Article
Microbiology
Mahmoud A. F. Khalil, Fatma A. Ahmed, Ahmed F. Elkhateeb, Eman E. Mahmoud, Mona Ahmed, Randa Ahmed, Amal Hosni, Saad Alghamdi, Ahmed Kabrah, Anas S. Dablool, Helal F. Hetta, Sawsan S. Moawad, Enas Mamdouh Hefzy
Summary: A. baumannii is a common pathogen causing pneumonia in ICU patients, with strong biofilm formation serving as a key virulence factor. The presence of carbapenemase-encoding genes may influence its resistance and pathogenicity.
Article
Multidisciplinary Sciences
Eden Mannix-Fisher, Samantha McLean
Summary: The study investigates the therapeutic effects of silver salts, particularly silver acetate, on bacterial infections. The results demonstrate selective toxicity of silver acetate for bacterial pathogens, leading to improved survival rates in infection treatment. However, well-defined doses of the antimicrobial are necessary to achieve effective treatment.
Article
Infectious Diseases
Livia M. A. Figueiredo-Godoi, Maira T. Garcia, Juliana G. Pinto, Juliana Ferreira-Strixino, Eliseu Gabriel Faustino, Lara Luise Castro Pedroso, Juliana C. Junqueira
Summary: This study evaluated the efficacy of a new photosensitizer derivative called Fotoenticine-FTC in antimicrobial photodynamic therapy (aPDT) against Acinetobacter baumannii. The results showed that methylene blue (MB) had greater antimicrobial activity compared to FTC, inhibiting the growth of bacterial cells in planktonic cultures, biofilms, and burn infections in Galleria mellonella.
Article
Multidisciplinary Sciences
Amy L. Bogue, Warunya Panmanee, Cameron T. McDaniel, Joel E. Mortensen, Edwin Kamau, Luis A. Actis, Jay A. Johannigman, Michael J. Schurr, Latha Satish, Nalinikanth Kotagiri, Daniel J. Hassett
Summary: The novel biocide AB569, composed of acidified nitrite and ethylenediaminetetraacetic acid, demonstrated bactericidal activity against multi-drug resistant Acinetobacter baumannii and Acinetobacter spp. AB569 treatment can prevent the bacteria from gaining an early growth advantage during infection and lead to extensive bactericidal activity upon subsequent exposures.
Article
Microbiology
Ahmad M. Aljohani, Cecile El-Chami, Muna Alhubail, Ruth G. Ledder, Catherine A. O'Neill, Andrew J. McBain
Summary: In this study, cell-free supernatants (CFS) from 25 human commensal and associated bacteria were tested for their activity against Pseudomonas aeruginosa. Among them, Escherichia coli Nissle 1917 CFS was found to inhibit biofilm formation and disperse existing Pseudomonas biofilms without affecting planktonic bacterial growth. The CFS also downregulated the expression of Pseudomonas aeruginosa proteins involved in motility and quorum sensing, which are associated with biofilm formation.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Infectious Diseases
Maha M. Ismail, Mariam Hassan, Sawsan S. Moawad, Mona M. Okba, Rehab M. Ashour, Nesrin M. Fayek, Fatema R. Saber
Summary: The study demonstrated that Callistemon citrinus leaf extract and Pulverulentone A have the potential to inhibit biofilm and pigment production by MDR P. aeruginosa. Pulverulentone A showed significant antivirulence effects against P. aeruginosa virulence factors, with good safety profiles in both in vitro and in vivo experiments.
Article
Biochemistry & Molecular Biology
Alba Arranz San Martin, Jan Vogel, Sandra C. C. Wullich, Wim J. J. Quax, Susanne Fetzner
Summary: This study analyzed the quorum quenching properties of various enzymes on the Pseudomonas aeruginosa signal molecule PQS. The results showed that these enzymes significantly reduced the production of virulence factors and delayed mortality in infected animals.
Article
Microbiology
Noor Andryan Ilsan, Yuarn-Jang Lee, Shu-Chen Kuo, I-Hui Lee, Tzu-Wen Huang
Summary: In a teaching hospital in Taipei, Taiwan, seven carbapenem-resistant Acinetobacter baumannii isolates with colistin resistance were identified. The resistance to carbapenem was attributed to the bla(OXA-23) gene, while colistin resistance was likely due to mutations in the sensor kinase domain of PmrB. Overexpression of pmrC, eptA, and naxD genes were observed in all isolates, and some isolates with mutations in lpxD exhibited altered lipopolysaccharide profiles contributing to colistin resistance. No fitness cost was observed in the resistant isolates compared to the reference strain. Interestingly, one isolate showed heteroresistance to colistin, and four isolates were more virulent to wax moth larvae.
Article
Microbiology
Laura Leukert, Manuela Tietgen, Felix F. Krause, Tilman G. Schultze, Dominik C. Fuhrmann, Charline Debruyne, Suzana P. Salcedo, Alexander Visekruna, Llka Wittig, Stephan Goettig
Summary: This study found that Acinetobacter baumannii can inhibit the mitochondrial function of human host cells and infect them through mechanisms such as perturbation of oxidative phosphorylation, disruption of mitochondrial ribosomes, and interference with mitochondrial metabolic pathways, leading to serious nosocomial infections.
MICROBIOLOGY SPECTRUM
(2023)
Article
Microbiology
Brenda Landvoigt Schmitt, Bruna Ferreira Leal, Mariana Leyser, Muriel Primon de Barros, Danielle Silva Trentin, Carlos Alexandre Sanchez Ferreira, Silvia Dias de Oliveira
Summary: The mechanism of antimicrobial resistance and persistence ability of Acinetobacter baumannii may be associated with the outer membrane proteins OmpW and OmpA, highlighting them as potential targets for drug development against A. baumannii persisters.
Review
Microbiology
Ye Tao, Luminita Duma, Yannick Rossez
Summary: The invertebrate model Galleria mellonella is a valuable tool for studying the pathogenesis mechanisms of multidrug resistant Acinetobacter baumannii, offering promising insights for clinical treatments.
Article
Microbiology
Hua Zhou, Michael J. Gebhardt, Daniel M. Czyz, Yake Yao, Howard A. Shuman
Summary: The study identified the key roles of gigA and gigB genes in both growth and virulence traits of Acinetobacter baumannii strain ATCC 17978, while being dispensable for other stress-resistance survival phenotypes, including aminoglycoside resistance. The deletion of gigA/gigB resulted in growth defects in laboratory medium, replication defects within murine macrophages, and an inability to kill Galleria mellonella larvae, demonstrating the importance of these genes for both bacterial growth and pathogenicity. Additionally, the loss of ptsP restored the phenotypes of the gigA/gigB mutant to that of the wild-type, highlighting the interplay between these genetic factors in stress response of the pathogen.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Chemistry, Medicinal
Deepa Dehari, Aiswarya Chaudhuri, Dulla Naveen Kumar, Rohit Patil, Mayank Gangwar, Sonam Rastogi, Dinesh Kumar, Gopal Nath, Ashish Kumar Agrawal
Summary: In this study, Acinetobacter baumannii (A. baumannii)-specific bacteriophages (BPAB & phi;1) were isolated and loaded into chitosan microparticles dispersed in a gel, showing therapeutic efficacy against MDR A. baumannii clinical strains. The isolated BPAB & phi;1 belonged to the Corticoviridae family with a burst size of 102.12 ± 2.65 PFUs per infected host cell. The developed formulation exhibited excellent antibiofilm eradication potential in vitro and effective wound healing after topical application.
Article
Multidisciplinary Sciences
Jasmine Martinez, Chelsea Razo-Gutierrez, Casin Le, Robert Courville, Camila Pimentel, Christine Liu, Sammie E. Fung, Marisel R. Tuttobene, Kimberly Phan, Alejandro J. Vila, Parvin Shahrestani, Veronica Jimenez, Marcelo E. Tolmasky, Scott A. Becka, Krisztina M. Papp-Wallace, Robert A. Bonomo, Alfonso Soler-Bistue, Rodrigo Sieira, Maria Soledad Ramirez
Summary: This study investigates the genetic changes and virulence factor expression of Acinetobacter baumannii in the cerebrospinal fluid (CSF) environment, showing its adaptability and survival capabilities. While a highly virulent strain showed no transcriptome changes in the presence of CSF, a low-virulence isolate exhibited significant differences in gene expression. Exposure to CSF induced increased expression of virulence factors without promoting bacterial growth, but rather increasing the expression of genes associated with transcription, translation, and ATP synthesis.
SCIENTIFIC REPORTS
(2021)
Article
Infectious Diseases
Enas Mamdouh Hefzy, Mahmoud A. F. Khalil, Amal A. Ibrahim Amin, Hossam M. Ashour, Yasser Fathy Abdelaliem
Summary: The study showed that BLISs from lactobacilli and streptococci have inhibitory effects on Candida species, with good stability against heat, pH, and surfactants but sensitivity to proteases. In vivo testing using Galleria mellonella larvae model demonstrated that BLISs significantly improved survival rates when treated with Candida isolates, suggesting the potential of BLISs as biotherapeutic agents in vulvovaginal candidiasis.
Article
Biochemical Research Methods
Carlos Redondo-Gomez, Soraya Padilla-Lopategui, Alvaro Mata, Helena S. Azevedo
Summary: The host-guest-mediated PA hydrogelation method relies on the formation of a host-guest homoternary complex with CB[8] and aromatic amino-acid-bearing PA nanofibers, resulting in hierarchical morphologies and increased stiffness compared to ion-based equivalents. This alternative cross-linking method can upgrade the design of PA materials and extend their biomedical applications, while maintaining similar biocompatibilities between the new and conventional hydrogels.
BIOCONJUGATE CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Chao Teng, Bingbing Li, Chenshi Lin, Xuyang Xing, Feifei Huang, Yi Yang, Yi Li, Helena S. Azevedo, Wei He
Summary: This study aimed to co-deliver p53 gene and baicalein to PASMCs for alleviating PAH. The prepared system targeted PASMCs in vitro and enabled effective gene transfection, efficient apoptosis, and inflammation suppression. In vivo results showed that the co-delivery system could reverse monocrotaline-induced PAH.
JOURNAL OF CONTROLLED RELEASE
(2022)
Review
Chemistry, Multidisciplinary
Minghao Wu, Shipeng He, Hua Tang, Honggang Hu, Yejiao Shi
Summary: The emergence of multi-drug resistant bacteria and the lack of novel antibiotics have led to the revival of polymyxin B. Molecular engineering strategies have been used to improve its clinical applications in targeted imaging and effective treatment of bacterial infections. This mini review summarizes recent advances and provides an outlook on the challenges and trends in this research area.
FRONTIERS IN CHEMISTRY
(2022)
Article
Medicine, Research & Experimental
Ruben de Dios, Chris R. Proctor, Evgenia Maslova, Sindija Dzalbe, Christian J. Rudolph, Ronan R. McCarthy
Summary: Research has found that three artificial sweeteners have antimicrobial effects on priority pathogens, and one of them can disable virulence behaviors of multidrug-resistant Acinetobacter baumannii. The mechanism involves cell lysis mediated by bulge and can be rescued by cation supplementation. Moreover, this sweetener can resensitize A. baumannii to last resort antibiotics and maintain antimicrobial activity in the wound microenvironment.
EMBO MOLECULAR MEDICINE
(2023)
Article
Chemistry, Multidisciplinary
Xiaoyuan Zhao, Shipeng He, Bo Li, Bin Liu, Yejiao Shi, Wei Cong, Fei Gao, Jingjing Li, Fan Wang, Kai Liu, Chunquan Sheng, Juanjuan Su, Hong-Gang Hu
Summary: A DUCNP@Mn-MOF nanocarrier was developed to load and deliver a cytotoxic antitumor agent effectively, exhibiting pH-responsive and peroxidase-like properties and unique optical features. It showed excellent tumor targeting capability and synergistic chemodynamic and chemotherapeutic effects, making it a promising theragnostic platform for cancer therapy.
Article
Health Care Sciences & Services
Hyunuk Kim, Chris R. Proctor, Dylan Walker, Ronan R. McCarthy
Summary: This study examined how AMR-related content is consumed on Twitter and identified some of the drivers of engagement. It found that specific pathogens gain more attention on Twitter, and the level of attention does not necessarily correspond to their status on the WHO priority pathogen list. This suggests the need for more targeted public health strategies to raise awareness about AMR among specific pathogens.
JOURNAL OF MEDICAL INTERNET RESEARCH
(2023)
Article
Microbiology
Evgenia Maslova, Shanga Osman, Ronan R. McCarthy
Summary: Burn wound infection, primarily caused by Pseudomonas aeruginosa, is a major cause of death in burn patients. Treating this multidrug-resistant pathogen is challenging, and seeding the wound bed with probiotic bacteria is one potential alternative treatment. Lactobacillus species have been shown to inhibit the growth of wound pathogens and promote wound healing. Using the G. mellonella invertebrate model, this study validates the effectiveness of the model in screening potential wound probiotics that can limit P. aeruginosa infection and improve survival.
Article
Engineering, Biomedical
Yichen Yuan, Yejiao Shi, Jayati Banerjee, Amin Sadeghpour, Helena S. Azevedo
Summary: The use of synthetic extracellular matrices (ECMs) has been important in investigating the interaction between cells and matrix components in cell culture studies. To provide cells with a more natural environment, designing matrices that mimic the composition and structure of natural ECMs is desirable. This study presents the supramolecular fabrication of peptide-hyaluronan (HA) hydrogels as potential ECM substitutes, which combine native HA and rationally designed cationic amphipatic peptides.
MATERIALS TODAY BIO
(2023)
Article
Microbiology
Sophie A. A. Howard, Clodagh M. M. Carr, Habteab Isaack Sbahtu, Uchechukwu Onwukwe, Maria J. J. Lopez, Alan D. W. Dobson, Ronan R. R. McCarthy
Summary: Plastic pollution is a global issue that needs to be urgently addressed. Despite increasing recycling rates worldwide, only a small percentage of plastic waste is actually recycled. In this study, researchers discovered that expanded polystyrene (EPS) promotes the formation of high levels of bacterial biofilms. Through enrichment experiments, they found that bacterial communities attached to EPS showed increased plastic-degrading activity, with Pseudomonas stutzeri being the most prominent polyester-degrading bacterium. This study suggests that waste plastic-associated biofilms could be a potential source of bacteria with plastic-degrading abilities.
ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Mengjun Zheng, Huixuan Chen, Xiang Li, Si Chen, Yejiao Shi, Honggang Hu
Summary: Aurein1.2, secreted by the Australian tree frog Litoria aurea, has broad-spectrum activity against various infectious microbes. One peptide, SAU2-4, synthesized through hydrocarbon stapling modification, showed improved helicity, protease resistance, and antifungal activity compared to the template linear peptide Aurein1.2. This study highlights the potential of hydrocarbon stapling modification in enhancing peptide pharmacological properties for antifungal agent development.
JOURNAL OF PEPTIDE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Shuangyan Wen, Yejiao Shi, Yanan Zhang, Qing Chang, Honggang Hu, Xiaoyong Deng, Yijun Xie
Summary: Cerium-doped MoO (x) (Ce-MoOv) nanomaterials with tunable Mo/Ce molar ratios were fabricated by a one-pot method and their effects on chemodynamic therapy (CDT) and photothermal therapy (PTT) were investigated. Ce-MoOv could self-assemble into nanoclusters in acidic conditions, and increasing the amount of Ce resulted in the generation of oxygen vacancy defects and changes in the valence states of Mo6+/Mo5+ and Ce4+/Ce3+. This led to strong near-infrared absorption and high photothermal conversion efficiency for 808 and 1064 nm. Ce-MoOv also demonstrated pH-/glutathione (GSH)-activated photoacoustic (PA) imaging capability and acted as a CDT reagent by converting H2O2 to reactive oxygen species and depleting GSH. The therapeutic effect of Ce-MoOv against HCT116 cells was highly effective under 1064 nm laser irradiation.
Article
Biotechnology & Applied Microbiology
Sophie A. Howard, Ronan R. McCarthy
Summary: Plastic pollution is a pressing global issue, and finding an alternative to recycling, which is costly and limited in downstream uses, is urgently needed. By identifying and studying enzymes that degrade plastic and enhancing bacteria's ability to form biofilms, the development of bioremediation solutions for plastic degradation can be accelerated.
NPJ BIOFILMS AND MICROBIOMES
(2023)
Review
Pharmacology & Pharmacy
Joana Silva, Helena S. Azevedo
Summary: Hyaluronan (HA) is a polymer with unique properties that can be easily crosslinked and conjugated with therapeutic molecules to form hydrogels, which have great potential in cell therapy and drug delivery.
ADVANCED THERAPEUTICS
(2023)
Meeting Abstract
Cell & Tissue Engineering
Yuanhao Wu, Babatunde O. Okesola, John Connelly, Richard O. C. Oreffo, Jose Carlos Rodriguez-Cabello, Giovanni Vozzi, Helena S. Azevedo, Nicola M. Pugno, Alvaro Mata
TISSUE ENGINEERING PART A
(2022)