Corrected and republished from: " Possesses Xds and Dns Nucleases That Differentially Influence Phosphate Scavenging, Aggregation, Competence, and Symbiotic Colonization of Squid".

Cells of colonize the light organ of , providing the squid bioluminescence in exchange for nutrients and protection. The bacteria encounter DNA-rich mucus throughout their transition to a symbiotic lifestyle, leading us to hypothesize a role for nuclease activity in the colonization process. In support of this, we detected abundant extracellular nuclease activity in growing cells of .

Lighting the way: how the model microbe reveals the complexity of Earth's "simplest" life forms.

() 's initial rise to fame derived from its alluring production of blue-green light. Subsequent studies to probe the mechanisms underlying this bioluminescence helped the field discover the phenomenon now known as quorum sensing. Orthologs of quorum-sensing regulators (i.

: a model for host-associated biofilm formation.

Multicellular communities of adherent bacteria known as biofilms are often detrimental in the context of a human host, making it important to study their formation and dispersal, especially in animal models. One such model is the symbiosis between the squid and the bacterium . Juvenile squid hatch aposymbiotically and selectively acquire their symbiont from natural seawater containing diverse environmental microbes.

The biofilm community resurfaces: new findings and post-pandemic progress.

The ninth American Society for Microbiology Conference on Biofilms was convened in-person on 13-17 November 2022 in Charlotte, NC. As the first of these conferences since prior to the start of the COVID-19 pandemic, the energy among the participants of the conference was clear, and the meeting was a tremendous success. The mixture of >330 oral and poster presentations resoundingly embodied the vitality of biofilm research across a wide range of topics and multiple scientific disciplines.

Genetic Analysis Reveals a Requirement for the Hybrid Sensor Kinase RscS in -Aminobenzoic Acid/Calcium-Induced Biofilm Formation by .

The marine bacterium Vibrio fischeri initiates symbiotic colonization of its squid host, , by forming and dispersing from a biofilm dependent on the mbiosis olysaccharide locus (). Historically, genetic manipulation of V. fischeri was needed to visualize -dependent biofilm formation , but recently, we discovered that the combination of two small molecules, -aminobenzoic acid (pABA) and calcium, was sufficient to induce wild-type strain ES114 to form biofilms.

Computational and cellular exploration of the protein-protein interaction between STAS domain protein SypA and serine kinase SypE.

Anti-sigma factor antagonists SpoIIAA and RsbV from are the archetypes for single-domain STAS proteins in bacteria. The structures and mechanisms of these proteins along with their cognate anti-sigma factors have been well studied. SpoIIAA and RsbV utilize a partner-switching mechanism to regulate gene expression through protein-protein interactions to control the activity of their downstream anti-sigma factor partners.

Vibrio fischeri Possesses Xds and Dns Nucleases That Differentially Influence Phosphate Scavenging, Aggregation, Competence, and Symbiotic Colonization of Squid.

Cells of Vibrio fischeri colonize the light organ of Euprymna scolopes, providing the squid bioluminescence in exchange for nutrients and protection. The bacteria encounter DNA-rich mucus throughout their transition to a symbiotic lifestyle, leading us to hypothesize a role for nuclease activity in the colonization process. In support of this, we detected abundant extracellular nuclease activity in growing cells of V.

High Levels of Cyclic Diguanylate Interfere with Beneficial Bacterial Colonization.

During colonization of the Hawaiian bobtail squid (), Vibrio fischeri bacteria undergo a lifestyle transition from a planktonic motile state in the environment to a biofilm state in host mucus. Cyclic diguanylate (c-di-GMP) is a cytoplasmic signaling molecule that is important for regulating motility-biofilm transitions in many bacterial species. V.

Mutational Analysis of c-di-GMP-Modulating Genes Reveals Complex Regulation of Motility.

The symbiont Vibrio fischeri uses motility to colonize its host. In numerous bacterial species, motility is negatively controlled by cyclic-di-GMP (c-di-GMP), which is produced by diguanylate cyclases (DGCs) with GGDEF domains and degraded by phosphodiesterases with either EAL or HD-GYP domains. To begin to decode the functions of the 50 Vibrio fischeri genes with GGDEF, EAL, and/or HD-GYP domains, we deleted each gene and assessed each mutant's migration through tryptone broth salt (TBS) soft agar medium containing or lacking magnesium (Mg) and calcium (Ca), which are known to influence V.

sRNA chaperone Hfq controls bioluminescence and other phenotypes through Qrr1-dependent and -independent mechanisms in Vibrio fischeri.

Colonization of the squid Euprymna scolopes by the bacterium Vibrio fischeri depends on bacterial biofilm formation, motility, and bioluminescence. Previous work has demonstrated an inhibitory role for the small RNA (sRNA) Qrr1 in quorum-induced bioluminescence of V. fischeri, but the contribution of the corresponding sRNA chaperone, Hfq, was not examined.

Calcium-Responsive Diguanylate Cyclase CasA Drives Cellulose-Dependent Biofilm Formation and Inhibits Motility in Vibrio fischeri.

The marine bacterium Vibrio fischeri colonizes its host, the Hawaiian bobtail squid, in a manner requiring both bacterial biofilm formation and motility. The decision to switch between sessile and motile states is often triggered by environmental signals and regulated by the widespread signaling molecule c-di-GMP. Calcium is an environmental signal previously shown to affect both biofilm formation and motility by V.

Quorum Sensing and Cyclic di-GMP Exert Control Over Motility of KB2B1.

Bacterial motility is critical for symbiotic colonization by of its host, the squid , facilitating movement from surface biofilms to spaces deep inside the symbiotic organ. While colonization has been studied traditionally using strain ES114, others, including KB2B1, can outcompete ES114 for colonization for a variety of reasons, including superior biofilm formation. We report here that KB2B1 also exhibits an unusual pattern of migration through a soft agar medium: whereas ES114 migrates rapidly and steadily, KB2B1 migrates slowly and then ceases migration.

A lasting symbiosis: how Vibrio fischeri finds a squid partner and persists within its natural host.

As our understanding of the human microbiome progresses, so does the need for natural experimental animal models that promote a mechanistic understanding of beneficial microorganism-host interactions. Years of research into the exclusive symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium Vibrio fischeri have permitted a detailed understanding of those bacterial genes underlying signal exchange and rhythmic activities that result in a persistent, beneficial association, as well as glimpses into the evolution of symbiotic competence. Migrating from the ambient seawater to regions deep inside the light-emitting organ of the squid, V.

Control of Competence in Vibrio fischeri.

species, including the squid symbiont , become competent to take up DNA under specific conditions. For example, becomes competent when grown in the presence of chitin oligosaccharides or upon overproduction of the competence regulatory factor TfoX. While little is known about the regulatory pathway(s) that controls competence, this microbe encodes homologs of factors that control competence in the well-studied To further develop as a genetically tractable organism, we evaluated the roles of some of these competence homologs.

Vibrio fischeri Amidase Activity Is Required for Normal Cell Division, Motility, and Symbiotic Competence.

-Acetylmuramoyl-l-alanine amidases are periplasmic hydrolases that cleave the amide bond between -acetylmuramic acid and alanine in peptidoglycan (PG). Unlike many Gram-negative bacteria that encode redundant periplasmic amidases, appears to encode a single protein that is homologous to AmiB of We screened a transposon mutant library for strains altered in biofilm production and discovered a biofilm-overproducing strain with an insertion in (). Further characterization of biofilm enhancement suggested that this phenotype was due to the overproduction of cellulose, and it was dependent on the cellulose synthase.

Genetic Manipulation of Vibrio fischeri.

Vibrio fischeri is a nonpathogenic organism related to pathogenic Vibrio species. The bacterium has been used as a model organism to study symbiosis in the context of its association with its host, the Hawaiian bobtail squid Euprymna scolopes. The genetic tractability of this bacterium has facilitated the mapping of pathways that mediate interactions between these organisms.

LapG mediates biofilm dispersal in Vibrio fischeri by controlling maintenance of the VCBS-containing adhesin LapV.

Efficient symbiotic colonization of the squid Euprymna scolopes by the bacterium Vibrio fischeri depends on bacterial biofilm formation on the surface of the squid's light organ. Subsequently, the bacteria disperse from the biofilm via an unknown mechanism and enter through pores to reach the interior colonization sites. Here, we identify a homolog of Pseudomonas fluorescens LapG as a dispersal factor that promotes cleavage of a biofilm-promoting adhesin, LapV.

Vibrio fischeri: Laboratory Cultivation, Storage, and Common Phenotypic Assays.

Vibrio fischeri is a nonpathogenic organism related to pathogenic Vibrio species that can be readily grown and stored with common laboratory equipment. In this article, protocols for routine growth, storage, and phenotypic assessment of V. fischeri, as well as recipes for useful media, are included.

Aerococcus urinae Isolated from Women with Lower Urinary Tract Symptoms: Aggregation and Genome Analysis.

is increasingly recognized as a potentially significant urinary tract bacterium. has been isolated from urine collected from both males and females with a wide range of clinical conditions, including urinary tract infection (UTI), urgency urinary incontinence (UUI), and overactive bladder (OAB). is of particular clinical concern because it is highly resistant to many antibiotics and, when undiagnosed, can cause invasive and life-threatening bacteremia, sepsis, or soft tissue infections.

Using Colonization Assays and Comparative Genomics To Discover Symbiosis Behaviors and Factors in Vibrio fischeri.

The luminous marine Gram-negative bacterium () is the natural light organ symbiont of several squid species, including the Hawaiian bobtail squid, , and the Japanese bobtail squid, Work with has shown how the bacteria establish their niche in the light organ of the newly hatched host. Two types of strains have been distinguished based upon their behavior in cocolonization competition assays in juvenile , i.e.

Biofilms 2018: A diversity of microbes and mechanisms.

The 8 ASM Conference on Biofilms was held in Washington D.C. on October 7-11, 2018.

Nitric oxide inhibits biofilm formation by Vibrio fischeri via the nitric oxide sensor HnoX.

Nitric oxide (NO) is an important defense molecule secreted by the squid Euprymna scolopes and sensed by the bacterial symbiont, Vibrio fischeri, via the NO sensor HnoX. HnoX inhibits colonization through an unknown mechanism. The genomic location of hnoX adjacent to hahK, a recently identified positive regulator of biofilm formation, suggested that HnoX may inhibit colonization by controlling biofilm formation, a key early step in colonization.

The model squid-vibrio symbiosis provides a window into the impact of strain- and species-level differences during the initial stages of symbiont engagement.

Among horizontally acquired symbioses, the mechanisms underlying microbial strain- and species-level specificity remain poorly understood. Here, confocal-microscopy analyses and genetic manipulation of the squid-vibrio association revealed quantitative differences in a symbiont's capacity to interact with the host during initial engagement. Specifically, dominant strains of Vibrio fischeri, 'D-type', previously named for their dominant, single-strain colonization of the squid's bioluminescent organ, were compared with 'S-type', or 'sharing', strains, which can co-colonize the organ.