Smiddy Mary, Kelly Alan L, Patterson Margaret F, Hill Colin
Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
Int J Food Microbiol. 2006 Feb 1;106(2):105-10. doi: 10.1016/j.ijfoodmicro.2005.05.015. Epub 2005 Oct 10.
High pressure (HP) treatment inactivates bacteria in shellfish, but its effects on viruses in shellfish have not yet been determined, although viral illness is frequently associated with shellfish consumption. The aim of this study was to investigate the baroresistance of two bacteriophage viruses, Qbeta coliphage and c2 phage, in oysters and in culture media. High numbers (>or=10(7) ml(-1) or g(-1)) of both phages were obtained in culture media and in oysters. Samples were HP treated at 200-800 MPa at 20 degrees C for up to 30 min. Little or no inactivation of either phage was observed in oysters or in culture media after treatment at <or=400 MPa. High levels of inactivation of both phages in oysters and in culture medium were observed following treatment at 500-700 MPa. Titres of both phages were reduced to non-detectable levels (up to 8 log inactivation) in oysters and in GM17 broth (for c2 phage) after treatment at 800 MPa. The level of Qbeta coliphage in tryptone soya broth with yeast extract (10(10) PFU ml(-1)) was reduced by approximately 7 log units following treatment of 800 MPa. Levels of inactivation of both phages in oysters were similar to those in culture media. Increasing the duration of treatment at 550 or 600 MPa increased the level of inactivation of both phages in oysters. HP treatment may effectively inactivate phage in shellfish but HP-induced inactivation of human enteric viruses in oysters needs to be studied directly, to more accurately assess the ability of this technology to inactivate these viruses.
高压（HP）处理可使贝类中的细菌失活，尽管食用贝类经常与病毒疾病相关，但高压处理对贝类中病毒的影响尚未确定。本研究的目的是调查两种噬菌体病毒，即Qβ噬菌体和c2噬菌体，在牡蛎和培养基中的耐压性。在培养基和牡蛎中均获得了大量（≥10⁷ ml⁻¹或g⁻¹）的这两种噬菌体。样品在20℃下以200 - 800 MPa进行高压处理，最长处理30分钟。在≤400 MPa处理后，在牡蛎或培养基中未观察到两种噬菌体有明显失活。在500 - 700 MPa处理后，观察到牡蛎和培养基中的两种噬菌体均有高水平失活。在800 MPa处理后，牡蛎和GM17肉汤（针对c2噬菌体）中两种噬菌体的滴度均降至不可检测水平（高达8个对数级的失活）。在含酵母提取物的胰蛋白胨大豆肉汤（10¹⁰ PFU ml⁻¹）中，Qβ噬菌体的水平在800 MPa处理后降低了约7个对数单位。牡蛎中两种噬菌体的失活水平与培养基中的相似。在550或600 MPa下增加处理时间会增加牡蛎中两种噬菌体的失活水平。高压处理可能有效地使贝类中的噬菌体失活，但需要直接研究高压诱导的牡蛎中人类肠道病毒的失活情况，以便更准确地评估该技术使这些病毒失活的能力。
