Article
Microbiology
Feroze A. Ganaie, Jamil S. Saad, Stephanie W. Lo, Lesley McGee, Stephen D. Bentley, Andries J. van Tonder, Paulina Hawkins, Jeremy D. Keenan, Juan J. Calix, Moon H. Nahm
Summary: Streptococcus pneumoniae produces diverse capsule types, posing a threat to vaccines targeting pneumococcal polysaccharide capsule. Many capsule types remain uncharacterized. Identifying functional determinants of capsule synthesis is important for improving typing methods and discovering novel variants.
JOURNAL OF CLINICAL MICROBIOLOGY
(2023)
Article
Microbiology
Wan-Zhen Chua, Matthias Maiwald, Kean Lee Chew, Raymond Tzer-Pin Lin, Sanduo Zheng, Lok-To Sham
Summary: MOP family transporters, responsible for transporting lipid-linked precursors to support glycoconjugate synthesis, were systematically tested for their ability to translocate noncognate cargo. Subtle changes in the transporter structure can accommodate different cargoes and potentially expand substrate selectivity. By evaluating the interchangeability of these transporters, important residues for substrate specificity and function were identified, with implications for glycoengineering, vaccine development, and antimicrobial discovery.
Article
Immunology
Sudhanshu Shekhar, Heidi A. Amdal, Fernanda Cristina Petersen
Summary: Mucosal immunization with S. mitis serotype 5 protects mice against S. pneumoniae serotype 5 infection and induces Th17 and predominant serotype-specific IgG/IgA antibody responses against pneumococcal infection.
FRONTIERS IN IMMUNOLOGY
(2021)
Article
Multidisciplinary Sciences
Rei Nakamoto, Jeric Mun Chung Kwan, Jasmine Fei Li Chin, Hui Ting Ong, Josue Flores-Kim, Caroline Midonet, Michael S. VanNieuwenhze, Xue Li Guan, Lok-To Sham
Summary: Many pathogenic bacteria rely on a layer of capsular polysaccharide (CPS) for virulence, with the bacterial tyrosine kinase (BY-kinase) playing a crucial role in regulating capsule synthesis. The interaction between BY-kinase CpsCD and other proteins influences CPS polymer length and peptidoglycan synthesis in Streptococcus pneumoniae. Autophosphorylation of BY-kinases fine-tunes the activity of CpsC, providing spatiotemporal coordination between CPS and PG synthesis.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Immunology
Joel P. Werren, Nadja Mostacci, Ilche Gjuroski, Lalaina Holivololona, Lukas J. Troxler, Lucy J. Hathaway, Julien Furrer, Markus Hilty
Summary: This study examined the impact of different carbon sources on the growth and capsule synthesis of Streptococcus pneumoniae. The results showed that growth was reduced in galactose, mannose, and GlcNAc, with differences in capsule size and adherence potential between different carbon sources. Transcription analysis also revealed carbon source-specific gene expression in clinical isolates.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2023)
Article
Polymer Science
Fulwah Y. Alqahtani, Fadilah S. Aleanizy, Eram El Tahir, Hessa Alowais, Assalh Binkelaib, Bdour Alwathlan, Asmaa Al-Bdrawy, Anders P. Hakansson, Ibrahim Alsarra
Summary: This study prepared polymeric nanoparticles (CNPs) with wide-spectrum antimicrobial activity against Streptococcus pneumoniae TIGR4 and its capsular mutant. The CNPs showed concentration-dependent reduction in bacterial hemolysis and were cytocompatible at lower concentrations, suggesting their potential in treating pneumococcal diseases.
Article
Microbiology
Benedetta Manca, Giada Buffi, Greta Magri, Mariangela Del Vecchio, Anna Rita Taddei, Alfredo Pezzicoli, Maria Giuliani
Summary: Polyphosphate (polyP) produced by Neisseria gonorrhoeae forms a protective shield on the cell surface, allowing the bacteria to evade the host immune system and survive various antimicrobial mechanisms.
Review
Microbiology
Tong Su, Rei Nakamoto, Ye-Yu Chun, Wan-Zhen Chua, Jia-Hui Chen, Justin J. Zik, Lok-To Sham
Summary: This review summarizes recent progress on elucidating the structure-function relationships of CPSs in Streptococcus pneumoniae, including their synthesis mechanisms, regulation, host immune responses, and vaccine development. Provisional models of unsolved CPS repeating units were generated based on genetic and structural information, and biosynthetic pathways of known CPSs were illustrated in a standardized format to facilitate cross-species comparisons. Studying the intricate steps of pneumococcal CPS assembly promises to provide novel insights for drug and vaccine development and enhance understanding of related pathways in other species.
FEMS MICROBIOLOGY REVIEWS
(2021)
Article
Multidisciplinary Sciences
Tong Su, Wan-Zhen Chua, Yao Liu, Jingsong Fan, Si-Yin Tan, Dai-wen Yang, Lok-To Sham
Summary: In this study, we developed a genetic glycoengineering platform to investigate and manipulate the specificity of glycosyltransferases and the structures of glycans. Our findings revealed that the central cleft of GT-B enzymes and the specificity of the precursor transporter play important roles in determining acceptor specificity and fidelity of glycan synthesis. We also demonstrated the significance of regiochemistry in a glycosidic linkage on the binding of glycans to lung epithelial cells and produced medically important mammalian glycans using the glycoengineering platform.
Article
Multidisciplinary Sciences
Sergio Arredondo-Alonso, George Blundell-Hunter, Zuyi Fu, Rebecca A. Gladstone, Alfred Fillol-Salom, Jessica Loraine, Elaine Cloutman-Green, Pal J. Johnsen, Orjan Samuelsen, Anna K. Poentinen, Francois Cleon, Susana Chavez-Bueno, Miguel A. De la Cruz, Miguel A. Ares, Manivanh Vongsouvath, Agnieszka Chmielarczyk, Carolyne Horner, Nigel Klein, Alan McNally, Joice N. Reis, Jose R. Penades, Nicholas R. Thomson, Jukka Corander, Peter W. Taylor, Alex J. McCarthy
Summary: Escherichia coli is a leading cause of invasive bacterial infections in humans. The study reveals the distribution, evolution, and functions of the K1 capsule, a potent capsule type, in E. coli. The findings emphasize the importance of assessing virulence factors in population levels to predict and control bacterial infections.
NATURE COMMUNICATIONS
(2023)
Article
Microbiology
Mary A. Carr, Dennis Marcelo, K. Michael Lovell, Angela H. Benton, Nathan A. Tullos, Erin W. Norcross, Brandon Myers, Marcus K. Robbins, Hayley Craddieth, Mary E. Marquart
Summary: The bacterial capsule in Streptococcus pneumoniae keratitis affects its pathogenicity, and the absence of the capsule impacts inflammation.
Article
Infectious Diseases
Clara Ines Agudelo, Carlos Castaneda-Orjuela, Maria Cristina de Cunto Brandileone, Gabriela Echaniz-Aviles, Samanta Cristine Grassi Almeida, Maria Noemi Carnalla-Barajas, Mabel Regueira, Sofia Fossati, Pedro Alarcon, Pamela Araya, Carolina Duarte, Jacqueline Sanchez, Mirna Novas, Gilda Torano-Peraza, Misladys Rodriguez-Ortega, Gustavo Chamorro-Cortesi, Anibal Kawabata, Gabriela Garcia-Gabarrot, Teresa Camou, Enza Spadola, Daisy Payares, Ana Lucia Andrade, Jose Luis Di Fabio, Elizabeth Castaneda
Summary: A multicentre, retrospective observational study in eight Latin American and Caribbean countries assessed the direct effect of pneumococcal conjugate vaccines (PCVs) on the distribution of pneumococcal serotypes causing invasive pneumococcal disease in children younger than 5 years. The study found a significant decrease in the percentage of vaccine serotypes in PCV countries after PCV introduction.
LANCET INFECTIOUS DISEASES
(2021)
Article
Immunology
Moon H. Nahm, Jigui Yu, Juan J. Calix, Feroze Ganaie
Summary: Reports conflict on which lectin-microbial ligand interactions trigger a protective response from the lectin pathway (LP) of complement. In this study, researchers demonstrate the binding of human lectin ficolin-2 to the capsule polysaccharide of Streptococcus pneumoniae serotype 11A, which leads to complement deposition and phagocytosis of the bacteria. The study also suggests that the gene wcjE plays a crucial role in ficolin-2's ligand expression and bacterial killing. The findings highlight the importance of glycopolymer-specific evaluation of LP's impact.
FRONTIERS IN IMMUNOLOGY
(2022)
Article
Microbiology
Stephanie Hirschmann, Alejandro Gomez-Mejia, Ulrike Maeder, Julia Karsunke, Dominik Driesch, Manfred Rohde, Susanne Haeussler, Gerhard Burchhardt, Sven Hammerschmidt
Summary: The study highlights the importance of TCS09 in pneumococcal metabolic fitness and resistance against oxidative stress by regulating carbohydrate metabolism, potentially indirectly affecting cell wall integrity and the amount of capsular polysaccharide.
Article
Immunology
Feroze Ganaie, Angela R. Branche, Michael Peasley, Jason W. Rosch, Moon H. Nahm
Summary: Detection of oral streptococci as pneumococci in the upper respiratory tract can affect the World Health Organization-recommended carriage procedure. Pneumococcal vaccines could reduce carriage of oral streptococci expressing cross-reactive capsules. However, culture-free PCR-based methods in upper respiratory tract samples have limited usefulness for carriage studies.
CLINICAL INFECTIOUS DISEASES
(2022)