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Benin BM, Kharel R, Hillyer T, Sun C, Cmolik A, Kuebler T, Sham YY, Bonomo R, Mighion JD, Shin WS. Development of non-β-Lactam covalent allosteric inhibitors targeting PBP2a in Methicillin-Resistant Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596450. [PMID: 38853829 PMCID: PMC11160701 DOI: 10.1101/2024.05.29.596450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA), a Gram-positive bacterial pathogen, continues to pose a serious threat to the current public health system in our society. The high level of resistance to β-lactam antibiotics in MRSA is attributed to the expression of penicillin-binding protein 2a (PBP2a), which catalyzes cell wall cross-linking. According to numerous research reports, the activity of the PBP2a protein is known to be regulated by an allosteric site distinct from the active site where cell wall cross-linking occurs. Here, we conducted a screening of 113 compounds containing a 1,3,4-oxadiazole core to design new covalent inhibitors targeting the allosteric site of PBP2a and establish their structural-activity relationship. The stereochemically selective synthesis of sulfonyl oxadiazole compounds identified in the initial screening resulted in a maximum eightfold enhancement in cell inhibition activity. The sulfonyl oxadiazole-based compounds formulated as PEG-based ointments, with low toxicity test results on human cells (CC 50 : >78μM), demonstrated potent antimicrobial effects not only in a mouse skin wound infection model but also against oxacillin-resistant clinical isolate MRSA (IC 50 ≈ 1μM), as evidenced by the results. Furthermore, additional studies utilizing LC-MS/MS and in-silico approaches clearly support the allosteric site covalent binding mechanism through the nucleophilic aromatic substitution (S N Ar) reaction, as well as its association with the closure of the major active site of PBP2a.
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Liu H, Hu Z, Li M, Yang Y, Lu S, Rao X. Therapeutic potential of bacteriophage endolysins for infections caused by Gram-positive bacteria. J Biomed Sci 2023; 30:29. [PMID: 37101261 PMCID: PMC10131408 DOI: 10.1186/s12929-023-00919-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 04/14/2023] [Indexed: 04/28/2023] Open
Abstract
Gram-positive (G+) bacterial infection is a great burden to both healthcare and community medical resources. As a result of the increasing prevalence of multidrug-resistant G+ bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), novel antimicrobial agents must urgently be developed for the treatment of infections caused by G+ bacteria. Endolysins are bacteriophage (phage)-encoded enzymes that can specifically hydrolyze the bacterial cell wall and quickly kill bacteria. Bacterial resistance to endolysins is low. Therefore, endolysins are considered promising alternatives for solving the mounting resistance problem. In this review, endolysins derived from phages targeting G+ bacteria were classified based on their structural characteristics. The active mechanisms, efficacy, and advantages of endolysins as antibacterial drug candidates were summarized. Moreover, the remarkable potential of phage endolysins in the treatment of G+ bacterial infections was described. In addition, the safety of endolysins, challenges, and possible solutions were addressed. Notwithstanding the limitations of endolysins, the trends in development indicate that endolysin-based drugs will be approved in the near future. Overall, this review presents crucial information of the current progress involving endolysins as potential therapeutic agents, and it provides a guideline for biomaterial researchers who are devoting themselves to fighting against bacterial infections.
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Affiliation(s)
- He Liu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China
| | - Zhen Hu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China
| | - Mengyang Li
- Department of Microbiology, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Yi Yang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China
| | - Shuguang Lu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China.
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China.
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Ju M, Joseph T, Hansanant N, Geng M, Williams M, Cothrell A, Buhrow AR, Austin F, Smith L. Evaluation of analogs of mutacin 1140 in systemic and cutaneous methicillin-resistant Staphylococcus aureus infection models in mice. Front Microbiol 2022; 13:1067410. [PMID: 36590413 PMCID: PMC9794991 DOI: 10.3389/fmicb.2022.1067410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
Mutacin 1140 (Mu1140) is a potent antibiotic against Gram-positive bacteria, such as Staphylococcus aureus. The antibiotic is produced by the oral bacterium Streptococcus mutans and is a member of the epidermin family of type AI lantibiotics. The antibiotic exerts its inhibitory activity by binding to the cell wall precursor lipid II, blocking cell wall synthesis, and by disrupting bacterial membranes. In previous studies, the novel K2A and R13A analogs of Mu1140 have been identified to have superior pharmacokinetic properties compared to native Mu1140. In this study, the use of a combined formulation of the Mu1140 K2A and R13A analogs was shown to be more effective at treating MRSA bacteremia than the native Mu1140 or vancomycin. The analogs were also shown to be effective in treating an MRSA skin infection. The use of K2A and R13A analogs may provide a future alternative for treating serious Gram-positive bacterial infections. In a previous study, the Mu1140 analogs were shown to have significantly longer drug clearance times, leading to higher plasma concentrations over time. These properties warranted further testing to determine whether the analogs are effective for the treatment of systemic MRSA and acute skin infections. In this study, Mu1140 analogs were shown to be more effective than currently available treatments for systemic and skin MRSA infections. Further, the study clearly shows that the new analogs are superior to native Mu1140 for the treatment of a systemic MRSA infection. These findings support continued drug product development efforts using the K2A and R13A Mu1140 analogs, and that these analogs may ameliorate the outcome of serious bacterial infections.
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Affiliation(s)
- Min Ju
- Antimicrobial Division, Sano Chemicals Inc., Bryan, TX, United States
| | - Thushinari Joseph
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Nopakorn Hansanant
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Mengxin Geng
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - McKinley Williams
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Andrew Cothrell
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Andrew Riley Buhrow
- Antimicrobial Division, Sano Chemicals Inc., Bryan, TX, United States,Department of Biology, Texas A&M University, College Station, TX, United States
| | - Frank Austin
- College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Leif Smith
- Antimicrobial Division, Sano Chemicals Inc., Bryan, TX, United States,Department of Biology, Texas A&M University, College Station, TX, United States,*Correspondence: Leif Smith,
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Riu F, Ruda A, Ibba R, Sestito S, Lupinu I, Piras S, Widmalm G, Carta A. Antibiotics and Carbohydrate-Containing Drugs Targeting Bacterial Cell Envelopes: An Overview. Pharmaceuticals (Basel) 2022; 15:942. [PMID: 36015090 PMCID: PMC9414505 DOI: 10.3390/ph15080942] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 02/07/2023] Open
Abstract
Certain bacteria constitute a threat to humans due to their ability to escape host defenses as they easily develop drug resistance. Bacteria are classified into gram-positive and gram-negative according to the composition of the cell membrane structure. Gram-negative bacteria have an additional outer membrane (OM) that is not present in their gram-positive counterpart; the latter instead hold a thicker peptidoglycan (PG) layer. This review covers the main structural and functional properties of cell wall polysaccharides (CWPs) and PG. Drugs targeting CWPs are discussed, both noncarbohydrate-related (β-lactams, fosfomycin, and lipopeptides) and carbohydrate-related (glycopeptides and lipoglycopeptides). Bacterial resistance to these drugs continues to evolve, which calls for novel antibacterial approaches to be developed. The use of carbohydrate-based vaccines as a valid strategy to prevent bacterial infections is also addressed.
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Affiliation(s)
- Federico Riu
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Via Muroni 23/A, 07100 Sassari, Italy; (F.R.); (I.L.); (S.P.); (A.C.)
| | - Alessandro Ruda
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden; (A.R.); (G.W.)
| | - Roberta Ibba
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Via Muroni 23/A, 07100 Sassari, Italy; (F.R.); (I.L.); (S.P.); (A.C.)
| | - Simona Sestito
- Department of Chemical, Physical, Mathematical and Natural Sciences, University of Sassari, Via Vienna 2, 07100 Sassari, Italy;
| | - Ilenia Lupinu
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Via Muroni 23/A, 07100 Sassari, Italy; (F.R.); (I.L.); (S.P.); (A.C.)
| | - Sandra Piras
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Via Muroni 23/A, 07100 Sassari, Italy; (F.R.); (I.L.); (S.P.); (A.C.)
| | - Göran Widmalm
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden; (A.R.); (G.W.)
| | - Antonio Carta
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Via Muroni 23/A, 07100 Sassari, Italy; (F.R.); (I.L.); (S.P.); (A.C.)
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