Dog/cat-origin quinolone-resistant Streptococcus agalactiae isolates with point mutations in quinolone resistance-determining regions: Relatedness with clonal complex 10

Takahiro Maeda; Yuzo Tsuyuki; Mieko Goto; Haruno Yoshida; Tomohiro Fujita; Takashi Takahashi

doi:10.1016/j.jiac.2021.11.015

Dog/cat-origin quinolone-resistant Streptococcus agalactiae isolates with point mutations in quinolone resistance-determining regions: Relatedness with clonal complex 10

J Infect Chemother. 2022 Mar;28(3):389-395. doi: 10.1016/j.jiac.2021.11.015. Epub 2021 Nov 27.

Authors

Takahiro Maeda¹, Yuzo Tsuyuki², Mieko Goto¹, Haruno Yoshida¹, Tomohiro Fujita³, Takashi Takahashi⁴

Affiliations

¹ Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan.
² Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan; Division of Clinical Laboratory, Sanritsu Zelkova Veterinary Laboratory, 3-5-5 Ogibashi, Koto-ku, Tokyo, 135-0011, Japan.
³ Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan; Department of Clinical Laboratory, Kitasato University Medical Center, 6-100 Arai, Kitamoto, Saitama, 364-8501, Japan.
⁴ Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan. Electronic address: taka2si@lisci.kitasato-u.ac.jp.

PMID: 34848122
DOI: 10.1016/j.jiac.2021.11.015

Abstract

Objective: We aimed to investigate dog/cat-origin quinolone-resistant Streptococcus agalactiae isolates with point mutations in quinolone resistance-determining regions (QRDRs) and to define the relatedness between quinolone-resistant isolates and their microbiological features of capsular genotype, sequence type (ST)/clonal complex (CC), and antimicrobial resistance (AMR) gene.

Methods: With dog/cat-origin 22 isolates, type strain, and human-origin 6 isolates, we performed antimicrobial susceptibility testing by agar plate dilution method using levofloxacin, ciprofloxacin, and moxifloxacin. We also determined amino acid sequences in QRDRs of gyrA/gyrB/parC/parE genes and their point mutations. We conducted capsular genotyping, multilocus sequence typing, and AMR genotyping in our previous investigations. Correlations between quinolone-resistant population and their microbiological features were examined.

Results: We found dog/cat-origin seven (31.8%) quinolone-resistant isolates harboring minimum inhibitory concentrations (MICs) of levofloxacin 16-32 μg/mL, ciprofloxacin 32 μg/mL, and moxifloxacin 2-4 μg/mL: human three isolates indicated MICs of levofloxacin 16-64 μg/mL, ciprofloxacin 32 μg/mL, and moxifloxacin 2-16 μg/mL. Point mutations Ser81Leu in gyrA and Ser79Phe/Ser79Tyr/Asp83Asn/Gly128Asp in parC were observed among these resistant isolates: mutations Leu495Ile/Val503Ile in parE was found among quinolone-nonresistant isolates. There was a significant correlation between dog/cat-origin quinolone-resistant population and ST10 (p = 0.023)/CC10 (p = 0.021).

Conclusion: To our best knowledge, this is the first report assessing dog/cat-origin quinolone-resistant S. agalactiae. Our observations could be applied in future, by veterinarians while treating dogs and cats with clinical symptoms/signs suggestive of streptococcal infections.

Keywords: Clonal complex; Companion animals; Point mutation; Quinolone-resistance; Streptococcus agalactiae.

MeSH terms

Animals
Anti-Bacterial Agents / pharmacology
Cat Diseases*
Cats
DNA Gyrase / genetics
DNA Topoisomerase IV / genetics
Dog Diseases*
Dogs
Drug Resistance, Bacterial / genetics
Microbial Sensitivity Tests
Mutation
Point Mutation
Quinolones* / pharmacology
Streptococcus agalactiae / genetics

Substances

Anti-Bacterial Agents
Quinolones
DNA Topoisomerase IV
DNA Gyrase