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Wagner TM, Pöntinen AK, Al Rubaye M, Sundsfjord A, Hegstad K. Adaptive cell wall thickening in Enterococcus faecalis is associated with decreased vancomycin susceptibility. Clin Microbiol Infect 2024; 30:396.e1-396.e5. [PMID: 38065364 DOI: 10.1016/j.cmi.2023.12.002] [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: 05/05/2023] [Revised: 11/28/2023] [Accepted: 12/02/2023] [Indexed: 12/25/2023]
Abstract
OBJECTIVES Enterococcus faecalis can adopt both a commensal and a nosocomial lifestyle, resisting numerous antibiotics. In this study, we aim to investigate the relationship between the cell wall (CW) thickness and decreased susceptibility to vancomycin (VD) in van-gene negative clinical isolates of E. faecalis (nMIC 8 = 2, nMIC 4 = 3, ST30, ST40, and ST59). METHODS The CW thickness was assessed in VD strains and compared with vancomycin susceptible isolates of the same sequence type (ST) (Vancomycin susceptible [VS]; nMIC 2 = 5). The VD and VS strains were subjected to serial passage (evolved [ev]) with and without vancomycin selection. Subsequent measurements of CW thickness and vancomycin MICs were performed. RESULTS The VD strains exhibited increased CW thickness when compared with ST-related VS strains (ΔCW thickness VD vs. VS ST30 25 nm, ST59 15 nm, and ST40 1 nm). Serial passages without vancomycin selection led to a decrease in CW thickness and vancomycin MIC in VD strains (ΔCW thickness VD vs. evVD ST30 22 nm, ST59 3 nm, and ST40 2 nm). Serial passages with vancomycin selection caused an increase in CW thickness and vancomycin MIC in ST-related VS strains (ΔCW thickness VS vs. evVS ST30 22 nm, ST59 16 nm, and ST40 1 nm). DISCUSSION Adaptive changes in CW thickness were observed in response to vancomycin exposure. Increased CW thickness correlated with decreased vancomycin susceptibility, whereas decreased CW thickness correlated with increased vancomycin susceptibility. Core single nucleotide polymorphisms in the evolved mutants were mostly found in genes encoding proteins associated with the cytoplasm or the cytoplasmic membrane. The potential relevance of these adaptive changes is underlined by the observed phenotypes in clinical isolates. Our findings emphasize the importance of monitoring adaptive changes, as vancomycin-resistant enterococci infections are a growing concern.
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Affiliation(s)
- Theresa Maria Wagner
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Anna K Pöntinen
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway; Department of Biostatistics, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Mushtaq Al Rubaye
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Arnfinn Sundsfjord
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - Kristin Hegstad
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway.
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Azuma T, Usui M, Hayashi T. Inactivation of antibiotic-resistant bacteria in hospital wastewater by ozone-based advanced water treatment processes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167432. [PMID: 37777130 DOI: 10.1016/j.scitotenv.2023.167432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/14/2023] [Accepted: 09/26/2023] [Indexed: 10/02/2023]
Abstract
The emergence and spread of antimicrobial resistance (AMR) continue on a global scale. The impacts of wastewater on the environment and human health have been identified, and understanding the environmental impacts of hospital wastewater and exploring appropriate forms of treatment are major societal challenges. In the present research, we evaluated the efficacy of ozone (O3)-based advanced wastewater treatment systems (O3, O3/H2O2, O3/UV, and O3/UV/H2O2) for the treatment of antimicrobials, antimicrobial-resistant bacteria (AMRB), and antimicrobial resistance genes (AMRGs) in wastewater from medical facilities. Our results indicated that the O3-based advanced wastewater treatment inactivated multiple antimicrobials (>99.9%) and AMRB after 10-30 min of treatment. Additionally, AMRGs were effectively removed (1.4-6.6 log10) during hospital wastewater treatment. The inactivation and/or removal performances of these pollutants through the O3/UV and O3/UV/H2O2 treatments were significantly (P < 0.05) better than those in the O3 and O3/H2O2 treatments. Altered taxonomic diversity of microorganisms based on 16S rRNA gene sequencing following the O3-based treatment showed that advanced wastewater treatments not only removed viable bacteria but also removed genes constituting microorganisms in the wastewater. Consequently, the objective of this study was to apply advanced wastewater treatments to treat wastewater, mitigate environmental pollution, and alleviate potential threats to environmental and human health associated with AMR. Our findings will contribute to enhancing the effectiveness of advanced wastewater treatment systems through on-site application, not only in wastewater treatment plants (WWTPs) but also in medical facilities. Moreover, our results will help reduce the discharge of AMRB and AMRGs into rivers and maintain the safety of aquatic environments.
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Affiliation(s)
- Takashi Azuma
- Department of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
| | - Masaru Usui
- Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyodai, Ebetsu, Hokkaido 069-8501, Japan
| | - Tetsuya Hayashi
- Department of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan; Faculty of Human Development, Department of Food and Nutrition Management Studies, Soai University, 4-4-1 Nankonaka, Osaka Suminoeku, Osaka 559-0033, Japan
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Chen X, Chen Z, Ngo HH, Mao Y, Cao K, Shi Q, Lu Y, Hu HY. Comparison of inactivation characteristics between Gram-positive and Gram-negative bacteria in water by synergistic UV and chlorine disinfection. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:122007. [PMID: 37302789 DOI: 10.1016/j.envpol.2023.122007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/23/2023] [Accepted: 06/08/2023] [Indexed: 06/13/2023]
Abstract
Disinfection is essential in water and wastewater treatment process as a guarantee for microbial safety. This study systematically investigated: (i) the inactivation characteristics of bacteria widely existed in water, including Gram-negative bacteria (Escherichiacoli) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis spores), by sequential UV and chlorine disinfection processes (UV-Cl and Cl-UV), simultaneous UV and chlorine disinfection process (UV/Cl); and (ii) the disinfection mechanisms on different bacteria. The combination of UV and chlorine disinfection could inactive bacteria at lower doses, but showed no synergistic effect on E. coli. Contrarily, disinfection results indicated that UV/Cl performed an obvious synergistic effect on highly disinfectant-resistant bacteria (e.g. S. aureus and B. subtilis spores). Specifically, UV/Cl at the UV dose of 9 mJ/cm2 and chlorine dose of 2 mg-Cl/L could inactivate S. aureus completely. Moreover, the effectiveness of UV/Cl on the removal of indigenous bacteria in actual water conditions was also confirmed. In short, the study provides significant theoretical and practical implications for ensuring microbial safety during water treatment and use.
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Affiliation(s)
- Xiaowen Chen
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China
| | - Zhuo Chen
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing, 100084, PR China.
| | - Huu Hao Ngo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW, 2007, Australia
| | - Yu Mao
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China
| | - Kefan Cao
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China
| | - Qi Shi
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China
| | - Yun Lu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing, 100084, PR China
| | - Hong-Ying Hu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing, 100084, PR China; Research Institute for Environmental Innovation (Suzhou), Tsinghua, Jiangsu, Suzhou, 215163, PR China
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Rozaini AZA, Abdulhameed A, Deivasigamani R, Nadzreen N, Zin NM, Kayani AA, Buyong MR. Dielectrophoresis microbial characterization and isolation of Staphylococcus aureus based on optimum crossover frequency. Electrophoresis 2023; 44:1220-1233. [PMID: 37259263 DOI: 10.1002/elps.202200276] [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: 08/01/2022] [Revised: 04/19/2023] [Accepted: 04/29/2023] [Indexed: 06/02/2023]
Abstract
Characterization of antibiotic-resistant bacteria is a significant concern that persists for the rapid classification and analysis of the bacteria. A technology that utilizes the manipulation of antibiotic-resistant bacteria is key to solving the significant threat of these pathogenic bacteria by rapid characterization profile. Dielectrophoresis (DEP) can differentiate between antibiotic-resistant and susceptible bacteria based on their physical structure and polarization properties. In this work, the DEP response of two Gram-positive bacteria, namely, Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible S. aureus (MSSA), was investigated and simulated. The DEP characterization was experimentally observed on the bacteria influenced by oxacillin and vancomycin antibiotics. MSSA control without antibiotics has crossover frequencies (f x 0 ${f_{x0}}$ ) from 6 to 8 MHz, whereas MRSA control is from 2 to 3 MHz. Thef x 0 ${f_{x0}}$ changed when bacteria were exposed to the antibiotic. As for MSSA, thef x 0 ${f_{x0}}$ decreased to 3.35 MHz compared tof x 0 ${f_{x0}}$ MSSA control without antibiotics, MRSA,f x 0 ${f_{x0}}$ increased to 7 MHz when compared to MRSA control. The changes in the DEP response of MSSA and MRSA with and without antibiotics were theoretically proven using MyDEP and COMSOL simulation and experimentally based on the modification to the bacteria cell walls. Thus, the DEP response can be employed as a label-free detectable method to sense and differentiate between resistant and susceptible strains with different antibiotic profiles. The developed method can be implemented on a single platform to analyze and identify bacteria for rapid, scalable, and accurate characterization.
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Affiliation(s)
- Arash Zulkarnain Ahmad Rozaini
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
- Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Abdullah Abdulhameed
- Center for Communication Systems and Sensing, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
| | - Revathy Deivasigamani
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Nurulhuda Nadzreen
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Noraziah Mohamad Zin
- Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Amin Ahmad Kayani
- Functional Materials and Microsystems Research Group and the Micro Nano Research Facility, RMIT University, Melbourne, Australia
- ARC Research Hub for Connected Sensors for Health, RMIT University, Melbourne, Australia
| | - Muhamad Ramdzan Buyong
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
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Staphylococcus aureus Cell Wall Phenotypic Changes Associated with Biofilm Maturation and Water Availability: A Key Contributing Factor for Chlorine Resistance. Int J Mol Sci 2023; 24:ijms24054983. [PMID: 36902413 PMCID: PMC10003762 DOI: 10.3390/ijms24054983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 02/25/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Staphylococcus aureus biofilms are resistant to both antibiotics and disinfectants. As Staphylococci cell walls are an important defence mechanism, we sought to examine changes to the bacterial cell wall under different growth conditions. Cell walls of S. aureus grown as 3-day hydrated biofilm, 12-day hydrated biofilm, and 12-day dry surface biofilm (DSB) were compared to cell walls of planktonic organisms. Additionally, proteomic analysis using high-throughput tandem mass tag-based mass spectrometry was performed. Proteins involved in cell wall synthesis in biofilms were upregulated in comparison to planktonic growth. Bacterial cell wall width (measured by transmission electron microscopy) and peptidoglycan production (detected using a silkworm larva plasma system) increased with biofilm culture duration (p < 0.001) and dehydration (p = 0.002). Similarly, disinfectant tolerance was greatest in DSB, followed by 12-day hydrated biofilm and then 3-day biofilm, and it was least in the planktonic bacteria--suggesting that changes to the cell wall may be a key factor for S. aureus biofilm biocide resistance. Our findings shed light on possible new targets to combat biofilm-related infections and hospital dry surface biofilms.
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Ahmad N, Joji RM, Shahid M. Evolution and implementation of One Health to control the dissemination of antibiotic-resistant bacteria and resistance genes: A review. Front Cell Infect Microbiol 2023; 12:1065796. [PMID: 36726644 PMCID: PMC9884834 DOI: 10.3389/fcimb.2022.1065796] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 12/16/2022] [Indexed: 01/19/2023] Open
Abstract
Antibiotic resistance is a serious threat to humanity and its environment. Aberrant usage of antibiotics in the human, animal, and environmental sectors, as well as the dissemination of resistant bacteria and resistance genes among these sectors and globally, are all contributing factors. In humans, antibiotics are generally used to treat infections and prevent illnesses. Antibiotic usage in food-producing animals has lately emerged as a major public health concern. These medicines are currently being utilized to prevent and treat infectious diseases and also for its growth-promoting qualities. These methods have resulted in the induction and spread of antibiotic resistant infections from animals to humans. Antibiotics can be introduced into the environment from a variety of sources, including human wastes, veterinary wastes, and livestock husbandry waste. The soil has been recognized as a reservoir of ABR genes, not only because of the presence of a wide and varied range of bacteria capable of producing natural antibiotics but also for the usage of natural manure on crop fields, which may contain ABR genes or antibiotics. Fears about the human health hazards of ABR related to environmental antibiotic residues include the possible threat of modifying the human microbiota and promoting the rise and selection of resistant bacteria, and the possible danger of generating a selection pressure on the environmental microflora resulting in environmental antibiotic resistance. Because of the connectivity of these sectors, antibiotic use, antibiotic residue persistence, and the existence of antibiotic-resistant bacteria in human-animal-environment habitats are all linked to the One Health triangle. The pillars of support including rigorous ABR surveillance among different sectors individually and in combination, and at national and international level, overcoming laboratory resource challenges, and core plan and action execution should be strictly implemented to combat and contain ABR under one health approach. Implementing One Health could help to avoid the emergence and dissemination of antibiotic resistance while also promoting a healthier One World. This review aims to emphasize antibiotic resistance and its regulatory approaches from the perspective of One Health by highlighting the interconnectedness and multi-sectoral nature of the human, animal, and environmental health or ill-health facets.
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Azuma T, Murakami M, Sonoda Y, Ozaki A, Hayashi T. Occurrence and Quantitative Microbial Risk Assessment of Methicillin-Resistant Staphylococcus aureus (MRSA) in a Sub-Catchment of the Yodo River Basin, Japan. Antibiotics (Basel) 2022; 11:antibiotics11101355. [PMID: 36290013 PMCID: PMC9598951 DOI: 10.3390/antibiotics11101355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/24/2022] Open
Abstract
The occurrence of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) in a sub-catchment of the Yodo River Basin, a representative water system of a drinking water source in Japan, was investigated. The chromogenic enzyme-substrate medium method was used for the detection of S. aureus and MRSA by the presence or absence of antimicrobials in the medium for viable bacteria in a culture-based setting. The contributions of S. aureus and MRSA from wastewater to the rivers were estimated based on mass flux-based analysis, and quantitative microbial risk assessment (QMRA) was further conducted for S. aureus and MRSA in river environments. The mean abundance of S. aureus and MRSA was 31 and 29 CFU/mL in hospital effluent, 124 and 117 CFU/mL in sewage treatment plant (STP) influent, 16 and 13 CFU/mL in STP effluent, and 8 and 9 CFU/mL in river water, respectively. Contribution of the pollution load derived from the target STP effluent to river water ranged from 2% to 25%. The QMRA showed that to achieve the established health benchmarks, the drinking water treatment process would need to yield 1.7 log10 and 2.9 log10 inactivation in terms of infection risk and disability-adjusted life year (DALY) indexes, respectively. These findings highlight the link between medical environment and the importance of environmental risk management for antimicrobial-resistant bacteria in aquatic environments.
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Affiliation(s)
- Takashi Azuma
- Department of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki 569-1094, Japan
- Correspondence: ; Tel./Fax: +81-72-690-1055
| | - Michio Murakami
- Center for Infectious Disease Education and Research (CiDER), Osaka University, Techno Alliance C209, 2-8 Yamadaoka, Suita 565-0871, Japan
| | - Yuki Sonoda
- Nursing Unit, Jyoban Hospital of Tokiwa Foundation, 57 Kaminodai, Jyoban-Kamiyunaga-Yamachi, Iwaki 972-8322, Japan
| | - Akihiko Ozaki
- Department of Breast and Thyroid Surgery, Jyoban Hospital of Tokiwa Foundation, 57 Kaminodai, Jyoban-Kamiyunaga-Yamachi, Iwaki 972-8322, Japan
- Department of Gastrointestinal Tract Surgery, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan
| | - Tetsuya Hayashi
- Department of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki 569-1094, Japan
- Department of Food and Nutrition Management Studies, Faculty of Human Development, Soai University, 4-4-1 Nankonaka, Osaka 559-0033, Japan
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Dysregulation of Cell Envelope Homeostasis in Staphylococcus aureus Exposed to Solvated Lignin. Appl Environ Microbiol 2022; 88:e0054822. [PMID: 35852361 PMCID: PMC9361832 DOI: 10.1128/aem.00548-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Lignin is an aromatic plant cell wall polymer that facilitates water transport through the vasculature of plants and is generated in large quantities as an inexpensive by-product of pulp and paper manufacturing and biorefineries. Although lignin's ability to reduce bacterial growth has been reported previously, its hydrophobicity complicates the ability to examine its biological effects on living cells in aqueous growth media. We recently described the ability to solvate lignin in Good's buffers with neutral pH, a breakthrough that allowed examination of lignin's antimicrobial effects against the human pathogen Staphylococcus aureus. These analyses showed that lignin damages the S. aureus cell membrane, causes increased cell clustering, and inhibits growth synergistically with tunicamycin, a teichoic acid synthesis inhibitor. In the present study, we examined the physiological and transcriptomic responses of S. aureus to lignin. Intriguingly, lignin restored the susceptibility of genetically resistant S. aureus isolates to penicillin and oxacillin, decreased intracellular pH, impaired normal cell division, and rendered cells more resistant to detergent-induced lysis. Additionally, transcriptome sequencing (RNA-Seq) differential expression (DE) analysis of lignin-treated cultures revealed significant gene expression changes (P < 0.05 with 5% false discovery rate [FDR]) related to the cell envelope, cell wall physiology, fatty acid metabolism, and stress resistance. Moreover, a pattern of concurrent up- and downregulation of genes within biochemical pathways involved in transmembrane transport and cell wall physiology was observed, which likely reflects an attempt to tolerate or compensate for lignin-induced damage. Together, these results represent the first comprehensive analysis of lignin's antibacterial activity against S. aureus. IMPORTANCE S. aureus is a leading cause of skin and soft tissue infections. The ability of S. aureus to acquire genetic resistance to antibiotics further compounds its ability to cause life-threatening infections. While the historical response to antibiotic resistance has been to develop new antibiotics, bacterial pathogens are notorious for rapidly acquiring genetic resistance mechanisms. As such, the development of adjuvants represents a viable way of extending the life span of current antibiotics to which pathogens may already be resistant. Here, we describe the phenotypic and transcriptomic response of S. aureus to treatment with lignin. Our results demonstrate that lignin extracted from sugarcane and sorghum bagasse restores S. aureus susceptibility to β-lactams, providing a premise for repurposing these antibiotics in treatment of resistant S. aureus strains, possibly in the form of topical lignin/β-lactam formulations.
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Awad M, Barnes TJ, Joyce P, Thomas N, Prestidge CA. Liquid crystalline lipid nanoparticle promotes the photodynamic activity of gallium protoporphyrin against S. aureus biofilms. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 232:112474. [PMID: 35644068 DOI: 10.1016/j.jphotobiol.2022.112474] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/04/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Antimicrobial photodynamic therapy (aPDT) has emerged as an innovative strategy to combat antibiotic resistant microbes; yet aPDT efficacies against biofilms are sub-optimal due to inability of photosenstizers to reach microbes embedded in biofilm matrix. To overcome this challenge, liquid crystal lipid nanoparticles (LCNP) were employed in this study as a smart, biocompatible and triggerable delivery system for the new photosensitizer gallium protoporphyrin (GaPP), due to their capabilities in promoting efficient antimicrobial delivery to biofilms. The relationship between GaPP loading of LCNP, reactive oxygen species (ROS) production and the in vitro antibacterial activity against two antibiotic resistant Staphylococcus aureus strains was established. LCNP substantially improved the antibacterial activity of GaPP, completely eradicating S. aureus and MRSA planktonic cultures, using a GaPP concentration of 0.8 μM and light dose 1.9 J/cm2. At the same concentration and light dose, unformulated GaPP triggered only a 4 log10 and 2 log10 reduction in respective planktonic cultures. Most importantly, the activity of GaPP against biofilms was enhanced by 2-fold compared to unformulated GaPP, reducing the viability of S. aureus and MRSA biofilms by 8 log10 and 5 log10, respectively. The biosafety of photoactivated GaPP-LCNP was evaluated against human fibroblasts, which indicated a high safety profile of the treatment. Therefore, these findings encourage further investigations of GaPP-LCNP as a potential treatment for localized chronic infections.
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Affiliation(s)
- Muhammed Awad
- Centre for Pharmaceutical Innovation, University of South Australia, Clinical and Health Sciences, Adelaide 5000, Australia; Basil Hetzel Institute for Translational Health Research, Woodville 5011, Australia.
| | - Timothy J Barnes
- Centre for Pharmaceutical Innovation, University of South Australia, Clinical and Health Sciences, Adelaide 5000, Australia.
| | - Paul Joyce
- Centre for Pharmaceutical Innovation, University of South Australia, Clinical and Health Sciences, Adelaide 5000, Australia.
| | - Nicky Thomas
- Centre for Pharmaceutical Innovation, University of South Australia, Clinical and Health Sciences, Adelaide 5000, Australia; Basil Hetzel Institute for Translational Health Research, Woodville 5011, Australia.
| | - Clive A Prestidge
- Centre for Pharmaceutical Innovation, University of South Australia, Clinical and Health Sciences, Adelaide 5000, Australia.
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Antistaphylococcal Activities and ADME-Related Properties of Chlorinated Arylcarbamoylnaphthalenylcarbamates. Pharmaceuticals (Basel) 2022; 15:ph15060715. [PMID: 35745634 PMCID: PMC9228535 DOI: 10.3390/ph15060715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 05/29/2022] [Accepted: 06/02/2022] [Indexed: 02/01/2023] Open
Abstract
Pattern 1-hydroxy-N-(2,4,5-trichlorophenyl)-2-naphthamide and the thirteen original carbamates derived from it were prepared and characterized. All the compounds were tested against Staphylococcus aureus ATCC 29213 as a reference and quality control strain and in addition against three clinical isolates of methicillin-resistant S. aureus (MRSA). Moreover, the compounds were evaluated against Enterococcus faecalis ATCC 29212, and preliminary in vitro cytotoxicity of the compounds was assessed using the human monocytic leukemia cell line (THP-1). The lipophilicity of the prepared compounds was experimentally determined and correlated with biological activity. While pattern anilide had no antibacterial activity, the prepared carbamates demonstrated high antistaphylococcal activity comparable to the used standards (ampicillin and ciprofloxacin), which unfortunately were ineffective against E. feacalis. 2-[(2,4,5-Trichlorophenyl)carba- moyl]naphthalen-1-yl ethylcarbamate (2) and 2-[(2,4,5-trichlorophenyl)carbamoyl]naphthalen-1-yl butylcarbamate (4) expressed the nanomolar minimum inhibitory concentrations (MICs 0.018−0.064 μM) against S. aureus and at least two other MRSA isolates. Microbicidal effects based on the minimum bactericidal concentrations (MBCs) against all the tested staphylococci were found for nine carbamates, while 2-[(2,4,5-trichlorophenyl)carbamoyl]naphthalen-1-yl heptylcarbamate (7) and 2-[(2,4,5-trichlorophenyl)carbamoyl]naphthalen-1-yl (4-phenylbutyl)carbamate (14) demonstrated MBCs in the range of 0.124−0.461 μM. The selectivity index (SI) for most investigated carbamates was >20 and for some derivatives even >100. The performed tests did not show an effect on the damage to the bacterial membrane, while the compounds were able to inhibit the respiratory chain of S. aureus.
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Inactivation of Antibiotic-Resistant Bacteria in Wastewater by Ozone-Based Advanced Water Treatment Processes. Antibiotics (Basel) 2022; 11:antibiotics11020210. [PMID: 35203813 PMCID: PMC8868322 DOI: 10.3390/antibiotics11020210] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/27/2022] [Accepted: 02/05/2022] [Indexed: 02/07/2023] Open
Abstract
The inactivating effect of ozone (O3)-based advanced oxidation processes (AOPs) (O3/H2O2, O3/UV, and O3/UV/H2O2 systems) on antimicrobial-resistant bacteria (AMRB) and antimicrobial-susceptible bacteria (AMSB) in sewage treatment plant (STP) wastewater was investigated. The AMRB were grouped into six classes: carbapenem-resistant Enterobacteriaceae (CRE), extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E), multidrug-resistant Acinetobacter (MDRA), multidrug-resistant Pseudomonas aeruginosa (MDRP), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE); these classes constituted the World Health Organization (WHO) global priority list of AMRB. The results indicate that O3-based advanced wastewater treatment inactivated all AMRB and AMSB (>99.9%) after 10 min of treatment, and significant differences (p < 0.5) were not observed in the disinfection of AMRB and AMSB by each treatment. Altered taxonomic diversity of micro-organisms based on 16S rRNA gene sequencing via O3/UV and O3/UV/H2O2 treatment showed that advanced wastewater treatments not only inactivated AMRB but also removed antimicrobial resistance genes (AMRGs) in the wastewater. Consequently, this study recommends the use of advanced wastewater treatments for treating the STP effluent, reducing environmental pollution, and alleviating the potential hazard to human health caused by AMRB, AMSB, and infectious diseases. Overall, this study provides a new method for assessing environmental risks associated with the spread of AMRB and AMSB in aquatic environments, while keeping the water environment safe and maintaining human health.
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Tu H, Xu F, Cheng Y, Pan Q, Cai X, Wang S, Ge S, Cao M, Su D, Li Y. Proteomic profiling of the endogenous peptides of MRSA and MSSA. PeerJ 2021; 9:e12508. [PMID: 34900427 PMCID: PMC8627652 DOI: 10.7717/peerj.12508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/26/2021] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is a Gram-positive bacterium that can cause diverse skin and soft tissue infections. Methicillin-resistant Staphylococcus aureus (MRSA) can cause more severe infections than methicillin-susceptible Staphylococcus aureus (MSSA). Nevertheless, the physiological and metabolic regulation of MSSA and MRSA has not been well studied. In light of the increased interest in endogenous peptides and recognition of the important roles that they play, we studied the endogenous peptidome of MSSA and MRSA. We identified 1,065 endogenous peptides, among which 435 were differentially expressed (DE), with 292 MSSA-abundant endogenous peptides and 35 MRSA-abundant endogenous peptides. MSSA-abundant endogenous peptides have significantly enriched “VXXXK” motif of at the C-terminus. MSSA-abundant endogenous peptides are involved in penicillin-binding and immune responses, whereas MRSA-abundant endogenous peptides are associated with antibiotic resistance and increased toxicity. Our characterization of the peptidome of MSSA and MRSA provides a rich resource for future studies to explore the functional regulation of drug resistance in S. aureus and may also help elucidate the mechanisms of its pathogenicity and the development of treatments.
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Affiliation(s)
- Haixia Tu
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Fei Xu
- Blood Transfusion Department, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Yiwei Cheng
- School of Basic Medicine, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Qianglong Pan
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Xiao Cai
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Shouxing Wang
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Shuting Ge
- School of Basic Medicine, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Min Cao
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Dongming Su
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Yan Li
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
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Tram NDT, Selvarajan V, Boags A, Mukherjee D, Marzinek JK, Cheng B, Jiang ZC, Goh P, Koh JJ, Teo JWP, Bond PJ, Ee PLR. Manipulating turn residues on de novo designed β-hairpin peptides for selectivity against drug-resistant bacteria. Acta Biomater 2021; 135:214-224. [PMID: 34506975 DOI: 10.1016/j.actbio.2021.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 11/19/2022]
Abstract
Synthetic β-hairpin antimicrobial peptides (AMPs) offer a useful source for the development of novel antimicrobial agents. β-hairpin peptides generally consist of two side strands bridged by a reverse turn. In literature, most studies focused on the modifications of the side strands to manipulate the stability and activity of β-hairpin peptides, and much less is known about the impact of the turn region. By designing a series of de novo β-hairpin peptides with identical side strands but varied turns, we demonstrated that mutations of only 2 to 4 amino acids at the turn region could impart a wide range of antimicrobial profiles among synthetic β-hairpin AMPs. BTT2-4 and BTT6 displayed selective potency against Gram-negative bacteria, with minimum inhibitory concentrations (MICs) of 4-8 µM. In contrast, BTT1 exhibited broad-spectrum activity, with MICs of 4-8 µM against both Gram-positive and Gram-negative strains. Additionally, BTT1 was potent against methicillin-resistant Staphylococcus aureus (MRSA) and colistin-resistant Enterobacterales. The antimicrobial potency of BTT1 persisted after 14 days of serial passage. Mechanistic studies revealed that interactions between lipopolysaccharide (LPS) and the peptides were critical to their membranolytic activity against the bacterial inner membrane. Aside from folding stability, we observed that a degree of conformational flexibility was required for disruptive membrane interactions. STATEMENT OF SIGNIFICANCE: By examining the significance of the turn region of β-hairpin peptides, we present valuable knowledge to the design toolkit of novel antimicrobial peptides as alternative therapeutics to overcome antibiotic resistance. Our de novo designed synthetic peptides displayed selective activity against Gram-negative bacteria and potent activity against clinically relevant antibiotic-resistant strains (e.g. colistin-resistant Enterobacterales and methicillin-resistant Staphylococcus aureus). The bactericidal activity of our peptides was shown to be robust in the presence of proteolytic trypsin and saline, conditions that could suppress peptide activity. Our peptides were also determined to be non-cytotoxic against a human cell line.
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Affiliation(s)
- Nhan D T Tram
- Department of Pharmacy, National University of Singapore, 117543, Singapore, Singapore
| | - Vanitha Selvarajan
- Department of Pharmacy, National University of Singapore, 117543, Singapore, Singapore
| | - Alister Boags
- Bioinformatics Institute, Agency of Science, Technology and Research (A*STAR), 138671, Singapore, Singapore; School of Chemistry, University of Southampton, SO17 1BJ, Southampton, United Kingdom
| | - Devika Mukherjee
- Department of Pharmacy, National University of Singapore, 117543, Singapore, Singapore
| | - Jan K Marzinek
- Bioinformatics Institute, Agency of Science, Technology and Research (A*STAR), 138671, Singapore, Singapore
| | - Bernadette Cheng
- Department of Laboratory Medicine, Microbiology Unit, National University Hospital, 119074, Singapore , Singapore
| | - Zi-Chen Jiang
- Department of Pharmacology and Toxicology, University of Toronto, M5S 1A1, Ontario, Canada
| | - Pascal Goh
- Department of Pharmacy, National University of Singapore, 117543, Singapore, Singapore
| | - Jun-Jie Koh
- Department of Pharmacy, National University of Singapore, 117543, Singapore, Singapore
| | - Jeanette W P Teo
- Department of Laboratory Medicine, Microbiology Unit, National University Hospital, 119074, Singapore , Singapore
| | - Peter J Bond
- Bioinformatics Institute, Agency of Science, Technology and Research (A*STAR), 138671, Singapore, Singapore; National University of Singapore, Department of Biological Sciences, 117558, Singapore, Singapore
| | - Pui Lai Rachel Ee
- Department of Pharmacy, National University of Singapore, 117543, Singapore, Singapore; NUS Graduate School for Integrative Sciences and Engineering, 119077, Singapore, Singapore.
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Ciloglu FU, Caliskan A, Saridag AM, Kilic IH, Tokmakci M, Kahraman M, Aydin O. Drug-resistant Staphylococcus aureus bacteria detection by combining surface-enhanced Raman spectroscopy (SERS) and deep learning techniques. Sci Rep 2021; 11:18444. [PMID: 34531449 PMCID: PMC8446005 DOI: 10.1038/s41598-021-97882-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/09/2021] [Indexed: 12/23/2022] Open
Abstract
Over the past year, the world's attention has focused on combating COVID-19 disease, but the other threat waiting at the door-antimicrobial resistance should not be forgotten. Although making the diagnosis rapidly and accurately is crucial in preventing antibiotic resistance development, bacterial identification techniques include some challenging processes. To address this challenge, we proposed a deep neural network (DNN) that can discriminate antibiotic-resistant bacteria using surface-enhanced Raman spectroscopy (SERS). Stacked autoencoder (SAE)-based DNN was used for the rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) bacteria using a label-free SERS technique. The performance of the DNN was compared with traditional classifiers. Since the SERS technique provides high signal-to-noise ratio (SNR) data, some subtle differences were found between MRSA and MSSA in relative band intensities. SAE-based DNN can learn features from raw data and classify them with an accuracy of 97.66%. Moreover, the model discriminates bacteria with an area under curve (AUC) of 0.99. Compared to traditional classifiers, SAE-based DNN was found superior in accuracy and AUC values. The obtained results are also supported by statistical analysis. These results demonstrate that deep learning has great potential to characterize and detect antibiotic-resistant bacteria by using SERS spectral data.
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Affiliation(s)
- Fatma Uysal Ciloglu
- Department of Biomedical Engineering, Erciyes University, 38039, Kayseri, Turkey
| | - Abdullah Caliskan
- IMaR Technology Gateway, Munster Technological University, Kerry, Ireland.,Department of Biomedical Engineering, Iskenderun Technical University, 31200, Hatay, Turkey
| | - Ayse Mine Saridag
- Department of Chemistry, Gaziantep University, 27310, Gaziantep, Turkey
| | | | - Mahmut Tokmakci
- Department of Biomedical Engineering, Erciyes University, 38039, Kayseri, Turkey
| | - Mehmet Kahraman
- Department of Chemistry, Gaziantep University, 27310, Gaziantep, Turkey.
| | - Omer Aydin
- Department of Biomedical Engineering, Erciyes University, 38039, Kayseri, Turkey. .,ERNAM-Nanotechnology Research and Application Center, Erciyes University, 38039, Kayseri, Turkey. .,ERKAM-Clinical Engineering Research and Application Center, Erciyes University, 38040, Kayseri, Turkey.
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Azuma T, Hayashi T. On-site chlorination responsible for effective disinfection of wastewater from hospital. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 776:145951. [PMID: 33647640 DOI: 10.1016/j.scitotenv.2021.145951] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/30/2021] [Accepted: 02/14/2021] [Indexed: 05/10/2023]
Abstract
Both hospital effluent and a model sewage treatment plant (STP) wastewater prepared by mixing STP influent and STP secondary effluent at a volume ratio of 1:9 were directly treated with chlorine for investigation of their effects on disinfection of antimicrobial-resistant bacteria (AMRB) and antimicrobial-susceptible bacteria (AMSB). The overall results indicate that the chlorine disinfection effectively inactivated the majority of AMRB and AMSB, expect for MRSA and Staphylococcus aureus in both wastewaters. No significant differences could further be observed in the taxonomic diversity of micro-organisms after the treatment. The degrees of disinfection given by the direct chlorination were comparable to those attained by combination of conventional activated sludge process and additional chlorine treatment at the STP. The results of this study evoked a recommendation to operate local chlorination treatment directly for the wastewater from medicinal facilities prior to its flow into the STP as sewage. Although additional disinfection treatment at the STP seems necessary to remove the recalcitrant MRSA and Staphylococcus aureus, the present study desirably contributes to a great reduction of the loads of STP and urgent prevention of spreading of infectious diseases in the present state.
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Affiliation(s)
- Takashi Azuma
- Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
| | - Tetsuya Hayashi
- Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan
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16
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Azuma T, Hayashi T. Effects of natural sunlight on antimicrobial-resistant bacteria (AMRB) and antimicrobial-susceptible bacteria (AMSB) in wastewater and river water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 766:142568. [PMID: 33066962 DOI: 10.1016/j.scitotenv.2020.142568] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 06/11/2023]
Abstract
The effects of natural sunlight on antimicrobial-resistant bacteria (AMRB) and antimicrobial-susceptible bacteria (AMSB) were investigated in three types of water: sewage treatment plant (STP) influent, STP secondary effluent, and river water in an urban area of Japan. The AMRB were grouped into six classes: carbapenem-resistant Enterobacteriaceae (CRE), extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E), multi-drug-resistant Acinetobacter (MDRA), multi-drug-resistant Pseudomonas aeruginosa (MDRP), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE). The amount of each group of bacteria present was estimated using specific chromogenic agar formulations. AMRB were detected in all water samples, with 13-2,407 colony-forming units (CFU)/mL in the STP influent, N.D. to 202 CFU/mL in the secondary STP effluent, and N.D. to 207 CFU/mL in the river water. The distribution profiles of the AMSB in water samples were similar to those of AMRB. The degree to which AMRB and AMSB present in the river water were inactivated by natural sunlight was tested as the main aim of this study. Irradiation by natural sunlight was found to inactivate almost 100% of all the target AMRB after 5 h of exposure, with no significant differences (P < 0.05) observed in the effects that sunlight had on AMSB and AMRB. Analysis of the bacterial community structure based on 16S rRNA gene sequencing showed that the structure of the bacterial community was apparently not affected by the exposure to sunlight. In addition, the taxonomic diversity in the STP secondary effluent did not change as a result of additional disinfection with chlorine. The results of this study suggest that it is possible that exposure to sunlight could be used as an alternative to disinfection via chlorine. To our knowledge, this is the first report to demonstrate the mitigation of AMSB and AMRB pollution in a river environment via the exposure to natural sunlight.
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Affiliation(s)
- Takashi Azuma
- Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
| | - Tetsuya Hayashi
- Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan
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Xie N, Jiang L, Chen M, Zhang G, Liu Y, Li J, Huang X. In vitro and in vivo Antibacterial Activity of Linezolid Plus Fosfomycin Against Staphylococcus aureus with Resistance to One Drug. Infect Drug Resist 2021; 14:639-649. [PMID: 33658805 PMCID: PMC7917344 DOI: 10.2147/idr.s290332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/14/2021] [Indexed: 12/29/2022] Open
Abstract
Objective The purpose of this study is to assess the in vitro/vivo activities of linezolid plus fosfomycin against Staphylococcus aureus (S. aureus) isolates with varying susceptibility to the study drugs. Methods The increasing concentration stepwise method was used to induce S. aureus resistant strains. The in vitro antibacterial activity of linezolid combined with fosfomycin against S. aureus in vitro was studied by time-kill curve and PAE. The transmission electron microscopy (TEM) was employed to observe the cell morphology of bacteria treated with drug, and the changes of cell wall thickness were recorded. The Galleria mellonella infection model was established to demonstrate the in vivo efficacy of linezolid and fosfomycin against S. aureus with varying susceptibility. Results The antibiotic combination showed excellent synergistic or additive effects on the original and the linezolid-resistant strain, but showed indifferent effect for fosfomycin-resistant strain. TEM images showed that fosfomycin alone and in combined could reduce the cell wall thickness of the strains resistant to linezolid and cell lysis, while linezolid increases the cell wall thickness of the strains resistant to fosfomycin. In the Galleria mellonella infection model, the survival rate of the antibiotic combined was improved compared with that of the single drug. There was a good correlation between in vivo efficacy and in vitro susceptibility. Conclusion The type of interaction expressed in the test combination was highly dependent on fosfomycin resistance.
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Affiliation(s)
- Na Xie
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Lifang Jiang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Mingtao Chen
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Guijun Zhang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Yanyan Liu
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Jiabin Li
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Xiaohui Huang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
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Flowering Poration-A Synergistic Multi-Mode Antibacterial Mechanism by a Bacteriocin Fold. iScience 2020; 23:101423. [PMID: 32795916 PMCID: PMC7424198 DOI: 10.1016/j.isci.2020.101423] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 07/10/2020] [Accepted: 07/27/2020] [Indexed: 11/21/2022] Open
Abstract
Bacteriocins are a distinct family of antimicrobial proteins postulated to porate bacterial membranes. However, direct experimental evidence of pore formation by these proteins is lacking. Here we report a multi-mode poration mechanism induced by four-helix bacteriocins, epidermicin NI01 and aureocin A53. Using a combination of crystallography, spectroscopy, bioassays, and nanoscale imaging, we established that individual two-helix segments of epidermicin retain antibacterial activity but each of these segments adopts a particular poration mode. In the intact protein these segments act synergistically to balance out antibacterial and hemolytic activities. The study sets a precedent of multi-mode membrane disruption advancing the current understanding of structure-activity relationships in pore-forming proteins. Bacteriocins are antibacterial proteins believed to form pores in bacterial membranes A multi-helix bacteriocin fold induces a multi-mode poration mechanism Each of two-helix segments of the bacteriocin adopts a particular poration mode These segments act synergistically balancing out antibacterial and hemolytic activities
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Cetylpyridinium Chloride: Mechanism of Action, Antimicrobial Efficacy in Biofilms, and Potential Risks of Resistance. Antimicrob Agents Chemother 2020; 64:AAC.00576-20. [PMID: 32513792 DOI: 10.1128/aac.00576-20] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Antimicrobial resistance is a serious issue for public health care all over the world. While resistance toward antibiotics has attracted strong interest among researchers and the general public over the last 2 decades, the directly related problem of resistance toward antiseptics and biocides has been somewhat left untended. In the field of dentistry, antiseptics are routinely used in professional care, but they are also included in lots of oral care products such as mouthwashes or dentifrices, which are easily available for consumers over-the-counter. Despite this fact, there is little awareness among the dental community about potential risks of the widespread, unreflected, and potentially even needless use of antiseptics in oral care. Cetylpyridinium chloride (CPC), a quaternary ammonium compound, which was first described in 1939, is one of the most commonly used antiseptics in oral care products and included in a wide range of over-the-counter products such as mouthwashes and dentifrices. The aim of the present review is to summarize the current literature on CPC, particularly focusing on its mechanism of action, its antimicrobial efficacy toward biofilms, and on potential risks of resistance toward this antiseptic as well as underlying mechanisms. Furthermore, this work aims to raise awareness among the dental community about the risk of resistance toward antiseptics in general.
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The Revaluation of Plant-Derived Terpenes to Fight Antibiotic-Resistant Infections. Antibiotics (Basel) 2020. [DOI: 10.3390/antibiotics9060325
expr 928323768 + 816400131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
The discovery of antibiotics has revolutionized the medicine and treatment of microbial infections. However, the current scenario has highlighted the difficulties in marketing new antibiotics and an exponential increase in the appearance of resistant strains. On the other hand, research in the field of drug-discovery has revaluated the potential of natural products as a unique source for new biologically active molecules and scaffolds for the medicinal chemistry. In this review, we first contextualized the worldwide problem of antibiotic resistance and the importance that natural products of plant origin acquire as a source of new lead compounds. We then focused on terpenes and their potential development as antimicrobials, highlighting those studies that showed an activity against conventional antibiotic-resistant strains.
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The Revaluation of Plant-Derived Terpenes to Fight Antibiotic-Resistant Infections. Antibiotics (Basel) 2020; 9:antibiotics9060325. [PMID: 32545761 PMCID: PMC7344648 DOI: 10.3390/antibiotics9060325] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/03/2020] [Accepted: 06/10/2020] [Indexed: 02/07/2023] Open
Abstract
The discovery of antibiotics has revolutionized the medicine and treatment of microbial infections. However, the current scenario has highlighted the difficulties in marketing new antibiotics and an exponential increase in the appearance of resistant strains. On the other hand, research in the field of drug-discovery has revaluated the potential of natural products as a unique source for new biologically active molecules and scaffolds for the medicinal chemistry. In this review, we first contextualized the worldwide problem of antibiotic resistance and the importance that natural products of plant origin acquire as a source of new lead compounds. We then focused on terpenes and their potential development as antimicrobials, highlighting those studies that showed an activity against conventional antibiotic-resistant strains.
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Cappiello F, Loffredo MR, Del Plato C, Cammarone S, Casciaro B, Quaglio D, Mangoni ML, Botta B, Ghirga F. The Revaluation of Plant-Derived Terpenes to Fight Antibiotic-Resistant Infections. Antibiotics (Basel) 2020; 9:325. [PMID: 32545761 PMCID: PMC7344648 DOI: 10.3390/antibiotics9060325&set/a 898859781+915895989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
The discovery of antibiotics has revolutionized the medicine and treatment of microbial infections. However, the current scenario has highlighted the difficulties in marketing new antibiotics and an exponential increase in the appearance of resistant strains. On the other hand, research in the field of drug-discovery has revaluated the potential of natural products as a unique source for new biologically active molecules and scaffolds for the medicinal chemistry. In this review, we first contextualized the worldwide problem of antibiotic resistance and the importance that natural products of plant origin acquire as a source of new lead compounds. We then focused on terpenes and their potential development as antimicrobials, highlighting those studies that showed an activity against conventional antibiotic-resistant strains.
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Affiliation(s)
- Floriana Cappiello
- Laboratory affiliated to Pasteur Italia-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (F.C.); (M.R.L.); (M.L.M.)
| | - Maria Rosa Loffredo
- Laboratory affiliated to Pasteur Italia-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (F.C.); (M.R.L.); (M.L.M.)
| | - Cristina Del Plato
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (C.D.P.); (S.C.); (B.B.)
- Center For Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy;
| | - Silvia Cammarone
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (C.D.P.); (S.C.); (B.B.)
| | - Bruno Casciaro
- Center For Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy;
- Correspondence: (B.C.); (D.Q.)
| | - Deborah Quaglio
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (C.D.P.); (S.C.); (B.B.)
- Correspondence: (B.C.); (D.Q.)
| | - Maria Luisa Mangoni
- Laboratory affiliated to Pasteur Italia-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (F.C.); (M.R.L.); (M.L.M.)
| | - Bruno Botta
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (C.D.P.); (S.C.); (B.B.)
| | - Francesca Ghirga
- Center For Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy;
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Extracellular vesicles produced by human and animal Staphylococcus aureus strains share a highly conserved core proteome. Sci Rep 2020; 10:8467. [PMID: 32439871 PMCID: PMC7242376 DOI: 10.1038/s41598-020-64952-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/24/2020] [Indexed: 12/24/2022] Open
Abstract
Staphylococcus aureus is an important opportunistic pathogen of humans and animals. It produces extracellular vesicles (EVs) that are involved in cellular communication and enable inter-kingdom crosstalk, the delivery of virulence factors and modulation of the host immune response. The protein content of EVs determines their biological functions. Clarifying which proteins are selected, and how, is of crucial value to understanding the role of EVs in pathogenesis and the development of molecular delivery systems. Here, we postulated that S. aureus EVs share a common proteome containing components involved in cargo sorting. The EV proteomes of five S. aureus strains originating from human, bovine, and ovine hosts were characterised. The clustering of EV proteomes reflected the diversity of the producing strains. A total of 253 proteins were identified, 119 of which composed a core EV proteome with functions in bacterial survival, pathogenesis, and putatively in EV biology. We also identified features in the sequences of EV proteins and the corresponding genes that could account for their packaging into EVs. Our findings corroborate the hypothesis of a selective sorting of proteins into EVs and offer new perspectives concerning the roles of EVs in S. aureus pathogenesis in specific host niches.
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Alsaeed A, Wright G, Deneer H, Rubin JE, Sanche SE, Blondeau JM. Methicillin-resistant Staphylococcus aureus replication in the presence of high (≥32 µg/ml) drug concentration of vancomycin as seen by electron microscopy. J Chemother 2020; 32:179-187. [PMID: 32393118 DOI: 10.1080/1120009x.2020.1761191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has unfortunately become a common pathogen in many healthcare facilities. In many institutions, vancomycin remains the preferred agent for treating serious MRSA infections including bacteraemia with or without endocarditis. The mutant prevention concentration (MPC) testing ≥109 colony forming units of bacteria, describes the antimicrobial drug concentration blocking the growth of the least susceptible cell from high density bacterial populations. With blood culture isolates of MRSA, we discovered strains with MPC values ≥32 µg/ml and viable cells could be readily recovered from agar plates containing 32 µg/ml of vancomycin. To investigate MRSA strains surviving in high concentrations of vancomycin on drug containing agar plates, we utilized electron microscopy to measure cell wall thickness as this has been previously reported as a potential mechanism of resistance1 along with septum thickening. Our data shows MRSA replication from high density bacterial populations in the presence of ≥32 µg/ml of vancomycin. Such observations may explain vancomycin failure in some patients and/or persistent bacteraemia and could potentially question the use of this drug in some critically ill patients in favour of an alternative agent.
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Affiliation(s)
- Amal Alsaeed
- University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Glenda Wright
- Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Harry Deneer
- Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Division of Clinical Microbiology, Royal University Hospital and Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada
| | - Joseph E Rubin
- Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Stephen E Sanche
- Division of Clinical Microbiology, Royal University Hospital and Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada.,Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Joseph M Blondeau
- Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Division of Clinical Microbiology, Royal University Hospital and Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada.,Departments of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Ophthalmology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Swain J, El Khoury M, Flament A, Dezanet C, Briée F, Van Der Smissen P, Décout JL, Mingeot-Leclercq MP. Antimicrobial activity of amphiphilic neamine derivatives: Understanding the mechanism of action on Gram-positive bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:182998. [DOI: 10.1016/j.bbamem.2019.05.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 05/22/2019] [Accepted: 05/28/2019] [Indexed: 01/06/2023]
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Kuroki A, Kengmo Tchoupa A, Hartlieb M, Peltier R, Locock KES, Unnikrishnan M, Perrier S. Targeting intracellular, multi-drug resistant Staphylococcus aureus with guanidinium polymers by elucidating the structure-activity relationship. Biomaterials 2019; 217:119249. [PMID: 31279102 DOI: 10.1016/j.biomaterials.2019.119249] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/20/2019] [Accepted: 06/05/2019] [Indexed: 11/29/2022]
Abstract
Intracellular persistence of bacteria represents a clinical challenge as bacteria can thrive in an environment protected from antibiotics and immune responses. Novel targeting strategies are critical in tackling antibiotic resistant infections. Synthetic antimicrobial peptides (SAMPs) are interesting candidates as they exhibit a very high antimicrobial activity. We first compared the activity of a library of ammonium and guanidinium polymers with different sequences (statistical, tetrablock and diblock) synthesized by RAFT polymerization against methicillin-resistant S. aureus (MRSA) and methicillin-sensitive strains (MSSA). As the guanidinium SAMPs were the most potent, they were used to treat intracellular S. aureus in keratinocytes. The diblock structure was the most active, reducing the amount of intracellular MSSA and MRSA by two-fold. We present here a potential treatment for intracellular, multi-drug resistant bacteria, using a simple and scalable strategy.
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Affiliation(s)
- Agnès Kuroki
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | | | - Matthias Hartlieb
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Raoul Peltier
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Katherine E S Locock
- CSIRO Manufacturing, Clayton, Victoria, 3168, Australia; Department of Chemical and Biomolecular Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | | | - Sébastien Perrier
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK; Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK; Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia.
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Liu Y, Du Q, Ma C, Xi X, Wang L, Zhou M, Burrows JF, Chen T, Wang H. Structure-activity relationship of an antimicrobial peptide, Phylloseptin-PHa: balance of hydrophobicity and charge determines the selectivity of bioactivities. DRUG DESIGN DEVELOPMENT AND THERAPY 2019; 13:447-458. [PMID: 30774309 PMCID: PMC6350648 DOI: 10.2147/dddt.s191072] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background Antimicrobial peptides (AMPs) from the skin secretions of amphibians are now considered as a potential alternative to conventional antibiotics. Phylloseptins are a family of AMPs identified in the skin secretions of Phyllomedusinae tree frogs which exhibit highly conserved structural characteristics. This study examines the structure–activity relationship of the newly discovered phylloseptin, Phylloseptin-PHa (PSPHa) from Pithecopus hypochondrialis. Materials and methods PSPHa and modified analogs were produced by solid phase synthesis and purified by reverse-phase HPLC. Rationally designed modified analogs incorporating changes in significant physicochemical parameters such as hydrophobicity, hydrophobic moment and net charge were investigated to determine their influence on secondary structure, antimicrobial activity, membrane permeabilization and cytotoxicity. Results Overall, we found that when rationally designing AMPs by altering their primary structure it is important to keep a balance between hydrophobicity and charge. Conclusion This study provides new insights which will help in the future development of AMPs as alternatives to conventional antibiotics for the treatment of Staphylococcus aureus and methicillin-resistant S. aureus infections.
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Affiliation(s)
- Yuzhang Liu
- School of Pharmacy, China Medical University, Shenyang 110001, Liaoning, China, .,Faculty of Medicine, Health and Life Sciences, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK,
| | - Qiang Du
- School of Pharmacy, China Medical University, Shenyang 110001, Liaoning, China,
| | - Chengbang Ma
- Faculty of Medicine, Health and Life Sciences, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK,
| | - Xinping Xi
- Faculty of Medicine, Health and Life Sciences, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK,
| | - Lei Wang
- Faculty of Medicine, Health and Life Sciences, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK,
| | - Mei Zhou
- Faculty of Medicine, Health and Life Sciences, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK,
| | - James F Burrows
- Faculty of Medicine, Health and Life Sciences, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK,
| | - Tianbao Chen
- Faculty of Medicine, Health and Life Sciences, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK,
| | - Hui Wang
- School of Pharmacy, China Medical University, Shenyang 110001, Liaoning, China,
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Transcriptomics Analysis of the Chinese Pear Pathotype of Alternaria alternata Gives Insights into Novel Mechanisms of HSAF Antifungal Activities. Int J Mol Sci 2018; 19:ijms19071841. [PMID: 29932128 PMCID: PMC6073358 DOI: 10.3390/ijms19071841] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/06/2018] [Accepted: 06/06/2018] [Indexed: 12/11/2022] Open
Abstract
Alternaria alternata (Fries) Keissler is a lethal pear pathogen that causes leaf black spot disease of pear in Southern China. Heat-stable activity factor (HSAF) is a polycyclic tetramate macrolactam (PTM) produced by Lysobacter enzymogenes and many other microbes with a broad-spectrum antifungal activity against many filamentous fungi. In this study, we evaluated the antifungal effect of HSAF against A. alternata and proposed its antifungal mechanism in A. alternata. We report that HSAF inhibited the mycelial growth of A. alternata in a dose-dependent manner. Transcriptomics analysis revealed that HSAF treatment resulted in an expression alteration of a wide range of genes, with 3729 genes being up-regulated, and 3640 genes being down-regulated. Furthermore, we observed that HSAF treatment disrupted multiple signaling networks and essential cellular metabolisms in A. alternata, including the AMPK signaling pathway, sphingolipid metabolism and signaling pathway, carbon metabolism and the TCA (tricarboxylic acid) cycle, cell cycle, nitrogen metabolism, cell wall synthesis and a key hub protein phosphatase 2A (PP2A). These observations suggest that HSAF breaches metabolism networks and ultimately induces increased thickness of the cell wall and apoptosis in A. alternata. The improved understanding of the antifungal mechanism of HSAF against filamentous fungi will aid in the future identification of the direct interaction target of HSAF and development of HSAF as a novel bio-fungicide.
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