Article
Immunology
Chiang-Ni Chuan, Chien-Yi Chiang, Yan-Wen Chen, Yong-An Shi, Yu-Tzu Chao, Shuying Wang, Pei-Jane Tsai, Cheng-Hsun Chiu
Summary: This study investigated the involvement of RopB in regulating the production of extracellular vesicles (EVs) in Streptococcus pyogenes. The results showed that while RopB did not affect EVs production, it did regulate the degradation of streptolysin O and bacterial proteins in EVs through the SpeB protease. Moreover, enolase was identified as a potential internal marker for studying GAS EVs as it was resistant to SpeB degradation.
Article
Multidisciplinary Sciences
Shifu Aggarwal, Elaine Huang, Hackwon Do, Nishanth Makthal, Yanyan Li, Eric Bapteste, Philippe Lopez, Charles Bernard, Muthiah Kumaraswami
Summary: This study discovers the existence of short peptide LCP in various bacteria and validates its role as intercellular signals regulating gene expression. This finding may uncover new signaling mechanisms and play a significant role in coordinating diverse bacterial traits.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Jenny Clarke, Murielle Baltazar, Mansoor Alsahag, Stavros Panagiotou, Marion Pouget, William A. Paxton, Georgios Pollakis, Dean Everett, Neil French, Aras Kadioglu
Summary: The study revealed the crucial role of Streptolysin O (SLO) from Group A Streptoccocus (GAS) in determining infection outcomes, with high levels of haemolytic SLO leading to sepsis and lower activity resulting in translocation of bacteria to joints. Careful consideration is needed for novel therapy or vaccination strategies targeting SLO, as neutralizing its activity may reduce severe invasive disease but potentially promote chronic inflammatory conditions like septic arthritis.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Electrical & Electronic
Chengfei Fan, Liyan Li, Ming-Min Zhao, An Liu, Min-Jian Zhao
Summary: Cooperative localization is a promising technique in wireless networks, and neighbor selection is crucial in reducing data exchange and improving localization accuracy. This paper proposes a general optimization framework for neighbor selection under resource constraints. Two distributed neighbor selection problems are formulated to balance energy consumption, one with implicit energy constraints and one with explicit energy constraints. In addition, a joint optimization of neighbor selection and power allocation is proposed to further improve localization performance. The resulting challenging problems are solved efficiently using novel algorithms based on the penalty dual decomposition method. Simulation results show that the proposed algorithms outperform benchmark algorithms, with the implicit case almost achieving the performance lower bound.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2023)
Article
Cell Biology
Shan Wu, Boon Heng Dennis Teo, Seng Yin Kelly Wee, Junjie Chen, Jinhua Lu
Summary: Nucleolar alarmins like nucleolin (NCL) can activate immune cells, suggesting a family of nucleolar alarmins that contribute to inducing self-limiting tissue inflammation and maintaining tissue homeostasis, with autoimmune diseases only occurring when surveillance breaks down.
CELL DEATH & DISEASE
(2021)
Article
Cell Biology
Patience Shumba, Thomas Sura, Kirsten Moll, Bhavya Chakrakodi, Lea Toelken, Joern Hossmann, Katharina Hoff, Ole Hyldegaard, Michael Nekludov, Mattias Svensson, Per Arnell, Steinar Skrede, Nikolai INFECT Study Group, Anna Norrby-Teglund, Nikolai Siemens
Summary: In this study, it was found that tissue inflammation, neutrophil influx, and degranulation positively correlate with increasing frequency of SpeB-negative GAS clones in patients with monomicrobial necrotizing soft tissue infections. Single colony proteomics revealed that GAS isolated directly from tissue express but do not secrete SpeB. These findings provide new information about GAS fitness and heterogeneity in the soft tissue milieu.
JOURNAL OF BIOMEDICAL SCIENCE
(2023)
Article
Multidisciplinary Sciences
Tebbe de Vries, William Martelly, Sebastien Campagne, Kevin Sabath, Chris P. Sarnowski, Jason Wong, Alexander Leitner, Stefanie Jonas, Shalini Sharma, Frederic H. -T. Allain
Summary: This study determined the 3D structure of the complex between SF3A1-UBL and U1-SL4 RNA and revealed the sequence-specific recognition of U1-SL4 by SF3A1-UBL. The results expand our understanding of RNA binding domains and demonstrate the specific binding capacity of RGG/RG motifs to RNA.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Review
Cell Biology
Mashiat N. Chowdhury, Hong Jin
Summary: Proteins with RGG motifs, rich in arginines and glycines, play essential roles in a wide range of cellular processes. The unique combination of arginine and glycine, along with repeated peptide motifs, enables these proteins to interact with various proteins and nucleic acids. Posttranslational modifications further regulate the functions of RGG motif proteins. This review focuses on the biochemical properties of RGG motifs, their interactions with RNAs and proteins, and the roles of posttranslational modifications in modulating these interactions.
WILEY INTERDISCIPLINARY REVIEWS-RNA
(2023)
Article
Multidisciplinary Sciences
Raju Roy, Gitartha Das, Ishwarya Achappa Kuttanda, Nupur Bhatter, Purusharth Rajyaguru
Summary: Processing bodies (PBs) are RNA-protein complexes that determine mRNA fate. The study shows that Sbp1 is responsible for PB disassembly and that repeats of the RGG motif in Sbp1 play a key role. Additionally, the study finds that the addition of purified Sbp1 leads to a significant decrease in Edc3 assemblies.
NATURE COMMUNICATIONS
(2022)
Article
Biochemistry & Molecular Biology
Constantin Bloechl, Christoph Holzner, Michela Luciano, Renate Bauer, Jutta Horejs-Hoeck, Ulrich Eckhard, Hans Brandstetter, Christian G. Huber
Summary: This study re-evaluates the proteolytic properties of Streptococcal pyrogenic exotoxin B (SpeB) and identifies potential host substrates involved in streptococcal infection. The research provides insights into the activation and specificity of SpeB and contributes to understanding its role in infection.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Immunology
Tao Ouyang, Zibing Yang, Jiawu Wan, Yanni Zhang, Xiaoling Wang, Lingbao Kong, Ting Wang, Yihan Li
Summary: In this study, the transcriptome analysis revealed that the nsp15 protein of porcine epidemic diarrhea virus (PEDV) can inhibit the expression of immune response and inflammation-related genes, providing a favorable intracellular environment for viral proliferation.
MICROBIAL PATHOGENESIS
(2022)
Article
Microbiology
Yong-An Shi, Tzu-Ching Chen, Yan-Wen Chen, Yen-Shan Liu, Yi-Ywan M. Chen, Chih-Ho Lai, Cheng-Hsun Chiu, Chuan Chiang-Ni
Summary: Necrotizing fasciitis is a rapidly progressive and life-threatening disease; however, there is currently no bacterial marker available to identify invasive clinical isolates. This study identified PepO as a potential bacterial marker to identify isolates with defects in the CovR/CovS pathway, which may be a strategy for preventing severe symptoms or poor prognosis after Streptococcus pyogenes infection.
MICROBIOLOGY SPECTRUM
(2022)
Article
Pharmacology & Pharmacy
Pauline Henrot, Edmee Eyraud, Elise Maurat, Sophie Point, Guillaume Cardouat, Jean-Francois Quignard, Pauline Esteves, Thomas Trian, Pierre-Olivier Girodet, Roger Marthan, Maeva Zysman, Patrick Berger, Isabelle Dupin
Summary: This study found that approximately 1/3 of fibrocytes in COPD patients express functional muscarinic M3 receptors. Cholinergic-induced fibrocyte contraction may contribute to the reduction in airway diameter and increase in airflow resistance in COPD patients. Inhibiting these processes may contribute to the beneficial effects of muscarinic antagonists in COPD treatment.
FRONTIERS IN PHARMACOLOGY
(2022)
Article
Virology
Ouyang Peng, Xiaona Wei, Usama Ashraf, Fangyu Hu, Yongbo Xia, Qiuping Xu, Guangli Hu, Chunyi Xue, Yongchang Cao, Hao Zhang
Summary: Using RNA sequencing, this study compared the gene expression patterns in pig intestinal epithelial cells infected with virulent and avirulent strains of PEDV. The findings revealed that over half of the dysregulated genes exhibited a down-regulated expression pattern, with immune response/inflammation genes being enriched in the avirulent strain group.
Article
Virology
Ouyang Peng, Yu Wu, Fangyu Hu, Yu Xia, Rui Geng, Yihui Huang, Siying Zeng, Guangli Hu, Chunyi Xue, Hao Zhang, Yongchang Cao
Summary: The emergence of variant strains of porcine epidemic diarrhea virus (PEDV) in 2010 has caused significant economic losses in the global porcine industry. Through comparative transcriptomic analysis, researchers found that the cell-attenuated strain CT-P120 of PEDV showed promise as a live attenuated vaccine candidate by providing satisfactory protection against variant PEDV infection in piglets. These findings provide invaluable insights for the development of effective PEDV vaccines.
Article
Microbiology
Stephen B. Beres, Luchang Zhu, Layne Pruitt, Randall J. Olsen, Ahmad Faili, Samer Kayal, James M. Musser
Summary: By analyzing the genome sequences of Streptococcus pyogenes, a human pathogen causing millions of infections annually, researchers have identified potential genetic changes that may be responsible for decreased susceptibility to β-lactam antibiotics. Further experiments confirmed that these genetic changes indeed reduce susceptibility to penicillin. The study also discovered a novel chimeric protein in S. pyogenes that leads to significantly decreased susceptibility to β-lactam antibiotics. This reverse genotype-to-phenotype strategy can be applied to other pathogens and may contribute to addressing the global public health problem of antimicrobial resistance.
Article
Biology
Daniel E. Morales-Mantilla, Bailee Kain, Duy Le, Anthony R. Flores, Silke Paust, Katherine Y. King
Summary: This study suggests that hematopoietic stem and progenitor cells (HSPCs) have the potential to be used as a new therapeutic strategy for sepsis. Infusion of HSPCs in mice with sepsis resulted in improved survival rates and reduced inflammation. These findings highlight the important immunomodulatory role of HSPCs and their potential for treating sepsis.
Article
Endocrinology & Metabolism
Elizabeth A. Jensen, Jonathan A. Young, Zachary Jackson, Joshua Busken, Jaycie Kuhn, Maria Onusko, Ronan K. Carroll, Edward O. List, J. Mark Brown, John J. Kopchick, Erin R. Murphy, Darlene E. Berryman
Summary: The gut microbiome is influenced by growth hormone, with excess GH leading to changes in microbial composition and impaired fat absorption in mice. This study provides insights into the age-dependent effects of excess GH on the gut microbiome and its metabolic pathways.
Article
Immunology
Luis Alberto Vega, Misu A. Sanson, Maria Belen Cubria, Shrijana Regmi, Brittany J. Shah, Samuel A. Shelburne, Anthony R. Flores
Summary: Antimicrobial resistance-encoding mobile genetic elements (MGEs) could contribute to the disease potential of bacterial pathogens. This study provides evidence that a 65-kb AMR-encoding MGE (ICESpyM92) enhances the virulence of Group A Streptococcus (GAS) in invasive disease by influencing global gene expression in a background-dependent manner.
INFECTION AND IMMUNITY
(2022)
Review
Microbiology
Magdalena Pilarczyk-Zurek, Izabela Sitkiewicz, Joanna Koziel
Summary: Three distinct species of streptococcal, known as Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus, have gained attention from clinicians and microbiologists as opportunistic pathogens. Their pathogenicity has been underestimated, but recent reports highlight their emergence as life-threatening infections. This review summarizes clinical reports and highlights the importance of accurate microbiological diagnostics for effective treatment.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Microbiology
J. Chase McNeil, Lauren M. Sommer, Jesus G. Vallejo, Kristina G. Hulten, Sheldon L. Kaplan, Anthony R. Flores
Summary: Ceftaroline is a promising therapy option for MRSA infections in pediatric patients. However, there is limited data on the frequency of ceftaroline resistance in this population. A study conducted at a tertiary children's hospital found that 2.9% of invasive MRSA isolates were resistant to ceftaroline, and this resistance was only observed in healthcare-associated infections. The resistant isolates were more often resistant to clindamycin, and sequencing data revealed the predominance of the CC5 lineage among the ceftaroline-resistant isolates.
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
(2022)
Article
Microbiology
Roshika Roshika, Ira Jain, Theodore Glenaldo, Tyler Sickler, James M. Musser, Paul Sumby
Summary: This study investigates why some isolates of group A Streptococcus (GAS) produce pili in lower abundance than others. It was found that the low pilus expression in M3 GAS isolates is a result of repression by the CovR/CovS regulatory system and a specific mutation in the nra gene. The study also reveals that the transcriptional regulators RofA and Nra, located in FCT-2 and FCT-3 respectively, are not functionally identical.
JOURNAL OF BACTERIOLOGY
(2022)
Article
Microbiology
Jessica L. Danger, Roshika Roshika, Sushila Baral, Paul Sumby
Summary: Group A Streptococcus (GAS) causes a variety of human diseases, and the variation in disease potential is due to the regulation of virulence factors at both the transcriptional and posttranscriptional levels. The small regulatory RNA FasX plays a crucial role in this regulation, enhancing the expression of certain factors while reducing the expression of others. This study identifies the M-related protein as a new target of FasX and reveals the importance of FasX in promoting GAS survival and proliferation in human blood. Additionally, this research expands our understanding of the regulatory network of FasX and its role in GAS pathogenesis.
JOURNAL OF BACTERIOLOGY
(2022)
Article
Pediatrics
Elizabeth Marie Sabroske, Misu Ailin Sanson Iglesias, Marcia Rench, Trevor Moore, Hanna Harvey, Morven Edwards, Carol J. Baker, Anthony R. Flores
Summary: This study investigated the changes in antibiotic resistance of a collection of GBS isolates over time and found a significant increase in clindamycin and erythromycin resistance. Obstetricians should be aware of this trend for penicillin-allergic women who may consider using clindamycin.
PEDIATRIC RESEARCH
(2023)
Article
Immunology
Aya Aboulhosn, Misu A. Sanson, Luis Alberto Vega, Maria G. Segura, Sommer Sommer, Marritta Joseph, J. Chase McNeil, Anthony R. Flores
Summary: Starting from October 2022, there has been a notable rise in the number of cases of invasive group A Streptococcus (GAS) disease among children in Houston, Texas. The prevalence of Emm12 GAS strains was disproportionately higher, but the overall proportion of invasive GAS infections during the current surge remains similar to pre-pandemic years.
CLINICAL INFECTIOUS DISEASES
(2023)
Article
Immunology
Joanna Budziaszek, Magdalena Pilarczyk-Zurek, Ewelina Dobosz, Aleksandra Kozinska, Dariusz Nowicki, Katarzyna Obszanska, Agnieszka Szalewska-Palasz, Izabela Kern-Zdanowicz, Izabela Sitkiewicz, Joanna Koziel
Summary: For many years, Streptococcus anginosus has been considered a commensal colonizing various parts of the body, but recent data suggests it is an emerging opportunistic pathogen. The molecular mechanism behind its virulence is not well understood. In this study, the authors developed infection models to study the virulence of S. anginosus and its interactions with the host immune system, and found that the models corresponded to the severity of clinical infection.
INFECTION AND IMMUNITY
(2023)
Article
Microbiology
Nicola Horstmann, Chau Nguyen Tran, Anthony R. Flores, Samuel A. Shelburne
Summary: The CovRS gene regulatory system plays a critical role in the pathogenesis of many streptococci. In this study, the researchers used chromatin immunoprecipitation sequencing (ChIPseq) to investigate the global DNA occupancy of CovR in emm3 group A streptococci. They found that elimination of CovS phosphatase activity increased CovR occupancy at the promoters of virulence factor-encoding genes, including the key regulator Mga and M protein. The study also identified different binding patterns of CovR at high and low phosphorylation levels, suggesting a dimeric and monomeric interaction, respectively.
JOURNAL OF BACTERIOLOGY
(2023)
Article
Microbiology
Marcus A. Wittekind, Paul Briaud, Jayanna L. Smith, Julia R. Tennant, Ronan K. Carroll
Summary: Staphylococcus aureus is a pathogen that causes potentially life-threatening infections, thanks to its multitude of toxins and virulence factors. This bacterium's ability to cause a wide range of illnesses is due to its complex regulatory network, which controls various virulence factors.
MICROBIOLOGY SPECTRUM
(2023)
Article
Microbiology
Stephen B. Beres, Randall J. Olsen, S. Wesley Long, Jesus M. Eraso, Sarrah Boukthir, Ahmad Faili, Samer Kayal, James M. Musser
Summary: Our studies addressed a critical knowledge gap in understanding the genomics and virulence of the bacterial pathogen Streptococcus dysgalactiae subsp. equisimilis. Certain strains of S. dysgalactiae subsp. equisimilis were found to be genetically descended from a common ancestor and capable of causing severe infections in a mouse model. Further studies on the genomics and pathogenic mechanisms of this understudied subspecies are needed.
MICROBIOLOGY SPECTRUM
(2023)
Article
Microbiology
William C. Shropshire, Benjamin Strope, Selvalakshmi Selvaraj Anand, Jordan Bremer, Patrick McDaneld, Micah M. Bhatti, Anthony R. Flores, Awdhesh Kalia, Samuel A. Shelburne
Summary: Using whole-genome sequencing, this study characterized the molecular epidemiology of extended-spectrum cephalosporin-resistant Escherichia coli (ESC-R-Ec) infections at a cancer center in Houston. The study identified a temporal dynamic of ESC-R-Ec infections, with peaks occurring in the last 6 months of the year, and a stable proportion of STc131 strains throughout the study period. The study also revealed the presence of genetically diverse ESC-R-Ec clonal complexes during infection peaks.