An Optimized Checkerboard Method for Phage-Antibiotic Synergy Detection

Isidora Nikolic; Darija Vukovic; Damir Gavric; Jelena Cvetanovic; Verica Aleksic Sabo; Sonja Gostimirovic; Jelena Narancic; Petar Knezevic

doi:10.3390/v14071542

Viruses (Jul 2022)

An Optimized Checkerboard Method for Phage-Antibiotic Synergy Detection

Isidora Nikolic,
Darija Vukovic,
Damir Gavric,
Jelena Cvetanovic,
Verica Aleksic Sabo,
Sonja Gostimirovic,
Jelena Narancic,
Petar Knezevic

Affiliations

Isidora Nikolic: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia
Darija Vukovic: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia
Damir Gavric: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia
Jelena Cvetanovic: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia
Verica Aleksic Sabo: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia
Sonja Gostimirovic: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia
Jelena Narancic: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia
Petar Knezevic: PK Laboratory, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia

DOI: https://doi.org/10.3390/v14071542
Journal volume & issue: Vol. 14, no. 7
p. 1542

Abstract

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Phage-antibiotic synergy is a promising therapeutic strategy, but there is no reliable method for synergism estimation. Although the time-kill curve assay is a gold standard, the method is not appropriate for fast and extensive screening of the synergy. The aim is to optimize the checkerboard method to determine phage-chemical agent interactions, to check its applicability by the time-kill curve method, and to examine whether the synergy can be obtained with both simultaneous and successive applications of these agents. In addition, the aim is to determine interactions of the Pseudomonas phage JG024 with ciprofloxacin, gentamicin, or ceftriaxone, as well as the Staphylococcus phage MSA6 and SES43300 with ciprofloxacin, gentamicin, and oxacillin. The results show that the optimized checkerboard method is reliable and that results correspond to those obtained by the time-kill curve. The synergy is detected with the phage JG024 and ciprofloxacin or ceftriaxone against Pseudomonas aeruginosa, and the phage SES43300 with ciprofloxacin against MRSA. The synergy was obtained after simultaneous applications, and in the case of P. aeruginosa, after application of the second agent with delay of one hour, indicating that simultaneous application is the best mode of synergy exploitation for therapy. The checkerboard method can be used for thorough clinical studies on synergy and in the future for personalized therapy when infections are caused by multiple resistant bacteria.

Published in Viruses

ISSN: 1999-4915 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Microbiology
Website: http://www.mdpi.com/journal/viruses

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