Abstract
β-Lactamase-nonproducing ampicillin-resistant Haemophilus influenzae are prevalent in Japan. Resistance has increased as a consequence of the expanded use of antimicrobial agents, raising concerns about the rise of multidrug (macrolide and fluoroquinolone)-resistant H. influenzae. In this study, we investigated susceptibility to fluoroquinolones in H. influenzae clinical isolates from 2013 to 2014 and identified the amino acid substitutions in quinolone resistance-determining regions of gyrA and parC. All isolates (n = 145) were susceptible to fluoroquinolones; however, some showed reduced susceptibility. The minimum inhibitory concentration of levofloxacin for these strains was 0.063-0.5 µg/mL, and the strains harbored the amino acid substitution S84L in GyrA. Such strains have seen a significant increase. Importantly, all mutants from 2014 were isolated from pediatric patients. In addition, we developed a simple polymerase chain reaction-based screening method for detecting isolates with reduced fluoroquinolone susceptibility. The mutation in GyrA is important as a first step in the development of fluoroquinolone resistance. Hence, detection of reduced susceptible strains may influence the choice of antimicrobial treatment.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.