1
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Paul D, Chawla M, Ahrodia T, Narendrakumar L, Das B. Antibiotic Potentiation as a Promising Strategy to Combat Macrolide Resistance in Bacterial Pathogens. Antibiotics (Basel) 2023; 12:1715. [PMID: 38136749 PMCID: PMC10740890 DOI: 10.3390/antibiotics12121715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/08/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023] Open
Abstract
Antibiotics, which hit the market with astounding impact, were once called miracle drugs, as these were considered the ultimate cure for infectious diseases in the mid-20th century. However, today, nearly all bacteria that afflict humankind have become resistant to these wonder drugs once developed to stop them, imperiling the foundation of modern medicine. During the COVID-19 pandemic, there was a surge in macrolide use to treat secondary infections and this persistent use of macrolide antibiotics has provoked the emergence of macrolide resistance. In view of the current dearth of new antibiotics in the pipeline, it is essential to find an alternative way to combat drug resistance. Antibiotic potentiators or adjuvants are non-antibacterial active molecules that, when combined with antibiotics, increase their activity. Thus, potentiating the existing antibiotics is one of the promising approaches to tackle and minimize the impact of antimicrobial resistance (AMR). Several natural and synthetic compounds have demonstrated effectiveness in potentiating macrolide antibiotics against multidrug-resistant (MDR) pathogens. The present review summarizes the different resistance mechanisms adapted by bacteria to resist macrolides and further emphasizes the major macrolide potentiators identified which could serve to revive the antibiotic and can be used for the reversal of macrolide resistance.
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Affiliation(s)
- Deepjyoti Paul
- Functional Genomics Laboratory, Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, Faridabad 121001, India
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2
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Hamamoto H, Panthee S, Paudel A, Ishii K, Yasukawa J, Su J, Miyashita A, Itoh H, Tokumoto K, Inoue M, Sekimizu K. Serum apolipoprotein A-I potentiates the therapeutic efficacy of lysocin E against Staphylococcus aureus. Nat Commun 2021; 12:6364. [PMID: 34737305 PMCID: PMC8568920 DOI: 10.1038/s41467-021-26702-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 10/07/2021] [Indexed: 01/29/2023] Open
Abstract
Lysocin E is a lipopeptide with antibiotic activity against methicillin-resistant Staphylococcus aureus. For unclear reasons, the antibacterial activity of lysocin E in a mouse systemic infection model is higher than expected from in vitro results, and the in vitro activity is enhanced by addition of bovine serum. Here, we confirm that serum from various species, including humans, increases lysocin E antimicrobial activity, and identify apolipoprotein A-I (ApoA-I) as an enhancing factor. ApoA-I increases the antibacterial activity of lysocin E when added in vitro, and the antibiotic displays reduced activity in ApoA-I gene knockout mice. Binding of ApoA-I to lysocin E is enhanced by lipid II, a cell-wall synthesis precursor found in the bacterial membrane. Thus, the antimicrobial activity of lysocin E is potentiated through interactions with host serum proteins and microbial components. Lysocin E is a lipopeptide with antibiotic activity against methicillin-resistant Staphylococcus aureus. Here, the authors show that the antimicrobial activity of lysocin E is potentiated through interactions with host serum proteins (such as apolipoprotein A-I) and bacterial membrane components.
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Affiliation(s)
- Hiroshi Hamamoto
- Teikyo University Institute of Medical Mycology, Tokyo, Japan.,Division of Sport and Health Science, Graduate School of Medical Care and Technology, Teikyo University, Tokyo, Japan
| | - Suresh Panthee
- Drug Discoveries by Silkworm Models, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan
| | - Atmika Paudel
- International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Kenichi Ishii
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Jyunichiro Yasukawa
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kyoto, Japan
| | - Jie Su
- National Marine Environmental Monitoring Center, Dalian, China
| | | | - Hiroaki Itoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kotaro Tokumoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kazuhisa Sekimizu
- Drug Discoveries by Silkworm Models, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan. .,Genome Pharmaceuticals Institute, Ltd, Tokyo, Japan.
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3
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Bettoni S, Maziarz K, Stone MRL, Blaskovich MAT, Potempa J, Bazzo ML, Unemo M, Ram S, Blom AM. Serum Complement Activation by C4BP-IgM Fusion Protein Can Restore Susceptibility to Antibiotics in Neisseria gonorrhoeae. Front Immunol 2021; 12:726801. [PMID: 34539665 PMCID: PMC8440848 DOI: 10.3389/fimmu.2021.726801] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/12/2021] [Indexed: 11/13/2022] Open
Abstract
Neisseria gonorrhoeae is the etiological agent of gonorrhea, the second most common bacterial sexually transmitted infection worldwide. Reproductive sequelae of gonorrhea include infertility, ectopic pregnancy and chronic pelvic pain. Most antibiotics currently in clinical use have been rendered ineffective due to the rapid spread of antimicrobial resistance among gonococci. The developmental pipeline of new antibiotics is sparse and novel therapeutic approaches are urgently needed. Previously, we utilized the ability of N. gonorrhoeae to bind the complement inhibitor C4b-binding protein (C4BP) to evade killing by human complement to design a chimeric protein that linked the two N-terminal gonococcal binding domains of C4BP with the Fc domain of IgM. The resulting molecule, C4BP-IgM, enhanced complement-mediated killing of gonococci. Here we show that C4BP-IgM induced membrane perturbation through complement deposition and membrane attack complex pore insertion facilitates the access of antibiotics to their intracellular targets. Consequently, bacteria become more susceptible to killing by antibiotics. Remarkably, C4BP-IgM restored susceptibility to azithromycin of two azithromycin-resistant clinical gonococcal strains because of overexpression of the MtrC-MtrD-MtrE efflux pump. Our data show that complement activation can potentiate activity of antibiotics and suggest a role for C4BP-IgM as an adjuvant for antibiotic treatment of drug-resistant gonorrhea.
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Affiliation(s)
- Serena Bettoni
- Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Karolina Maziarz
- Department of Translational Medicine, Lund University, Malmö, Sweden
| | - M Rhia L Stone
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Jan Potempa
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Oral Immunity and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, United States
| | - Maria Luiza Bazzo
- Molecular Biology, Microbiology and Serology Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Magnus Unemo
- World Health Organization (WHO) Collaborating Centre for Gonorrhoea and other STIs, Department of Laboratory Medicine, Örebro University, Örebro, Sweden
| | - Sanjay Ram
- Department of Medicine, Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, MA, United States
| | - Anna M. Blom
- Department of Translational Medicine, Lund University, Malmö, Sweden
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4
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Weber BS, De Jong AM, Guo AB, Dharavath S, French S, Fiebig-Comyn AA, Coombes BK, Magolan J, Brown ED. Genetic and Chemical Screening in Human Blood Serum Reveals Unique Antibacterial Targets and Compounds against Klebsiella pneumoniae. Cell Rep 2020; 32:107927. [DOI: 10.1016/j.celrep.2020.107927] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/30/2020] [Accepted: 06/26/2020] [Indexed: 12/15/2022] Open
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5
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Zhou YF, Bu MX, Liu P, Sun J, Liu YH, Liao XP. Epidemiological and PK/PD cutoff values determination and PK/PD-based dose assessment of gamithromycin against Haemophilus parasuis in piglets. BMC Vet Res 2020; 16:81. [PMID: 32138735 PMCID: PMC7059257 DOI: 10.1186/s12917-020-02300-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 02/25/2020] [Indexed: 01/08/2023] Open
Abstract
Background Gamithromycin is a macrolide approved for the treatment of bovine and swine respiratory diseases. Our study aims to establish the clinical breakpoint and optimum dose regimen for gamithromycin against Haemophilus parasuis in piglets. Results Gamithromycin was well absorbed and fully bioavailable (87.2–101%) after intramuscular and subcutaneous administrations. The MICs of gamithromycin for 192 clinical H. parasuis isolates ranged from 0.008 to 128 mg/L and the epidemiological cutoff (ECOFF) was calculated as 1.0 mg/L. A large potentiation effect of serum on in vitro susceptibility of gamithromycin was observed for H. parasuis, with broth/serum ratios of 8.93 for MICs and 4.46 for MBCs, respectively. The postantibiotic effects were 1.5 h (1 × MIC) and 2.4 h (4 × MIC), and the postantibiotic sub-MIC effects ranged from 2.7 to 4.3 h. Gamithromycin had rapid and concentration-dependent killing against H. parasuis, and the AUC24h/MIC ratio correlated well with ex vivo efficacy (R2 = 0.97). The AUC24h/MIC targets in serum associated with bacteriostatic, bactericidal and eradication activities were 15.8, 30.3 and 41.2, respectively. The PK/PD-based population dose prediction indicated a probability of target attainment (PTA) for the current marketed dose (6 mg/kg) of 88.9% against H. parasuis. The calculated gamithromycin dose for a PTA ≥ 90% was 6.55 mg/kg. Based on Monte Carlo simulations, the PK/PD cutoff (COPD) was determined to be 0.25 mg/L. Conclusion The determined cutoffs and PK/PD-based dose prediction will be of great importance in gamithromycin resistance surveillance and serve as an important step in the establishment of optimum dose regimen and clinical breakpoints.
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Affiliation(s)
- Yu-Feng Zhou
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Ming-Xiao Bu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Ping Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Jian Sun
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Ya-Hong Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Xiao-Ping Liao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China. .,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China. .,Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.
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6
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Farha MA, French S, Stokes JM, Brown ED. Bicarbonate Alters Bacterial Susceptibility to Antibiotics by Targeting the Proton Motive Force. ACS Infect Dis 2018; 4:382-390. [PMID: 29264917 DOI: 10.1021/acsinfecdis.7b00194] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The antibacterial properties of sodium bicarbonate have been known for years, yet the molecular understanding of its mechanism of action is still lacking. Utilizing chemical-chemical combinations, we first explored the effect of bicarbonate on the activity of conventional antibiotics to infer on the mechanism. Remarkably, the activity of 8 classes of antibiotics differed in the presence of this ubiquitous buffer. These interactions and a study of mechanism of action revealed that, at physiological concentrations, bicarbonate is a selective dissipater of the pH gradient of the proton motive force across the cytoplasmic membrane of both Gram-negative and Gram-positive bacteria. Further, while components that make up innate immunity have been extensively studied, a link to bicarbonate, the dominant buffer in the extracellular fluid, has never been made. Here, we also explored the effects of bicarbonate on components of innate immunity. Although the immune response and the buffering system have distinct functions in the body, we posit there is interplay between these, as the antimicrobial properties of several components of innate immunity were enhanced by a physiological concentration of bicarbonate. Our findings implicate bicarbonate as an overlooked potentiator of host immunity in the defense against pathogens. Overall, the unique mechanism of action of bicarbonate has far-reaching and predictable effects on the activity of innate immune components and antibiotics. We conclude that bicarbonate has remarkable power as an antibiotic adjuvant and suggest that there is great potential to exploit this activity in the discovery and development of new antibacterial drugs by leveraging testing paradigms that better reflect the physiological concentration of bicarbonate.
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Affiliation(s)
- Maya A. Farha
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
| | - Shawn French
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
| | - Jonathan M. Stokes
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
| | - Eric D. Brown
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
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7
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Abstract
This review summarizes evidence that the impact of protein binding of the activity of antibiotics is multifaceted and more complex than indicated by the numerical value of protein binding alone. A plethora of studies has proven that protein binding of antibiotics matters, as the free fraction only is antibacterially active and governs pharmacokinetics. Several studies have indicated that independent from protein binding of immunoglobulin G, albumin, α1-acid-glycoprotein, and pulmonary surfactant acted synergistically with antibacterial agents, thus suggesting that some intrinsic properties of serum proteins may have mediated serum-antibiotic synergisms. It has been demonstrated that IgG and albumin permeabilized Gram-negative and Gram-positive bacteria and facilitated the uptake of poorly penetrating antibiotics. Alpha-1-acid-glycoprotein and pulmonary surfactant also exerted a permeabilizing activity, but proof that this property results in a sensitizing effect is missing. The permeabilizing effect of serum proteins may explain why serum-antibiotic synergisms do not represent a general phenomenon but are limited to specific drug-bug associations only. Although evidence has been generated to support the hypothesis that native serum proteins interact synergistically with antibiotics, systematic and well-controlled studies have to be performed to substantiate this phenomenon. The interactions between serum proteins and bacterial surfaces are driven by physicochemical forces. However, preparative techniques, storage conditions, and incubation methods have a significant impact on the intrinsic activities of these serum proteins affecting serum-antibiotic synergisms, so these techniques have to be standardized; otherwise, contradictory data or even artifacts will be generated.
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Affiliation(s)
- Axel Dalhoff
- Christian-Albrechts-University of Kiel, Institute for Infection Medicine, Kiel, Germany
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8
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Zhou YF, Peng HM, Bu MX, Liu YH, Sun J, Liao XP. Pharmacodynamic Evaluation and PK/PD-Based Dose Prediction of Tulathromycin: A Potential New Indication for Streptococcus suis Infection. Front Pharmacol 2017; 8:684. [PMID: 29033841 PMCID: PMC5627010 DOI: 10.3389/fphar.2017.00684] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/13/2017] [Indexed: 12/30/2022] Open
Abstract
Tulathromycin is the first member of the triamilide antimicrobial drugs that has been registered in more than 30 countries. The goal of this study is to provide a potential new indication of tulathromycin for Streptococcus suis infections. We investigated the pharmacokinetic and ex vivo pharmacodynamics of tulathromycin against experimental S. suis infection in piglets. Tulathromycin demonstrated a relatively long elimination half-life (74.1 h) and a mean residence time of 97.6 h after a single intramuscular administration. The minimal inhibitory concentration (MIC) and bactericidal concentration in serum were markedly lower than those in broth culture, with Mueller–Hinton broth/serum ratios of 40.3 and 11.4, respectively. The post-antibiotic effects were at 1.27 h (1× MIC) and 2.03 h (4× MIC) and the post-antibiotic sub-MIC effect values ranged from 2.47 to 3.10 h. The ratio of the area under the concentration–time curve divided by the MIC (AUC/MIC) correlated well with the ex vivo antimicrobial effectiveness of tulathromycin (R2 = 0.9711). The calculated AUC12h/MIC ratios in serum required to produce the net bacterial stasis, 1-log10 and 2-log10 killing activities were 9.62, 18.9, and 32.7, respectively. Based on the results of Monte Carlo simulation, a dosage regimen of 3.56 mg/kg tulathromycin was estimated to be effective, achieving for a bacteriostatic activity against S. suis infection over 5 days period. Tulathromycin may become a potential option for the treatment of S. suis infections.
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Affiliation(s)
- Yu-Feng Zhou
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Hui-Min Peng
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Ming-Xiao Bu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Ya-Hong Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jian Sun
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xiao-Ping Liao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
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9
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Lees P, Illambas J, Potter TJ, Pelligand L, Rycroft A, Toutain PL. A large potentiation effect of serum on the in vitro
potency of tulathromycin against Mannheimia haemolytica
and Pasteurella multocida. J Vet Pharmacol Ther 2016; 40:419-428. [DOI: 10.1111/jvp.12372] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 09/14/2016] [Indexed: 12/01/2022]
Affiliation(s)
- P. Lees
- The Royal Veterinary College; Hatfield Herts UK
| | - J. Illambas
- The Royal Veterinary College; Hatfield Herts UK
| | | | | | - A. Rycroft
- The Royal Veterinary College; Hatfield Herts UK
| | - P.-L. Toutain
- UMR 1331 Toxalim INRA-INPT; École Nationale Vétérinaire de Toulouse; Toulouse France
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10
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Sy SKB, Zhuang L, Derendorf H. Pharmacokinetics and pharmacodynamics in antibiotic dose optimization. Expert Opin Drug Metab Toxicol 2015; 12:93-114. [DOI: 10.1517/17425255.2016.1123250] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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11
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Albumin Enhances Caspofungin Activity against Aspergillus Species by Facilitating Drug Delivery to Germinating Hyphae. Antimicrob Agents Chemother 2015; 60:1226-33. [PMID: 26643329 DOI: 10.1128/aac.02026-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/29/2015] [Indexed: 01/03/2023] Open
Abstract
The modest in vitro activity of echinocandins against Aspergillus implies that host-related factors augment the action of these antifungal agents in vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against various Aspergillus species under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P = 0. 0005). Importantly, the enhanced activity of caspofungin against Aspergillus spp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinating Aspergillus hyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin with Aspergillus hyphae (P < 0.0001). Collectively, we found a novel synergistic interaction between albumin and caspofungin, with albumin acting as a potential carrier molecule to facilitate antifungal drug delivery to Aspergillus hyphae.
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12
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Lin L, Nonejuie P, Munguia J, Hollands A, Olson J, Dam Q, Kumaraswamy M, Rivera H, Corriden R, Rohde M, Hensler ME, Burkart MD, Pogliano J, Sakoulas G, Nizet V. Azithromycin Synergizes with Cationic Antimicrobial Peptides to Exert Bactericidal and Therapeutic Activity Against Highly Multidrug-Resistant Gram-Negative Bacterial Pathogens. EBioMedicine 2015; 2:690-8. [PMID: 26288841 PMCID: PMC4534682 DOI: 10.1016/j.ebiom.2015.05.021] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 05/21/2015] [Accepted: 05/21/2015] [Indexed: 12/22/2022] Open
Abstract
Antibiotic resistance poses an increasingly grave threat to the public health. Of pressing concern, rapid spread of carbapenem-resistance among multidrug-resistant (MDR) Gram-negative rods (GNR) is associated with few treatment options and high mortality rates. Current antibiotic susceptibility testing guiding patient management is performed in a standardized manner, identifying minimum inhibitory concentrations (MIC) in bacteriologic media, but ignoring host immune factors. Lacking activity in standard MIC testing, azithromycin (AZM), the most commonly prescribed antibiotic in the U.S., is never recommended for MDR GNR infection. Here we report a potent bactericidal action of AZM against MDR carbapenem-resistant isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. This pharmaceutical activity is associated with enhanced AZM cell penetration in eukaryotic tissue culture media and striking multi-log-fold synergies with host cathelicidin antimicrobial peptide LL-37 or the last line antibiotic colistin. Finally, AZM monotherapy exerts clear therapeutic effects in murine models of MDR GNR infection. Our results suggest that AZM, currently ignored as a treatment option, could benefit patients with MDR GNR infections, especially in combination with colistin. Standard MIC testing conditions overlook a potent activity of azithromycin vs. multidrug-resistant Gram-negative bacteria. Colistin and endogenous host defense peptide LL-37 markedly potentiate azithromycin penetration into bacterial cells. Azithromycin reduced bacterial load and mortality in mouse models of multidrug-resistant Gram-negative infection.
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Affiliation(s)
- Leo Lin
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Poochit Nonejuie
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jason Munguia
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew Hollands
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joshua Olson
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Quang Dam
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Monika Kumaraswamy
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heriberto Rivera
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla CA 92093, USA
| | - Ross Corriden
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Mary E Hensler
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla CA 92093, USA
| | - Joe Pogliano
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - George Sakoulas
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA ; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA ; Rady Children's Hospital, San Diego, CA 92123, USA
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13
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Washington AZ, Tapadar S, George A, Oyelere AK. Exploiting translational stalling peptides in an effort to extend azithromycin interaction within the prokaryotic ribosome nascent peptide exit tunnel. Bioorg Med Chem 2015; 23:5198-209. [PMID: 26037612 DOI: 10.1016/j.bmc.2015.04.078] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 04/18/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022]
Abstract
The ribosome is the primary protein synthesis machine in the cell and is a target for treatment of a variety of diseases including bacterial infection and cancer. The ribosomal peptide exit tunnel, the route of egress for the nascent peptide, is an inviting site for drug design. Toward a rational engagement of the nascent peptide components for the design of small molecule inhibitors of ribosome function, we designed and disclosed herein a set of N-10 indole functionalized azithromycin analogs. The indole moiety of these compounds is designed to mimic the translation stalling interaction of SecM W155 side-chain with the prokaryotic (Escherichia coli) ribosome A751 residue. Many of these N-10 functionalized compounds have enhanced translation inhibition activities against E. coli ribosome relative to azithromycin while a subset inhibited the growth of representative susceptible bacteria strains to about the same extent as azithromycin. Moreover, the inclusion of bovine serum in the bacterial growth media enhanced the anti-bacterial potency of the N-10 functionalized azithromycin analogs by as high as 10-fold.
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Affiliation(s)
- Arren Z Washington
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Subhasish Tapadar
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Alex George
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Adegboyega K Oyelere
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA; Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA.
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14
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Fu TH, Li Y, Thaker HD, Scott RW, Tew GN. Expedient Synthesis of SMAMPs via Click Chemistry. ACS Med Chem Lett 2013; 4:841-5. [PMID: 24936243 DOI: 10.1021/ml400155a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/22/2013] [Indexed: 02/07/2023] Open
Abstract
A novel series of synthetic mimics of antimicrobial peptides (SMAMPs) containing triazole linkers were assembled using click chemistry. While only moderately active in buffer alone, an increase in antimicrobial activity against Staphylococcus aureus and Escherichia coli was observed when these SMAMPs were administered in the presence of mouse serum. One compound had minimum inhibitory concentrations (MICs) of 0.39 μg/mL and 6.25 μg/mL, respectively, and an HC50 of 693 μg/mL. These values compared favorably to peptide-based antimicrobials. A correlation between the net positive charge and SMAMP antimicrobial activity was observed. The triazole linker, an amide surrogate, was found to provide better antimicrobial activity against both S. aureus and E. coli when compared to other analogues.
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Affiliation(s)
- Tsung-hao Fu
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
| | - Yan Li
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
| | - Hitesh D. Thaker
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
| | - Richard W. Scott
- PolyMedix, Inc., 170 North Radnor-Chester Road, Suite 300, Radnor, Pennsylvania 19087, United States
| | - Gregory N. Tew
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
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15
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Mitchell JD, Goh S, McKellar QA, McKeever DJ. In vitro pharmacodynamics of gamithromycin against Mycoplasma mycoides subspecies mycoides Small Colony. Vet J 2013; 197:806-11. [PMID: 23810743 DOI: 10.1016/j.tvjl.2013.05.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 04/01/2013] [Accepted: 05/06/2013] [Indexed: 11/24/2022]
Abstract
Mycoplasma mycoides mycoides Small Colony (MmmSC) is the causative agent of contagious bovine pleuropneumonia (CBPP), which is responsible for major economic losses in sub-Saharan Africa. Current control relies on live attenuated vaccines, which are of limited efficacy, and antimicrobials are now being assessed as an alternative or adjunct to vaccination. The objective of this study was to determine the in vitro effector kinetics of the macrolide antimicrobial, gamithromycin, against MmmSC in artificial medium and adult bovine serum. Furthermore, it was determined if any differences in gamithromycin activity between these two matrices were mirrored by the older macrolides, tylosin and tilmicosin. Minimum inhibitory concentrations (MICs) for gamithromycin, tylosin and tilmicosin against MmmSC strains B237 and Tan8 were determined in artificial medium and serum. Time-kill curves were constructed at concentrations corresponding to multiples of the MIC for all three macrolides in artificial medium and for gamithromycin in serum. Data were fitted to sigmoid Emax models. Post-antibiotic effects (PAE) were established by exposing strain B237 to antimicrobials at 10× MIC for 1h and monitoring mycoplasma growth thereafter. MICs for gamithromycin, tylosin and tilmicosin were 64-, 8- and 64-fold lower, respectively, in serum than in artificial medium at an inoculum size of 10(6)cfu/mL B237. A similar pattern emerged for Tan8. All three antimicrobials were mycoplasmastatic with maximum effects of -0.44, -0.32 and -0.49log10(cfu/mL) units for gamithromycin, tylosin and tilmicosin, respectively, against B237 in artificial medium. Tylosin and tilmicosin elicited longer PAEs than gamithromycin. In conclusion, gamithromycin, tylosin and tilmicosin all demonstrated in vitro efficacy against MmmSC and represent potential candidates for clinical studies to assess their therapeutic effect against CBPP.
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Affiliation(s)
- John D Mitchell
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom.
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16
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Macrolides and β-lactam antibiotics enhance C3b deposition on the surface of multidrug-resistant Streptococcus pneumoniae strains by a LytA autolysin-dependent mechanism. Antimicrob Agents Chemother 2012; 56:5534-40. [PMID: 22890762 DOI: 10.1128/aac.01470-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The emergence of Streptococcus pneumoniae strains displaying high levels of multidrug resistance is of great concern worldwide and a serious threat for the outcome of the infection. Modifications of the bacterial envelope by antibiotics may assist the recognition and clearance of the pathogen by the host immune system. Recognition of S. pneumoniae resistant strains by the complement component C3b was increased in the presence of specific anti-pneumococcal antibodies and subinhibitory concentrations of different macrolides and β-lactam antibiotics for all the strains investigated. However, C3b levels were unchanged in the presence of serum containing specific antibodies and sub-MICs of levofloxacin. To investigate whether LytA, the main cell wall hydrolase of S. pneumoniae, might be involved in this process, lytA-deficient mutants were constructed. In the presence of antibiotics, loss of LytA was not associated with enhanced C3b deposition on the pneumococcal surface, which confirms the importance of LytA in this interaction. The results of this study offer new insights into the development of novel therapeutic strategies using certain antibiotics by increasing the efficacy of the host immune response to efficiently recognize pneumococcal resistant strains.
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17
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Drew RH, Gallis HA. Azithromycin-Spectrum of Activity, Pharmacokinetics, and Clinical Applications. Pharmacotherapy 2012. [DOI: 10.1002/j.1875-9114.1992.tb04504.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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18
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Impact of a low-oxygen environment on the efficacy of antimicrobials against intracellular Chlamydia trachomatis. Antimicrob Agents Chemother 2011; 55:2319-24. [PMID: 21321137 DOI: 10.1128/aac.01655-10] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Emergence of chronic inflammation in the urogenital tract induced by Chlamydia trachomatis infection in females is a long-standing concern. To avoid the severe sequelae of C. trachomatis infection, such as pelvic inflammatory diseases (PID), ectopic pregnancies, and tubal infertility, antibiotic strategies aim to eradicate the pathogen even in asymptomatic and uncomplicated infections. Although first-line antimicrobials have proven successful for the treatment of C. trachomatis infection, treatment failures have been observed in a notable number of cases. Due to the obligate intracellular growth of C. trachomatis, reliable antimicrobial susceptibility assays have to consider environmental conditions and host cell-specific factors. Oxygen concentrations in the female urogenital tract are physiologically low and decrease further during an inflammatory process. We compared MIC testing and time-kill curves (TKC) for doxycycline, azithromycin, rifampin, and moxifloxacin under hypoxia (2% O2) and normoxia (20% O2). While low oxygen availability only moderately decreased the antichlamydial activity of azithromycin in conventional MIC testing (0.08 μg/ml versus 0.04 μg/ml; P<0.05), TKC analyses revealed profound divergences for antibiotic efficacies between the two conditions. Thus, C. trachomatis was significantly less rapidly killed by doxycycline and azithromycin under hypoxia, whereas the efficacies of moxifloxacin and rifampin remained unaffected using concentrations at therapeutic serum levels. Chemical inhibition of multidrug resistance protein 1 (MDR-1), but not multidrug resistance-associated protein 1 (MRP-1), restored doxycycline activity against intracellular C. trachomatis under hypoxia. We suggest careful consideration of tissue-specific characteristics, including oxygen availability, when testing antimicrobial activities of antibiotics against intracellular bacteria.
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19
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TW Chu D. Section Review Anti-infectives: Recent developments in 14- and 15-membered macrolides. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.4.2.65] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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Godinho KS. Susceptibility testing of tulathromycin: interpretative breakpoints and susceptibility of field isolates. Vet Microbiol 2007; 129:426-32. [PMID: 18187275 DOI: 10.1016/j.vetmic.2007.11.033] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2007] [Revised: 11/26/2007] [Accepted: 11/28/2007] [Indexed: 10/22/2022]
Abstract
In vitro susceptibility tests were conducted on bovine and porcine respiratory pathogens isolated from European countries during 2004-2006 for susceptibility to tulathromycin using the recommended methodologies for broth microdilution. The results were compared with data from a similar survey conducted prior to launch in 1998-2001 to monitor for any shift in susceptibility. The importance of maintaining the pH of the culture media within the range 7.2-7.4 was re-affirmed as a key factor in obtaining consistent minimum inhibitory concentration data. The use of recently established interpretative breakpoints would indicate that to date there has been no apparent decrease in susceptibility to tulathromycin since it became widely used across Europe.
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Affiliation(s)
- K S Godinho
- Veterinary Research & Development, Pfizer Ltd, Sandwich, Kent, UK.
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Benchaoui HA, Nowakowski M, Sherington J, Rowan TG, Sunderland SJ. Pharmacokinetics and lung tissue concentrations of tulathromycin in swine. J Vet Pharmacol Ther 2004; 27:203-10. [PMID: 15305848 DOI: 10.1111/j.1365-2885.2004.00586.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The absolute bioavailability and lung tissue distribution of the triamilide antimicrobial, tulathromycin, were investigated in swine. Fifty-six pigs received 2.5 mg/kg of tulathromycin 10% formulation by either intramuscular (i.m.) or intravenous (i.v.) route in two studies: study A (10 pigs, i.m. and 10 pigs, i.v.) and study B (36 pigs, i.m.). After i.m. administration the mean maximum plasma concentration (C(max)) was 616 ng/mL, which was reached by 0.25 h postinjection (t(max)). The mean apparent elimination half-life (t(1/2)) in plasma was 75.6 h. After i.v. injection plasma clearance (Cl) was 181 mL/kg.h, the volume of distribution at steady-state (V(ss)) was 13.2 L/kg and the elimination t(1/2) was 67.5 h. The systemic bioavailability following i.m. administration was >87% and the ratio of lung drug concentration for i.m. vs. i.v. injection was > or =0.96. Following i.m. administration, a mean tulathromycin concentration of 2840 ng/g was detected in lung tissue at 12 h postdosing. The mean lung C(max) of 3470 ng/g was reached by 24 h postdose (t(max)). Mean lung drug concentrations after 6 and 10 days were 1700 and 1240 ng/g, respectively. The AUC(inf) was 61.4 times greater for the lung than for plasma. The apparent elimination t(1/2) for tulathromycin in the lung was 142 h (6 days). Following i.m. administration to pigs at 2.5 mg/kg body weight, tulathromycin was rapidly absorbed and highly bioavailable. The high distribution to lung and slow elimination following a single dose of tulathromycin, are desirable pharmacokinetic attributes for an antimicrobial drug indicated for the treatment of respiratory disease in swine.
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Affiliation(s)
- H A Benchaoui
- Pfizer Animal Health, Veterinary Medicine Research and Development, Pfizer Ltd., Sandwich, Kent CT13 9NJ, UK.
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22
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Mercier RC, Dietz RM, Mazzola JL, Bayer AS, Yeaman MR. Beneficial influence of platelets on antibiotic efficacy in an in vitro model of Staphylococcus aureus-induced endocarditis. Antimicrob Agents Chemother 2004; 48:2551-7. [PMID: 15215108 PMCID: PMC434186 DOI: 10.1128/aac.48.7.2551-2557.2004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelets contribute to antimicrobial host defense against infective endocarditis (IE) by releasing platelet microbicidal proteins (PMPs). We investigated the influence of thrombin-stimulated human platelets on the evolution of simulated IE in the presence and absence of vancomycin or nafcillin. Staphylococcus aureus strains differing in intrinsic susceptibility to PMPs or antibiotics were studied: ISP479C (thrombin-induced PMP-1 [tPMP-1] susceptible; nafcillin and vancomycin susceptible), ISP479R (tPMP-1 resistant; nafcillin and vancomycin susceptible), and GISA-NJ (tPMP-1 intermediate-susceptible; vancomycin intermediate-susceptible). Platelets were introduced and thrombin activated within the in vitro IE model 30 min prior to inoculation with S. aureus. At 0 to 24 h postinoculation, bacterial densities in chamber fluid and simulated endocardial vegetations (SEVs) were quantified and compared among groups. Activated platelets alone, or in combination with antibiotics, inhibited the proliferation of ISP479C in chamber fluid or SEVs over the initial 4-h period (P < 0.05 versus controls). Moreover, nafcillin-containing regimens exerted inhibitory effects beyond 4 h against ISP479C in both model phases. By comparison, activated platelets inhibited GISA-NJ proliferation in SEVs but not in chamber fluid. The combination of platelets plus nafcillin or vancomycin significantly inhibited proliferation of the GISA-NJ strain in SEVs compared to the effect of platelets or antibiotics alone (P < 0.05). In contrast, platelets did not significantly alter the antistaphylococcal efficacies of nafcillin or vancomycin against ISP479R. These data support our hypothesis that a beneficial antimicrobial effect may result from the interaction among platelets, PMPs, and anti-infective agents against antibiotic-susceptible or -resistant staphylococci that exhibit a tPMP-1-susceptible or -intermediate-susceptible phenotype.
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Affiliation(s)
- Renee-Claude Mercier
- College of Pharmacy MSC09 5360, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA.
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23
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Yeaman MR, Gank KD, Bayer AS, Brass EP. Synthetic peptides that exert antimicrobial activities in whole blood and blood-derived matrices. Antimicrob Agents Chemother 2002; 46:3883-91. [PMID: 12435692 PMCID: PMC132762 DOI: 10.1128/aac.46.12.3883-3891.2002] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Peptides that exert antimicrobial activity in artificial media may lack activity within blood or other complex biological matrices. To facilitate the evaluation of antimicrobial peptides for possible therapeutic utility, an ex vivo assay was developed to assess the extent and durability of peptide antimicrobial activities in complex fluid biomatrices of whole blood, plasma, and serum compared with those in conventional media. Novel antimicrobial peptides (RP-1 and RP-11) were designed based in part on platelet microbicidal proteins. RP-1, RP-11, or gentamicin was introduced into biomatrices either coincident with, or 2 h prior to, inoculation with an Escherichia coli target organism. Antimicrobial activities of peptides were assessed by quantitative culture 2 h after bacterial inoculation and compared to those of peptide-free and gentamicin controls. In whole blood and homologous plasma or serum, introduction of RP-1 or RP-11 coincident with E. coli was associated with a significant reduction in CFU per milliliter versus the respective peptide-free controls. Moreover, substantial antimicrobial activity remained when RP-1 or RP-11 was placed into whole blood or plasma 2 h prior to E. coli inoculation. These results suggest that the peptides were not rapidly inactivated within these biomatrices. Peptide antimicrobial activities were negatively affected by preincubation in serum or in heat-inactivated serum, compared with those of the respective controls. Peptides RP-1 and RP-11 were consistently effective at lower concentrations in biomatrices than in artificial media, indicating favorable antimicrobial interactions with components of blood or blood fractions. Collectively, these findings support the concept that synthetic peptides can be designed to exert potent antimicrobial activities in relevant and complex biological matrices.
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Affiliation(s)
- Michael R Yeaman
- Department of Medicine, Division of Infectious Diseases, Harbor-UCLA Medical Center, Research and Education Institute at Harbor-UCLA, Torrance, California 90502, USA.
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24
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Abstract
The azalide antibiotic azithromycin and the newer macrolides, such as clarithromycin, dirithromycin and roxithromycin, can be regarded as 'advanced-generation' macrolides compared with erythromycin, the first macrolide used clinically as an antibiotic. Their pharmacokinetics are characterized by a combination of low serum concentrations, high tissue concentrations and, in the case of azithromycin, an extended tissue elimination half-life. Azithromycin is particularly noted for high and prolonged concentrations at the site of infection. This allows once-daily dosing for 3 days in the treatment of respiratory tract infections, in contrast to longer dosage periods required for erythromycin, clarithromycin, roxithromycin and agents belonging to other classes of antibiotics. The spectrum of activity of the advanced-generation macrolides comprises Gram-positive, atypical and upper respiratory anaerobic pathogens. Azithromycin and the active metabolite of clarithromycin also demonstrate activity against community-acquired Gram-negative organisms, such as Haemophilus influenzae. Advanced-generation macrolides, and in particular azithromycin, are highly concentrated within polymorphonuclear leucocytes, which gravitate by chemotactic mechanisms to sites of infection. Following phagocytosis of the pathogens at the infection site, they are exposed to very high, and sometimes cidal, intracellular concentrations of antibacterial agent. Pharmacodynamic models and susceptibility breakpoints derived from studies with other classes of drugs, such as the beta-lactams and aminoglycosides, do not adequately explain the clinical utility of antibacterial agents that achieve high intracellular concentrations. In the case of azithromycin, attention should focus on tissue pharmacokinetic and pharmacodynamic concepts.
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Affiliation(s)
- G W Amsden
- The Clinical Pharmacology Research Center, Bassett Healthcare, One Atwell Road, Cooperstown, NY 13326-1394, USA.
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25
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McDonald PJ, Pruul H. Tailoring Antibiotic Treatment to Host Immune Status: The Host, Not the Drug, Determines Outcome. Curr Infect Dis Rep 2001; 3:309-311. [PMID: 11470020 DOI: 10.1007/s11908-001-0065-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Peter J. McDonald
- Department of Microbiology and Infectious Diseases, Flinders University of South Australia, Bedford Park SA 5042, Australia. ; u
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26
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Rapp RP. Pharmacokinetics and pharmacodynamics of intravenous and oral azithromycin: enhanced tissue activity and minimal drug interactions. Ann Pharmacother 1998; 32:785-93. [PMID: 9681095 DOI: 10.1345/aph.17299] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE To review the pharmacokinetics and pharmacodynamics of oral and intravenous azithromycin compared with other macrolide antibiotics, and to evaluate these differences and their relation to clinical effectiveness. DATA SOURCE A MEDLINE search (1966-May 1998) was performed to identify applicable English-language clinical, animal, and microbiologic studies pertaining to pharmacokinetic and pharmacodynamic parameters. STUDY SELECTION Relevant studies concerning microbiology, pharmacokinetics, tissue concentrations, pharmacodynamics, and the clinical effects of these parameters were selected. DATA SYNTHESIS The structural modification that distinguishes the azalide antibiotics from the macrolide antibiotics is responsible for the pharmacokinetic and pharmacodynamic behavior of azithromycin, resulting in the high and sustained tissue and intracellular concentrations seen with this agent. Drug delivery to the site of infection by phagocytes and fibroblasts is the hallmark of azithromycin's tissue-directed pharmacodynamics, allowing for convenient once-daily, 5-day regimens for most infections that respond to oral therapy and 7-10 days for more serious infections requiring initial intravenous therapy. Metabolism is via hepatic pathways other than cytochrome P450, thus minimizing the risk of drug interactions. CONCLUSIONS Compared with other macrolide antibiotics, the unique pharmacokinetic and pharmacodynamic features of azithromycin offer the potential for improved efficacy and safety from drug interactions. These attributes, combined with its once-daily dosing schedule, make azithromycin suitable for the treatment of many types of bacterial infection.
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Affiliation(s)
- R P Rapp
- Division of Pharmacy Practice and Science, College of Pharmacy, University of Kentucky, Lexington 40536, USA
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27
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Rapp RP, McCraney SA, Goodman NL, Shaddick DJ. New macrolide antibiotics: usefulness in infections caused by mycobacteria other than Mycobacterium tuberculosis. Ann Pharmacother 1994; 28:1255-63. [PMID: 7849341 DOI: 10.1177/106002809402801109] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
OBJECTIVE To compare the pharmacology, in vitro activity, and clinical use of the new macrolide antibiotics, azithromycin and clarithromycin, in the treatment of infections caused by mycobacteria other than Mycobacterium tuberculosis. DATA IDENTIFICATION An English-language literature search using MEDLINE (1987-1994), Index Medicus (1987-1994), Program and abstracts of the 31st (1991) and 32nd (1992) Interscience Conference on Antimicrobial Agents and Chemotherapy, and bibliographic reviews of related textbooks, review articles, and professional society publications. STUDY SELECTION 105 articles were selected. In vitro and in vivo reports on the pharmacokinetics, microbiology, pharmacology, and effectiveness of clarithromycin and azithromycin were assessed to compare their effectiveness and safety. Emphasis was placed on the use of these new drugs in treating infections caused by Mycobacterium avium complex, Mycobacterium chelonae, and Mycobacterium fortuitum infections. RESULTS A review of the in vitro activity of the new macrolides revealed moderate to very good activity against many strains of mycobacteria other than M. tuberculosis. Early clinical trials show promising results in pulmonary infections, lymphadenitis, cutaneous infections, and disseminated infections. CONCLUSIONS The new macrolides, azithromycin and clarithromycin, show great promise for treating infections caused by these acid-fast bacteria. Clarithromycin is recommended as a component of combination therapy for the treatment of M. avium complex infections in patients with AIDS. The development of resistance in patients, particularly when these agents are used alone, has been reported.
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Affiliation(s)
- R P Rapp
- Division of Pharmacy Practice and Science, College of Pharmacy, University of Kentucky, Chandler Medical Center, Lexington 40536
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28
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Abstract
The in vitro activity of azithromycin, an orally active azalide, was compared with that of erythromycin and oral beta-lactams against 893 clinical isolates of staphylococci, streptococci, enterococci, Haemophilus influenzae and Salmonella typhi. MIC90 of azithromycin for streptococci was 0.12 mg/L, 0.5 mg/L for H. influenzae, 8.0 mg/L for Salmonella typhi and methicillin-susceptible Staphylococcus aureus. Like erythromycin and the beta-lactams tested, it had little or no activity against enterococci, methicillin-resistant S. aureus and coagulase negative staphylococci.
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Affiliation(s)
- S H Qadri
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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Stanley D, McGrath BJ, Lamp KC, Rybak MJ. Effect of human serum on killing activity of vancomycin and teicoplanin against Staphylococcus aureus. Pharmacotherapy 1994; 14:35-9. [PMID: 8159599 DOI: 10.1002/j.1875-9114.1994.tb02786.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
STUDY OBJECTIVE To investigate the effects of pooled human serum (PHS) on the killing activity of vancomycin and teicoplanin against two isolates of Staphylococcus aureus from patients treated for endocarditis. DESIGN An in vitro assessment of antibiotic susceptibility and killing rates. SETTING An urban university teaching hospital. PATIENTS Pooled human serum from patients treated for endocarditis. INTERVENTIONS Two clinical isolates of Staphylococcus aureus were obtained from patients treated for endocarditis. Media consisted of cation-supplemented Mueller-Hinton broth alone and in 1:1 dilutions with PHS, 2-hour heat-inactivated PHS (HI-PHS), ultrafiltrate (UF), and 2-hour heat-inactivated ultrafiltrate (HI-UF). Heat inactivation of PHS and UF was accomplished by treatment at 56 degrees C for 2 hours. MEASUREMENTS AND MAIN RESULTS Killing curves with vancomycin and teicoplanin were performed using drug concentrations of 45 micrograms/ml and a starting inoculum of approximately 1 x 10(6) colony-forming units (cfu)/ml. Bactericidal rates (-log cfu/ml/hr) were calculated from the slope of the killing curves over 0-12 hours (mean 3-8 replicates). CONCLUSIONS The killing activity of vancomycin in PHS and HI-PHS against both isolates was significantly greater than all other media tested (p < 0.0001). Ultrafiltrate tended to reverse this enhancement effect. Addition of PHS or UF did not enhance teicoplanin's killing activity against either isolate. Further investigations in our laboratory will determine if the factor is antibiotic class or organism specific.
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Affiliation(s)
- D Stanley
- College of Pharmacy, Wayne State University, Detroit, Michigan
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30
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Chapter 13. Recent Advances in Anti-Infective Agents. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1993. [DOI: 10.1016/s0065-7743(08)60883-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Peters DH, Friedel HA, McTavish D. Azithromycin. A review of its antimicrobial activity, pharmacokinetic properties and clinical efficacy. Drugs 1992; 44:750-99. [PMID: 1280567 DOI: 10.2165/00003495-199244050-00007] [Citation(s) in RCA: 176] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Azithromycin is an acid stable orally administered macrolide antimicrobial drug, structurally related to erythromycin, with a similar spectrum of antimicrobial activity. Azithromycin is marginally less active than erythromycin in vitro against Gram-positive organisms, although this is of doubtful clinical significance as susceptibility concentrations fall within the range of achievable tissue azithromycin concentrations. In contrast, azithromycin appears to be more active than erythromycin against many Gram-negative pathogens and several other pathogens, notably Haemophilus influenzae, H. parainfluenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, Urea-plasma urealyticum and Borrelia burgdorferi. Like erythromycin and other macrolides, the activity of azithromycin is unaffected by the production of beta-lactamase. However, erythromycin-resistant organisms are also resistant to azithromycin. Following oral administration, serum concentrations of azithromycin are lower than those of erythromycin, but this reflects the rapid and extensive movement of the drug from the circulation into intracellular compartments resulting in tissue concentrations exceeding those commonly seen with erythromycin. Azithromycin is subsequently slowly released, reflecting its long terminal phase elimination half-life relative to that of erythromycin. These factors allow for a single dose or single daily dose regimen in most infections, with the potential for increased compliance among outpatients where a more frequent antimicrobial regimen might traditionally be indicated. The potential disadvantage of low azithromycin serum concentrations, however, is that breakthrough bacteraemia may occur in patients who are severely ill; nevertheless, animal studies suggest that tissue concentrations of azithromycin are more important than those in serum when treating respiratory and other infections. The clinical efficacy of azithromycin has been confirmed in the treatment of infections of the lower and upper respiratory tracts (the latter including paediatric patients), skin and soft tissues (again including paediatric patients), in uncomplicated urethritis/cervicitis associated with N. gonorrhoeae, Chlamydia trachomatis or U. urealyticum and in the treatment of early Lyme disease. Azithromycin was as effective as erythromycin and other commonly used drugs including clarithromycin, beta-lactams (penicillins and cephalosporins), and quinolone and tetracycline antibiotics in some of the above infections. Some patients with acute exacerbations of chronic bronchitis due to H. influenzae may be refractory to therapy with azithromycin (as is the case with erythromycin) indicating the need for physician vigilance, although it should be noted that azithromycin is of equivalent efficacy to amoxicillin in the treatment of such patients. In the therapy of urethritis/cervicitis associated with C. trachomatis, N. gonorrhoea or U. urealyticum, a single dose azithromycin regimen offers a distinct advantage over currently available pharmacological options, while providing effective therapy.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- D H Peters
- Adis International Limited, Auckland, New Zealand
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