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Jang JH, Lee JE, Kim KT, Ahn DU, Paik HD. Anti-biofilm effect of enzymatic hydrolysates of ovomucin in Listeria monocytogenes and Staphylococcus aureus. Microb Pathog 2024; 193:106771. [PMID: 38969185 DOI: 10.1016/j.micpath.2024.106771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 06/02/2024] [Accepted: 06/30/2024] [Indexed: 07/07/2024]
Abstract
Despite modern advances in food hygiene, food poisoning due to microbial contamination remains a global problem, and poses a great threat to human health. Especially, Listeria monocytogenes and Staphylococcus aureus are gram-positive bacteria found on food-contact surfaces with biofilms. These foodborne pathogens cause a considerable number of food poisoning and infections annually. Ovomucin (OM) is a water-insoluble gel-type glycoprotein in egg whites. Enzymatic hydrolysis can be used to improve the bioactive properties of OM. This study aimed to investigate whether ovomucin hydrolysates (OMHs) produced using five commercial enzymes (Alcalase®, Bromelain, α-Chymotrypsin, Papain, and Pancreatin) can inhibit the biofilm formation of L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7. Particularly, OMH prepared with papain (OMPP; 500 μg/mL) significantly inhibited biofilm formation in L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7 by 85.56 %, 80.28 %, 91.70 %, and 79.00 %, respectively. In addition, OMPP reduced the metabolic activity, exopolysaccharide production (EPS), adhesion ability, and gene expression associated with the biofilm formation of these bacterial strains. These results suggest that OMH, especially OMPP, exerts anti-biofilm effects against L. monocytogenes and S. aureus. Therefore, OMPP can be used as a natural anti-biofilm agent to control food poisoning in the food industry.
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Affiliation(s)
- Jin-Hong Jang
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul, 05029, Republic of Korea
| | - Ji-Eun Lee
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul, 05029, Republic of Korea
| | - Kee-Tae Kim
- Research Institute, WithBio Inc, Seoul, 05029, Republic of Korea
| | - Dong Uk Ahn
- Department of Animal Science, Iowa State University, Ames, IA, 50011, USA
| | - Hyun-Dong Paik
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul, 05029, Republic of Korea.
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2
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Nguyen VT, Birhanu BT, Miguel-Ruano V, Kim C, Batuecas M, Yang J, El-Araby AM, Jiménez-Faraco E, Schroeder VA, Alba A, Rana N, Sader S, Thomas CA, Feltzer R, Lee M, Fisher JF, Hermoso JA, Chang M, Mobashery S. Restoring susceptibility to β-lactam antibiotics in methicillin-resistant Staphylococcus aureus. Nat Chem Biol 2024:10.1038/s41589-024-01688-0. [PMID: 39060390 DOI: 10.1038/s41589-024-01688-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 06/26/2024] [Indexed: 07/28/2024]
Abstract
Infections by Staphylococcus aureus have been treated historically with β-lactam antibiotics. However, these antibiotics have become obsolete in methicillin-resistant S. aureus by acquisition of the bla and mec operons. The presence of the β-lactam antibiotic is detected by the sensor domains of BlaR and/or MecR, and the information is transmitted to the cytoplasm, resulting in derepression of the antibiotic-resistance genes. We hypothesized that inhibition of the sensor domain would shut down this response system, and β-lactam susceptibility would be restored. An in silico search of 11 million compounds led to a benzimidazole-based hit and, ultimately, to the boronate 4. The X-ray structure of 4 is covalently engaged with the active-site serine of BlaR. Compound 4 potentiates by 16- to 4,096-fold the activities of oxacillin and of meropenem against methicillin-resistant S. aureus strains. The combination of 4 with oxacillin or meropenem shows efficacy in infected mice, validating the strategy.
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Affiliation(s)
- Van T Nguyen
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Biruk T Birhanu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Vega Miguel-Ruano
- Department of Crystallography and Structural Biology, Instituto de Química-Física 'Blas Cabrera', Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Choon Kim
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Mayte Batuecas
- Department of Crystallography and Structural Biology, Instituto de Química-Física 'Blas Cabrera', Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Jingdong Yang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Amr M El-Araby
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Eva Jiménez-Faraco
- Department of Crystallography and Structural Biology, Instituto de Química-Física 'Blas Cabrera', Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Valerie A Schroeder
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Alejandra Alba
- Department of Crystallography and Structural Biology, Instituto de Química-Física 'Blas Cabrera', Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Neha Rana
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Safaa Sader
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Caitlyn A Thomas
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Rhona Feltzer
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física 'Blas Cabrera', Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.
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3
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Tao Y, Liu Q, Cheng N. Sea hedgehog-inspired surface-enhanced Raman scattering biosensor probe for ultrasensitive determination of Staphylococcus aureus in food supplements. Biosens Bioelectron 2024; 252:116146. [PMID: 38417286 DOI: 10.1016/j.bios.2024.116146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/01/2024]
Abstract
Staphylococcus aureus contamination in food supplements poses substantial challenges to public health and large-scale production but the sensitive detection in a timely manner remains a bottleneck. Drawing inspiration from the sea hedgehog, gold nanostars (AuNSs) were leveraged to design an ultrasensitive surface-enhanced Raman scattering (SERS) biosensor for the determination of Staphylococcus aureus in food supplements. Besides the surface enhancement furnished by the AuNSs, Raman reporter molecules and specific aptamers sequentially self-assembled onto these AuNSs to construct the "three-in-one" SERS biosensor probe for label-based quantitation of Staphylococcus aureus. Following incubation with contaminated health product samples, the gold nanostars@Raman reporter-aptamer specifically recognize and assemble around Staphylococcus aureus cells, forming a distinctive sea hedgehog structure. This unique configuration results in an amplified Raman signal at 1338 cm-1 and an enhancement factor of up to 6.71 × 107. The entire quantitative detection process can be completed within 30 min, boasting an exceptional limit of detection as low as 1.0 CFU mL-1. The method exhibits a broad working range for the determination of Staphylococcus aureus, with concentrations spanning 2.15 CFU mL-1 to 2.15 × 105 CFU mL-1. Furthermore, it demonstrates outstanding precision, with relative standard deviation values consistently below 5.0%. As a showcase to validate the practicality of the SERS method, we conducted tests on determining Staphylococcus aureus in a herbal food supplement, i.e., Ginkgo Biloba extract (GBE); the results align closely with those obtained through the conventional lysogeny broth agar plate method, pointing to the potential applicability in real-world scenarios.
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Affiliation(s)
- Yi Tao
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, China.
| | - Qing Liu
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, China
| | - Ningtao Cheng
- School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.
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4
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Zhang J, Liu M, Guo H, Gao S, Hu Y, Zeng G, Yang D. Nanotechnology-driven strategies to enhance the treatment of drug-resistant bacterial infections. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2024; 16:e1968. [PMID: 38772565 DOI: 10.1002/wnan.1968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/04/2024] [Accepted: 05/02/2024] [Indexed: 05/23/2024]
Abstract
The misuse of antibiotics has led to increased bacterial resistance, posing a global public health crisis and seriously endangering lives. Currently, antibiotic therapy remains the most common approach for treating bacterial infections, but its effectiveness against multidrug-resistant bacteria is diminishing due to the slow development of new antibiotics and the increase of bacterial drug resistance. Consequently, developing new a\ntimicrobial strategies and improving antibiotic efficacy to combat bacterial infection has become an urgent priority. The emergence of nanotechnology has revolutionized the traditional antibiotic treatment, presenting new opportunities for refractory bacterial infection. Here we comprehensively review the research progress in nanotechnology-based antimicrobial drug delivery and highlight diverse platforms designed to target different bacterial resistance mechanisms. We also outline the use of nanotechnology in combining antibiotic therapy with other therapeutic modalities to enhance the therapeutic effectiveness of drug-resistant bacterial infections. These innovative therapeutic strategies have the potential to enhance bacterial susceptibility and overcome bacterial resistance. Finally, the challenges and prospects for the application of nanomaterial-based antimicrobial strategies in combating bacterial resistance are discussed. This article is categorized under: Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.
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Affiliation(s)
- Junjie Zhang
- School of Fundamental Sciences, Bengbu Medical University, Bengbu, China
| | - Ming Liu
- School of Fundamental Sciences, Bengbu Medical University, Bengbu, China
| | - Haiyang Guo
- School of Fundamental Sciences, Bengbu Medical University, Bengbu, China
| | - Shuwen Gao
- School of Fundamental Sciences, Bengbu Medical University, Bengbu, China
| | - Yanling Hu
- College of Life and Health, Nanjing Polytechnic Institute, Nanjing, China
| | - Guisheng Zeng
- Infectious Diseases Labs (ID Labs), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Dongliang Yang
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), School of Physical and Mathematical Sciences, Nanjing Tech University (NanjingTech), Nanjing, China
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5
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Dai W, Shu R, Yang F, Li B, Johnson HM, Yu S, Yang H, Chan YK, Yang W, Bai D, Deng Y. Engineered Bio-Heterojunction Confers Extra- and Intracellular Bacterial Ferroptosis and Hunger-Triggered Cell Protection for Diabetic Wound Repair. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2305277. [PMID: 37526952 DOI: 10.1002/adma.202305277] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/30/2023] [Indexed: 08/02/2023]
Abstract
Nanomaterial-mediated ferroptosis has garnered considerable interest in the antibacterial field, as it invokes the disequilibrium of ion homeostasis and boosts lipid peroxidation in extra- and intracellular bacteria. However, current ferroptosis-associated antibacterial strategies indiscriminately pose damage to healthy cells, ultimately compromising their biocompatibility. To address this daunting issue, this work has designed a precise ferroptosis bio-heterojunction (F-bio-HJ) consisting of Fe2 O3 , Ti3 C2 -MXene, and glucose oxidase (GOx) to induce extra-intracellular bacteria-targeted ferroptosis for infected diabetic cutaneous regeneration. Fe2 O3 /Ti3 C2 -MXene@GOx (FMG) catalytically generates a considerable amount of ROS which assaults the membrane of extracellular bacteria, facilitating the permeation of synchronously generated Fe2+ /Fe3+ into bacteria under near-infrared (NIR) irradiation, causing planktonic bacterial death via ferroptosis, Fe2+ overload, and lipid peroxidation. Additionally, FMG facilitates intracellular bacterial ferroptosis by transporting Fe2+ into intracellular bacteria via inward ferroportin (FPN). With GOx consuming glucose, FMG creates hunger protection which helps macrophages escape cell ferroptosis by activating the adenosine 5'-monophosphate (AMP) activated protein kinase (AMPK) pathway. In vivo results authenticate that FMG boosts diabetic infectious cutaneous regeneration without triggering ferroptosis in normal cells. As envisaged, the proposed tactic provides a promising approach to combat intractable infections by precisely terminating extra-intracellular infection via steerable ferroptosis, thereby markedly elevating the biocompatibility of therapeutic ferroptosis-mediated strategies.
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Affiliation(s)
- Wenyu Dai
- West China School of Stomatology College of Biomedical Engineering, School of Chemical Engineering, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Orthodontics and Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Rui Shu
- West China School of Stomatology College of Biomedical Engineering, School of Chemical Engineering, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Orthodontics and Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Fan Yang
- West China School of Stomatology College of Biomedical Engineering, School of Chemical Engineering, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Orthodontics and Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Bin Li
- West China School of Stomatology College of Biomedical Engineering, School of Chemical Engineering, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Orthodontics and Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Hannah M Johnson
- Department of Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Sheng Yu
- Department of Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Hang Yang
- College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Yau Kei Chan
- Department of Ophthalmology, The University of Hong Kong, Hong Kong, 999077, China
| | - Weizhong Yang
- West China School of Stomatology College of Biomedical Engineering, School of Chemical Engineering, Sichuan University, Chengdu, 610041, China
| | - Ding Bai
- West China School of Stomatology College of Biomedical Engineering, School of Chemical Engineering, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Orthodontics and Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Yi Deng
- West China School of Stomatology College of Biomedical Engineering, School of Chemical Engineering, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, 999077, China
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6
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Jiao F, Bao Y, Li M, Zhang Y, Zhang F, Wang P, Tao J, Tong HHY, Guo J. Unraveling the mechanism of ceftaroline-induced allosteric regulation in penicillin-binding protein 2a: insights for novel antibiotic development against methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2023; 67:e0089523. [PMID: 37971241 PMCID: PMC10720500 DOI: 10.1128/aac.00895-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/11/2023] [Indexed: 11/19/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) acquires high-level resistance against β-lactam antibiotics by expressing penicillin-binding protein 2a (PBP2a). PBP2a is a cell wall-synthesizing protein whose closed active site exhibits a reduced binding affinity toward β-lactam antibiotics. Ceftaroline (CFT), a fifth-generation cephalosporin, can effectively inhibit the PBP2a activity by binding to an allosteric site to trigger the active site opening, allowing a second CFT to access the active site. However, the essential mechanism behind the allosteric behavior of PBP2a remains unclear. Herein, computational simulations are employed to elucidate how CFT allosterically regulates the conformation and dynamics of the active site of PBP2a. While CFT stabilizes the allosteric domain surrounding it, it simultaneously enhances the dynamics of the catalytic domain. Specifically, the study successfully captured the opening process of the active pocket in the allosteric CFT-bound systems and discovered that CFT alters the potential signal-propagating pathways from the allosteric site to the active site. These findings reveal the implied mechanism of the CFT-mediated allostery in PBP2a and provide new insights into dual-site drug design or combination therapy against MRSA targeting PBP2a.
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Affiliation(s)
- Fangfang Jiao
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
| | - Yiqiong Bao
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Mengrong Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yan Zhang
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Feng Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Pinkai Wang
- Department of Orthopedics, Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jun Tao
- Department of Orthopedics, Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Henry H. Y. Tong
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
| | - Jingjing Guo
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
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7
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Ramdass AC, Rampersad SN. Genome features of a novel hydrocarbonoclastic Chryseobacterium oranimense strain and its comparison to bacterial oil-degraders and to other C. oranimense strains. DNA Res 2023; 30:dsad025. [PMID: 37952165 PMCID: PMC10710014 DOI: 10.1093/dnares/dsad025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/29/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023] Open
Abstract
For the first time, we report the whole genome sequence of a hydrocarbonoclastic Chryseobacterium oranimense strain isolated from Trinidad and Tobago (COTT) and its genes involved in the biotransformation of hydrocarbons and xenobiotics through functional annotation. The assembly consisted of 11 contigs with 2,794 predicted protein-coding genes which included a diverse group of gene families involved in aliphatic and polycyclic hydrocarbon degradation. Comparative genomic analyses with 18 crude-oil degrading bacteria in addition to two C. oranimense strains not associated with oil were carried out. The data revealed important differences in terms of annotated genes involved in the hydrocarbon degradation process that may explain the molecular mechanisms of hydrocarbon and xenobiotic biotransformation. Notably, many gene families were expanded to explain COTT's competitive ability to manage habitat-specific stressors. Gene-based evidence of the metabolic potential of COTT supports the application of indigenous microbes for the remediation of polluted terrestrial environments and provides a genomic resource for improving our understanding of how to optimize these characteristics for more effective bioremediation.
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Affiliation(s)
- Amanda Christine Ramdass
- Biochemistry Research Lab (Rm216), Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies
| | - Sephra Nalini Rampersad
- Biochemistry Research Lab (Rm216), Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies
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8
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Vase H, Nemattalab M, Rohani M, Hesari Z. Comparison of chitosan and SLN nano-delivery systems for antibacterial effect of tea tree (Melaleuca alternifolia) oil against P. aeruginosa and S. aureus. Lett Appl Microbiol 2023; 76:ovad130. [PMID: 37989849 DOI: 10.1093/lambio/ovad130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/07/2023] [Accepted: 11/20/2023] [Indexed: 11/23/2023]
Abstract
Treatment of wounds is challenging due to bacterial infections, including Staphylococcus aureus and Pseudomonas aeruginosa. Using the merits of alternative antimicrobials like tea tree oil (TTO) and nanotechnology, they can be helpful in combatting bacterial infections. Solid lipid nanoparticle (SLN) and chitosan (CS) nanoparticles show great potential as carriers for enhancing the stability and therapeutic benefits of oils. The aim of this study is to compare the influence of nanocarriers in enhancing the antibacterial effects of TTO. The study evaluates the physicochemical and antibacterial properties of TTO-SLN and TTO-CS against P. aeruginosa and S. aureus. The TTO-SLN nanoparticles showed a clear round shape with the average diameter size of 477 nm, while the TTO-CS nanoparticles illustrated very homogeneous morphology with 144 nm size. The encapsulation efficiency for TTO-CS and TTO-SLN was ∼88.3% and 73.5%, respectively. Minimum inhibitory concentration against S. aureus and P. aeruginosa for TTO-CS, TTO-SLN, and pure TTO were 35 and 45 µg ml-1, 130 and 170 µg ml-1, and 380 and 410 µg ml-1, respectively. Since TTO-CS revealed an impressively higher antimicrobial effects in comparison with TTO-SLN and TTO alone, it can be considered as a nanocarrier that produces the same antimicrobial effects with lower required amounts of the active substance.
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Affiliation(s)
- Hasti Vase
- Department of Pharmaceutics, School of Pharmacy, Guilan University of Medical Sciences, 73774-41941 Rasht, Iran
| | - Mehran Nemattalab
- Department of Pharmaceutics, School of Pharmacy, Guilan University of Medical Sciences, 73774-41941 Rasht, Iran
- Department of Microbiology, School of Medicine, Guilan University of Medical Sciences, 73774-41941 Rasht, Iran
| | - Masoumeh Rohani
- Department of Pharmaceutics, School of Pharmacy, Guilan University of Medical Sciences, 73774-41941 Rasht, Iran
| | - Zahra Hesari
- Department of Pharmaceutics, School of Pharmacy, Guilan University of Medical Sciences, 73774-41941 Rasht, Iran
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9
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Lade H, Kim JS. Molecular Determinants of β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus (MRSA): An Updated Review. Antibiotics (Basel) 2023; 12:1362. [PMID: 37760659 PMCID: PMC10525618 DOI: 10.3390/antibiotics12091362] [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: 08/07/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
The development of antibiotic resistance in Staphylococcus aureus, particularly in methicillin-resistant S. aureus (MRSA), has become a significant health concern worldwide. The acquired mecA gene encodes penicillin-binding protein 2a (PBP2a), which takes over the activities of endogenous PBPs and, due to its low affinity for β-lactam antibiotics, is the main determinant of MRSA. In addition to PBP2a, other genetic factors that regulate cell wall synthesis, cell signaling pathways, and metabolism are required to develop high-level β-lactam resistance in MRSA. Although several genetic factors that modulate β-lactam resistance have been identified, it remains unclear how they alter PBP2a expression and affect antibiotic resistance. This review describes the molecular determinants of β-lactam resistance in MRSA, with a focus on recent developments in our understanding of the role of mecA-encoded PBP2a and on other genetic factors that modulate the level of β-lactam resistance. Understanding the molecular determinants of β-lactam resistance can aid in developing novel strategies to combat MRSA.
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Affiliation(s)
| | - Jae-Seok Kim
- Department of Laboratory Medicine, Hallym University College of Medicine, Kangdong Sacred Heart Hospital, Seoul 05355, Republic of Korea;
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10
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Chen Z, Yan Y, Lu C, Lin X, Fu Z, Shi W, Guo F. Photocatalytic Self-Fenton System of g-C 3N 4-Based for Degradation of Emerging Contaminants: A Review of Advances and Prospects. Molecules 2023; 28:5916. [PMID: 37570886 PMCID: PMC10421113 DOI: 10.3390/molecules28155916] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/31/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023] Open
Abstract
The discharge of emerging pollutants in the industrial process poses a severe threat to the ecological environment and human health. Photocatalytic self-Fenton technology combines the advantages of photocatalysis and Fenton oxidation technology through the in situ generation of hydrogen peroxide (H2O2) and interaction with iron (Fe) ions to generate a large number of strong reactive oxygen species (ROS) to effectively degrade pollutants in the environment. Graphite carbon nitride (g-C3N4) is considered as the most potential photocatalytic oxygen reduction reaction (ORR) photocatalyst for H2O2 production due to its excellent chemical/thermal stability, unique electronic structure, easy manufacturing, and moderate band gap (2.70 eV). Hence, in this review, we briefly introduce the advantages of the photocatalytic self-Fenton and its degradation mechanisms. In addition, the modification strategy of the g-C3N4-based photocatalytic self-Fenton system and related applications in environmental remediation are fully discussed and summarized in detail. Finally, the prospects and challenges of the g-C3N4-based photocatalytic self-Fenton system are discussed. We believe that this review can promote the construction of novel and efficient photocatalytic self-Fenton systems as well as further application in environmental remediation and other research fields.
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Affiliation(s)
- Zhouze Chen
- School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China (Y.Y.)
| | - Yujie Yan
- School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China (Y.Y.)
| | - Changyu Lu
- School of Water Resource and Environment, Hebei Province Key Laboratory of Sustained Utilization and Development of Water Recourse, Hebei Geo University, Shijiazhuang 050031, China
| | - Xue Lin
- School of Material Science and Engineering, Beihua University, Jilin 132013, China
| | - Zhijing Fu
- School of Water Resource and Environment, Hebei Province Key Laboratory of Sustained Utilization and Development of Water Recourse, Hebei Geo University, Shijiazhuang 050031, China
| | - Weilong Shi
- School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China (Y.Y.)
| | - Feng Guo
- School of Energy and Power, Jiangsu University of Science and Technology, Zhenjiang 212003, China
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11
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Jun I, Cohen SA, Ser SE, Marini S, Lucero RJ, Bian J, Prosperi M. Optimizing Dynamic Antibiotic Treatment Strategies against Invasive Methicillin-Resistant Staphylococcus Aureus Infections using Causal Survival Forests and G-Formula on Statewide Electronic Health Record Data. PROCEEDINGS OF MACHINE LEARNING RESEARCH 2023; 218:98-115. [PMID: 37854935 PMCID: PMC10584043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Developing models for individualized, time-varying treatment optimization from observational data with large variable spaces, e.g., electronic health records (EHR), is problematic because of inherent, complex bias that can change over time. Traditional methods such as the g-formula are robust, but must identify critical subsets of variables due to combinatorial issues. Machine learning approaches such as causal survival forests have fewer constraints and can provide fine-tuned, individualized counterfactual predictions. In this study, we aimed to optimize time-varying antibiotic treatment -identifying treatment heterogeneity and conditional treatment effects- against invasive methicillin-resistant Staphylococcus Aureus (MRSA) infections, using statewide EHR data collected in Florida, USA. While many previous studies focused on measuring the effects of the first empiric treatment (i.e., usually vancomycin), our study focuses on dynamic sequential treatment changes, comparing possible vancomycin switches with other antibiotics at clinically relevant time points, e.g., after obtaining a bacterial culture and susceptibility testing. Our study population included adult individuals admitted to the hospital with invasive MRSA. We collected demographic, clinical, medication, and laboratory information from the EHR for these patients. Then, we followed three sequential antibiotic choices (i.e., their empiric treatment, subsequent directed treatment, and final sustaining treatment), evaluating 30-day mortality as the outcome. We applied both causal survival forests and g-formula using different clinical intervention policies. We found that switching from vancomycin to another antibiotic improved survival probability, yet there was a benefit from initiating vancomycin compared to not using it at any time point. These findings show consistency with the empiric choice of vancomycin before confirmation of MRSA and shed light on how to manage switches on course. In conclusion, this application of causal machine learning on EHR demonstrates utility in modeling dynamic, heterogeneous treatment effects that cannot be evaluated precisely using randomized clinical trials.
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Affiliation(s)
- Inyoung Jun
- Department of Epidemiology, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32610, USA
| | - Scott A Cohen
- Department of Epidemiology, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32610, USA
| | - Sarah E Ser
- Department of Epidemiology, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32610, USA
| | - Simone Marini
- Department of Epidemiology, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32610, USA
| | - Robert J Lucero
- School of Nursing, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jiang Bian
- Department of Health Outcomes and Biomedical Informatics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mattia Prosperi
- Department of Epidemiology, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32610, USA
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