当前位置： SCI文献检索 > BMC INFECTIOUS DISEASES期刊下所有文献 > Genotypic and phenotypic characterization of Mycobacterium tuberculosis resistance against fluoroquinolones in the northeast of Iran.

Genotypic and phenotypic characterization of Mycobacterium tuberculosis resistance against fluoroquinolones in the northeast of Iran.

Abstract：

BACKGROUND:Fluoroquinolones are broad-spectrum antibiotics that are recommended, and increasingly important, for the treatment of multidrug-resistant tuberculosis (MDR-TB). Resistance to fluoroquinolones is caused by mutations in the Quinolone Resistance Determining Region (QRDR) of gyrA and gyrB genes of Mycobacterium tuberculosis. In this study, we characterized the phenotypic and genotypic resistance to fluoroquinolones for the first time in northeast Iran. METHODS:A total of 123 Mycobacterium tuberculosis isolates, including 111 clinical and 12 collected multidrug-resistant isolates were studied. Also, 19 WHO quality control strains were included in the study. The phenotypic susceptibility was determined by the proportion method on Löwenstein-Jensen medium. The molecular cause of resistance to the fluoroquinolone drugs ofloxacin and levofloxacin was investigated by sequencing of the QRDR region of the gyrA and gyrB genes. RESULTS:Among 123 isolates, six (4.8%) were fluoroquinolone-resistant according to phenotypic methods, and genotypically three of them had a mutation at codon 94 of the gyrA gene (Asp→ Gly) which was earlier reported to cause resistance. All three remaining phenotypically resistant isolates had a nucleotide change in codon 95. No mutations were found in the gyrB gene. Five of the 19 WHO quality control strains, were phenotypically fluoroquinolone-resistant, four of them were genotypically resistant with mutations at codon 90, 91 of the gyrA gene and one resistant strain had no detected mutation. CONCLUSIONS:Mutation at codon 94 of the gyrA gene, was the main cause of fluoroquinolone resistance among M. tuberculosis isolates in our region. In 3/6 fluoroquinolone-resistant isolates, no mutations were found in either gyrA or gyrB. Therefore, it can be concluded that various other factors may lead to fluoroquinolone resistance, such as active efflux pumps, decreased cell wall permeability, and drug inactivation.

journal_name

BMC Infect Dis

journal_title

BMC infectious diseases

authors

Sayadi M,Zare H,Jamedar SA,Hashemy SI,Meshkat Z,Soleimanpour S,Hoffner S,Ghazvini K

doi

10.1186/s12879-020-05112-5

subject

Has Abstract

pub_date

2020-06-01 00:00:00

pages

390

issue

issn

1471-2334

pii

10.1186/s12879-020-05112-5

journal_volume

pub_type

杂志文章

在线工具

Genotypic and phenotypic characterization of Mycobacterium tuberculosis resistance against fluoroquinolones in the northeast of Iran.