Advancing the Discovery and Development of New Antibiotics through Drug Repurposing

A special issue of Antibiotics (ISSN 2079-6382). This special issue belongs to the section "Novel Antimicrobial Agents".

Deadline for manuscript submissions: 31 December 2024 | Viewed by 2873

Special Issue Editor


E-Mail Website
Guest Editor
Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44240, USA
Interests: antibiotics; durg design; medicinal chemistry

Special Issue Information

Dear Colleagues,

Antimicrobial resistance (AMR) has now evolved in every class of antibiotics that have ever entered clinical use. The situation is worsened by the shrinking rate of return on the discovery of novel antibiotics. Current commercial antibiotics have two different origins: (1) natural products excreted by soil-dwelling Streptomyces, and (2) synthetic organic compounds. After eight decades of intensive screening and development, soil samples have failed to yield new classes of antibiotics since the end of the so-called golden era of antibiotic discovery. Although synthetic organic compounds have provided some important complementary classes of antibiotics, as represented by the advent of fluoroquinolones (e.g., ciprofloxacin), newer members from the family of synthetic antibiotics often share the known antimicrobial targets with the existing drugs in this class, making them susceptible to the development of the same type of resistance evolved in the previous members. In light of the high failure rates, considerable costs, and particularly substantial time spans of drug discovery and development, repurposing existing non-antibiotic drugs to treat multidrug-resistant bacterial infections should constitute an attractive approach to mitigating the threat of AMR. 

Prof. Dr. Songping Huang
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Antibiotics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

19 pages, 4683 KiB  
Article
Efficacy of Tamoxifen Metabolites in Combination with Colistin and Tigecycline in Experimental Murine Models of Escherichia coli and Acinetobacter baumannii
by Soraya Herrera-Espejo, Andrea Vila-Domínguez, Tania Cebrero-Cangueiro, Younes Smani, Jerónimo Pachón, Manuel E. Jiménez-Mejías and María E. Pachón-Ibáñez
Antibiotics 2024, 13(5), 386; https://doi.org/10.3390/antibiotics13050386 - 24 Apr 2024
Viewed by 341
Abstract
This study aimed to evaluate the potential of tamoxifen and N-desmethyltamoxifen metabolites as therapeutic agents against multidrug-resistant Escherichia coli and Acinetobacter baumannii, using a repurposing approach to shorten the time required to obtain a new effective treatment against multidrug-resistant bacterial infections. Characterisation and [...] Read more.
This study aimed to evaluate the potential of tamoxifen and N-desmethyltamoxifen metabolites as therapeutic agents against multidrug-resistant Escherichia coli and Acinetobacter baumannii, using a repurposing approach to shorten the time required to obtain a new effective treatment against multidrug-resistant bacterial infections. Characterisation and virulence studies were conducted on E. coli (colistin-susceptible C1-7-LE and colistin-resistant MCR-1+) and A. baumannii (tigecycline-susceptible Ab#9 and tigecycline-resistant Ab#186) strains. The efficacy of the metabolite mix (33.3% each) and N-desmethyltamoxifen in combination with colistimethate sodium (CMS) or tigecycline was evaluated in experimental models in mice. In the pneumonia model, N-desmethyltamoxifen exhibited significant efficacy against Ab#9 and both E. coli strains, especially E. coli MCR-1+ (−2.86 log10 CFU/g lungs, −5.88 log10 CFU/mL blood, and −50% mortality), and against the Ab#186 strain when combined with CMS (−2.27 log10 CFU/g lungs, −2.73 log10 CFU/mL blood, and −40% mortality) or tigecycline (−3.27 log10 CFU/g lungs, −4.95 log10 CFU/mL blood, and −50% mortality). Moreover, the metabolite mix in combination with both antibiotics decreased the bacterial concentrations in the lungs and blood for both A. baumannii strains. In the sepsis model, the significant efficacy of the metabolite mix was restricted to the colistin-susceptible E. coli C1-7-LE strain (−3.32 log10 CFU/g lung, −6.06 log10 CFU/mL blood, and −79% mortality). N-desmethyltamoxifen could be a new therapeutic option in combination with CMS or tigecycline for combating multidrug-resistant GNB, specifically A. baumannii. Full article
Show Figures

Figure 1

15 pages, 6487 KiB  
Article
Repurposing Mitomycin C in Combination with Pentamidine or Gentamicin to Treat Infections with Multi-Drug-Resistant (MDR) Pseudomonas aeruginosa
by Elin Svedholm, Benjamin Bruce, Benjamin J. Parcell and Peter J. Coote
Antibiotics 2024, 13(2), 177; https://doi.org/10.3390/antibiotics13020177 - 10 Feb 2024
Cited by 1 | Viewed by 1164
Abstract
The aims of this study were (i) to determine if the combination of mitomycin C with pentamidine or existing antibiotics resulted in enhanced efficacy versus infections with MDR P. aeruginosa in vivo; and (ii) to determine if the doses of mitomycin C and [...] Read more.
The aims of this study were (i) to determine if the combination of mitomycin C with pentamidine or existing antibiotics resulted in enhanced efficacy versus infections with MDR P. aeruginosa in vivo; and (ii) to determine if the doses of mitomycin C and pentamidine in combination can be reduced to levels that are non-toxic in humans but still retain antibacterial activity. Resistant clinical isolates of P. aeruginosa, a mutant strain over-expressing the MexAB-OprM resistance nodulation division (RND) efflux pump and a strain with three RND pumps deleted, were used. MIC assays indicated that all strains were sensitive to mitomycin C, but deletion of three RND pumps resulted in hypersensitivity and over-expression of MexAB-OprM caused some resistance. These results imply that mitomycin C is a substrate of the RND efflux pumps. Mitomycin C monotherapy successfully treated infected Galleria mellonella larvae, albeit at doses too high for human administration. Checkerboard and time–kill assays showed that the combination of mitomycin C with pentamidine, or the antibiotic gentamicin, resulted in synergistic inhibition of most P. aeruginosa strains in vitro. In vivo, administration of a combination therapy of mitomycin C with pentamidine, or gentamicin, to G. mellonella larvae infected with P. aeruginosa resulted in enhanced efficacy compared with monotherapies for the majority of MDR clinical isolates. Notably, the therapeutic benefit conferred by the combination therapy occurred with doses of mitomycin C close to those used in human medicine. Thus, repurposing mitomycin C in combination therapies to target MDR P. aeruginosa infections merits further investigation. Full article
Show Figures

Figure 1

17 pages, 3616 KiB  
Article
Unexpected Inhibitory Effect of Octenidine Dihydrochloride on Candida albicans Filamentation by Impairing Ergosterol Biosynthesis and Disrupting Cell Membrane Integrity
by Ting Fang, Juan Xiong, Li Wang, Zhe Feng, Sijin Hang, Jinhua Yu, Wanqian Li, Yanru Feng, Hui Lu and Yuanying Jiang
Antibiotics 2023, 12(12), 1675; https://doi.org/10.3390/antibiotics12121675 - 28 Nov 2023
Cited by 3 | Viewed by 1094
Abstract
Candida albicans filamentation plays a significant role in developing both mucosal and invasive candidiasis, making it a crucial virulence factor. Consequently, exploring and identifying inhibitors that impede fungal hyphal formation presents an intriguing approach toward antifungal strategies. In line with this anti-filamentation strategy, [...] Read more.
Candida albicans filamentation plays a significant role in developing both mucosal and invasive candidiasis, making it a crucial virulence factor. Consequently, exploring and identifying inhibitors that impede fungal hyphal formation presents an intriguing approach toward antifungal strategies. In line with this anti-filamentation strategy, we conducted a comprehensive screening of a library of FDA-approved drugs to identify compounds that possess inhibitory properties against hyphal growth. The compound octenidine dihydrochloride (OCT) exhibits potent inhibition of hyphal growth in C. albicans across different hyphae-inducing media at concentrations below or equal to 3.125 μM. This remarkable inhibitory effect extends to biofilm formation and the disruption of mature biofilm. The mechanism underlying OCT’s inhibition of hyphal growth is likely attributed to its capacity to impede ergosterol biosynthesis and induce the generation of reactive oxygen species (ROS), compromising the integrity of the cell membrane. Furthermore, it has been observed that OCT demonstrates protective attributes against invasive candidiasis in Galleria mellonella larvae through its proficient eradication of C. albicans colonization in infected G. mellonella larvae by impeding hyphal formation. Although additional investigation is required to mitigate the toxicity of OCT in mammals, it possesses considerable promise as a potent filamentation inhibitor against invasive candidiasis. Full article
Show Figures

Figure 1

Back to TopTop