Effect of immunosuppression associated with point-of-lay on Salmonella infection and immunity in laying hens

肠炎沙门氏菌是世界范围内细菌性食物中毒的主要原因之一。一种名为肠炎沙门氏菌的沙门氏菌能够感染感染沙门氏菌的鸡的鸡蛋。如果感染的鸡蛋生吃或煮得不熟，这个人就有可能生病。在大多数情况下，这会导致腹泻和短期疾病，但在幼儿、老年人或免疫系统不起作用的人中，沙门氏菌感染可能非常严重。在某些情况下，它可能会导致死亡。近年来，疫苗接种已被用作控制鸡只沙门氏菌的一部分。然而，就在母鸡开始下蛋(产蛋点)之前，它们的免疫系统会受到抑制或变得不那么有效。这可能意味着，即使接种了疫苗的鸡，在这一点上也更有可能感染沙门氏菌。这项研究将找出免疫系统的哪些部分在层面上不能很好地工作。然后我们将测试沙门氏菌疫苗，并测量它们在产蛋点刺激免疫系统的效果，以及这些接种疫苗的禽类是否更有可能在这个时候感染沙门氏菌。这项研究将使我们能够改进我们为鸡接种沙门氏菌疫苗的方式和时间，以便在鸡开始下蛋时保护它们。它还将帮助我们制造更好的疫苗，比目前的疫苗更好地保护鸡，保护时间更长。

Salmonella enterica is one of main causes of bacterial food poisoning in the world. One type of Salmonella called Salmonella Enteritidis has the ability to infect the eggs of chickens that are infected with Salmonella bacteria. If infected eggs are eaten raw or poorly cooked, there is a chance that the person may become ill. In most cases this results in diarrheoa and a short term illness but in young children, the elderly or people with immune systems that do not work well, Salmonella infection can be very serious. In some case it may result in death. In recent years vaccination has been used as part of the control of Salmonella in chickens. However just before hens begin laying eggs (point-of-lay), their immune system becomes suppressed or less effective. This may mean that even vaccinated chickens are more likely to catch a Salmonella infection at this point. This research will find out which parts of the immune system do not work well at the point-of lay. We will then test Salmonella vaccines and measure how well they stimulate the immune system at point-of-lay and whether these vaccinated birds are more likely to get Salmonella at this time.The research will allow us to improve how and when we vaccinate chickens against Salmonella so they are protected when they start to lay eggs. It will also help us make better vaccines that protect chickens better and for longer than current vaccines.