Identification, characterization and antibiotic susceptibility testing for Bacillus species
-
Noha Alaa Eldin Fahim
,
Ghada Abd El-Wahed Ismail
,
Moataz Bellah Abdelaleem
,
Mervat Elanany
,
Sally Mohamed Saber
,
Marwa Abd EL-Rasoul EL-Ashry
Abstract
Background and Objectives: With the increase in immunosuppressed patients and antimicrobial misuse, Bacillus species have risen as opportunistic pathogens in hospitalized patients. The present study aimed at comparing chromogenic media, automated identification cards versus MALDI-TOF as the gold standard method for identification of different Bacillus species and determining minimal inhibitory concentration (MIC) of different antibiotics by broth microdilution method (BMD) to suggest recommendations for Bacillus treatment.
Materials and Methods: The study included 30 Bacillus species isolates recovered from normally sterile sites of the human body and were subjected to identification by MALDI-TOF, Vitek-2c, and HiCrome Bacillus Agar. BMD test was performed to determine the MIC of vancomycin, gentamicin, and ciprofloxacin.
Results: Our study showed B. cereus was the most commonly isolated species (76.66%) followed by B. subtilis (23.33%). Regarding the different methods of identification, the highest agreement with MALDI-TOF was exhibited by HiCrome agar without polymyxin B (93.3%) followed by Vitek-2C and HiCrome agar with polymyxin with an agreement of 83.3%. Concerning the antibiogram, the tested isolates showed a susceptibility of 93.3%, 86.6%, and 83.3% towards vancomycin, gentamicin, and ciprofloxacin respectively.
Conclusion: In conclusion, we spotlight that Bacillus species should no longer be considered contaminant bacteria in cultures, particularly in immunosuppressed patients. HiCrome Bacillus Agar without polymyxin B displayed the highest agreement with MALDI-TOF. Hence, it represents a good option for identification for routine laboratories where expensive instruments are unavailable. The high susceptibility towards the tested antibiotics can suggest the possibility of empirical use of vancomycin, gentamicin, and ciprofloxacin.
2. Tran SL, Ramarao N. Bacillus cereus immune escape: a journey within macrophages. FEMS Microbiol Lett 2013; 347: 1-6.
3. Farrar WE, Reboli AC. (2006). The Genus Bacillus—Medical. In: Dworkin M, Falkow S, Rosenberg E, Schleifer KH, Stackebrandt E. (eds). The Prokaryotes. Springer, 3rd ed. Volume 4. New York, NY, pp.609-630.
4. Ehling-Schulz M, Lereclus D, Koehler TM. The Bacillus cereus group: Bacillus species with pathogenic potential. Microbiol Spectr 2019; 7: 10.
5. Fricker M, Reissbrodt R, Ehling-Schulz M. Evaluation of standard and new chromogenic selective plating media for isolation and identification of Bacillus cereus. Int J Food Microbiol 2008; 121: 27-34.
6. Wieser A, Schneider L, Jung J, Schubert S. MALDI-TOF MS in microbiological diagnostics-identification of microorganisms and beyond (mini review). Appl Microbiol Biotechnol 2012; 93: 965-974.
7. Marko DC, Saffert RT, Cunningham SA, Hyman J, Walsh J, Arbefeville S, et al. Evaluation of the Bruker Biotyper and Vitek MS Matrix-Assisted laser desorption ionization–time of flight mass spectrometry systems for identification of nonfermenting gram-negative bacilli isolated from cultures from cystic fibrosis patients. J Clin Microbiol 2012; 50: 2034-2039.
8. Halket G, Dinsdale AE, Logan NA. Evaluation of the VITEK2 BCL card for identification of Bacillus species and other aerobic endosporeformers. Lett Appl Microbiol 2010; 50: 120-126.
9. Alippi AM, Abrahamovich E. HiCrome Bacillus agar for presumptive identification of Bacillus and related species isolated from honey samples. Int J Food Microbiol 2019; 305: 108245.
10. Clinical and Laboratory Standards Institute. 2016. Methods for antimicrobial dilution and disk susceptibility testing of infrequently isolated or fastidious bacteria, 3rd ed CLSI guideline M45 Clinical and Laboratory Standards Institute, Wayne, PA.
11. Glasset B, Herbin S, Granier SA, Cavalié L, Lafeuille E, Guérin C, et al. Bacillus cereus, a serious cause of nosocomial infections: Epidemiologic and genetic survey. PLoS One 2018; 13(5): e0194346.
12. Celandroni F, Vecchione A, Cara A, Mazzantini D, Lupetti A, Ghelardi E. Identification of Bacillus species: Implication on the quality of probiotic formulations. PLoS One 2019; 14(5): e0217021.
13. Fujita T, Nishiura H. Environmental drivers of Bacillus-positive blood cultures in a cancer hospital, Sapporo, Japan. Int J Environ Res Public Health 2018; 15: 2201.
14. Celandroni F, Salvetti S, Gueye SA, Mazzantini D, Lupetti A, Senesi S, et al. Identification and pathogenic potential of clinical Bacillus and Paenibacillus isolates. PLoS One 2016; 11(3): e0152831.
15. Lasch P, Beyer W, Nattermann H, Stämmler M, Siegbrecht E, Grunow R, et al. Identification of Bacillus anthracis by using Matrix-Assisted laser desorption ionization-time of flight mass spectrometry and artificial neural networks. Appl Environ Microbiol 2009; 75: 7229-7242.
16. Aygun FD, Aygun F, Cam H. Successful Treatment of Bacillus cereus bacteremia in a patient with propionic acidemia. Case Rep Pediatr 2016; 2016: 6380929.
17. Hilliard NJ, Schelonka RL, Waites KB. Bacillus cereus bacteremia in a preterm neonate. J Clin Microbiol 2003; 41: 3441-3444.
18. Ozkocaman V, Ozcelik T, Ali R, Ozkalemkas F, Ozkan A, Ozakin C, et al. Bacillus spp. among hospitalized patients with haematological malignancies: clinical features, epidemics and outcomes. J Hosp Infect 2006; 64: 169-176.
19. Ikeda M, Yagihara Y, Tatsuno K, Okazaki M, Okugawa S, Moriya K. Clinical characteristics and antimicrobial susceptibility of Bacillus cereus blood stream infections. Ann Clin Microbiol Antimicrob 2015; 14: 43.
| Files | ||
| Issue | Vol 14 No 4 (2022) | |
| Section | Original Article(s) | |
| DOI | https://doi.org/10.18502/ijm.v14i4.10234 | |
| Keywords | ||
| Bacillus cereus; Bacillus subtilis; Identification; Antibiotic resistance | ||
| Rights and permissions | |
|
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
