尿路致病性大肠埃希菌的体外生物膜形成及其抗菌药物敏感性模式。

In vitro biofilm formation by uropathogenic Escherichia coli and their antimicrobial susceptibility pattern.

机构信息

Department of Microbiology, Dr. N.G.P Arts and Science College, Coimbatore, Tamil Nadu, India.

出版信息

Asian Pac J Trop Med. 2012 Mar;5(3):210-3. doi: 10.1016/S1995-7645(12)60026-1.

DOI:10.1016/S1995-7645(12)60026-1

PMID:22305786

Abstract

OBJECTIVE

To detect in vitro biofilm formation of uropathogenic Escherichia coli (E. coli) (UPEC) strains isolated from urine specimens and also to determine their antimicrobial susceptibility pattern using 13 commonly used antibiotics.

METHODS

The present study comprised of 166 urine specimens collected from tertiary care hospitals in and around Coimbatore, South India. All the specimens were subjected to gram staining, bacterial culture and the E. coli strains were screened for biofilm formation using Tube Method (TM), Congo Red Agar (CRA) and Tissue Culture Plate method (TCP) respectively. Subsequently, the antimicrobial susceptibility test was performed by Kirby Bauer-disk diffusion method for the biofilm and non-biofilm producing E. coli strains.

RESULTS

Of the 100 (60.2 %) E. coli strains, 72 strains displayed a biofilm positive phenotype under the optimized conditions in the Tube Method and the strains were classified as highly positive (17, 23.6%), moderate positive (19, 26.3 %) and weakly positive (36, 50.0 %), similarly under the optimized conditions on Congo Red agar medium, biofilm positive phenotype strains were classified as highly positive (23, 23 %), moderate positive (37, 37 %) and weakly positive (40, 40%). While in TCP method, the biofilm positive phenotype strains were also classified as highly positive (6, 6 %), moderate positive (80, 80 %) and weakly positive (14, 14 %), it didn't not correlate well with the tube method for detecting biofilm formation in E. coli. The rates of antibiotic resistance of biofilm producing E. coli were found to be 100 % for chloramphenicol and amoxyclav (amoxicillin and clavulanic acid), 86% for gentamicin and cefotaxime, 84% for ceftazidime, 83% for cotrimoxazole and piperacillin/tazobactam, 75% for tetracycline and 70% for amikacin.

CONCLUSIONS

This study reveals the prevalence and antimicrobial susceptibility pattern of biofilm and non-biofilm producing uropathogenic E. coli strains.

摘要

目的

检测来自尿液标本的尿路致病性大肠杆菌（E. coli）（UPEC）菌株的体外生物膜形成，并使用 13 种常用抗生素确定其抗菌药敏模式。

方法

本研究包括来自印度南部哥印拜陀及周边地区的 3 家三级医院的 166 份尿液标本。所有标本均进行革兰氏染色、细菌培养，分别采用管法（TM）、刚果红琼脂（CRA）和组织培养板法（TCP）检测 E. coli 菌株的生物膜形成。随后，采用 Kirby Bauer 圆盘扩散法对生物膜和非生物膜产生的 E. coli 菌株进行抗菌药敏试验。

结果

在管法的优化条件下，100 株（60.2%）E. coli 菌株中 72 株显示生物膜阳性表型，这些菌株被分类为高度阳性（17 株，23.6%）、中度阳性（19 株，26.3%）和弱阳性（36 株，50.0%），同样在刚果红琼脂培养基的优化条件下，生物膜阳性表型菌株被分类为高度阳性（23 株，23%）、中度阳性（37 株，37%）和弱阳性（40 株，40%）。而在 TCP 法中，生物膜阳性表型菌株也被分类为高度阳性（6 株，6%）、中度阳性（80 株，80%）和弱阳性（14 株，14%），但与管法检测 E. coli 生物膜形成的结果并不吻合。产生物膜的 E. coli 对氯霉素和氨芐西林/克拉维酸（阿莫西林和克拉维酸）的耐药率为 100%，对庆大霉素和头孢噻肟的耐药率为 86%，对头孢他啶的耐药率为 84%，对复方新诺明和哌拉西林/他唑巴坦的耐药率为 83%，对四环素的耐药率为 75%，对阿米卡星的耐药率为 70%。