medium is a valuable tool for rapid pathogen identification from positive blood cultures. Int J Med Microbiol 2015; 305 (4-5):469-79.
  • 16. Christner M., Rohde H., Wolters M., Sobottka I., Wegscheider K., Aepfelbacher M. Rapid identification of bacteria from positive blood culture bottles by use of matrix-assisted laser desorption-ionization time of flight mass spectrometry fingerprinting. J Сlin Microbiol 2010; 48(5):1584-91.
  • 17. Spanu T., Posteraro B., Fiori B., et al. Direct MALDITOF mass spectrometry assay of blood culture broths for rapid identification of Candida species causing bloodstream infections: an observational study in two large microbiology laboratories. J Сlin Microbiol 2012; 50(1):176-9.
  • 18. Schmidt V., Jarosch A., März P., Sander C., Vacata V., Kalka-Moll W. Rapid identification of bacteria in positive blood culture by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Eur J Clin Microbiol Infect Dis 2011; 31(3):311-7.
  • 19. Idelevich E.A., Grünastel B., Peters G., Becker K. Direct blood culturing on solid medium outperforms an automated continuously monitored broth-based blood culture system in terms of time to identification and susceptibility testing. J New microbes and new infections 2015; 10:19-24.
  • 20. Попов Д.А., Вострикова Т.Ю. Микробиологический мониторинг в кардиохирургическом стационаре – опыт за 10 лет. Бюллетень НЦ ССХ им. А.Н. Бакулева РАМН «Сердечно-сосудистые заболевания» 2012; 5:68-76.
Views
0 Abstract
0 PDF
0 Crossref citations
Shared