We used the multilocus sequence typing (MLST) method to evaluate the genetic diversity of 46 Campylobacter jejuni isolates from chickens and to determine the link between quinolone resistance and sequence type (ST). There were a total of 16 ST genotypes, and the majority of them belonged to seven clonal complexes previously identified by using isolates from human disease. The ST-353 complex was...

Fluoroquinolones are an important class of wide-spectrum antibacterial agents. The first quinolone described was nalidixic acid, which showed a narrow spectrum of activity. The evolution of quinolones to more potent molecules was based on changes at positions 1, 6, 7 and 8 of the chemical structure of nalidixic acid. Quinolones inhibit DNA gyrase and topoisomerase IV activities, two enzymes ess...

In a study of the quinolone resistance genes in Staphylococcus aureus, a recG homolog was cloned as a gene affecting quinolone susceptibility. Sequencing analysis revealed that the gene consists of 2,061 nucleotides and encodes a 686-amino-acid polypeptide, which shows 38, 39, and 50% amino acid identity with the RecGs of Escherichia coli, Haemophilus influenzae, and Streptococcus pneumoniae, r...

The purpose of this study was to determine the prevalence and molecular characterization of plasmid-mediated quinolone resistance (PMQR) genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA) among ESBL-producing Klebsiella pneumoniae isolates in Kashan, Iran. A total of 185 K. pneumoniae isolates were tested for quinolone resistance and ESBL-producing using the disk diffusion method and double disk...

INTRODUCTION Plasmid-mediated quinolone resistance (PMQR) is a growing clinical concern worldwide. The main aims of this study were to detect qnr-encoding genes and to evaluate the clonal relatedness of qnr-positive Enterobacter cloacae isolates. METHODS A total of 116 E. cloacae isolates that were not susceptible to quinolone were obtained from seven hospitals in Tehran, five hospitals in Qa...

Antibiotic resistance poses a major threat to human health. It is therefore important to characterize the frequency of resistance within natural bacterial environments. Many studies have focused on characterizing the frequencies with which horizontally acquired resistance genes segregate within natural bacterial populations. Yet, very little is currently understood regarding the frequency of se...

Quinolone-resistant Neisseria gonorrhoeae rates have increased worldwide since 1994. The objective of this study was to appraise: (i) the antimicrobial susceptibility of Neisseria gonorrhoeae in a venereology clinic in Paris, between 2005 and 2007; and (ii) the factors associated with quinolone-resistant N. gonorrhoeae. A prospective study of consecutive cases was performed for the period 2005 ...

This study assessed the functional importance of residues located at the i(-2) position of face 4 of the tandem repeat loops of the quinolone resistance protein QnrVC7 through mutagenesis studies. The i(-2) position of face 4 on different coils required residues with different natures. Some substitutions reduced the protective activity of QnrVC7, while some of them increased it. These findings ...

Pseudomonas Quinolone Signal Modulates Cystic Fibrosis Epithelial Cell Response through the TollLike Receptor 4 Patricia R. Wardwell1,2, David R. Wilson1,2, Dewayne L. Garner1,2 and Rebecca A. Bader1,2* 1Department of Biomedical & Chemical Engineering, Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY, USA 2Onondaga Community College, Syracuse, NY, USA SOJ Immunology Open Acces...