Combination Therapy against Multidrug-Resistant Pathogens

A special issue of Antibiotics (ISSN 2079-6382). This special issue belongs to the section "Antibiotics Use and Antimicrobial Stewardship".

Deadline for manuscript submissions: 30 June 2025 | Viewed by 14616

Special Issue Editors


E-Mail Website
Guest Editor
Department of Molecular Epidemiology and Biomedical Sciences, Aichi Medical University, Aichi, Japan
Interests: pharmacokinetics; pharmacodynamics; antimicrobial; multi-drug resistant pathogen; therapeutic drug monitoring; in vivo study
Special Issues, Collections and Topics in MDPI journals
1. Department of Pharmacy, Mie University Hospital, Mie 5148507, Japan
2. Department of Clinical Pharmaceutics, Mie University Graduate School of Medicine, Mie 5148507, Japan
3. Department of Clinical Infectious Diseases, Aichi Medical University, Aichi 4801195, Japan
Interests: infections and antibiotic use; efficacy and safety of antibiotics; antibiotic resistance; PK/PD study; animal infectious model; meta-analysis
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Antibiotic combination therapy is often used to enhance and improve clinical efficacy in patients where a given therapy is thought to have limitations when used alone. The majority of the data evaluating combination therapy were determined using in vitro techniques or animal models with some types of infections. Through analyses of this information, coupled with the available clinical data, it is possible to identify a number of clinical situations where combination therapy can be supported. When used appropriately at optimal doses, combination therapy may offer an excellent opportunity to maximize clinical outcomes, particularly in the face of antibacterial resistance. Therefore, clinicians should evaluate carefully the risks and the potential benefits before adding additional antibiotics to standard single-drug therapies.

This Special Issue invites researchers interested in antibacterial combination therapy against antibacterial resistance pathogens, to optimize antibacterial use with special emphasis to help in the development of antibacterial treatment guidelines.

Dr. Mao Hagihara
Dr. Hideo Kato
Guest Editors

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.

Keywords

  • combination therapy
  • multidrug-resistant pathogens
  • in vitro
  • in vivo
  • clinical study
  • pharmacokinetics
  • pharmacodynamics.

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Published Papers (5 papers)

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

Research

14 pages, 1309 KiB  
Article
One Earth-One Health (OE-OH): Antibacterial Effects of Plant Flavonoids in Combination with Clinical Antibiotics with Various Mechanisms
by Ganjun Yuan, Fengxian Lian, Yu Yan, Yu Wang, Li Zhang, Jianping Zhu, Aiman Fatima and Yuxing Qian
Antibiotics 2025, 14(1), 8; https://doi.org/10.3390/antibiotics14010008 - 25 Dec 2024
Cited by 1 | Viewed by 1200
Abstract
Background/Objectives: Antimicrobial resistance (AMR) poses a significant threat to human health, and combination therapy has proven effective in combating it. It has been reported that some plant flavonoids can enhance the antibacterial effects of antibiotics and even reverse AMR. This study systematically evaluated [...] Read more.
Background/Objectives: Antimicrobial resistance (AMR) poses a significant threat to human health, and combination therapy has proven effective in combating it. It has been reported that some plant flavonoids can enhance the antibacterial effects of antibiotics and even reverse AMR. This study systematically evaluated the synergistic effects of plant flavonoids and clinical antibiotics. Methods: The antibacterial activities of thirty-seven plant flavonoids and nine clinical antibiotics with various antimicrobial mechanisms were determined using the microbroth dilution method. Subsequently, the combined effects of twelve plant flavonoids presenting definite MICs against Staphylococcus aureus with these nine antibiotics were determined using the checkerboard test, together with those of thirty-two plant flavonoids presenting definite MICs against Escherichia coli with these nine antibiotics. Results: Plant flavonoids in combination with antibiotics present extensive synergistic effects, and 25% of combinations exhibited synergy against S. aureus and 50% against E. coli, particularly with antibiotics affecting cell membranes or ribosomes. Conclusions: The findings align with the drug selection principle of synergistic combinations and suggest that plant flavonoids could extensively enhance antibiotic efficacy. Considering that various metabolites from microorganisms, plants, and animals on the Earth would definitely impact the evolution of AMR, together with the rules, key factors, and important principles of drug combination for preventing AMR, we further propose the “One Earth-One Health (OE-OH)” concept, emphasizing ecosystem interactions in AMR prevention. Full article
(This article belongs to the Special Issue Combination Therapy against Multidrug-Resistant Pathogens)
Show Figures

Figure 1

19 pages, 2117 KiB  
Article
Combinatory Effect of Nitroxoline and Gentamicin in the Control of Uropathogenic Enterococci Infections
by Davorka Repac Antić, Bruno Kovač, Marko Kolenc, Irena Brčić Karačonji, Ivana Gobin and Mirna Petković Didović
Antibiotics 2024, 13(9), 829; https://doi.org/10.3390/antibiotics13090829 - 1 Sep 2024
Cited by 1 | Viewed by 1939
Abstract
Enterococcus faecalis, responsible for a majority of human and nosocomial enterococcal infections, is intrinsically resistant to aminoglycoside antibiotics (such as gentamicin, GEN), which must be used in a combined therapy to be effective. Nitroxoline (NTX) is an old antibiotic, underused for decades, [...] Read more.
Enterococcus faecalis, responsible for a majority of human and nosocomial enterococcal infections, is intrinsically resistant to aminoglycoside antibiotics (such as gentamicin, GEN), which must be used in a combined therapy to be effective. Nitroxoline (NTX) is an old antibiotic, underused for decades, but rediscovered now in an era of growing antibiotic resistance. In this in vitro study, the types of interactions between NTX and GEN on 29 E. faecalis strains were analyzed with an aim to find synergistic antimicrobial and antiadhesion combinations. Transmission electron microscopy (TEM) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to analyze changes in cell morphology and bacterial proteome after monotreatments and combined treatments. The results showed the synergistic effect for six combinations on eight strains, including the ATCC29212, and an additive effect for most strains. Combinations causing a complete inhibition of adhesion were established. Cell membrane integrity was affected by NTX, while combined NTX/GEN treatment caused dramatic changes in cell morphology. Upregulation of the expression of many proteins was established, with some emerging only after combined treatment. The results strongly imply that NTX has the potential for use in combined therapy with GEN against enterococci and it could further provide a substantial contribution to an ongoing fight against antimicrobial resistance and nosocomial infections. Full article
(This article belongs to the Special Issue Combination Therapy against Multidrug-Resistant Pathogens)
Show Figures

Figure 1

15 pages, 1706 KiB  
Article
Combination of Amphiphilic Cyclic Peptide [R4W4] and Levofloxacin against Multidrug-Resistant Bacteria
by Muhammad Imran Sajid, Sandeep Lohan, Shun Kato and Rakesh Kumar Tiwari
Antibiotics 2022, 11(3), 416; https://doi.org/10.3390/antibiotics11030416 - 20 Mar 2022
Cited by 10 | Viewed by 4219
Abstract
Bacterial resistance is a growing global concern necessitating the discovery and development of antibiotics effective against the drug-resistant bacterial strain. Previously, we reported a cyclic antimicrobial peptide [R4W4] containing arginine (R) and tryptophan (W) with a MIC of 2.67 [...] Read more.
Bacterial resistance is a growing global concern necessitating the discovery and development of antibiotics effective against the drug-resistant bacterial strain. Previously, we reported a cyclic antimicrobial peptide [R4W4] containing arginine (R) and tryptophan (W) with a MIC of 2.67 µg/mL (1.95 µM) against methicillin-resistant Staphylococcus aureus (MRSA). Herein, we investigated the cyclic peptides [R4W4] or linear (R4W4) and their conjugates (covalent or noncovalent) with levofloxacin (Levo) with the intent to improve their potency to target drug-resistant bacteria. The physical mixture of the Levo with the cyclic [R4W4] proved to be significantly effective against all strains of bacteria used in the study as compared to covalent conjugation. Furthermore, the checkerboard assay revealed the significant synergistic effect of the peptides against all studied strains except for the wild type S. aureus, in which the partial synergy was observed. The hemolysis assay revealed less cytotoxicity of the physical mixture of the Levo with [R4W4] (22%) as compared to [R4W4] alone (80%). The linear peptide (R4W4) and the cyclic [R4W4] demonstrated ~90% and 85% cell viability at 300 µg/mL in the triple-negative breast cancer cells (MDA-MB-231) and the normal kidney cells (HEK-293), respectively. Similar trends were also observed in the cell viability of Levo-conjugates on these cell lines. Furthermore, the time-kill kinetic study of the combination of [R4W4] and Levo demonstrate rapid killing action at 4 h for MRSA (ATCC BAA-1556) and 12 h for E. coli (ATCC BAA-2452), P. aeruginosa (ATCC BAA-1744), and K. pneumoniae (ATCC BAA-1705). These results provide the effectiveness of a combination of Levo with cyclic [R4W4] peptide, which may provide an opportunity to solve the intriguing puzzle of treating bacterial resistance. Full article
(This article belongs to the Special Issue Combination Therapy against Multidrug-Resistant Pathogens)
Show Figures

Figure 1

10 pages, 922 KiB  
Article
In Vitro Efficacy of Antibiotic Combinations with Carbapenems and Other Agents against Anaerobic Bacteria
by Takumi Umemura, Mao Hagihara, Takeshi Mori and Hiroshige Mikamo
Antibiotics 2022, 11(3), 292; https://doi.org/10.3390/antibiotics11030292 - 22 Feb 2022
Cited by 1 | Viewed by 2272
Abstract
We investigated the in vitro efficacy of combinations of carbapenems with clindamycin (CLDM) and minocycline (MINO) against Bacteroides fragilis and Peptostreptococcus species. We selected the carbapenems imipenem, meropenem, panipenem, doripenem, and biapenem. To evaluate the antibiotic efficacy of these combination regimens, the fractional [...] Read more.
We investigated the in vitro efficacy of combinations of carbapenems with clindamycin (CLDM) and minocycline (MINO) against Bacteroides fragilis and Peptostreptococcus species. We selected the carbapenems imipenem, meropenem, panipenem, doripenem, and biapenem. To evaluate the antibiotic efficacy of these combination regimens, the fractional inhibitory concentration index (FICI) was calculated against clinical isolates. Consequently, combination regimens of each carbapenem with CLDM or MINO showed synergistic or additive effects against 83.3–100.0% and no antagonistic effects against P. anaerobius isolates. However, against the B. fragilis group (B. fragilis, B. thetaiotaomicron, and Parabacteroides distasonis), although the combination with other carbapenems and CLDM or MINO did not show remarkable synergistic effects, the combination regimen of IPM with CLDM or MINO indicated mainly additive antibiotic efficacies (FICIs: >0.5 to ≤1.0) to B. fragilis groups. Then, antagonistic effects were admitted in only 5.6% of B. fragilis groups. The effectiveness of antibiotic combination therapy against pathogenic anaerobes has remained unclear. Then, our results can provide new insights to explore the effective combination regimens against multidrug-resistant anaerobic bacteria as empirical and definitive therapies, while this study used only carbapenem susceptible isolates. Hence, further studies are needed to use highly antibiotic-resistant anaerobic isolates to carbapenems. Full article
(This article belongs to the Special Issue Combination Therapy against Multidrug-Resistant Pathogens)
Show Figures

Figure 1

11 pages, 2105 KiB  
Article
In Vivo Pharmacodynamics of β-Lactams/Nacubactam against Carbapenem-Resistant and/or Carbapenemase-Producing Enterobacter cloacae and Klebsiella pneumoniae in Murine Pneumonia Model
by Mao Hagihara, Hideo Kato, Toshie Sugano, Hayato Okade, Nobuo Sato, Yuichi Shibata, Daisuke Sakanashi, Jun Hirai, Nobuhiro Asai, Hiroyuki Suematsu, Yuka Yamagishi and Hiroshige Mikamo
Antibiotics 2021, 10(10), 1179; https://doi.org/10.3390/antibiotics10101179 - 28 Sep 2021
Cited by 5 | Viewed by 3511
Abstract
Carbapenem-resistant Enterobacterales (CRE) and carbapenemase-producing Enterobacterales (CPE) have become global threats. CRE− and CPE− derived infections have been associated with high mortality due to limited treatment options. Nacubactam is a β-lactamase inhibitor and belongs to the new class of diazabicyclooctane. The agent has [...] Read more.
Carbapenem-resistant Enterobacterales (CRE) and carbapenemase-producing Enterobacterales (CPE) have become global threats. CRE− and CPE− derived infections have been associated with high mortality due to limited treatment options. Nacubactam is a β-lactamase inhibitor and belongs to the new class of diazabicyclooctane. The agent has an in vitro antimicrobial activity against several classes of β-lactamase-producing Enterobacterales. This study evaluated antimicrobial activity of combination therapies including β-lactams (aztreonam, cefepime, and meropenem) and nacubactam against four Enterobacter cloacae and six Klebsiella pneumoniae isolates with murine pneumonia model. Based on changes in bacterial quantity, antimicrobial activities of some regimens were assessed. Combination therapies including β-lactams (aztreonam, cefepime, and meropenem) with nacubactam showed enhanced antimicrobial activity against CRE E. cloacae (−3.70 to −2.08 Δlog10 CFU/lungs) and K. pneumoniae (−4.24 to 1.47 Δlog10 CFU/lungs) with IMP-1, IMP-6, or KPC genes, compared with aztreonam, cefepime, meropenem, and nacubactam monotherapies. Most combination therapies showed bacteriostatic (−3.0 to 0 Δlog10 CFU/lungs) to bactericidal (<−3.0 Δlog10 CFU/lungs) activities against CRE isolates. This study revealed that combination regimens with β-lactams (aztreonam, cefepime, and meropenem) and nacubactam are preferable candidates to treat pneumonia due to CRE and CPE. Full article
(This article belongs to the Special Issue Combination Therapy against Multidrug-Resistant Pathogens)
Show Figures

Figure 1

Back to TopTop