Phage-antibiotic synergy against daptomycin-nonsusceptible MRSA in an ex vivo simulated endocardial pharmacokinetic/pharmacodynamic model
Phage-antibiotic combinations (PAC) offer a potential solution for treating refractory daptomycin-nonsusceptible (DNS) methicillin-resistant (MRSA) infections. We examined PAC activity against two well-characterized DNS MRSA strains (C4 and C37) and . PACs comprising daptomycin (DAP) ± ceftaroline (...
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| Vydáno v: | Antimicrobial agents and chemotherapy Ročník 68; číslo 4; s. e0138823 |
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| Hlavní autoři: | , , , , , , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
United States
03.04.2024
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| Témata: | |
| ISSN: | 1098-6596, 1098-6596 |
| On-line přístup: | Zjistit podrobnosti o přístupu |
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| Shrnutí: | Phage-antibiotic combinations (PAC) offer a potential solution for treating refractory daptomycin-nonsusceptible (DNS) methicillin-resistant
(MRSA) infections. We examined PAC activity against two well-characterized DNS MRSA strains (C4 and C37)
and
. PACs comprising daptomycin (DAP) ± ceftaroline (CPT) and a two-phage cocktail (Intesti13 + Sb-1) were evaluated for phage-antibiotic synergy (PAS) against high MRSA inoculum (10
CFU/mL) using (i) modified checkerboards (CB), (ii) 24-h time-kill assays (TKA), and (iii) 168-h
simulated endocardial vegetation (SEV) models. PAS was defined as a fractional inhibitory concentration ≤0.5 in CB minimum inhibitory concentration (MIC) or a ≥2 log
CFU/mL reduction compared to the next best regimen in time-kill assays and SEV models. Significant differences between regimens were assessed by analysis of variance with Tukey's post hoc modification (α = 0.05). CB assays revealed PAS with Intesti13 + Sb-1 + DAP ± CPT. In 24-h time-kill assays against C4, Intesti13 + Sb-1 + DAP ± CPT demonstrated synergistic activity (-Δ7.21 and -Δ7.39 log
CFU/mL, respectively) (
< 0.05 each). Against C37, Intesti13 + Sb-1 + CPT ± DAP was equally effective (-Δ7.14 log
CFU/mL each) and not significantly different from DAP + Intesti13 + Sb-1 (-Δ6.65 log
CFU/mL). In 168-h SEV models against C4 and C37, DAP ± CPT + the phage cocktail exerted synergistic activities, significantly reducing bio-burdens to the detection limit [2 log
CFU/g (-Δ7.07 and -Δ7.11 log
CFU/g, respectively)] (
< 0.001). At 168 h, both models maintained stable MICs, and no treatment-emergent phage resistance occurred with DAP or DAP + CPT regimens. The two-phage cocktail demonstrated synergistic activity against two DNS MRSA isolates in combination with DAP + CPT
and
. Further
PAC investigations are needed. |
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| Bibliografie: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1098-6596 1098-6596 |
| DOI: | 10.1128/aac.01388-23 |