兰州市区志贺菌毒力基因型及毒力研究

发布时间：2018-06-13 20:14

  本文选题：志贺菌 + 兰州市区　； 参考：《兰州大学》2008年硕士论文

【摘要】： 目的:调查兰州市区腹泻患者中志贺菌的感染率和感染型别;确定兰州市区分离志贺菌株的毒力基因型;测定不同毒力基因型志贺菌的毒力,以探讨毒力与毒力基因型的关系。 方法:选择兰州市区三家三甲医院门、急诊急性腹泻患者,采用分离培养、生化反应和血清学鉴别确定兰州市区腹泻患者中志贺菌的感染率和感染型别;设计引物,应用聚合酶链反应(PCR)方法,检测志贺菌肠毒素1基因(setlA和setlB)、志贺菌肠毒素2基因(sen)、侵袭性质粒抗原H基因(ipaH)、侵袭相关位点基因(ial)以及多重调控基因virA,确定兰州市区分离志贺菌株的毒力基因型;以腹腔注射为感染途径,测定不同毒力基因型的志贺菌对昆明种小鼠的半数致死量(LD50)。 结果: 1.从80例急性腹泻患者粪便中分离出志贺菌16株,阳性率为20.0%。其中福氏志贺菌9株,占56.2%,宋内志贺菌6株,占37.5%,痢疾志贺菌1株,占6.2%。同一菌群的不同志贺菌间在生化反应和抗原性方面存在差异。 2.兰州市区的志贺菌毒力基因virA、setlA阳性率最高,为100%;ipaH次之,阳性率为93.7%;ial、sen阳性率分别为56.2%、62.5%;setlB阳性率最低,仅为25.0%。除virA、ipaH、setlA外,宋内志贺菌sen阳性率较高,为50.0%;ial检出率较低,为33.3%,6株宋内志贺菌均未检出setlB。福氏志贺菌ial、setlB、sen阳性率分别为66.7%、44.4%、66.7%均高于宋内志贺菌。 3.7株不同毒力基因型(virA+ipaH+setlA,virA+ial+ipaH+setlA+setlB+sen,virA+setlA,virA+ial+ipaH+setlA+sen,virA+ipaH+setlA+sen,virA+ipaH+setlA+setlB,virA+ial+ipaH+setlA+setlB)志贺菌LD50测定的结果分别为:1.422×10~9cfu/ml、6.653×10~7 cfu/ml、阴性、6.653×10~8 cfu/ml、1.422×10~9 cfu/ml、1.422×10~9cfu/ml、6.653×10~8 cfu/ml;对照宋内志贺菌51334的LD50为3.062×10~9 cfu/ml。 结论: 1.兰州市区腹泻患者中志贺菌的感染率为20.0%左右,感染菌群以福氏志贺菌为主,其次为宋内志贺菌。宋内志贺菌感染的比例相对较高,占37.5%。 2.兰州市区志贺菌中存在virA、ial、ipaH、setlA、setlB、sen毒力基因,以virA,setlA,ipaH较稳定。志贺菌相关毒力基因检测中,福氏志贺菌检出率高于宋内志贺菌。宋内志贺菌携带setlA。 3兰州市区志贺菌的毒力与毒力基因型密切相关,以virA、ial、ipaH、setlA、setlB和sen均阳性的福氏志贺菌Ⅳ型毒力最强。 4.virA,setlA,ipaH基因可作为靶基因用于兰州市区志贺菌的检验。setlB可用于筛选福氏志贺菌Ⅳ型菌株。
[Abstract]:Objective: to investigate the infection rate and type of Shigella in diarrhea patients in Lanzhou city, determine the virulence genotype of Shigella isolated from Lanzhou city, and determine the virulence of Shigella virulent in different virulence genotypes, so as to explore the relationship between virulence and virulence genotypes. Methods: the isolated culture, biochemical reaction and serology were used to identify the infection rate and type of Shigella in three hospitals of Lanzhou district, and the primers were designed. Polymerase chain reaction (PCR) method was used. The virulence genotypes of Shigella enterotoxin 1 gene, Shigella enterotoxin 2 gene, invasive plasmid antigen H gene, invasion related locus gene, and multiple regulatory gene vira were detected, and the virulence genotypes of Shigella isolates were determined. The lethal dose (LD50) of Shigella with different virulence genotypes on Kunming mice was determined by intraperitoneal injection. Results: 1. Sixteen Shigella strains were isolated from the feces of 80 patients with acute diarrhea, and the positive rate was 20.0%. Among them, 9 strains of Shigella flexneri, 6 strains of Shigella sonnei, 1 strain of Shigella flexneri, 6 strains of Shigella sonnei, 1 strain of Shigella flexneri, accounted for 6. 2% of Shigella flexneri. There were differences in biochemical reaction and antigenicity among different Shigella strains of the same flora. 2. The positive rate of Shigella virulence gene virAtsetlA was the highest in Lanzhou city, with a positive rate of 100% ipaH, followed by 93.7% ialsen positive rate. The positive rate of Shigella virulence gene was 56.2% and 62.5% respectively, the lowest was 25.0%. The positive rate of sen in Shigella sonnei was higher than that in the other 6 strains of Shigella sonnei, and the detection rate of 50.0ial Shigella was lower than that of 33.3 strains of Shigella sonnei, and no setlB was detected in all the 6 strains of Shigella sonnei. The positive rates of Shigella flexneri were 66.7% and 44.4%, respectively, which were higher than those of Shigella sonnei. The results of LD50 determination of ial ipaH setlA setlB senvira ial ipaH setlA senvirA setlA ial setlA setlB of Shigella flexneri The LD50 of Shigella sonnei 51334 was 3.062 脳 10 9 cfuml-1 / ml, and the LD50 of Shigella sonnei 51334 was 3.062 脳 10 9 cfuml-1 路ml, and 1.422 脳 10 9 cfumlr / ml of 1.422 脳 10 9 cfuml-1 / ml, respectively, and the LD50 of Shigella sonnei 51334 was 3.062 脳 10 9 cfuml / r / ml, and the LD50 of Shigella sonnei 51334 was 3.062 脳 10 9 cfuml-1 / ml, instead of 1. 422 脳 10 9 cfuml / r = 1.422 脳 10 9 cfuml-1 / ml. Conclusion: 1. The infection rate of Shigella was about 20.0% in diarrhea patients in Lanzhou city. Shigella flexneri was the main infection group, followed by Shigella sonnei. The proportion of Shigella sonnei infection was relatively high, accounting for 37.5%. The virulence gene of Shigella spp. The detection rate of Shigella flexneri was higher than that of Shigella sonnei. The virulence of Shigella sonnei carrying setlA.3 was closely related to virulence genotypes. The virulence of Shigella flexneri type 鈪，

本文编号：2015273