Dolatyar Dehkharghani A, Haghighat S, Rahnamaye Farzami M, Douraghi M, Rahbar M. Subtyping β-lactamase-producing
Escherichia coli strains isolated from patients with UTI by MLVA and PFGE methods.
IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2021;
24:437-443. [PMID:
34094024 PMCID:
PMC8143711 DOI:
10.22038/ijbms.2021.49790.11372]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 03/07/2021] [Indexed: 12/03/2022]
Abstract
OBJECTIVES
Strain subtyping is an important epidemiological tool to trace contamination, determine clonal relationships between different strains, and the cause of outbreaks. Current subtyping methods, however, yield less than optimal subtype discrimination. Pulsed-field gel electrophoresis is the gold standard method for Escherichia coli and Multiple-Locus Variable-number tandem repeat Analysis is a rapid PCR-based method. The purpose of this study was to evaluate MLVA and PFGE methods for subtyping β -lactamase-producing E. coli strains isolated from urinary tract infections.
MATERIALS AND METHODS
Overall, 230 E. coli isolates from patients with urinary tract infections were examined for antimicrobial susceptibility testing. 10-loci and 7-loci MLVA and PFGE methods were used for molecular typing of β -lactamase-producing E. coli isolates.
RESULTS
Out of 230 isolates, 130 (56.5%) β -lactamase-producing E. coli isolates were found in this study. The diversity indices of the VNTR loci showed an average diversity of 0.48 and 0.54 for 7-loci and 10-loci MLVA, respectively. The discriminatory power of PFGE showed a value of 0.87. The discordance between the methods was high.
CONCLUSION
Our study showed that PFGE is more discriminatory than MVLA. MLVA is a PCR- based method and can generate unmistakable data, in contrast to PFGE. Optimization of polymorphic VNTR is essential to improve the discriminatory power of MLVA based on geographical region.
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