Bile tolerance characteristics of different Aeromonas species

  Objective  To understand the bile tolerance of different Aeromonas species and explore the reasons for the different infection sites of Aeromonas hydrophila and other Aeromonas.

  Methods  A total of 20 Aeromonas strains from 8 species were selected, and the bile minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) to these strains were tested, and the growth curves of common Aeromonas species under different bile concentrations, anaerobic or aerobic environments were described.

  Results  Different strains of Aeromonas had different tolerance to bile. A. veronii and A. enteropelogenes were more resistant to bile, with MIC of 9%–11% and MBC of 11%–12%; A. hydrophila, A. caviae, A. media and A. bivalvium were less resistant to bile, with MIC of 4% and MBC of 6%–10%. There were different bile tolerance among different strains of A. dhakensis. Increasing the initial amount of bacteria, the Aeromonas' tolerance to bile would be higher, and A. hydrophila has the best tolerance to bile. The anaerobic environment was helpful for the early adaptation of Aeromonas to bile.

  Conclusion  Different strains of Aeromonas had different tolerance to bile; initial amount of bacteria and oxygen affected the tolerance of Aeromonas to bile.