Article
Microbiology
Niclas Nordholt, Kate O'Hara, Ute Resch-Genger, Mark A. T. Blaskovich, Bastian Ruehle, Frank Schreiber
Summary: Quaternary ammonium compounds (QACs) are widely used in disinfectants and preservatives, but their mode-of-action and resistance mechanisms in bacteria are not fully understood. Researchers synthesized a fluorescent QAC, NBD-DDA, and demonstrated its usefulness in molecular and single-cell studies. The results showed that NBD-DDA has comparable antimicrobial activity to widely used QACs, and provided insights into its mode-of-action and resistance mechanisms.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Microbiology
Carmine J. Slipski, Taylor R. Jamieson-Datzkiw, George G. Zhanel, Denice C. Bay
Summary: This study identified 37 unique qac sequences from >2,000 plasmids, representing five representative motifs. These qac genes from proteobacterial multidrug-resistant plasmids encode efflux pumps that confer resistance to QAC antiseptics, with distinctive susceptibility patterns observed when cells grew as biofilms.
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
(2021)
Article
Biochemistry & Molecular Biology
Xingkai Cheng, Junting Zhang, Zhengya Liang, Zhaochen Wu, Pengfei Liu, Jianjun Hao, Xili Liu
Summary: This study found that plant pathogens can develop multidrug resistance (MDR) through metabolomic and efflux activities. The genes encoding ABC and MFS transporters were identified to be associated with MDR in Rhizoctonia solani, and their expression levels were higher in MDR mutant compared to the wild-type strain. Two of these transporters were found to be related to MDR and their roles were confirmed by detecting their protein products and high accumulation of an antifungal compound. These findings contribute to our understanding of fungicide resistance and the development of MDR.
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
(2023)
Article
Multidisciplinary Sciences
Jianping Li, Ampon Sae Her, Nathaniel J. Traaseth
Summary: EmrE is a multidrug efflux pump in Escherichia coli that transports drugs as a homodimer using energy from the proton motive force. Research suggests that the two Glu14 residues in the dimer have independent pKa values and are not electrostatically coupled, supporting a transport pathway with well-defined protonation states in each monomer of the dimer. The findings also propose a model, hop-free exchange, for how exchangers with conformation-dependent pKa values reduce proton leakage, relevant to the SMR family and transporters with inverted repeat domains.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Engineering, Environmental
Dingchang Li, Jingfeng Gao, Huihui Dai, Zhiqi Wang, Yingchao Cui, Yifan Zhao, Zhixiang Zhou
Summary: This study revealed the long-term microbiological responses of the partial nitrification/anammox (PN/A) system to hexadecyl trimethyl ammonium chloride (ATMAC-C16). The system showed tolerance to ATMAC-C16 and enriched specific anammox bacteria under the pressure. ATMAC-C16 decreased the relative abundance of most antibiotics resistance genes but significantly enriched QACs resistance genes. The resistance strain Pseudoxanthomonas mexicana was identified and its resistance might be due to the qacH gene and its own efflux pump system.
Article
Microbiology
Seiji Yamasaki, Naoki Koga, Martijn Zwama, Keisuke Sakurai, Ryosuke Nakashima, Akihito Yamaguchi, Kunihiko Nishino
Summary: This study found that different Trp mutations at different locations in the structure of MexB can affect the inhibitory effect of EPIs, without affecting the function of the efflux pumps.
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
(2022)
Article
Chemistry, Multidisciplinary
Alexander A. Shcherbakov, Merissa Brousseau, Katherine A. Henzler-Wildman, Mei Hong
Summary: EmrE is a bacterial transporter protein that effluxes cationic polyaromatic substrates against the concentration gradient by coupling to proton transport. The structure and dynamics of EmrE provide insights into the mechanism of transport by this family of proteins.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Medicinal
Wei Shi, Ping Zhang, Feng Zou, Jiaqi Zhou, Ziyu Yin, Zilong Cai, Hesham Ghaleb, Yuxuan Jiang, Wenlong Huang, Yan Liu, Qianqian Qiu, Hai Qian
Summary: Chemotherapy is a crucial treatment for cancer, but resistance can occur. Researchers developed and synthesized compounds with dual inhibition to overcome resistance and improve the bioavailability of oral chemotherapy drugs.
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Alexander A. Shcherbakov, Peyton J. Spreacker, Aurelio J. Dregni, Katherine A. Henzler-Wildman, Mei Hong
Summary: The structure of EmrE protein in different pH conditions has been solved using solid-state NMR, providing insights into the alternating-access model of EmrE. The study reveals that the conformation of EmrE at high pH exposes the substrate to both sides of the membrane, while the conformation at low pH asymmetically exposes the substrate to one side. These findings are crucial for understanding the substrate transport mechanism.
NATURE COMMUNICATIONS
(2022)
Article
Microbiology
Meinan Lyu, Julio C. Ayala, Isabella Chirakos, Chih-Chia Su, William M. Shafer, Edward W. Yu
Summary: In this study, a cationic antibiotic-sensitizing peptide (CASP) that binds to the periplasmic cleft of a specific RND transporter protein was identified. CASP was found to render Gram-negative rod-shaped bacteria susceptible to an antibiotic that is normally exported by the RND efflux pump. CASP (or its derivatives) could be used as an adjuvant to treat multidrug-resistant infections caused by RND transporters.
MICROBIOLOGY SPECTRUM
(2022)
Article
Microbiology
Heng Quan, Xiaowei Gong, Qiwei Chen, Fuying Zheng, Yongfeng Yu, Donghui Liu, Wenhui Wang, Yuefeng Chu
Summary: In this study, the GE296_RS02355 gene in R. anatipestifer strain LZ-01 was characterized. The mutation of this gene did not affect the growth, virulence, and drug resistance of the strain. This study helps to elucidate the biological functions of the SMR-type efflux pump in R. anatipestifer.
Article
Biochemical Research Methods
Jakub Jurasz, Maciej Baginski, Jacek Czub, Milosz Wieczor
Summary: The current surge in bacterial multi-drug resistance poses a major challenge to public health, highlighting the importance of understanding various factors contributing to MDR from a global health perspective. The study focuses on the prototypical proton-coupled antiporter EmrE, providing insights into its mechanisms and revealing two complementary ligand translocation pathways. This research sheds light on the structural features of EmrE and its selectivity towards aromatic cations.
PLOS COMPUTATIONAL BIOLOGY
(2021)
Article
Infectious Diseases
Wen-Jung Lu, Pang-Hung Hsu, Chun-Ju Chang, Cheng-Kuan Su, Yan-Jyun Huang, Hsuan-Ju Lin, Margaret Lai, Gui-Xia Ooi, Jing-Yi Dai, Hong-Ting Victor Lin
Summary: The study found that the seaweed compound diphenylmethane (DPM) has potential efflux pump inhibitory activity against drug-resistant Escherichia coli, enhancing the antibacterial activity of antibiotics without damaging E. coli membranes. Cell toxicity tests showed that DPM has mild toxicity towards human cells.
Review
Infectious Diseases
Jerusha Stephen, Fathima Salam, Manjusha Lekshmi, Sanath H. Kumar, Manuel F. Varela
Summary: This review article discusses the S. aureus-specific MFS multidrug efflux pump systems from a molecular mechanistic perspective, including structure-function relationships, modulation of antimicrobial resistance mediated by MFS drug efflux pumps, and direction for future investigation.
Article
Pharmacology & Pharmacy
Ole Jensen, Johannes Matthaei, Henry G. Klemp, Marleen J. Meyer, Jurgen Brockmoller, Mladen V. Tzvetkov
Summary: This study confirmed IBC as an endogenous biomarker of OCT1 activity in humans, with OCT1 potentially regulating cellular concentrations of specific regulators or co-substrates in lipid and energy metabolism. Unlike in mice, OCT1 in humans may not directly mediate the efflux of IBC, suggesting a different mechanism for the association between blood concentrations of carnitine derivatives and OCT1 genotype in humans.
FRONTIERS IN PHARMACOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
A. Firrincieli, D. Zannoni, E. Donini, H. Dostalova, R. Radisch, L. Iommarini, R. J. Turner, T. Busche, M. Patek, M. Cappelletti
Summary: Members of the genus Rhodococcus exhibit high metabolic versatility and tolerance to toxic metals. In this study, the response of R. aetherivorans BCP1 to two inorganic arsenic oxyanions, arsenite [As(III)] and arsenate [As(V)], was investigated. The results shed light on the plasticity of Rhodococcus' response to arsenic stress and provide insights into its energetic metabolism.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Infectious Diseases
Ali Pormohammad, Dylan Greening, Raymond J. Turner
Summary: The combination of silver nitrate and potassium tellurite has been found to be the most effective agent against Pseudomonas aeruginosa biofilm. Clinical isolates are resistant to antibiotics and silver, but susceptible to tellurite and the silver/tellurite combination. The chance of future resistance to the silver/tellurite mixture is remarkably lower than when each metal is used individually, and tellurite has significantly lower cytotoxicity than silver.
JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY
(2022)
Article
Multidisciplinary Sciences
Marzia Guerrini, Simone d'Agostino, Fabrizia Grepioni, Dario Braga, Andrii Lekhan, Raymond J. Turner
Summary: This study reports the use of gallium oxalate complex to form a drug-drug salt with the antimicrobial agent proflavine. The compounds were characterized and evaluated for their antimicrobial activity. The drug-drug salt showed effectiveness against all three bacterial strains, while the gallium oxalate salt exhibited impressive selectivity against Pseudomonas aeruginosa.
SCIENTIFIC REPORTS
(2022)
Editorial Material
Microbiology
Rob Van Houdt, Jon L. Hobman, Jean-Yves Matroule, Raymond J. Turner
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Infectious Diseases
Ali Pormohammad, Dave Hansen, Raymond J. Turner
Summary: This study compares and explores the efficacy and safety of plant-based natural compounds as antibacterial agents. Certain compounds from Cannabis plants show promising antibacterial and antibiofilm effects. These compounds primarily target the bacterial cell membrane to exert their antibacterial effects.
Article
Biochemistry & Molecular Biology
Elena Piacenza, Simona Campora, Francesco Carfi Pavia, Delia Francesca Chillura Martino, Vito Armando Laudicina, Rosa Alduina, Raymond Joseph Turner, Davide Zannoni, Alessandro Presentato
Summary: The intense use and improper disposal of tellurium in industrial applications have led to its accumulation in the environment. This study fills the knowledge gap in microbial processing of tellurite and provides a suitable strategy for circular economy by exploring the microbial biotransformation of tellurium. The Micromonospora strain investigated in this study shows promising cell tolerance, adaptation, and response to tellurite, making it a valuable asset for biotechnological purposes.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Biochemistry & Molecular Biology
Renren Sun, Lucia Casali, Raymond J. Turner, Dario Braga, Fabrizia Grepioni
Summary: Co-crystallization of kojic acid with metal salts yielded coordination polymers and complexes, which were fully characterized. The antimicrobial activity of these compounds was tested against bacterial strains, and appreciable activity was observed in the order of silver, zinc, copper, and gallium complexes.
Article
Biochemistry & Molecular Biology
Cecilia Fiore, Andrii Lekhan, Simone Bordignon, Michele R. R. Chierotti, Roberto Gobetto, Fabrizia Grepioni, Raymond J. J. Turner, Dario Braga
Summary: The antimicrobial activity of coordination polymers obtained by co-crystallizing amino acids with metal salts was investigated. The effects of chirality on enantiopure and racemic forms of arginine and histidine were explored. The coordination polymers showed comparable or superior antimicrobial activity compared to metal salts alone against Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Editorial Material
Biotechnology & Applied Microbiology
Manuel Carmona, Ignacio Poblete-Castro, Mahendra Rai, Raymond J. Turner
Summary: Metallic nanoparticles (MeNPs) have wide applications in various fields such as biomedicine, packaging, cosmetics, agriculture, and energy industries. Some MeNPs also exhibit quantum properties, making them suitable for photonics, electronics, and energy. Microbes can be considered as nanofactories in the production of enzymes, metabolites, and capping materials for the synthesis and stabilization of MeNPs. However, there are still challenges in microbial synthesis of MeNPs as an alternative to chemical synthesis.
MICROBIAL BIOTECHNOLOGY
(2023)
Review
Microbiology
Elham Lashani, Mohammad Ali Amoozegar, Raymond J. Turner, Hamid Moghimi
Summary: Microorganisms play a crucial role in reducing metalloid contamination risks through their ability to tolerate and detoxify these elements.
Article
Environmental Sciences
Elham Lashani, Hamid Moghimi, Raymond J. Turner, Mohammad Ali Amoozegar
Summary: Selenium oxyanions are released into environments from various activities and are present in wastewater in many locations worldwide. Excessive amounts of selenium have negative impacts on living organisms. Halophilic and halotolerant microorganisms were used for selenium oxyanion remediation in wastewater containing salt. Factors such as aeration, carbon sources, competitive electron acceptors, and reductase inhibitors were investigated for their effects on SeO32- removal. The study also explored the remediation of SeO32- in agricultural effluents containing NO3-. The results showed that aerobic conditions with succinate as a carbon source were most effective for SeO32- removal. Certain ions, such as WO42- and TeO32-, decreased the removal percentage, while SO42- and PO43- had minimal interference. NO3- had an adverse effect on SeO32- biotransformation. Consortia of halophilic/halotolerant bacteria and yeasts were able to reduce SeO32- in synthetic agricultural wastewater by 45-53% within 120 hours. This study suggests that these consortia could be used for the bioremediation of selenium-contaminated drainage water.
ENVIRONMENTAL POLLUTION
(2023)
Article
Chemistry, Multidisciplinary
Elena Piacenza, Kevin Sule, Alessandro Presentato, Frieda Wells, Raymond J. J. Turner, Elmar J. J. Prenner
Summary: Microbial nanotechnology is a growing research area focused on producing biogenic metal and metalloid nanomaterials using microorganisms. This study evaluated the toxicity of well-characterized biogenic selenium nanoparticles (bSeNPs) produced by the Stenotrophomonasmaltophilia strain SeITE02 on the model yeast Saccharomyces cerevisiae, comparing it to chemogenic selenium nanoparticles (cSeNPs). The results showed that the biogenic extract mediated changes in the fluidity of lipid vesicles, while the chemogenic nanoparticles had negligible effects.
Article
Microbiology
Ali Pormohammad, Andrea Firrincieli, Daniel A. Salazar-Aleman, Mehdi Mohammadi, Dave Hansen, Martina Cappelletti, Davide Zannoni, Mohammad Zarei, Raymond J. Turner
Summary: The constant, ever-increasing antibiotic resistance crisis requires urgent development of novel antibiotics according to the World Health Organization. Silver-tellurite combination treatment shows promising synergistic antibacterial activity, surpassing common antibiotics and reducing the risk of future resistance chance. The mechanism involves targeting cellular processes and amplifying changes. Adding tellurite improves the efficacy of silver in biomedical applications, providing alternative antimicrobial options with greater stability and lower toxicity.
MICROBIOLOGY SPECTRUM
(2023)
Article
Nanoscience & Nanotechnology
Andrii Lekhan, Cecilia Fiore, Oleksii Shemchuk, Fabrizia Grepioni, Dario Braga, Raymond J. Turner
Summary: In this study, the mechanochemical synthesis was used for co-crystallization of an organic antiseptic, proflavine, with metal-based antimicrobials including silver, copper, zinc, and gallium. The co-crystals showed good bacteriostatic and antibiofilm activities, with the silver-proflavine co-crystal exhibiting the best overall antibiofilm activity against multiple bacterial strains.
ACS APPLIED BIO MATERIALS
(2022)
Article
Environmental Sciences
Pablo Alviz-Gazitua, Anna Espinoza-Tofalos, Francesca Formicola, Nicolas Guiliani, Raymond J. Turner, Andrea Franzetti, Michael Seeger
Summary: Electroactive bacteria expressing active DGC can increase c-di-GMP levels, promoting biofilm formation and electrical current production. The results of this study suggest that the active DGC in C. metallidurans strain CH34 pJBpleD* enhances exoelectrogenic activity by activating the formation of an electroactive biofilm.