鸡志贺氏菌产超广谱β内酰胺酶（ESBLs）的分子进化

 【目的】检测鸡志贺氏菌分离株和诱导株所产ESBLs的基因型,探讨其产酶耐药的分子进化机制。【方法】对1株诱导和5株临床分离产ESBLs细菌分别用TEM、SHV、CTX-M 3种通用引物进行PCR扩增、基因克隆及测序分析，确定鸡福氏志贺氏菌ESBLs的基因型和基因亚型。【结果】5株临床福氏志贺氏菌质粒上具有相同的TEM序列和相同的SHV序列，TEM型序列与AY903309（TEM-116）序列相比发生了2个位点基因突变即G157A、C409T,其中409位点碱基突变为沉默突变，157位点碱基突变导致相应氨基酸序列53位发生突变Gly53Ser,此氨基酸突变为新的突变位点，所以该TEM型ESBLs是一种新的TEM亚型，暂命名为TEM-1V型;SHV型与AY826418（SHV-12）序列完全相同，为SHV-12型。头孢噻呋诱导标准福氏志贺氏菌，诱导10代时产生了TEM-1型β－内酰胺酶，诱导50代时产生了TEM-1V型ESBLs。【结论】临床分离鸡福氏志贺氏菌ESBLs的基因型为TEM-1V型和SHV-12型，鸡福氏志贺氏菌TEM-1V型ESBLs是由 TEM-1型β内酰胺酶直接进化而来。

Studies on the Preparation and Immunity Effect of NDV Chitosan Microsphere

NDV Chitosan Microsphere can be prepared using chitosan as capsule wall material, NDV as core material, glutaraldehyde as cross-lingking material. To evaluate vaccine’s effect with live LaSota and inactivated NDV vaccine, we immune SPF chicken ,detect MTT, IgG and protected activity. The results show that NDV Chitosan Microsphere educe good immune activity.