Article
Chemistry, Multidisciplinary
Guocheng Xie, Sijia Gao, Jinzhao Ou, Meng Zhu, Man Wu, Xiaoyan Ju, Zhuang Li, Ye Tian, Zhongwei Niu
Summary: By conjugating peptides onto tobacco mosaic virus, the resulting nanoparticles show significantly enhanced antibacterial effects against Gram-negative bacteria. The high osmotic pressure and reactive oxygen species generated by the peptide-TMV cause the death of Escherichia coli, while also downregulating biofilm-related genes to inhibit biofilm formation. This study opens up new possibilities for combating Gram-negative bacteria-related infections.
Article
Biochemistry & Molecular Biology
Kunhong Zhong, Yuelong Wang, Zeng Wang, Zongliang Zhang, Shasha Zhao, Hexian Li, Jianhan Huang, Wenhao Guo, Xi Zheng, Gang Guo, Liangxue Zhou, Hui Yang, Aiping Tong
Summary: The study identified a human antimicrobial peptide called AP-64, which displayed significant antibacterial activity against Gram-negative bacteria, effectively combating Escherichia coli O157:H7 infections and exhibiting cytotoxic effects against human lymphoma cells. Additionally, a mouse homologous gene encoded peptide Gm94 showed similar antibacterial properties to AP-64.
Article
Microbiology
Edwin Esau Hernandez-Arvizu, Teresa Monserrat Silis-Moreno, Jose Alejandro Garcia-Arredondo, Angelina Rodriguez-Torres, Jose Antonio Cervantes-Chavez, Juan Mosqueda
Summary: Anti-microbial peptides play a crucial role in the defense mechanisms of various organisms. In this study, a cathelicidin-like peptide called Aquiluscidin was identified for the first time in Crotalus aquilus, exhibiting remarkable inhibitory activity against multiple bacteria. It has the potential to be a candidate for further antimicrobial research.
Article
Food Science & Technology
Zonghong Luo, Guanhong Chang, Yang Liu, Ke Ni, Ting Zhou, Xin Lv, Jiangtao Yu, Junqing Bai, Xin Wang
Summary: This study evaluated the effect of electron beam irradiation on the inactivation of Gram-negative bacteria and the destruction of extracellular polymers (EPS) in biofilms. The results showed that electron beam irradiation significantly reduced the number of viable bacteria both in vitro and on the surface of seafood samples, and it damaged the plasma membrane of bacterial cells by increasing reactive oxygen species (ROS) levels. Furthermore, the nucleic acids of the bacteria were also significantly damaged, while the primary protein structure remained unchanged.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Microbiology
Mariana Albano, Melissa J. Karau, Audrey N. Schuetz, Robin Patel
Summary: The study found that the standard agar dilution method (AD) for determining CFDC MICs is unreliable for carbapenem-resistant bacteria, showing significant discordance compared to iron-depleted broth microdilution (ID-BMD). When testing different types of organisms, AD showed lower accuracy and consistency compared to ID-BMD.
JOURNAL OF CLINICAL MICROBIOLOGY
(2021)
Article
Multidisciplinary Sciences
Kumar Sachin Singh, Rishabh Sharma, Poli Adi Narayana Reddy, Prashanthi Vonteddu, Madeline Good, Anjana Sundarrajan, Hyeree Choi, Kar Muthumani, Andrew Kossenkov, Aaron R. Goldman, Hsin-Yao Tang, Maxim Totrov, Joel Cassel, Maureen E. Murphy, Rajasekharan Somasundaram, Meenhard Herlyn, Joseph M. Salvino, Farokh Dotiwala
Summary: Isoprenoids are essential for maintaining cellular functions and IspH is a crucial enzyme in their synthesis pathway. Through structure-guided design, a class of IspH inhibitors with nanomolar potency were identified, showing efficacy against multidrug-resistant bacteria while being relatively non-toxic to mammalian cells. These prodrugs also induce expansion and activation of human V gamma 9V delta 2 T cells, suggesting a potential strategy to limit antibiotic-resistant bacterial populations.
Article
Materials Science, Biomaterials
Li Su, Sainan Qin, Xinai Yu, Yifei Chen, Liang Wang, Wenpei Dong, Zhongjian Xie, Han Zhang
Summary: Bacterial infections, especially Gram-negative ones, have become a growing problem due to antibiotic resistance. Nanozymes offer a promising solution by using reactive oxygen species (ROS) to kill bacteria. In this study, NiCo layered double hydroxide (LDH) nanozymes were synthesized and shown to selectively kill Gram-negative bacteria through their peroxide-like (POD-like) activity. Ni4Co6 LDHs exhibited the highest POD and antibacterial activity, and were able to selectively sterilize Gram-negative bacteria through electrostatic adsorption and hydrophilic interactions with the bacterial cell wall. Animal experiments demonstrated effective healing of G(-) bacteria-infected wounds without harming normal tissues. This research provides a new direction for the application of nanozymes.
JOURNAL OF MATERIALS CHEMISTRY B
(2023)
Article
Chemistry, Multidisciplinary
Christian Rohrbacher, Robert Zscherp, Stefanie C. Weck, Philipp Klahn, Christian Ducho
Summary: Overcoming antibiotic resistance requires the development of novel antibacterial agents that target new bacterial cell mechanisms. This study presents a new approach by conjugating a synthetic muraymycin analogue with an enterobactin derivative to enhance cellular uptake and improve antibacterial activity against Gram-negative bacteria.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Neurosciences
Hyeon Soo Kim, Sujin Kim, Soo Jung Shin, Yong Ho Park, Yunkwon Nam, Chae Won Kim, Kang Won Lee, Sung-Min Kim, In Duk Jung, Hyun Duk Yang, Yeong-Min Park, Minho Moon
Summary: Alzheimer's disease (AD) is a severe age-related neurodegenerative disease that may be associated with gram-negative bacteria and their LPS. These bacteria and LPS play important roles in the pathogenesis and pathology of AD.
TRANSLATIONAL NEURODEGENERATION
(2021)
Article
Microbiology
Huijing Zhou, Mengxin Xu, Wenhui Guo, Zhuocheng Yao, Xin Du, Lijiang Chen, Yao Sun, Shiyi Shi, Jianming Cao, Tieli Zhou
Summary: The combination of colistin and kaempferol shows synergistic antibacterial and antibiofilm activities, providing an effective alternative treatment option for colistin-resistant Gram-negative bacteria infections.
MICROBIOLOGY SPECTRUM
(2022)
Article
Microbiology
Dee Shortridge, Jennifer M. Streit, Rodrigo Mendes, Mariana Castanheira
Summary: Cefiderocol is a broad-spectrum cephalosporin with activity against Gram-negative bacteria, making it a valuable therapeutic option for drug-resistant infections.
MICROBIOLOGY SPECTRUM
(2022)
Article
Infectious Diseases
Yijia Han, Yi Zhang, Weiliang Zeng, Zeyu Huang, Haojun Cheng, Jingchun Kong, Chunquan Xu, Mengxin Xu, Tieli Zhou, Jianming Cao
Summary: In this study, a strategy of combining farnesol (FAR) with colistin (COL) to restart COL activity against colistin-resistant (COL-R) Gram-negative bacteria was proposed. The synergistic antibacterial activity of the COL-FAR combination was confirmed in various experiments, including checkerboard assay, time-killing assay, and bacterial cell viability assay. Moreover, COL-FAR prevented biofilm formation and eradicated pre-existing biofilm, and showed low cytotoxicity. In vivo experiments demonstrated that COL-FAR increased survival rate and reduced bacterial load in infected models, implicating its potential effectiveness against COL-R GNB infections.
INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS
(2023)
Article
Infectious Diseases
Nityanand Jain, Inese Jansone, Tatjana Obidenova, Raimonds Simanis, Janis Meisters, Dagnija Straupmane, Aigars Reinis
Summary: This study conducted a retrospective analysis of microbiological data from a large public hospital in Latvia from 2017 to 2020, investigating antimicrobial resistance trends for 19 gram-negative bacterial genera. It found that carbapenems were most effective against GNBs while some bacteria showed significant increases in resistance rates against certain antibiotics. Despite lower prescription levels of penicillin group antimicrobials compared to the European average, GNBs exhibited high average resistant rates, indicating the role of ESBL+ isolates in resistance rates. Constant vigilance and proper infection control measures are necessary to track emerging trends in AMR in GNBs.
Article
Microbiology
Weijie Wang, Xiaoli Zhu, Huan Luo, Zheng Wang, Anjin Hong, Jie Zeng, Li Li, Dai Wang, Xianming Deng, Xilin Zhao
Summary: As the increase in antimicrobial resistance continues, the options for effectively treating multidrug-resistant (MDR) Gram-negative infections are decreasing. Finding ways to enhance the lethality of old agents with unique molecular targets is important, as new antimicrobial development is increasingly difficult. This study showed that the old antibiotic bicyclomycin has good bacteriostatic activity against multiple clinical isolates of MDR Gram-negative pathogens. Additionally, the combination of bicyclomycin with doxycycline showed enhanced efficacy in inhibiting bacterial growth and in vivo killing, suggesting the potential of bicyclomycin-containing regimens as new treatment options for MDR Gram-negative infections caused by specific pathogens.
MICROBIOLOGY SPECTRUM
(2023)
Review
Biochemistry & Molecular Biology
Jinane Tabcheh, Julia Vergalli, Anne Davin-Regli, Noha Ghanem, Jean-Marie Pages, Charbel Al-Bayssari, Jean Michel Brunel
Summary: Antibiotic resistance is increasing morbidity and mortality for non-curable infectious diseases. Novel strategies, such as effective antibiotic combinations and antibiotics with non-antibiotic activity-enhancing compounds, have emerged to combat multidrug-resistant microorganisms.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Microbiology
Ariel Chazan, Andrey Rozenberg, Kentaro Mannen, Takashi Nagata, Ran Tahan, Shir Yaish, Shirley Larom, Keiichi Inoue, Oded Beja, Alina Pushkarev
Summary: The recently discovered rhodopsin family of heliorhodopsins (HeRs) are found in diverse microbial environments and their functional and biological roles remain unknown. Through experimental and computational screens, 10 readily expressed HeR genes were identified, and they were found to have diverse kinetic characteristics in terms of light absorption and photocycles. Analysis of genes neighboring HeRs suggests a potential involvement in light-induced membrane lipid modifications.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Ecology
Alexander L. Jaffe, Masae Konno, Yuma Kawasaki, Chihiro Kataoka, Oded Beja, Hideki Kandori, Keiichi Inoue, Jillian F. Banfield
Summary: This study found that Saccharibacteria Type-1 rhodopsins function as outward proton pumps and can rapidly uptake the chromophore retinal. The co-occurring microorganisms with Saccharibacteria showed evidence of the ability to produce retinal from beta-carotene, suggesting a potential association between them.
Article
Ecology
Karel Simek, Indranil Mukherjee, Tiberiu Szoke-Nagy, Markus Haber, Michaela M. Salcher, Rohit Ghai
Summary: Morphologically indistinguishable aplastidic cryptophytes were found to be ubiquitous and prominent protistan bacterivores in freshwater ecosystems, playing important roles in carbon flow. These heterotrophic cryptophytes were generally smaller and more abundant than their chloroplast-bearing counterparts, and their diversity has been largely undiscovered.
Article
Biology
Shoko Hososhima, Ritsu Mizutori, Rei Abe-Yoshizumi, Andrey Rozenberg, Shunta Shigemura, Alina Pushkarev, Masae Konno, Kota Katayama, Keiichi Inoue, Satoshi P. Tsunoda, Oded Beja, Hideki Kandori
Summary: Rhodopsins, including the newly discovered Heliorhodopsins (HeRs), are proteins that convert light into signals and energy. A viral HeR, V2HeR3, was found to be a light-activated proton transporter with potential applications in optogenetics. The function of HeRs in different organisms and viruses remains diverse and not fully understood.
Article
Multidisciplinary Sciences
David Kamanda Ngugi, Michaela M. Salcher, Adrian-Stefan Andrei, Rohit Ghai, Franziska Klotz, Maria-Cecilia Chiriac, Danny Ionescu, Petra Buesing, Hans-Peter Grossart, Peng Xing, John C. Priscu, Salmor Alymkulov, Michael Pester
Summary: A study has found that the species diversity of ammonia-oxidizing archaea (AOA) in freshwater is lower compared to marine environments. The research also reveals that an uncultured freshwater AOA, Candidatus Nitrosopumilus limneticus, evolved in European lakes 13 million years ago and has remained genetically stable. These findings provide insights into the genetic diversity and adaptive mechanisms of AOA in lakes.
Article
Biochemistry & Molecular Biology
Shunpei Hanai, Takashi Nagata, Kota Katayama, Shino Inukai, Mitsumasa Koyanagi, Keiichi Inoue, Akihisa Terakita, Hideki Kandori
Summary: Animal visual rhodopsins can be classified into monostable and bistable rhodopsins, typically found in vertebrates and invertebrates respectively. Bovine rhodopsin (BovRh) is an example of monostable rhodopsin with extensively studied structures and functions. On the other hand, the structures and functions of bistable rhodopsins, despite their importance in optogenetics, are less known. In this study, low-temperature Fourier transform infrared (FTIR) spectroscopy was used to compare the spectral changes of jumping spider rhodopsin-1 (SpiRh1), squid rhodopsin (SquRh), and BovRh. The analysis showed that while the chromophore distortion in the resting state is not distinctive between invertebrate and vertebrate rhodopsins, the distortion after photoisomerization is unique for BovRh. Moreover, the analysis of O-D stretching vibrations revealed unique features of protein-bound water molecules. The absence of strongly hydrogen-bonded water molecules is a distinct characteristic of animal rhodopsins compared to microbial rhodopsins.
Article
Biochemistry & Molecular Biology
Naoya Morimoto, Takashi Nagata, Keiichi Inoue
Summary: This study revealed that human and chicken RGRs form blue-absorbing pigments similar to bovine RGR, and they are bistable rhodopsins displaying a reversible photoreaction. These findings provide insight into the behavior of RGR as a retinal photoisomerase and aid in understanding its role in the visual system.
Article
Chemistry, Multidisciplinary
Maria del Carmen Marin, Masae Konno, Hiromu Yawo, Keiichi Inoue
Summary: Microbial rhodopsins are a large family of photoreceptive membrane proteins that have diverse light-regulated functions. New subfamilies of microbial rhodopsins that transport H+ inwardly, known as light-driven inward H+ pumps, have recently been discovered. This study conducted the first functional conversion study by mutating key amino acids in a natural outward H+-pumping rhodopsin, resulting in the creation of an artificial inward H+ pump. This finding provides insights into the key processes that differentiate between outward and inward H+ pumps, and could contribute to the understanding of ion transport mechanisms in other ion-pumping proteins.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Keisei Shibata, Kazumasa Oda, Tomohiro Nishizawa, Yuji Hazama, Ryohei Ono, Shunki Takaramoto, Reza Bagherzadeh, Hiromu Yaw, Osamu Nureki, Keiichi Inoue, Hudefumim Akiyama
Summary: Channelrhodopsins (ChRs) are light-gated ion channels that can control neuronal activity with high temporal resolution. The mechanism of how their channels open and close is still unknown. This study investigated the structural changes in the retinal chromophore of ChR C1C2 and the factors that limit the kinetics of the channel gating. The results showed that the retinal chromophore twists upon RSB deprotonation, causing the surrounding helices to move and open the channel, and the RSB reprotonation rate-limits the channel closing.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Manish Singh, Shota Ito, Shoko Hososhima, Rei Abe-Yoshizumi, Satoshi P. Tsunoda, Keiichi Inoue, Hideki Kandori
Summary: AaClR is a natural light-driven chloride pump that binds chloride ions in the resting state. It is also able to pump sulfate ions, although with lower efficiency. The photocycle dynamics of the AaClR sulfate pump resemble a non-functional cycle, but there is evidence of transient binding of sulfate ions to AaClR. The molecular mechanism of this unusual active transport by AaClR is discussed.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Keiichi Inoue
Summary: Microbial rhodopsins are photoreceptive membrane proteins that exhibit diverse photobiological functions. The chromophore of these rhodopsins, all-trans-retinal, undergoes isomerization upon photoexcitation, leading to sequential conformational changes in the protein and the emergence of active states with biological functions. Recent studies have revealed new photochemical characteristics of retinal in some microbial rhodopsins, including red-shifted absorption, isomerization to different forms, and energy transfer from a secondary chromophore. These findings challenge the established understanding of retinal photochemistry in canonical microbial rhodopsins.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Chun-Fu Chang, Masae Konno, Keiichi Inoue, Tahei Tahara
Summary: Schizorhodopsin (SzR) is a newly discovered microbial rhodopsin subfamily that functions as an unusual inward-proton pump upon absorbing light. The unique chromophore-protein interactions resulting from two major protein structural differences around the chromophore may be responsible for its unusual function. Therefore, it is crucial to understand how these differences affect the primary photoreaction dynamics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Editorial Material
Microbiology
Oded Beja, Keiichi Inoue
Summary: Marine diatoms are capable of switching their photosynthetic mode from chlorophyll-based to rhodopsin-based under iron-limitation conditions.
NATURE MICROBIOLOGY
(2023)
Article
Biophysics
Maria del Carmen Marin, Alexander L. Jaffe, Patrick T. West, Masae Konno, Jillian F. Banfield, Keiichi Inoue
Summary: Recent genomic and metagenomic analysis have identified many microbial rhodopsins with unique sequences. Functional characterization of these new microbial rhodopsins will enhance our understanding of their physiological roles.
BIOPHYSICS AND PHYSICOBIOLOGY
(2023)
Article
Chemistry, Physical
Yusuke Nakasone, Yuma Kawasaki, Masae Konno, Keiichi Inoue, Masahide Terazima
Summary: Heliorhodopsins (HeRs) are a new category of rhodopsins, which exist as dimers and have an inverted topology. This study investigated the conformational changes of HeRs using the transient grating (TG) and circular dichroism (CD) methods. The results showed that there were no significant conformation changes on the protein's surface during the early steps of the reaction, but a decrease in diffusion coefficient (D) was observed after the formation of the O intermediate. The contribution of the ICL1 helix in the conformational changes was examined. The study suggests that the hydrophilic residues in the ICL1 helix undergo structural changes during the process. Rating: 8/10
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
