Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Section for Food Safety, Oslo, Norway.
FEMS Microbiol Lett. 2011 Apr;317(2):196-202. doi: 10.1111/j.1574-6968.2011.02229.x. Epub 2011 Feb 17.
The closely related bacterial species Bacillus cereus and Bacillus weihenstephanensis are adapted to the mesophilic and the psychrotrophic temperature range, respectively. While B. cereus strains are associated with foodborne diseases, B. weihenstephanensis strains are so far not, although similar virulence genes are found in both species. Our investigations show that both species were virulent in the insect model, Galleria mellonella, following infection via oral and haemocoel routes. However, virulence of B. weihenstephanensis was much higher at 15°C than at 37°C. Furthermore, a temperature-dependent difference between the species was seen in a cell culture cytotoxicity assay. In summary, our results demonstrate for the first time virulence of B. weihenstephanensis strains in an in vivo model. In addition, we found that G. mellonella is a useful model for studies of the psychrotolerant species of the B. cereus group, suggesting that insects might be an ecological growth niche for several members of this bacterial group.
密切相关的细菌物种蜡状芽孢杆菌和魏氏芽孢杆菌分别适应中温和嗜冷温度范围。虽然蜡状芽孢杆菌菌株与食源性疾病有关，但魏氏芽孢杆菌菌株迄今没有，尽管在这两个物种中都发现了类似的毒力基因。我们的研究表明，这两个物种在昆虫模型（家蚕）中都具有毒力，通过口服和血腔途径感染后。然而，魏氏芽孢杆菌在 15°C 时的毒力比在 37°C 时高得多。此外，在细胞培养细胞毒性测定中观察到了物种之间的温度依赖性差异。总之，我们的结果首次证明了魏氏芽孢杆菌菌株在体内模型中的毒力。此外，我们发现家蚕是研究蜡状芽孢杆菌组中嗜冷物种的有用模型，这表明昆虫可能是该细菌组的几个成员的生态生长小生境。
