Toxin-antitoxin (TA) systems are bicistronic genetic modules that are ubiquitously present in bacterial genomes. The Mycobacterium tuberculosis genome encodes 90 putative TA systems, and these are considered to be associated with maintenance of bacterial genomic stability or bacterial survival under unfavorable environmental conditions. The majority of these in M. tuberculosis have been annotated as belonging to the virulence-associated protein B and C (VapBC) family. However, their precise role in bacterial physiology has not been elucidated. Here, we functionally characterized VapC toxins from M. tuberculosis and show that overexpression of some homologs inhibits growth of Mycobacterium bovis bacillus Calmette-Guérin in a bacteriostatic manner. Expression profiling of messenger RNA revealed that these VapC toxins were differentially induced upon exposure of M. tuberculosis to stress conditions. We also unraveled that transcriptional cross-activation exists between TA systems in M. tuberculosis. This study provides the first evidence for the essentiality of VapBC3 and VapBC4 systems in M. tuberculosis virulence.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/infdis/jiy109 | DOI Listing |
Sci Rep
January 2025
Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada.
Metals have been used throughout history to manage disease. With the rising incidence of antibiotic-resistant bacterial strains, metal-based antimicrobials (MBAs) have re-emerged as an alternative to combat infections. Gallium nitrate has shown promising efficacy against several pathogens.
View Article and Find Full Text PDFPoult Sci
January 2025
Institute of Agricultural Science and Technology Development, College of Veterinary Medicine, Yangzhou University, Yangzhou, PR China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, PR China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou, PR China; Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou, PR China. Electronic address:
Avian pathogenic Escherichia coli (APEC) is a major threat to the poultry industry, causing bloodstream and extraintestinal infections. Type II toxin-antitoxin (TA) systems are known to aid bacterial pathogens in adapting to stress, promoting persister cell formation, and enhancing virulence. While type II TA systems have been extensively studied in many pathogens, APEC-derived TAs have received limited attention.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia.
Expression of recombinant genes can be controlled using inducible promoters. However, the most commonly used IPTG- and arabinose-inducible promoters result in an 'all-or-nothing' response, leading to fully induced and uninduced bacterial subpopulations. Here, we investigate whether appropriate modifications to these promoter systems can be combined into a single vector system, enabling homogenous expression of two genes of interest that can be precisely tuned using inducer concentration.
View Article and Find Full Text PDFAntonie Van Leeuwenhoek
December 2024
Biological Resource Center/Korean Collection for Type Cultures (KCTC), Korea Research Institute of Bioscience and Biotechnology, Jeongeup, 56212, Republic of Korea.
A thermophilic cellulase-producing bacterium, strain HSW-8, isolated from hot spring waters in South Korea, was subjected to a taxonomic analysis. Cells of strain HSW-8 were gram-stain-negative, facultatively anaerobic, rod-shaped, with optimum growth at 45 °C, pH 7.0, in the presence of 0% (w/v) NaCl.
View Article and Find Full Text PDFPLoS Pathog
December 2024
Center for Infection Biology, School of Basic Medical Sciences, Tsinghua University, Beijing, China.
Human pathogen Streptococcus pneumoniae forms multiple epigenetically and phenotypically distinct intra-populations by invertase PsrA-driven inversions of DNA methyltransferase hsdS genes in the colony opacity-determinant (cod) locus. As manifested by phase switch between opaque and transparent colonies, different genome methylation patterns or epigenomes confer pathogenesis-associated traits, but it is unknown how the pathogen controls the hsdS inversion orientations. Here, we report our finding of the SpxA1-TenA toxin-antitoxin (TA) system that regulates the orientations of hsdS inversions, and thereby bacterial epigenome and associated traits (e.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!