Bacteriology articles within Nature Communications

Microbes often produce molecules (termed siderophores) that bind iron and then are taken up using specific receptors for iron acquisition. Here, the authors show that a compound produced by Bacillus subtilis plays a more complex role, by modulating iron availability and conferring protection against oxidative stress during inter-species competition.

Bacteria produce several high molecular weight polysaccharides with ill-defined anti-adhesion properties. Here, the authors identified key molecular and biophysical determinants of active antibiofilm polysaccharides, opening new perspectives to identify or engineer new compounds able to control bacterial adhesion and biofilm formation.

The type three secretion system (T3SS) is a membrane-anchored nano-machine utilized by many pathogenic bacteria to inject effector proteins and thus take control of host cells. In a recent article, Kaval et al. reveal a striking colocalization of a T3SS-encoding locus, its transcriptional activators, protein products, and the complete structure at the cell membrane, which they claim provides evidence for a mechanism known as ‘transertion’.

The two-component regulatory system VraRS regulates transcription of penicillin-binding protein 2 in response to cell wall antimicrobials. Here, Lu et al. show that an enzyme from the wall teichoic acid biosynthetic pathway of MRSA can also modulate the expression of virulence factors such as Staphylococcal protein A via VraRS.

Pathogenic Brucella abortus, containing a mix of lipopolysaccharides with or without O-antigen, grows its envelope in a unipolar manner. Here, Servais et al, localize the LPS translocation machinery and identify the main O-antigen ligase in Brucella species, shedding light on the basic biology of this organism.

Bacteria undergo nutrient fluctuations during repeated feast and famine cycles and need to metabolically adapt to these changes. Using quantitative proteomics, Zhu & Dai show that the stringent response of (p)ppGpp is crucial for the timely adaption of bacterial growth to both amino acid and carbon downshift.

Conjugation is a contact-dependent mechanism for the transfer of plasmid DNA between bacterial cells. Here, Couturier et al. use live-cell microscopy to visualise the intracellular dynamics of conjugation in real time, revealing a molecular strategy that allows the sequential production of factors involved in establishing, maintaining and disseminating the plasmid.

β-lactam-induced bacterial killing is complex and not fully resolved. Authors carry out a genome-wide analysis, through penicillin-binding protein replacement, to identify genes essential for drug efficacy.

Uncultured bacteria of the genus Quinella are found in the rumen of ruminant animals, especially in sheep that emit low amounts of methane. Here, Kumar et al. reconstruct genomic sequences from Quinella cells to provide insights into their metabolic capabilities, including lactate and propionate formation as major fermentation pathways and an apparent lack of production of H₂, a major precursor of methane.

The response regulator SsrB, a master activator of the Salmonella pathogenicity island-2 gene cluster, is under allosteric control of thioredoxin. Authors utilise in vitro and in vivo models to investigate if other members of the response regulator family might have adopted thioredoxin as a regulator.

Magnetotactic bacteria use intracellular chains of ferrimagnetic nanocrystals, produced within magnetosome organelles, to align and navigate along the geomagnetic field. Here, Wan et al. identify two proteins involved in magnetosome positioning in Magnetospirillum magneticum, homologs of which are widespread among magnetotactic bacteria.

Here, the authors inversely associate Blautia wexlerae with obesity and type 2 diabetes mellitus in humans and further show that administration of B. wexlerae to mice decrease both high-fat diet–induced obesity and diabetes via modulating gut microbial metabolism.

Synthesis of lipopolysaccharides, essential components for most gram-negative bacteria, is under tight control. Here, authors use in vitro reconstitution and structural approaches to elucidate some of these regulatory mechanisms involving essential membrane proteins LapB and YejM.

Antibiotics of the β-lactam class inhibit bacterial cell wall synthesis by targeting penicillin-binding proteins (PBPs). Here, Sacco et al. study the four PBPs present in the pathogen C. difficile, revealing unique structural features and shedding light on the mechanisms underlying β-lactam resistance in this organism.

The genus Bordetella includes environmental bacteria as well as human pathogens. Here, the authors present a large database of environmental and clinical Bordetella isolates and genome sequences, and develop genotyping systems to facilitate evolutionary and epidemiological studies.

The bacterial respiratory electron transport system (ETS) is branched to allow condition-specific modulation of energy metabolism. Here the authors examine the systems level properties of aerobic electron transport system using adaptive laboratory evolution and multi-omics analyses.

A subset of uropathogenic Escherichia coli are able to halt division and grow into highly filamentous cells during infection of bladder epithelial cells. Here, authors aim to determine the mechanism, and understand the dynamics of cell division machinery during infection-related filamentation.

Quorum-sensing bacteria produce and secrete autoinducers that trigger a behavioral change in the population when reaching a certain threshold. Here, Bettenworth et al. show that autoinducer synthase gene expression in Sinorhizobium meliloti occurs in asynchronous stochastic pulses, and that physiological cues modulate pulse frequency and, consequently, response behavior dynamics. Frequency-modulated pulsing in autoinducer synthase gene expression thus represents a time-based mechanism for information integration and collective decision-making.

The pathogen Mycobacterium tuberculosis uses the siderophores called mycobactins and carboxymycobactins to acquire iron from the host. Here, Zhang et al. identify a protein that is important for siderophore secretion and for the pathogen’s growth in low-iron medium.

The host environment can impact the outcomes of antimicrobial therapies through unclear mechanisms. Here, Ledger et al. show that human serum reduces the efficacy of the antibiotic daptomycin against Staphylococcus aureus by inducing specific pathways leading to changes in the composition of the bacterial membrane and cell wall.

Orthologs of natural competence genes are conserved in non-competent bacterial species, suggesting they have a role other than in transformation. Here, the authors show that competence induction in Staphylococcus aureus occurs in response to reactive oxygen species and host defenses that compromise bacterial respiration during infection, leading to increased DNA and glucose uptake and glycolytic flux.

Cells of the predatory bacterium Bdellovibrio bacteriovorus, which invades and replicates within the periplasm of other bacteria, have a characteristic curved rod shape. Here, Banks et al. show that a peptidoglycan hydrolase is required for the curved shape, and this facilitates invasion of prey cells.

Use of antimicrobials in livestock contributes to development of antimicrobial resistance but there are few large-scale surveillance studies. Here, the authors describe E. coli surveillance in pig farms in China, reporting high levels of multidrug-resistance across all mainland provinces.

Legionella pneumophila expresses a range of bacterial determinants that mimic eukaryotic functions. Here the authors show small RNAs of L.pneumophila mimic eukaryotic microRNA and modulate the host response to infection.

Vancomycin-resistant Enterococcus faecium is an important healthcare-associated pathogen and genomic analyses could inform targeted interventions. Here, the authors optimise an analysis pipeline for identification of putative transmission events using core genome multilocus sequence type clustering and split kmer analysis.

Microbial communities employ a variety of strategies to compete against competitors sharing their niche, for instance, by producing antibiotics. This study reveals that antibiotics produced by Bacillus subtilis act synergistically to eliminate phylogenetically distinct competitors and are regulated accordingly.

Nutrient acquisition is crucial for the growth of pathogens within their hosts. Here, Bateman et al. identify a set of proteins required for heme uptake from host hemoglobin and serum albumin in the pathogen Acinetobacter baumannii.

Several bacteria in the gut microbiota have been associated with colorectal cancer (CRC) but it is not completely clear whether they have a role in tumourigenesis. Here, the authors show enrichment of 12 bacterial taxa in two cohorts of CRC patients and that two Porphyromonas species accelerate CRC onset through butyrate secretion.

OqxB is an RND (Resistance-Nodulation-Division) transporter that contributes to the antibiotic resistance in Klebsiella pneumoniae. Here, the authors report structural and functional characterization of OqxB, with insights into its substrate binding pocket and the role in fluoroquinolone resistance.

Salmonella enterica serovar 4,[5],12:i:- (Salmonella 4,[5],12:i:-) is a major pathogen of humans and animals with a reported incidence in Australia three times higher than the UK and USA. Here, the authors report the circulation, antimicrobial resistance signatures, and effects on host cells, of three Salmonella4,[5],12:i:- lineages within Australia.

R-bodies are long, extendable protein polymers formed in the cytoplasm of some bacteria. Here, Wang et al. show that Pseudomonas aeruginosa produces R-bodies during colonization of plant and nematode hosts, and R-bodies induce ribosome cleavage and translational inhibition in nematodes.

The variability of plasmid fitness effects on wild-type bacterial hosts have been largely unknown until this study, which shows that plasmid persistence increases with bacterial diversity and becomes less dependent on conjugation. This could explain why plasmids remain so common in nature.

Biotin is an essential enzyme cofactor and two pathways for the generation of the biotin precursor pimeloyl-ACP are known. Here, the authors identify and characterize a third pathway for biotin precursor synthesis involving BioZ and they also present the Agrobacterium tumefaciens BioZ crystal structure.

Bacterial cells actively change their size and shape in response to external environments. Here, Shi et al. explore how cells regulate their morphology during rapid environmental changes, showing that the characteristic dynamics of surface area-to-volume ratio are conserved across genetic and chemical perturbations, as well as across species and growth temperatures.

Prokaryotic cell transcriptomics has been limited to mixed or sub-population dynamics and individual cells within heterogeneous populations. Here the authors develop a ‘TRANSITomic’ approach to profile transcriptomes of single Burkholderia pseudomallei cells as they transit through host cell infection.

In several bacteria, cyclic di-AMP mediates potassium (K+) and osmotic homeostasis. Here, the authors show that DarB, a Bacillus subtilis protein previously reported to bind cyclic di-AMP, interacts with the (p)ppGpp synthetase/hydrolase Rel in a K+-dependent manner in turn leading to Rel-dependent accumulation of pppGpp under conditions of K+ starvation.

Colibactin-producing pks+ Escherichia coli are frequent constituents of the human intestinal microbiota. Here, the authors show that short exposure of cells to pks+ E. coli induces chromosomal aberrations, genomic instability, and multiple features of transformation reminiscent of colorectal cancer.

Transcription by bacterial RNA polymerase is interrupted by pausing events that play diverse regulatory roles. Here, the authors find that a large number of E. coli sigma70-dependent pauses, clustered at a 10−20-bp distance from promoters, are regulated by Gre cleavage factors constituting a mechanism for rapid response to changing environmental cues.

Many newly-discovered microbial phyla have been studied solely by cultivation-independent techniques such as metagenomics. Much of their biology thus remains elusive, because the organisms have not yet been isolated and grown in the lab. Katayama et al. lift the curtain on some intriguing biology by cultivating and studying bacteria from the elusive OP9 phylum (Atribacterota).

In Bacteroidetes, SusCD complexes mediate uptake of large nutrients across the outer membrane. SusCD structures in the apo state and in complex with β2,6 fructo-oligosaccharides reveal several substrate molecules in the binding cavity and suggest details of the pedal bin mechanism employed in glycan import.

Chlamydia trachomatis does not possess TrpL-mediated transcription attenuation of its trp operon. Here, the authors show that an iron-dependent regulator, YtgR, acts as a tryptophan-dependent attenuator of the trp operon in this organism, due to translational regulation of YtgR levels via a triple tryptophan motif.

Here, the authors characterize the effects of Lactobacillus casei strains engineered to express pathogenic or non-pathogenic Listeria adhesion protein (LAP) in systemic colonization and protection against lethal Listeria monocytogenes infection in mice and show that these engineered strains can colonize the intestine and prevent dissemination of L. monocytogenes and protect against lethal infection while promoting immunomodulatory effects.

The bacterium Neisseria meningitidis causes life-threatening meningitis and sepsis. Here, Muir et al. construct a complete collection of defined mutants in protein-coding genes of this organism, which they use to identify its essential genome and to shed light on the functions of multiple genes.

The pathogenesis of Streptococcus pyogenes (GAS) causing scarlet fever has been associated with the presence of prophages, such as ΦHKU.vir, and their products. Here, the authors characterize the exotoxins SpeC and Spd1 of ΦHKU.vir and show these to act synergistically to facilitate nasopharyngeal colonization in mice.

Pandemic cholera was reintroduced to Argentina in 1992, leading to epidemic spread. Here, the authors use whole genome sequencing to show how, over 6 years, epidemic cholera was caused by invariant 7PET lineage Vibrio cholerae, against a background of sporadic disease caused by diverse local strains.

Histones have a role in antimicrobial defense. Here, the authors show that the histone H2A and the antimicrobial peptide LL-37 exert synergistic effects by enhancing bacterial membrane pores and enabling H2A entry into the bacterial cytoplasm, where it reorganizes DNA and inhibits transcription.

High levels of Fusobacterium nucleatum have been associated with poor overall survival in patients with colorectal and esophageal cancer. Here, the authors show that F. nucleatum is abundant in breast cancer samples and that the colonization by F. nucleatum accelerates tumor growth and metastasis in preclinical breast cancer models.

A membrane-embedded complex (called T4CC) is essential for injection of Legionella pneumophila effector proteins into human macrophages via a Type IV secretion system. Here, the authors purify and study the T4CC using functional and cryo-EM structural analyses, providing insights into the secretion mechanisms.

Multidrug resistance of the opportunistic pathogen Stenotrophomonas maltophilia is an increasing problem. Here, analyzing strains from 22 countries, the authors show that the S. maltophilia complex is divided into 23 monophyletic lineages and find evidence for intra-hospital transmission.