1. In vitro activity of daptomycin against Staphylococcus aureus
Main Article Content
Abstract
Daptomycin MIC values of 210 Staphylococcus aureus strains isolated from blood specimens in the Microbiology department, Bach Mai Hospital from July 2022 to June 2023 were determined by the broth microdilution method. 11 strains were randomly selected for analysis by the time-kill assay and for investigation of the effect of inoculum size on the activity of daptomycin and vancomycin named as the inoculum effect. 75.7% of strains are MRSA. All S. aureus isolates were found susceptible to daptomycin. The MIC values ranged from 0.125 to 0.75 μg/ml. The time-kill assay demonstrated that daptomycin had a bactericidal effect faster than vancomycin. Daptomycin was bactericidal at 8 hours for 9/11 strains (reduced 4.13-log10 CFU/ml, averagely) while vancomycin reduced averagely 2.15-log10 CFU/mL at 8h, compared with growth control tubes (without antibiotics). We calculated the MIC value of daptomycin and vancomycin at low, medium, and high inocula of S. aureus to investigate the effect of inoculum size on the activity of daptomycin and vancomycin. There is a significant increase in MIC values of both daptomycin and vancomycin. MIC values of daptomycin were increased over 256 times between the medium and high inocula and MIC values of vancomycin were increased over 112 times between medium and high inocula.
Article Details
Keywords
Staphylococcus aureus, MIC, daptomycin
References
2. Võ Thị Hà, Nguyễn Thanh Huyền, Nguyễn Minh Hà và cộng sự. Khảo sát tình hình đề kháng kháng sinh của chủng vi khuẩn Staphylococcus tại Bệnh viện NGuyễn Tri Phương giai đoạn 2019 - 2021. VMJ. 2023; 525(1B). doi:10.51298/vmj.v525i1B.5124.
3. F.R. Bruniera, F.M. Ferreira, L.R.M. Saviolli, et al. The use of vancomycin with its therapeutic and adverse effects: a review. European Review. Published February 27, 2015. Accessed July 20, 2023. https://www.europeanreview.org/article/8585.
4. CDC Reminds Clinical Laboratories and Healthcare Infection Preventionists of their Role in the Search and Containment of Vancomycin-Resistant Staphylococcus aureus (VRSA) | HAI | CDC. Published January 11, 2022. Accessed August 1, 2022. https://www.cdc.gov/hai/settings/lab/vrsa_lab_search_containment.html.
5. Claeys KC, Zasowski EJ, Casapao AM, et al. Daptomycin Improves Outcomes Regardless of Vancomycin MIC in a Propensity-Matched Analysis of Methicillin-Resistant Staphylococcus aureus Bloodstream Infections. Antimicrob Agents Chemother. 2016; 60(10): 5841-5848. doi:10.1128/AAC.00227-16.
6. Gonzalez-Ruiz A, Seaton RA, Hamed K. Daptomycin: an evidence-based review of its role in the treatment of Gram-positive infections. Infect Drug Resist. 2016; 9:47-58. doi:10.2147/IDR.S99046.
7. Sauermann R, Rothenburger M, Graninger W, Joukhadar C. Daptomycin: A Review 4 Years after First Approval. PHA. 2008; 81(2): 79-91. doi:10.1159/000109868.
8. Yamada T, Soda M, Nishida R, et al. Simplified daptomycin dosing regimen for adult patients with methicillin-resistant Staphylococcus aureus infections based on population pharmacokinetic analysis. Drug Metabolism and Pharmacokinetics. 2022; 44:100444. doi:10.1016/j.dmpk.2022.100444.
9. Rio-MarquesLaura, HartkeAxel, BizziniAlain. The Effect of Inoculum Size on Selection of In Vitro Resistance to Vancomycin, Daptomycin, and Linezolid in Methicillin-Resistant Staphylococcus aureus. Microbial Drug Resistance. Published online December 3, 2014. doi:10.1089/mdr.2014.0059.
10. Mishra NN, Lew C, Abdelhady W, et al. Synergy Mechanisms of Daptomycin-Fosfomycin Combinations in Daptomycin-Susceptible and -Resistant Methicillin-Resistant Staphylococcus aureus: In Vitro, Ex Vivo, and In Vivo Metrics. Antimicrob Agents Chemother. 66(1):e01649-21. doi:10.1128/AAC.01649-21.
11. Shah AA, Abbasi SA, Ali Y, Maqbool A. In vitro efficacy of Daptomycin against clinical isolates of Methicillin-resistant Staphylococcus aureus (MRSA). J Pak Med Assoc. 2021; 71(1(B)):338-340. doi:10.47391/JPMA.145.
12. Afşar I, Güngör S, Sener AG, Demirci M. [In vitro activity of daptomycin against methicillin-resistant Staphylococcus aureus strains isolated from blood cultures]. Mikrobiyol Bul. 2011; 45(4):755-757.
13. Rybak MJ, Hershberger E, Moldovan T, Grucz RG. In Vitro Activities of Daptomycin, Vancomycin, Linezolid, and Quinupristin-Dalfopristin against Staphylococci and Enterococci, Including Vancomycin- Intermediate and -Resistant Strains. Antimicrob Agents Chemother. 2000; 44(4): 1062-1066.
14. Maraolo AE, Giaccone A, Gentile I, Saracino A, Bavaro DF. Daptomycin versus Vancomycin for the Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infection with or without Endocarditis: A Systematic Review and Meta-Analysis. Antibiotics (Basel). 2021; 10(8): 1014. doi:10.3390/antibiotics10081014.
15. LaPlante KL, Rybak MJ. Impact of high-inoculum Staphylococcus aureus on the activities of nafcillin, vancomycin, linezolid, and daptomycin, alone and in combination with gentamicin, in an in vitro pharmacodynamic model. Antimicrob Agents Chemother. 2004; 48(12): 4665-4672. doi:10.1128/AAC.48.12.4665-4672.2004.