Wahid Syeda Umme Habiba, Campbell Bronwyn E, Moore Robert J, Istivan Taghrid
School of Science, RMIT University, Bundoora, Victoria, Australia.
R Soc Open Sci. 2024 May 29;11(5):240088. doi: 10.1098/rsos.240088. eCollection 2024 May.
is an opportunistic bacterial pathogen linked with a range of human diseases. The objective of this study was to investigate the viable but nonculturable (VBNC) state of the bacterium. To induce the VBNC state, cells were maintained in sterilized phosphate-buffered saline at 4°C for three weeks. The VBNC cells were monitored using quantitative analysis by propidium monoazide (PMAxx) coupled with quantitative real-time PCR (PMAxx-qPCR), targeting the subunit B gene. The results demonstrated that ATCC 51562 entered the VBNC state in 15 days, while ATCC 51561 entered the VBNC state in 9 days. The viable cell counts, assessed by PMAxx-qPCR, consistently remained close to the initial level of 10 CFU ml, indicating a substantial portion of the cell population had entered the VBNC state. Notably, morphological analysis revealed that the VBNC cells became coccoid and significantly smaller. The cells could be resuscitated through a temperature increase in the presence of a highly nutritious growth medium. In conclusion, under environmental stress, most cells converted to the VBNC state. The VBNC state of may be important for its environmental survival and spread, and the presence of VBNC forms should be considered in environmental and clinical monitoring.
是一种与多种人类疾病相关的机会性细菌病原体。本研究的目的是调查该细菌的活的但不可培养（VBNC）状态。为诱导VBNC状态，将细胞在4°C的无菌磷酸盐缓冲盐水中维持三周。使用单叠氮丙啶（PMAxx）定量分析结合定量实时PCR（PMAxx-qPCR）监测VBNC细胞，靶向β亚基B基因。结果表明，ATCC 51562在15天内进入VBNC状态，而ATCC 51561在9天内进入VBNC状态。通过PMAxx-qPCR评估的活细胞计数始终保持接近初始水平10 CFU ml，表明大部分细胞群体已进入VBNC状态。值得注意的是，形态学分析表明VBNC细胞变成球形且明显变小。在高营养生长培养基存在下，通过升温可使细胞复苏。总之，在环境压力下，大多数细胞转变为VBNC状态。该菌的VBNC状态可能对其在环境中的存活和传播很重要，在环境和临床监测中应考虑VBNC形式的存在。
