Bacteria that synthesize c-di-AMP also encode several mechanisms for controlling c-di-AMP levels within the cytoplasm. One major class of phosphodiesterases comprises GdpP and DhhP homologs, which degrade c-di-AMP into the linear molecule 5'-pApA or AMP by the DHH-DHHA1 domain. The other major class comprises PgpH homologs, which degrade c-di-AMP by the HD domain. Both GdpP and PgpH harbor sensory domains, likely to regulate c-di-AMP hydrolysis activity in response to signal input. As another possible mechanism for controlling cytoplasmic c-di-AMP levels, bacteria also secrete c-di-AMP via multidrug resistance transporters, as demonstrated for Listeria monocytogenes. Mutants that accumulate high c-di-AMP levels, by deletion of phosphodiesterases or multidrug resistance transporters, exhibit aberrant physiology, growth defects, and attenuated virulence in infection.
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http://dx.doi.org/10.1016/j.mib.2015.12.007 | DOI Listing |
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
January 2025
Department of Microbiology and Pathogenic Biology, Air Force Military Medical University, Xi'an 710032, China. *Corresponding authors, E-mail:
Objective The prevalence of drug-resistant Mycobacterium tuberculosis (Mtb) strains is exacerbating the global burden of tuberculosis (TB), highlighting the urgent need for new treatment strategies for TB. Methods The recombinant adenovirus vaccine expressing cyclic di-adenosine monophosphate (c-di-AMP) phosphodiesterase B (CnpB) (rAd-CnpB), was administered to normal mice via mucosal immunization, either alone or in combination with drug therapy, to treat Mtb respiratory infections in mice.Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of antibodies in serum and bronchoalveolar lavage fluid (BALF).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Department of Biochemistry, Brandeis University, Waltham, MA 02453.
The bacterial pathogen forms multicellular communities known as biofilms in which cells are held together by an extracellular matrix principally composed of repurposed cytoplasmic proteins and extracellular DNA. These biofilms assemble during infections or under laboratory conditions by growth on medium containing glucose, but the intracellular signal for biofilm formation and its downstream targets were unknown. Here, we present evidence that biofilm formation is triggered by a drop in the levels of the second messenger cyclic-di-AMP.
View Article and Find Full Text PDFFront Immunol
December 2024
Laboratorio VacSal, Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT-CONICET La Plata, La Plata, Argentina.
Introduction: We previously identified -derived outer membrane vesicles (OMVs) as a promising immunogen for improving pertussis vaccines. In this study, we evaluated the efficacy of our vaccine prototype in immunization strategies aimed at reducing disease transmission by targeting colonization in the upper airways while maintaining protection against severe disease by reducing colonization in the lower respiratory tract.
Methods: We assessed different mucosal administration strategies in a murine model, including homologous mucosal 2-dose prime-boost schedules and heterologous prime-boost strategies combining intramuscular (IM) systemic immunization with mucosal routes (intranasal, IN; or sublingual, SL).
Infect Immun
December 2024
Food Science Department, University of Wisconsin-Madison, Madison, Wisconsin, USA.
mBio
December 2024
Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA.
Unlabelled: Resistance to ampicillin and imipenem in is infrequent. However, the evolution of resistance can occur through prolonged antibiotic exposure during the treatment of chronic infections. In this study, we conducted a long-term evolution experiment using four genetically diverse strains of with varying susceptibilities to ampicillin and imipenem.
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