{"title":"尿路致病性大肠杆菌gyrA和parC基因突变与氟喹诺酮类药物耐药性关系的研究","authors":"Erfan Ghaffari Lashkenari, Maryam Sadat Mir, Mohsen Mohammadi, Kasra Javadi, Mehrdad Halaji","doi":"10.1177/10766294251377378","DOIUrl":null,"url":null,"abstract":"<p><p><b><i>Introduction:</i></b> Fluoroquinolone resistance in <i>Escherichia coli</i>, particularly uropathogenic <i>E. coli</i> (UPEC), is a growing concern worldwide. This study investigates the association between mutations in the <i>gyrA</i> and <i>parC</i> genes and fluoroquinolone resistance in UPEC isolates from Urine samples in Iran. <b><i>Materials and Methods:</i></b> In total, 150 UPEC isolates were collected, and then, 12 ciprofloxacin-resistant isolates were selected for molecular analysis. Antimicrobial susceptibility testing was performed using the disk diffusion method, and minimum inhibitory concentrations (MICs) of ciprofloxacin were determined by microbroth dilution. Polymerase chain reaction and sequencing were used to detect mutations in the quinolone resistance-determining regions (QRDRs) of <i>gyrA</i> and <i>parC</i>. <b><i>Results:</i></b> All isolates had MIC >4 and were resistant to all four fluoroquinolones and quinolones tested, including ciprofloxacin, norfloxacin, ofloxacin, and nalidixic acid. All isolates harbored mutations in both genes. The most frequent mutations in <i>gyrA</i> were Ser-83→Leu and Asp-87→Asn, found in 100% of isolates. Similarly, mutations in <i>parC</i>, including Ser-80→Ile (83.3%) and Glu-84→Val (58.3%), were prevalent. Additional nucleotide substitutions in both genes were observed. These mutations likely contribute to the high-level fluoroquinolone resistance observed in the isolates. <b><i>Conclusions:</i></b> The results of this study confirm that mutations in the <i>gyrA</i> and <i>parC</i> genes primarily drive fluoroquinolone resistance in UPEC isolates. The presence of specific alterations within the QRDRs significantly reduces bacterial susceptibility to fluoroquinolones, contributing to the persistence and spread of resistant strains. Identifying these mutations provides critical insights into resistance mechanisms, which can aid in developing more effective antimicrobial therapy strategies.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":""},"PeriodicalIF":1.9000,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Investigating the Relationship Between Mutations in <i>gyrA</i> and <i>parC</i> Genes and Resistance to Fluoroquinolones in Uropathogenic <i>Escherichia coli</i> Isolates.\",\"authors\":\"Erfan Ghaffari Lashkenari, Maryam Sadat Mir, Mohsen Mohammadi, Kasra Javadi, Mehrdad Halaji\",\"doi\":\"10.1177/10766294251377378\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p><b><i>Introduction:</i></b> Fluoroquinolone resistance in <i>Escherichia coli</i>, particularly uropathogenic <i>E. coli</i> (UPEC), is a growing concern worldwide. This study investigates the association between mutations in the <i>gyrA</i> and <i>parC</i> genes and fluoroquinolone resistance in UPEC isolates from Urine samples in Iran. <b><i>Materials and Methods:</i></b> In total, 150 UPEC isolates were collected, and then, 12 ciprofloxacin-resistant isolates were selected for molecular analysis. Antimicrobial susceptibility testing was performed using the disk diffusion method, and minimum inhibitory concentrations (MICs) of ciprofloxacin were determined by microbroth dilution. Polymerase chain reaction and sequencing were used to detect mutations in the quinolone resistance-determining regions (QRDRs) of <i>gyrA</i> and <i>parC</i>. <b><i>Results:</i></b> All isolates had MIC >4 and were resistant to all four fluoroquinolones and quinolones tested, including ciprofloxacin, norfloxacin, ofloxacin, and nalidixic acid. All isolates harbored mutations in both genes. The most frequent mutations in <i>gyrA</i> were Ser-83→Leu and Asp-87→Asn, found in 100% of isolates. Similarly, mutations in <i>parC</i>, including Ser-80→Ile (83.3%) and Glu-84→Val (58.3%), were prevalent. Additional nucleotide substitutions in both genes were observed. These mutations likely contribute to the high-level fluoroquinolone resistance observed in the isolates. <b><i>Conclusions:</i></b> The results of this study confirm that mutations in the <i>gyrA</i> and <i>parC</i> genes primarily drive fluoroquinolone resistance in UPEC isolates. The presence of specific alterations within the QRDRs significantly reduces bacterial susceptibility to fluoroquinolones, contributing to the persistence and spread of resistant strains. Identifying these mutations provides critical insights into resistance mechanisms, which can aid in developing more effective antimicrobial therapy strategies.</p>\",\"PeriodicalId\":18701,\"journal\":{\"name\":\"Microbial drug resistance\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":1.9000,\"publicationDate\":\"2025-09-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Microbial drug resistance\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1177/10766294251377378\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"INFECTIOUS DISEASES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microbial drug resistance","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1177/10766294251377378","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}
Investigating the Relationship Between Mutations in gyrA and parC Genes and Resistance to Fluoroquinolones in Uropathogenic Escherichia coli Isolates.
Introduction: Fluoroquinolone resistance in Escherichia coli, particularly uropathogenic E. coli (UPEC), is a growing concern worldwide. This study investigates the association between mutations in the gyrA and parC genes and fluoroquinolone resistance in UPEC isolates from Urine samples in Iran. Materials and Methods: In total, 150 UPEC isolates were collected, and then, 12 ciprofloxacin-resistant isolates were selected for molecular analysis. Antimicrobial susceptibility testing was performed using the disk diffusion method, and minimum inhibitory concentrations (MICs) of ciprofloxacin were determined by microbroth dilution. Polymerase chain reaction and sequencing were used to detect mutations in the quinolone resistance-determining regions (QRDRs) of gyrA and parC. Results: All isolates had MIC >4 and were resistant to all four fluoroquinolones and quinolones tested, including ciprofloxacin, norfloxacin, ofloxacin, and nalidixic acid. All isolates harbored mutations in both genes. The most frequent mutations in gyrA were Ser-83→Leu and Asp-87→Asn, found in 100% of isolates. Similarly, mutations in parC, including Ser-80→Ile (83.3%) and Glu-84→Val (58.3%), were prevalent. Additional nucleotide substitutions in both genes were observed. These mutations likely contribute to the high-level fluoroquinolone resistance observed in the isolates. Conclusions: The results of this study confirm that mutations in the gyrA and parC genes primarily drive fluoroquinolone resistance in UPEC isolates. The presence of specific alterations within the QRDRs significantly reduces bacterial susceptibility to fluoroquinolones, contributing to the persistence and spread of resistant strains. Identifying these mutations provides critical insights into resistance mechanisms, which can aid in developing more effective antimicrobial therapy strategies.
期刊介绍:
Microbial Drug Resistance (MDR) is an international, peer-reviewed journal that covers the global spread and threat of multi-drug resistant clones of major pathogens that are widely documented in hospitals and the scientific community. The Journal addresses the serious challenges of trying to decipher the molecular mechanisms of drug resistance. MDR provides a multidisciplinary forum for peer-reviewed original publications as well as topical reviews and special reports.
MDR coverage includes:
Molecular biology of resistance mechanisms
Virulence genes and disease
Molecular epidemiology
Drug design
Infection control.