Title:Two Years Study of Frequency and Antimicrobial Resistance Patterns of
Escherichia coli Strains Isolated from Clinical Specimens in Northern
Iran
Volume: 21
Issue: 1
Author(s): Zahra Norouzi Bazgir, Mehrdad Gholami and Hamid Reza Goli*
Affiliation:
- Department of Medical Microbiology and Virology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari,
Iran
- Molecular and Cell Biology Research Center (MCBRC), Mazandaran University of Medical Sciences, Sari, Iran
Keywords:
Escherichia coli, antibiotic resistance, multidrug-resistant, nosocomial infections, clinical specimens, neonatal ICU.
Abstract:
Background: According to the reports from the World Health Organization, increased
use of antibiotics and bacterial resistance has become a worldwide issue. Resistance to
antimicrobial agents in Escherichia coli clinical strains is increasing.
Objective: The objective of this study was to determine the antibiotic resistance patterns and
frequency of multidrug resistance (MDR) phenotype in E. coli isolated from patients in two
major hospitals in Sari, north Iran.
Methods: In this descriptive-analytical study, a total of 13322 clinical specimens were collected
from patients. All the specimens were evaluated to determine the presence of E. coli strains
using conventional biochemical tests and API kit. Susceptibility testing against twelve antibiotics
was determined using the disk-diffusion method. Results were interpreted in accordance
with the Clinical and Laboratory Standard Institute (CLSI) protocol.
Results: Out of 13322 studied samples, 964 (7.23%) E. coli strains were identified. In two
hospitals, high resistance to ampicillin and cefalexin was presented in 621 (64.4%) and 402
(41.7%) isolates, respectively. The highest antibiotic resistance was observed in the burn unit,
the burn intensive care unit (ICU) and the burn restoration section, while all the strains (eight)
that were isolated from the neonatal-ICU, were sensitive to all the tested antibiotics except cefalexin,
nitrofurantoin, nalidixic acid, and ampicillin. Also, strains isolated from urine, wound,
stool, and blood samples were resistant to all tested antibiotics.
Conclusion: Increased resistance to different antibiotics in burn hospitals has created increasing
concern. Very high resistance to some antibiotics indicates that these drugs are misused in
therapeutic centers and highlights that infection control measures should be arranged in the
ICUs of our hospitals.
