尿源大肠杆菌毒力因子及其与耐药性关系的探讨

发布时间：2019-04-19 18:00

【摘要】：[目的]探讨尿源大肠杆菌毒力因子的分布及其与耐药性之间的关系。 [方法]本文对1992～2004年天津市5所医院确诊为尿路感染的门珍和住院患者尿标本中分离的81株大肠杆菌用PCR方法扩增其黏附基因群上的papC基因和1型菌毛黏附素fimH基因;采用多重PCR方法扩增尿源大肠杆菌溶血素hly、细胞坏死因子1cnfl、产气杆菌素aer等毒力因子基因;用纸片扩散法(K-B法)对尿源大肠杆菌进行15种抗菌药物的敏感试验。 [结果]根据papC基因扩增结果将尿源大肠杆菌分为两组,papC阳性组作为具有P菌毛的致肾盂肾炎大肠杆菌(Pyelonephritic E.coli,UPEC)组,papC阴性组作为不具有P菌毛的非UPEC组,前者占50.6%(41/81),后者占49.4%(40/81)。其他毒力因子hly,aer,fimH及cnfl的总检出率为67.9%(55/81);UPEC组上述四种毒力因子的检出率依次为63.41%、60.98%、53.66%和34.15%;非UPEC组依次为10%、35%、12.5%和5%;经列联表资料x~2检验表明两组之间四种毒力因子的检出率均有统计学意义(P0.01)。进一步分析发现,UPEC组hty和cnfl同时阳性占31.71%,cnfl阳性菌株中只有一株向hly阴性,cnfl阳性菌株中87.5%携带papC基因,hly阳性菌株中86.67%携带papC基因。药敏试验结果显示,尿源大肠杆菌对15种药物的总耐药率为87.65%(71/81),耐三种药物以上的多重耐药率为69.14%(56/81)。对青霉素类抗生素氨苄西林和羧苄西林的耐药率最高,分别为88.89%和85.19%。其次是坏丙沙星、氧氟沙星、复方磺胺和庆大霉素,分别为56.79%、56.79%、54.32%和45.68%。再次是头孢唑林、头孢噻肟、氨曲南和阿米卡星,分别为41.98%、29.63%、23.46%和11.11%。头孢他啶、头孢匹肟、呋喃妥因和亚胺培南的耐药率最低,分别为
[Abstract]:[objective] to investigate the distribution of virulence factors in urine-derived Escherichia coli and its relationship with drug resistance. [methods] 81 strains of Escherichia coli isolated from urine samples of Mengzhen and inpatients with urinary tract infection diagnosed as urinary tract infection in 5 hospitals of Tianjin in 1992-2004 were used to amplify the papC gene and fimH gene of mucin type 1 in the adhesion gene group by PCR. The virulence factor genes such as hemolysin hly, cell necrosis factor 1cnfland pneumogenin aer were amplified by multiplex PCR, and the susceptibility tests of 15 antimicrobial agents were carried out by disk diffusion method. [results] according to the results of papC gene amplification, the urine-derived Escherichia coli was divided into two groups. The papC-positive group was used as the Pyelonephritic E. coli (UPEC) group with P-pili, and the papC-negative group was regarded as the non-UPEC group without P-pili. The former accounted for 50.6% (41 / 81) and the latter 49.4% (40 / 81). The positive rates of other virulence factors hly,aer,fimH and cnfl were 67.9% (63.41%, 60.98%, 53.66% and 34.15%, respectively) in 55 / 81); UPEC group. The non-UPEC group was 10%, 35%, 12.5% and 5%, respectively, and the detection rate of the four virulence factors between the two groups was statistically significant (P0.01). Further analysis showed that the positive rate of both hty and cnfl in UPEC group was 31.71%, only one positive strain of CNF1 was negative to hly, 87.5% of cnfl positive strains carried papC gene, 86.67% of hly positive strains carried papC gene. The results of drug sensitivity test showed that the total resistance rate of urine-derived Escherichia coli to 15 drugs was 87.65% (71 / 81), and the multiple drug resistance rate of more than three drugs was 69.14% (56 / 81). The resistance rates to penicillin antibiotics ampicillin and carbenicillin were 88.89% and 85.19%, respectively. It was followed by ciprofloxacin, ofloxacin, sulfamide and gentamicin (56.79%, 56.79%, 54.32% and 45.68%, respectively). The third was cefazolin, cefotaxime, aztreonam and amikacin, which were 41.98%, 29.63%, 23.46% and 11.11%, respectively. The resistance rates of ceftazidime, cefpixime, furantoin and imipenem were the lowest, respectively.
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R378.2

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