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Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin

BACKGROUND: The mutant prevention concentration (MPC) is an important parameter to evaluate the likelihood of growth of fluoroquinolone-resistant mutants for antimicrobial-pathogen combinations. The MPCs of fluoroquinolones for different canine pathogens have not been compared. In this study, we com...

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Autores principales: Shimizu, Takae, Harada, Kazuki, Kataoka, Yasushi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646708/
https://www.ncbi.nlm.nih.gov/pubmed/23634902
http://dx.doi.org/10.1186/1751-0147-55-37
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author Shimizu, Takae
Harada, Kazuki
Kataoka, Yasushi
author_facet Shimizu, Takae
Harada, Kazuki
Kataoka, Yasushi
author_sort Shimizu, Takae
collection PubMed
description BACKGROUND: The mutant prevention concentration (MPC) is an important parameter to evaluate the likelihood of growth of fluoroquinolone-resistant mutants for antimicrobial-pathogen combinations. The MPCs of fluoroquinolones for different canine pathogens have not been compared. In this study, we compared for the first time orbifloxacin MPCs between susceptible strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin. METHODS: More than 10(10) CFU/ml of 10 strains of each bacterial species were inoculated onto Muller-Hinton agar supplemented with different concentrations of orbifloxacin from 1× to 64× minimum inhibitory concentration (MIC) and the MPCs were recorded. MICs of original strains and of mutants arising after exposure to sub-MPC concentrations (one per original strain) were determined in the presence or absence of efflux pump inhibitors (EPIs). The effects of quinolone resistance-determining region (QRDR) mutations were also examined. RESULTS: MPCs were significantly higher for P. aeruginosa (16–128 μg/ml) than for E. coli (0.5–32 μg/ml). MPCs for S. pseudintermedius varied between the low-susceptible (16–128 μg/ml) and the high-susceptible strains (4–16 μg/ml) and were the most broadly distributed among the three species. Regarding resistance mechanisms, only one QRDR mutation in gyrA was found in all of the 10 mutants of E. coli and in 4 of the 10 mutants of P. aeruginosa, whereas mutations in both grlA and gyrA were found in 3 mutants and one mutation in grlA was found in 2 mutants among the 10 mutants of S. pseudintermedius. In the presence of an EPI, the MICs of P. aeruginosa mutants decreased markedly, those of E. coli mutants decreased moderately, and those of S. pseudintermedius mutants were unaffected. CONCLUSIONS: MPCs of orbifloxacin vary between bacterial species of canine pathogens, possibly due to the diversity of the main fluoroquinolone resistance mechanism among these species. Therefore, the type of bacterial species should be taken into consideration when using fluoroquinolone drugs such as orbifloxacin in canines.
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spelling pubmed-36467082013-05-08 Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin Shimizu, Takae Harada, Kazuki Kataoka, Yasushi Acta Vet Scand Research BACKGROUND: The mutant prevention concentration (MPC) is an important parameter to evaluate the likelihood of growth of fluoroquinolone-resistant mutants for antimicrobial-pathogen combinations. The MPCs of fluoroquinolones for different canine pathogens have not been compared. In this study, we compared for the first time orbifloxacin MPCs between susceptible strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin. METHODS: More than 10(10) CFU/ml of 10 strains of each bacterial species were inoculated onto Muller-Hinton agar supplemented with different concentrations of orbifloxacin from 1× to 64× minimum inhibitory concentration (MIC) and the MPCs were recorded. MICs of original strains and of mutants arising after exposure to sub-MPC concentrations (one per original strain) were determined in the presence or absence of efflux pump inhibitors (EPIs). The effects of quinolone resistance-determining region (QRDR) mutations were also examined. RESULTS: MPCs were significantly higher for P. aeruginosa (16–128 μg/ml) than for E. coli (0.5–32 μg/ml). MPCs for S. pseudintermedius varied between the low-susceptible (16–128 μg/ml) and the high-susceptible strains (4–16 μg/ml) and were the most broadly distributed among the three species. Regarding resistance mechanisms, only one QRDR mutation in gyrA was found in all of the 10 mutants of E. coli and in 4 of the 10 mutants of P. aeruginosa, whereas mutations in both grlA and gyrA were found in 3 mutants and one mutation in grlA was found in 2 mutants among the 10 mutants of S. pseudintermedius. In the presence of an EPI, the MICs of P. aeruginosa mutants decreased markedly, those of E. coli mutants decreased moderately, and those of S. pseudintermedius mutants were unaffected. CONCLUSIONS: MPCs of orbifloxacin vary between bacterial species of canine pathogens, possibly due to the diversity of the main fluoroquinolone resistance mechanism among these species. Therefore, the type of bacterial species should be taken into consideration when using fluoroquinolone drugs such as orbifloxacin in canines. BioMed Central 2013-05-01 /pmc/articles/PMC3646708/ /pubmed/23634902 http://dx.doi.org/10.1186/1751-0147-55-37 Text en Copyright © 2013 Shimizu et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Shimizu, Takae
Harada, Kazuki
Kataoka, Yasushi
Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin
title Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin
title_full Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin
title_fullStr Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin
title_full_unstemmed Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin
title_short Mutant prevention concentration of orbifloxacin: comparison between Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin
title_sort mutant prevention concentration of orbifloxacin: comparison between escherichia coli, pseudomonas aeruginosa, and staphylococcus pseudintermedius of canine origin
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646708/
https://www.ncbi.nlm.nih.gov/pubmed/23634902
http://dx.doi.org/10.1186/1751-0147-55-37
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