Vittoria Maria, Saggese Anella, Di Gregorio Barletta Giovanni, Castaldi Stefany, Isticato Rachele, Baccigalupi Loredana, Ricca Ezio
Department of Biology, Federico II University of Naples, Italy.
Department of Molecular Medicine and Medical Biotechnology, Federico II University of Naples, Italy.
Res Microbiol. 2023 Jul-Aug;174(6):104030. doi: 10.1016/j.resmic.2023.104030. Epub 2023 Feb 3.
Bacteria classified as Bacillus cereus sensu stricto cause two different type of gastrointestinal diseases associated with food poisoning. Outbreaks of this opportunistic pathogen are generally due to the resistance of its spores to heat, pH and desiccation that makes hard their complete inactivation from food products. B. cereus is commonly isolated from a variety of environments, including intestinal samples of infected and healthy people. We report the genomic and physiological characterization of MV19, a human intestinal strain closely related (ANI value of 98.81%) to the reference strain B. cereus ATCC 14579. MV19 cells were able to grow in a range of temperatures between 20 and 44 °C. At the optimal temperature the sporulation process was rapidly induced and mature spores efficiently released, however these appeared structurally and morphologically defective. At the sub-optimal growth temperature of 25 °C sporulation was slow and less efficient but a high total number of fully functional spores was produced. These results indicate that the reduced rapidity and efficiency of sporulation at 25 °C are compensated by a high quality and quantity of released spores, suggesting the relevance of different performances at different growth conditions for the adaptation of this bacterium to diverse environmental niches.
归类为狭义蜡样芽孢杆菌的细菌会引发两种与食物中毒相关的不同类型的胃肠道疾病。这种机会致病菌的爆发通常是由于其孢子对热、pH值和干燥具有抗性，使得很难将其从食品中完全灭活。蜡样芽孢杆菌通常从各种环境中分离得到，包括受感染和健康人群的肠道样本。我们报告了MV19的基因组和生理特征，MV19是一株与参考菌株蜡样芽孢杆菌ATCC 14579密切相关（ANI值为98.81%）的人肠道菌株。MV19细胞能够在20至44°C的温度范围内生长。在最佳温度下，孢子形成过程迅速诱导，成熟孢子有效释放，但这些孢子在结构和形态上存在缺陷。在25°C的次优生长温度下，孢子形成缓慢且效率较低，但产生的全功能孢子总数较高。这些结果表明，25°C时孢子形成速度和效率的降低被释放孢子的高质量和数量所补偿，这表明不同生长条件下的不同表现对于这种细菌适应不同环境生态位具有相关性。
