Phage-antibiotic combination is a superior treatment against Acinetobacter baumannii in a preclinical study

Fernando L. Gordillo Altamirano; Xenia Kostoulias; Dinesh Subedi; Denis Korneev; Anton Y. Peleg; Jeremy J. Barr

doi:10.1016/j.ebiom.2022.104045

Phage-antibiotic combination is a superior treatment against Acinetobacter baumannii in a preclinical study

Fernando L. Gordillo Altamirano, Xenia Kostoulias, Dinesh Subedi, Denis Korneev, Anton Y. Peleg, Jeremy J. Barr

Research output: Contribution to journal › Article › Research › peer-review

6 Citations (Scopus)

Abstract

Background: Clinical phage therapy is often delivered alongside antibiotics. However, the phenomenon of phage-antibiotic synergy has been mostly studied in vitro. Here, we assessed the in vivo bactericidal effect of a phage-antibiotic combination on Acinetobacter baumannii AB900 using phage øFG02, which binds to capsular polysaccharides and leads to antimicrobial resensitisation in vitro.

Methods: We performed a two-stage preclinical study using a murine model of severe A. baumannii AB900 bacteraemia. In the first stage, with an endpoint of 11 h, mice (n = 4 per group) were treated with either PBS, ceftazidime, phage øFG02, or the combination of phage and ceftazidime. The second stage involved only the latter two groups (n = 5 per group), with a prolonged endpoint of 16 h. The primary outcome was the average bacterial burden from four body sites (blood, liver, kidney, and spleen). Bacterial colonies from phage-treated mice were retrieved and screened for phage-resistance. Findings: In the first stage, the bacterial burden (CFU/g of tissue) of the combination group (median: 4.55 × 10⁵; interquartile range [IQR]: 2.79 × 10⁵–2.81 × 10⁶) was significantly lower than the PBS (median: 2.42 × 10⁹; IQR: 1.97 × 10⁹–3.48 × 10⁹) and ceftazidime groups (median: 3.86 × 10⁸; IQR: 2.15 × 10⁸–6.35 × 10⁸), but not the phage-only group (median: 1.28 × 10⁷; IQR: 4.71 × 10⁶–7.13 × 10⁷). In the second stage, the combination treatment (median: 1.72 × 10⁶; IQR: 5.11 × 10⁵–4.00 × 10⁶) outperformed the phage-only treatment (median: 7.46 × 10⁷; IQR: 1.43 × 10⁷–1.57 × 10⁸). Phage-resistance emerged in 96% of animals receiving phages, and all the tested isolates (n = 11) had loss-of-function mutations in genes involved in capsule biosynthesis and increased sensitivity to ceftazidime.

Interpretation: øFG02 reliably drives the in vivo evolution of A. baumannii AB900 towards a capsule-deficient, phage-resistant phenotype that is resensitised to ceftazidime. This mechanism highlights the clinical potential of using phage therapy to target A. baumannii and restore antibiotic activity.

Funding: National Health and Medical Research Council (Australia).

Original language	English
Article number	104045
Number of pages	15
Journal	EBioMedicine
Volume	80
DOIs	https://doi.org/10.1016/j.ebiom.2022.104045
Publication status	Published - Jun 2022

Keywords

Acinetobacter baumannii
Antimicrobial resistance
Ceftazidime
Phage therapy
Phage-resistance
Preclinical study
Synergism

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10.1016/j.ebiom.2022.104045

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@article{d069f152ca254a59808d774c846664f6,

title = "Phage-antibiotic combination is a superior treatment against Acinetobacter baumannii in a preclinical study",

abstract = "Background: Clinical phage therapy is often delivered alongside antibiotics. However, the phenomenon of phage-antibiotic synergy has been mostly studied in vitro. Here, we assessed the in vivo bactericidal effect of a phage-antibiotic combination on Acinetobacter baumannii AB900 using phage {\o}FG02, which binds to capsular polysaccharides and leads to antimicrobial resensitisation in vitro. Methods: We performed a two-stage preclinical study using a murine model of severe A. baumannii AB900 bacteraemia. In the first stage, with an endpoint of 11 h, mice (n = 4 per group) were treated with either PBS, ceftazidime, phage {\o}FG02, or the combination of phage and ceftazidime. The second stage involved only the latter two groups (n = 5 per group), with a prolonged endpoint of 16 h. The primary outcome was the average bacterial burden from four body sites (blood, liver, kidney, and spleen). Bacterial colonies from phage-treated mice were retrieved and screened for phage-resistance. Findings: In the first stage, the bacterial burden (CFU/g of tissue) of the combination group (median: 4.55 × 105; interquartile range [IQR]: 2.79 × 105–2.81 × 106) was significantly lower than the PBS (median: 2.42 × 109; IQR: 1.97 × 109–3.48 × 109) and ceftazidime groups (median: 3.86 × 108; IQR: 2.15 × 108–6.35 × 108), but not the phage-only group (median: 1.28 × 107; IQR: 4.71 × 106–7.13 × 107). In the second stage, the combination treatment (median: 1.72 × 106; IQR: 5.11 × 105–4.00 × 106) outperformed the phage-only treatment (median: 7.46 × 107; IQR: 1.43 × 107–1.57 × 108). Phage-resistance emerged in 96% of animals receiving phages, and all the tested isolates (n = 11) had loss-of-function mutations in genes involved in capsule biosynthesis and increased sensitivity to ceftazidime. Interpretation: {\o}FG02 reliably drives the in vivo evolution of A. baumannii AB900 towards a capsule-deficient, phage-resistant phenotype that is resensitised to ceftazidime. This mechanism highlights the clinical potential of using phage therapy to target A. baumannii and restore antibiotic activity. Funding: National Health and Medical Research Council (Australia).",

keywords = "Acinetobacter baumannii, Antimicrobial resistance, Ceftazidime, Phage therapy, Phage-resistance, Preclinical study, Synergism",

author = "{Gordillo Altamirano}, {Fernando L.} and Xenia Kostoulias and Dinesh Subedi and Denis Korneev and Peleg, {Anton Y.} and Barr, {Jeremy J.}",

note = "Funding Information: Fernando L. Gordillo Altamirano acknowledges the support from Monash University through the Monash Postgraduate Research Scholarships that funded his doctoral studies, and the Monash Postgraduate Publication Award (Round 1, 2021). Anton Y. Peleg is supported by a National Health and Medical Research Council Practitioner Fellowship (APP1117940). This work, including the efforts of Jeremy J. Barr, was funded by the National Health and Medical Research Council (NHMRC: 1156588), Perpetual Trustees Australia award (2018HIG00007), and Frontier Health Medical Research (RFRHPI000017). We thank the Monash Ramaciotti Cryo-EM platform for the use of the facility and Alex de Marco for granting access to the SEM; as well as the MASSIVE high performance computing facility ( www.massive.org.au ) for providing us cluster time for data analysis. We also thank Dr Mar{\'i}a Jos{\'e} Fierro for her comments on the structure and readability of the manuscript. Figure 1 a,b was made using BioRender (biorender.com). Publisher Copyright: {\textcopyright} 2022 The Author(s)",

year = "2022",

month = jun,

doi = "10.1016/j.ebiom.2022.104045",

language = "English",

volume = "80",

journal = "EBioMedicine",

issn = "2352-3964",

publisher = "The Lancet Publishing Group",

}

TY - JOUR

T1 - Phage-antibiotic combination is a superior treatment against Acinetobacter baumannii in a preclinical study

AU - Gordillo Altamirano, Fernando L.

AU - Kostoulias, Xenia

AU - Subedi, Dinesh

AU - Korneev, Denis

AU - Peleg, Anton Y.

AU - Barr, Jeremy J.

N1 - Funding Information: Fernando L. Gordillo Altamirano acknowledges the support from Monash University through the Monash Postgraduate Research Scholarships that funded his doctoral studies, and the Monash Postgraduate Publication Award (Round 1, 2021). Anton Y. Peleg is supported by a National Health and Medical Research Council Practitioner Fellowship (APP1117940). This work, including the efforts of Jeremy J. Barr, was funded by the National Health and Medical Research Council (NHMRC: 1156588), Perpetual Trustees Australia award (2018HIG00007), and Frontier Health Medical Research (RFRHPI000017). We thank the Monash Ramaciotti Cryo-EM platform for the use of the facility and Alex de Marco for granting access to the SEM; as well as the MASSIVE high performance computing facility ( www.massive.org.au ) for providing us cluster time for data analysis. We also thank Dr María José Fierro for her comments on the structure and readability of the manuscript. Figure 1 a,b was made using BioRender (biorender.com). Publisher Copyright: © 2022 The Author(s)

PY - 2022/6

Y1 - 2022/6

N2 - Background: Clinical phage therapy is often delivered alongside antibiotics. However, the phenomenon of phage-antibiotic synergy has been mostly studied in vitro. Here, we assessed the in vivo bactericidal effect of a phage-antibiotic combination on Acinetobacter baumannii AB900 using phage øFG02, which binds to capsular polysaccharides and leads to antimicrobial resensitisation in vitro. Methods: We performed a two-stage preclinical study using a murine model of severe A. baumannii AB900 bacteraemia. In the first stage, with an endpoint of 11 h, mice (n = 4 per group) were treated with either PBS, ceftazidime, phage øFG02, or the combination of phage and ceftazidime. The second stage involved only the latter two groups (n = 5 per group), with a prolonged endpoint of 16 h. The primary outcome was the average bacterial burden from four body sites (blood, liver, kidney, and spleen). Bacterial colonies from phage-treated mice were retrieved and screened for phage-resistance. Findings: In the first stage, the bacterial burden (CFU/g of tissue) of the combination group (median: 4.55 × 105; interquartile range [IQR]: 2.79 × 105–2.81 × 106) was significantly lower than the PBS (median: 2.42 × 109; IQR: 1.97 × 109–3.48 × 109) and ceftazidime groups (median: 3.86 × 108; IQR: 2.15 × 108–6.35 × 108), but not the phage-only group (median: 1.28 × 107; IQR: 4.71 × 106–7.13 × 107). In the second stage, the combination treatment (median: 1.72 × 106; IQR: 5.11 × 105–4.00 × 106) outperformed the phage-only treatment (median: 7.46 × 107; IQR: 1.43 × 107–1.57 × 108). Phage-resistance emerged in 96% of animals receiving phages, and all the tested isolates (n = 11) had loss-of-function mutations in genes involved in capsule biosynthesis and increased sensitivity to ceftazidime. Interpretation: øFG02 reliably drives the in vivo evolution of A. baumannii AB900 towards a capsule-deficient, phage-resistant phenotype that is resensitised to ceftazidime. This mechanism highlights the clinical potential of using phage therapy to target A. baumannii and restore antibiotic activity. Funding: National Health and Medical Research Council (Australia).

AB - Background: Clinical phage therapy is often delivered alongside antibiotics. However, the phenomenon of phage-antibiotic synergy has been mostly studied in vitro. Here, we assessed the in vivo bactericidal effect of a phage-antibiotic combination on Acinetobacter baumannii AB900 using phage øFG02, which binds to capsular polysaccharides and leads to antimicrobial resensitisation in vitro. Methods: We performed a two-stage preclinical study using a murine model of severe A. baumannii AB900 bacteraemia. In the first stage, with an endpoint of 11 h, mice (n = 4 per group) were treated with either PBS, ceftazidime, phage øFG02, or the combination of phage and ceftazidime. The second stage involved only the latter two groups (n = 5 per group), with a prolonged endpoint of 16 h. The primary outcome was the average bacterial burden from four body sites (blood, liver, kidney, and spleen). Bacterial colonies from phage-treated mice were retrieved and screened for phage-resistance. Findings: In the first stage, the bacterial burden (CFU/g of tissue) of the combination group (median: 4.55 × 105; interquartile range [IQR]: 2.79 × 105–2.81 × 106) was significantly lower than the PBS (median: 2.42 × 109; IQR: 1.97 × 109–3.48 × 109) and ceftazidime groups (median: 3.86 × 108; IQR: 2.15 × 108–6.35 × 108), but not the phage-only group (median: 1.28 × 107; IQR: 4.71 × 106–7.13 × 107). In the second stage, the combination treatment (median: 1.72 × 106; IQR: 5.11 × 105–4.00 × 106) outperformed the phage-only treatment (median: 7.46 × 107; IQR: 1.43 × 107–1.57 × 108). Phage-resistance emerged in 96% of animals receiving phages, and all the tested isolates (n = 11) had loss-of-function mutations in genes involved in capsule biosynthesis and increased sensitivity to ceftazidime. Interpretation: øFG02 reliably drives the in vivo evolution of A. baumannii AB900 towards a capsule-deficient, phage-resistant phenotype that is resensitised to ceftazidime. This mechanism highlights the clinical potential of using phage therapy to target A. baumannii and restore antibiotic activity. Funding: National Health and Medical Research Council (Australia).

KW - Acinetobacter baumannii

KW - Antimicrobial resistance

KW - Ceftazidime

KW - Phage therapy

KW - Phage-resistance

KW - Preclinical study

KW - Synergism

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U2 - 10.1016/j.ebiom.2022.104045

DO - 10.1016/j.ebiom.2022.104045

M3 - Article

C2 - 35537278

AN - SCOPUS:85129954890

VL - 80

JO - EBioMedicine

JF - EBioMedicine

SN - 2352-3964

M1 - 104045

ER -

Phage-antibiotic combination is a superior treatment against Acinetobacter baumannii in a preclinical study

Abstract

Keywords

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Phage Australia

Development of a novel bacteriophage treatment regime to combat and re-sensitise multiply antibiotic resistant Acinetobacter baumannii infections

Bacteriophage therapy increases antibiotic sensitivities in multiply antibiotic resistant Acinetobacter baumannii

Scientists discover new phage therapy combination to combat antibiotic-resistance

Ramaciotti Centre for Cryo-Electron Microscopy

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Phage-antibiotic combination is a superior treatment against Acinetobacter baumannii in a preclinical study

Abstract

Keywords

Access to Document

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Phage Australia

Development of a novel bacteriophage treatment regime to combat and re-sensitise multiply antibiotic resistant Acinetobacter baumannii infections

Bacteriophage therapy increases antibiotic sensitivities in multiply antibiotic resistant Acinetobacter baumannii

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Scientists discover new phage therapy combination to combat antibiotic-resistance

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Ramaciotti Centre for Cryo-Electron Microscopy

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