Fernández-Delgado Milagro, García-Amado María Alexandra, Contreras Monica, Incani Renzo Nino, Chirinos Humberto, Rojas Héctor, Suárez Paula
Departamento de Biología de Organismos, Universidad Simón Bolívar, Caracas, Venezuela.
Centro de Biofísica y Bioquímica, Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe, Edo. Miranda, Venezuela.
Rev Inst Med Trop Sao Paulo. 2015 Jan-Feb;57(1):21-6. doi: 10.1590/S0036-46652015000100003.
The causative agent of cholera, Vibrio cholerae, can enter into a viable but non-culturable (VBNC) state in response to unfavorable conditions. The aim of this study was to evaluate the in situ survival of V. cholerae in an aquatic environment of the Southern Caribbean Sea, and its induction and resuscitation from the VBNC state. V. cholerae non-O1, non-O139 was inoculated into diffusion chambers placed at the Cuare Wildlife Refuge, Venezuela, and monitored for plate, total and viable cells counts. At 119 days of exposure to the environment, the colony count was < 10 CFU/mL and a portion of the bacterial population entered the VBNC state. Additionally, the viability decreased two orders of magnitude and morphological changes occurred from rod to coccoid cells. Among the aquatic environmental variables, the salinity had negative correlation with the colony counts in the dry season. Resuscitation studies showed significant recovery of cell cultivability with spent media addition (p < 0.05). These results suggest that V. cholerae can persist in the VBNC state in this Caribbean environment and revert to a cultivable form under favorable conditions. The VBNC state might represent a critical step in cholera transmission in susceptible areas.
霍乱病原体霍乱弧菌在不利条件下可进入活的但不可培养(VBNC)状态。本研究的目的是评估霍乱弧菌在加勒比海南部海域水生环境中的原位存活情况,以及其从VBNC状态的诱导和复苏。将非O1、非O139霍乱弧菌接种到置于委内瑞拉夸雷野生动物保护区的扩散室中,并监测平板计数、总细胞数和活菌数。在暴露于该环境119天时,菌落计数<10 CFU/mL,部分细菌群体进入VBNC状态。此外,活力下降了两个数量级,形态从杆状细胞变为球状细胞。在水生环境变量中,旱季盐度与菌落计数呈负相关。复苏研究表明,添加用过的培养基后细胞可培养性有显著恢复(p<0.05)。这些结果表明,霍乱弧菌在该加勒比环境中可保持在VBNC状态,并在有利条件下恢复为可培养形式。VBNC状态可能是霍乱在易感地区传播的关键步骤。