Jones J L, Lydon K A, Kinsey T P, Friedman B, Curtis M, Schuster R, Bowers J C
FDA, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, AL, USA.
FDA, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, AL, USA.
Int J Food Microbiol. 2017 Jul 17;253:54-58. doi: 10.1016/j.ijfoodmicro.2017.04.016. Epub 2017 Apr 27.
Vibrio vulnificus (Vv) and V. parahaemolyticus (Vp) illnesses are typically acquired through the consumption of raw molluscan shellfish, particularly oysters. As Vibrio spp. are naturally-occurring bacteria, one means of mitigation of illness is achieved by limiting post-harvest growth. In this study, effects of ambient air storage, refrigeration, and icing of oysters on Vibrio spp. abundances were examined at two sites in Alabama (AL) [Dog River (DR) and Cedar Point (CP)] and one site in Delaware Bay, New Jersey (NJ). As the United States shellfish program recommendations include testing for total these organisms and gene targets, Vv and total (tlh) and pathogenic (tdh+ and trh+) Vp were enumerated from samples using MPN-real-time-PCR approaches. Mean Vv and Vp abundances in oysters from AL-DR were lowest in immediately iced samples (2.3 and -0.1 log MPN/g, respectively) and highest in the 5h ambient then refrigerated samples (3.4 and 0.5 log MPN/g, respectively). Similarly, in AL-CP Vv and Vp mean levels in oysters were lowest in immediately iced samples (3.6 and 1.2 log MPN/g, respectively) and highest in 5h ambient then refrigerated samples (5.1 and 3.2 log MPN/g, respectively). Mean levels of pathogenic Vp from AL sites were frequently below the limit of detection (<0.3 MPN/g). In NJ, Vv and Vp mean abundances in oysters were highest in samples which were held for 7h in the shade (5.3 and 4.8 log MPN/g, respectively). Mean pathogenic Vp levels in oysters at initial harvest were also highest in oysters 7h in the shade (2.1 and 2.2 log MPN/g for tdh+ and trh+ Vp). Regardless of sampling location, Vibrio spp. levels were generally significantly (p<0.05) greater in oysters exposed to 5h of air storage compared to the initially harvested samples. In addition, the data demonstrated that the use of layered ice resulted in lower Vibrio spp. levels in oysters, compared to those that were refrigerated post-harvest. These results suggest vibriosis risk can be mitigated by shorter storage times and more rapid cooling of oysters, providing data regulatory authorities can use to evaluate Vibrio spp. control plans.
创伤弧菌（Vv）和副溶血性弧菌（Vp）疾病通常是通过食用生的软体贝类，特别是牡蛎而感染的。由于弧菌属是自然存在的细菌，减轻疾病的一种方法是限制收获后的生长。在本研究中，在阿拉巴马州（AL）的两个地点[多格河（DR）和雪松角（CP）]以及新泽西州特拉华湾的一个地点（NJ），研究了牡蛎的常温空气储存、冷藏和加冰处理对弧菌属丰度的影响。由于美国贝类计划的建议包括对这些微生物和基因靶点进行全面检测，因此使用MPN实时PCR方法从样本中对Vv以及总弧菌（tlh）和致病性弧菌（tdh +和trh +）的Vp进行计数。来自AL-DR的牡蛎中的Vv和Vp平均丰度在立即加冰的样本中最低（分别为2.3和-0.1 log MPN/g），在5小时常温后冷藏的样本中最高（分别为3.4和0.5 log MPN/g）。同样，在AL-CP，牡蛎中的Vv和Vp平均水平在立即加冰的样本中最低（分别为3.6和1.2 log MPN/g），在5小时常温后冷藏的样本中最高（分别为5.1和3.2 log MPN/g）。来自AL各地点的致病性Vp平均水平经常低于检测限（<0.3 MPN/g）。在新泽西州，在阴凉处放置7小时的牡蛎样本中Vv和Vp的平均丰度最高（分别为5.3和4.8 log MPN/g）。收获初期牡蛎中的致病性Vp平均水平在阴凉处放置7小时的牡蛎中也最高（tdh +和trh + Vp分别为2.1和2.2 log MPN/g）。无论采样地点如何，与最初收获的样本相比，暴露于5小时空气储存的牡蛎中的弧菌属水平通常显著更高（p<0.05）。此外，数据表明，与收获后冷藏的牡蛎相比，使用分层冰可使牡蛎中的弧菌属水平更低。这些结果表明，通过缩短储存时间和更快地冷却牡蛎，可以降低弧菌病风险，为监管当局评估弧菌属控制计划提供了可用数据。
