Journal of Bacteriology

ABSTRACT The flagellar motor of Pseudomonas aeruginosa operates in a near-unbiased manner, extending the classical paradigm established by Escherichia coli . Rather than altering rotational bias, P. aeruginosa achieves chemotaxis by symmetrically modulating the dwell times of the two rotational states. This strategy is associated with a mechanically adaptive dual-stator architecture (MotAB and Mo…

ABSTRACT Toxin–antitoxin (TA) systems are genetic modules widely distributed across bacterial chromosomes and mobile genetic elements. Initially described as plasmid addiction systems that ensure vertical inheritance through post-segregational killing, they are now recognized as versatile regulators of bacterial adaptability. In Helicobacter pylori , a gastric pathogen infecting nearly half of th…

ABSTRACT Prevotella species are an extremely common and abundant bacteria detected within the low microbial biomass of the lungs and are a core component of the oral microbiome. Clinical studies have drawn associations between Prevotella abundance and lung homeostasis, indicating potential relationships between Prevotella and lung inflammation, infection defense, and lung function. Across several…

ABSTRACT Biofilm dispersion is a regulated process that enables bacteria to escape as free-living cells. This response coincides with matrix degradation, reduced cyclic di-GMP levels, heightened antibiotic susceptibility, and restored flagellar motility. While dispersed cells have been reported to be motile, the mechanisms enabling motility upon induction of dispersion remain unclear. Here, we ex…

ABSTRACT Type IV pili (T4P) drive social (S) motility in Myxococcus xanthus through cycles of extension and retraction powered by the ATPases PilB and PilT. Although the canonical retraction ATPase PilT is essential for force generation, M. xanthus encodes four PilT-like paralogs whose contributions to motility remain unclear. Here, we identify MXAN_1995 as the long-sought PilU protein that serve…

ABSTRACT Precise regulation of gene expression is essential for all living systems. Genes encoded on mobile genetic elements such as conjugative plasmids are also highly regulated to ensure stable inheritance, successful horizontal transfer, and adaptation to diverse bacterial hosts. The multi-drug resistance plasmid RK2 encodes an intricate regulatory network centered on the ParB-CTPase family p…

Biofilms are the predominant lifestyle for bacteria. Biofilm abundance makes understanding their behavior important for different research domains. These domains can have different information and reporting standards. Information reporting standards have been proposed for some biofilm research methods. Standard methods and consensus standards have also been promulgated. We propose dimensional ana…

ABSTRACT Staphylococcus aureus is a leading cause of biofilm-associated infections, in which communities of bacterial cells are encased in an extracellular matrix composed of polysaccharides, proteins, and extracellular DNA (eDNA) that protect bacteria from host immune defense and antibiotics. Despite their importance, the mechanisms by which matrix components are released from bacterial cells an…

ABSTRACT Pathogenic and persistent biofilms are a major challenge in medicine and industry, acting as resilient microbial communities that resist antibiotics and cause persistent infections. In this review, we discuss pulcherriminic acid, a promising iron-chelating molecule produced by antagonistic Bacillus subtilis as a natural weapon against persistent biofilms, particularly those formed by pat…

ABSTRACT The genus Neisseria includes two human pathogens, Neisseria gonorrhoeae and Neisseria meningitidis , in addition to commensal species that also inhabit human and animal hosts. One of the features that occurs during neisserial host colonization is biofilm formation. In other bacteria, biofilm formation enables persistence as well as evasion of the host immune system. Extracellular DNA (eD…

ABSTRACT Bacterial ribosomes initiate translation while the nascent transcript is still engaged with RNA polymerase, creating a risk that translating ribosomes will become trapped if RNA polymerase is blocked before transcription of the stop codon. Here we show that DNA-binding proteins block RNA polymerase and translating ribosomes in vitro and in vivo . Translating ribosomes are rescued after t…

ABSTRACT Since its isolation from a Yellowstone hot spring in 1972, Sulfolobus acidocaldarius has become one of the most important model organisms for archaeal biology. Initially studied for its remarkable adaptation to high temperature and low pH, it has evolved into a genetically tractable system that has contributed substantially to our understanding of archaeal physiology, molecular biology, …

Iron is a crucial micronutrient for <i>Pseudomonas aeruginosa</i> survival and virulence, yet it can also be toxic due to the production of reactive oxygen species. The PrrF small regulatory RNAs (sRNAs) are transcribed in iron-limiting conditions and block the expression of several mRNAs involved in <i>P. aeruginosa</i>'s oxidative stress response. Here, we make the surprising discovery that oxi…

Iron availability affects oceanic primary productivity and the strength of the biological carbon pump. However, the mechanism of iron solubility in hypersaline environments is poorly understood. In this work, we investigated the extremely halophilic archaeon <i>Haloferax volcanii</i> to reduce ferrihydrite under 25% salinity, aiming to elucidate its energy metabolism associated with extracellular…

Uropathogenic <i>Escherichia coli</i> (UPEC) is the leading causative agent of urinary tract infection (UTI). Copper (Cu) is a host effector mobilized to the bladder during the innate immune response activated by acute UTI. <i>E. coli</i> precisely regulates Cu homeostasis via efflux systems because excess Cu is toxic. Long-chain fatty acid (LCFA) homeostasis is critical for the survival of <i>E.…

Nitrogen (N) is essential for bacterial growth, and adaptation to N starvation involves extensive reprogramming of metabolism and gene expression. A hallmark subcellular feature in long-term N-starved <i>Escherichia coli</i> cells is the presence of biomolecular condensates of the major bacterial RNA regulator Hfq. The Hfq condensates, which accumulate gradually during N starvation, contribute to…

Nitrogen-related phosphotransferase (PTS^Ntr) systems are highly conserved and widely distributed in proteobacteria. These systems are thought to enable bacteria to sense and respond to changes in cellular carbon and nitrogen availability. The PTS^Ntr is analogous to the carbohydrate phosphotransferase systems that carry out phosphorylation and uptake of specific carbohydrates…

Surface proteins of gram-positive bacteria are key virulence factors in the human pathogen <i>Staphylococcus aureus</i>. Most surface proteins carry a YSIRK/G-S type signal peptide that promotes cross-wall trafficking and attachment to the septal cell wall during cell division. This study identified several new factors regulating this process through a comprehensive screen. The mutants identified…

Plasmid conjugation drives the spread of antimicrobial resistance genes between different bacterial species. In IncF plasmids, this process relies on tight interactions between an outer-membrane protein in the recipient and the plasmid-encoded TraN, which consists of conserved base and variable tip domains. So far, TraN was only studied in IncF plasmids. We show that IncA/C and IncH plasmids enco…

<i>Pseudomonas syringae</i> pv. tomato (Pst), the causal agent of bacterial speck in tomato, is a model for understanding plant-pathogen coevolution. Within this pathosystem, the emergence of race 1 has traditionally been interpreted as a direct adaptive response to the development of Pto/Prf-mediated resistance in tomato. While race 0 strains are recognized through the type III effectors AvrPto …