广东水禽源大肠埃希菌耐药性及氨基糖苷类耐药基因研究

为了调查广东地区水禽源大肠埃希菌对氨基糖苷类药物耐药现状和耐药基因的流行情况,探索大肠埃希菌的氨基糖苷类耐药基因型与耐药表型之间的关系,本研究采用琼脂梯度稀释法测定251株广东地区水禽源大肠埃希菌对氨基糖苷类药物的耐药性和采用PCR方法检测耐药基因。药敏试验结果显示,大肠埃希菌对链霉素耐药较严重,鸭源和鹅源的耐药率分别为81.58%和75.43%,对庆大霉素和卡那霉素较敏感,耐药率分别为25%和54.86%,对阿米卡星最为敏感,其中鸭源的菌株耐药率仅为1.32%。PCR方法检测显示,aadA1和aph(3′)-1检出率较高,为84.6%和91.9%,表明携带aadA1和aph(3′)-1耐药基因的水禽源大肠埃希菌在广东地区呈流行趋势。耐药基因型与耐药表型相关性分析结果显示,耐药基因rmtB的携带与4种药物(庆大霉素、阿米卡星、卡那霉素和壮观霉素)耐药株的产生具有显著相关性,表明耐药基因rmtB对大肠埃希菌耐药株的产生起重要的作用。本试验结果可为指导广东地区水禽大肠埃希菌病的临床用药提供理论基础和研究大肠埃希菌的耐药基因提供相关的数据。     

Isolation and characterization of antimicrobial-resistant Escherichia coli from national horse racetracks and private horse-riding courses in Korea

Limited information is available regarding horse-associated antimicrobial resistant (AR) Escherichia (E.) coli. This study was designed to evaluate the frequency and characterize the pattern of AR E. coli from healthy horse-associated samples. A total of 143 E. coli (4.6%) were isolated from 3,078 samples collected from three national racetracks and 14 private horse-riding courses in Korea. Thirty of the E. coli isolates (21%) showed antimicrobial resistance to at least one antimicrobial agent, and four of the AR E. coli (13.3%) were defined as multi-drug resistance. Most of the AR E. coli harbored AR genes corresponding to their antimicrobial resistance phenotypes. Four of the AR E. coli carried class 1 integrase gene (intI1), a gene associated with multi-drug resistance. Pulsed-field gel electrophoretic analysis showed no genetic relatedness among AR E. coli isolated from different facilities; however, cross-transmissions between horses or horses and environments were detected in two facilities. Although cross-transmission of AR E. coli in horses and their environments was generally low, our study suggests a risk of transmission of AR bacteria between horses and humans. Further studies are needed to evaluate the risk of possible transmission of horse-associated AR bacteria to human communities through horse riders and horse-care workers.     

安徽药用牡丹炭疽病病原菌鉴定

<正>牡丹(Paeonia suffruticosa Andr.)是芍药科植物,为多年生落叶灌木,具有很高的观赏和药用价值。因其风姿华丽、色彩艳丽、品种繁多、深受大家喜爱,是中国传统名花和世界著名花卉之一。其根皮也被称为丹皮,具有抗炎、抑制血小板、止痛、清热等作用,是六味地黄丸等著名中成药的主要配方,也是饮片中的常用品[1-2]。近年来,随着牡丹种植面积的不断扩大,造成牡丹病害的大面积发生,已给牡丹生产带来严重影响。     

国内外致泻大肠埃希氏菌O157:H7的检测标准比较及建议

致泻大肠埃希氏菌O157:H7（STEC O157:H7）是大肠埃希氏菌中致病性最严重的一种食源性致病菌,主要存在于牛肉、牛奶、水果及其制品中,对身体健康造成很大危害,甚至引发死亡。食品中STEC O157:H7检测尤为重要。本文对国内外STEC O157:H7的检测标准进行比较,提出我国标准在样品前处理、快速筛选方法的应用等方面需要加强,以便为该菌快速准确检测提供帮助,实现与国际标准化体系建设接轨,满足实验室检测需要。     

猪源ST9型耐甲氧西林金黄色葡萄球菌中前噬菌体的流行状况与转导分析

本研究旨在分析猪源ST9型耐甲氧西林金黄色葡萄球菌(Staphylococcus aureus,MRSA)中前噬菌体的流行情况、结构特点和转导能力,探究前噬菌体在猪源MRSA流行克隆形成中的作用。基于全基因组信息,分析了近年来从我国多省分离的131株ST9型MRSA中前噬菌体的流行率、分型、亲缘关系和结构特征;选取含不同分型前噬菌体的菌株进行诱导,对诱导获得的噬菌体颗粒进行转导,测定转导子的耐药表型及体外适应性。研究结果显示：猪源ST9型MRSA的前噬菌体携带率为78.6%(103/131株),其中,63株携带完整前噬菌体序列,所有前噬菌体序列均不含耐药基因,仅2.9%(3/103株)的前噬菌体序列含毒力基因;前噬菌体谱型丰富,其整合酶分型主要为Sa2int和Sa4int;各型别前噬菌体结构同源性较高,完整前噬菌体可被诱导为长尾噬菌体;噬菌体颗粒可包装供体菌的aadD、tet(L)耐药基因并转导至受体菌中;转导子可获得卡那霉素、四环素耐药表型,体外生长能力与受体菌株无明显差异(P>0.05)。研究结果表明：猪源ST9型MRSA的前噬菌体携带率较高,谱型丰富,不携带耐药基因,部分噬菌体可包装供体菌的耐药基因转导至受体菌,产生的适应性代价小。     

植物表达载体pGMAR-BADH的构建

将甜菜碱醛脱氢酶基因BADH和植物表达载体pGMAR通过内切酶BamHI和KpnI双酶切,T4连接酶进行连接反应。重组质粒在大肠杆菌菌株DH5α内扩增,提取并纯化质粒。经鉴定,基因BADH已被完整、正确的插入到pGMAR载体中,并成功将BADH插入到载体pGMAR的两个MAR序列之间。     

Biocompatibility of Acellular Porcine Dermis

In vitro cultured vascular endothelial cells (VEC) and mouse 3T3 fibroblasts (3T3) on the acellular dermal matrix , which were made of porcine skins. We made the cell proliferation test with MTT assay and the histological observation after cells were seeded on the acelluar dermis for 1 week with histological section. The cell growth curves showed VEC and 3T3 grew much rapidly on the acelluar dermis.The histological observation revealed VEC had formed a monolayer, some places even had formed 2 to 3 layer. The results suggest that the acelluar porcine dermal matrix have good biocompatibility , it will be widely applied.     

草莓根腐病病原菌分离与鉴定

为了有效防控草莓根腐病,采用组织分离法,对徐州地区草莓根腐病病原菌进行分离与鉴定,分离、纯化后获取了5个真菌菌株,经形态学与分子生物学碱基序列测定结果比对发现：CMGF-1是胶孢炭疽菌或其亚种,CMGF-2和CMGF-3是棒孢拟盘多毛孢或其亚种,CMGF-4和CMGF-5是串珠镰刀菌或其亚种。黑根根腐的致病菌主要是镰刀菌和拟盘多毛孢菌,而红中柱根腐的致病菌是胶孢炭疽菌。