Tavakkoli M, Soudi M, Malekzadeh F, Hajy Zarghany G. Effects of quinolones on biofilm formed by Staphylococcus epidermidisisolated from patients with urinary tract infection. Iran J Med Microbiol 2008; 2 (1) :23-30
URL:
http://ijmm.ir/article-1-109-en.html
1- Islamic Azad university, Institute of Science and Research, Tehran , minoo _Tavakkoli@yahoo.com
2- Department of Biological Science, School of Science, Alzahra university , Tehran
3- Department of microbiology, School of Biology , Pardis Olum , Tehran university , Tehran
4- Islamic Azad university, Institute of Science and Research, Tehran
Abstract: (20837 Views)
Background and Objectives: Bacterial cells of Staphylococcus epidermidis are naturally occurring on skin
and human mucosal membranes. They also cause nosocomial infections. Capability of biofilm formation
plays an important role in the bacterial virulence. Quinolones have been used to treat urinary tract infections
caused by S. epidermidis for several years. Thus, resistance to this type of antibiotics has emerged among the
strains of this organism. Since the bacterial cells residing within biofilm structures are more resistant than
those in planctonic stage, we conduct this study to examine the effect of quinolnes was the main goal of
ones study of higher resistance of native biofilm producing strains is the goal of this project.
Material and Methods: In this research ten native isolates of S. epidermidis were obtained from pathients
with urinary tract infection. Also standard strain of S. epidermidis PTCC 1435 was used as a control.
Identification of strains was confirmed using morphological and biochemical tests. Challenge tests against
the isolated was performed using three quinolone antibiotics including Ciprofluxacin, Ofluxacin, Nalidixic
acid, with two different procedures :kirby bauer disk diffusion test, and broth dilution test.
Results: Average of MICs of above mentioned antibiotics against ten isolated was obtained as follow:
Ciprofluxacin (7/375 µg/µl), Ofluxacin (11/53 µg/µl), Nalidixic acid (259/ 2 µg/µl). Experimental biofilm
model of these bacteria showed much higher resistance to quinolone antibiotic, from 15 times in case of
Nalidixic acid to 18 times greater resistance in case of Ciprofluxacin. Average of MICs amang ten isolates
against the three antibiotics also showed increased resistance as follow: Ciprofluxacin ( 128/4 µg/µl ),
Ofluxacin (177/8 µg/µl ), Nalidixic acid (3942 /4 µg/µl ).
Conclusion: S. epidermidis showed increased resistance to different quinolone antibiotics in biofilm
structure, comparing to those of planktonic form. Results obtained from this research is in agreement with
those of other similar projects and emphesize on applying of a de quaite doses of antibiotics against urinary
infection caused by biofilmic Staphylococcus epidermidis.
Type of Study:
Original Research Article |
Subject:
Antimicrobial Substances Received: 2013/11/14 | Accepted: 2013/11/14 | ePublished: 2013/11/14