Deletion of increases luminescence of .

Unlabelled: Bioluminescence in is regulated by a quorum-dependent signaling system composed of LuxI and LuxR. LuxI generates 3-oxohexanoyl homoserine lactone (3OC6-HSL), which triggers LuxR to activate transcription of the operon responsible for bioluminescence. Surprisingly, a ∆ mutant produced more bioluminescence than the wild type in culture.

Complete genome sequence of strain H905, a planktonic isolate among squid symbiotic congeners.

Here we describe the genome sequence of () H905, a non-symbiotic isolate from Kaneohe Bay, Hawaii. Despite its close phylogenetic relationship to squid symbiont strains, H905 is not adept at colonization. Its genome serves as a valuable comparator, illustrating the complex evolutionary dynamics within clades.

Complete genome sequence of ST36 strain MAVP-26, a clinical isolate from an oyster-borne human gastric infection.

A Pacific native lineage of ST36 serotype O4:K12 was introduced into the Atlantic, which increased local source illnesses. To identify genetic determinants of virulence and ecological resiliency and track their transfer into endemic populations, we constructed a complete genome of a 2013 Atlantic-traced clinical isolate by hybrid assembly.

Gut dysbiosis was inevitable, but tolerance was not: temporal responses of the murine microbiota that maintain its capacity for butyrate production correlate with sustained antinociception to chronic morphine.

The therapeutic benefits of opioids are compromised by the development of analgesic tolerance, which necessitates higher dosing for pain management thereby increasing the liability for drug dependence and addiction. Rodent models indicate opposing roles of the gut microbiota in tolerance: morphine-induced gut dysbiosis exacerbates tolerance, whereas probiotics ameliorate tolerance. Not all individuals develop tolerance which could be influenced by differences in microbiota, and yet no study design has capitalized upon this natural variation.

Deletion of arrestin-3 does not improve compulsive drug-seeking behavior in a longitudinal paradigm of oral morphine self-administration.

Opioid drugs are potent analgesics that mimic the endogenous opioid peptides, endorphins and enkephalins, by activating the μ-opioid receptor. Opioid use is limited by side effects, including significant risk of opioid use disorder. Improvement of the effect/side effect profile of opioid medications is a key pursuit of opioid research, yet there is no consensus on how to achieve this goal.

Coastal water bacteriophages infect various sets of sequence types.

Introduction: Gastrointestinal illnesses associated with the consumption of shellfish contaminated with have a negative impact on the shellfish industry due to recalls and loss of consumer confidence in products. This bacterial pathogen is very diverse and specific sequence types (STs), ST631 and ST36, have emerged as prevalent causes of foodborne disease outbreaks in the US, though other STs have been implicated in sporadic cases. We investigated whether bacteriophages could be used as a proxy to monitor for the presence of distinct STs in coastal waters.

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.

The Seasonal Microbial Ecology of Plankton and Plankton-Associated Vibrio parahaemolyticus in the Northeast United States.

Microbial ecology studies have proven to be important resources for improving infectious disease response and outbreak prevention. Vibrio parahaemolyticus is an ongoing source of shellfish-borne food illness in the Northeast United States, and there is keen interest in understanding the environmental conditions that coincide with V. parahaemolyticus disease risk, in order to aid harvest management and prevent further illness.

Forecasting Seasonal Concentrations in New England Shellfish.

Seafood-borne illness is a global public health issue facing resource managers and the seafood industry. The recent increase in shellfish-borne illnesses in the Northeast United States has resulted in the application of intensive management practices based on a limited understanding of when and where risks are present. We aim to determine the contribution of factors that affect concentrations in oysters () using ten years of surveillance data for environmental and climate conditions in the Great Bay Estuary of New Hampshire from 2007 to 2016.

Parallel Evolution of Two Clades of an Atlantic-Endemic Pathogenic Lineage of Vibrio parahaemolyticus by Independent Acquisition of Related Pathogenicity Islands.

Shellfish-transmitted infections have recently increased from locations with historically low disease incidence, such as the Northeast United States. This change coincided with a bacterial population shift toward human-pathogenic variants occurring in part through the introduction of several Pacific native lineages (ST36, ST43, and ST636) to nearshore areas off the Atlantic coast of the Northeast United States. Concomitantly, ST631 emerged as a major endemic pathogen.

Host-selected mutations converging on a global regulator drive an adaptive leap towards symbiosis in bacteria.

Host immune and physical barriers protect against pathogens but also impede the establishment of essential symbiotic partnerships. To reveal mechanisms by which beneficial organisms adapt to circumvent host defenses, we experimentally evolved ecologically distinct bioluminescent by colonization and growth within the light organs of the squid . Serial squid passaging of bacteria produced eight distinct mutations in the sensor kinase gene, which conferred an exceptional selective advantage that could be demonstrated through both empirical and theoretical analysis.

Environmental Conditions Associated with Elevated Vibrio parahaemolyticus Concentrations in Great Bay Estuary, New Hampshire.

Reports from state health departments and the Centers for Disease Control and Prevention indicate that the annual number of reported human vibriosis cases in New England has increased in the past decade. Concurrently, there has been a shift in both the spatial distribution and seasonal detection of Vibrio spp. throughout the region based on limited monitoring data.

Spontaneous phenotypic suppression of GacA-defective Vibrio fischeri is achieved via mutation of csrA and ihfA.

Background: Symbiosis defective GacA-mutant derivatives of Vibrio fischeri are growth impaired thereby creating a selective advantage for growth-enhanced spontaneous suppressors. Suppressors were isolated and characterized for effects of the mutations on gacA-mutant defects of growth, siderophore activity and luminescence. The mutations were identified by targeted and whole genome sequencing.

Use of Whole-Genome Phylogeny and Comparisons for Development of a Multiplex PCR Assay To Identify Sequence Type 36 Vibrio parahaemolyticus.

Vibrio parahaemolyticus sequence type 36 (ST36) strains that are native to the Pacific Ocean have recently caused multistate outbreaks of gastroenteritis linked to shellfish harvested from the Atlantic Ocean. Whole-genome comparisons of 295 genomes of V. parahaemolyticus, including several traced to northeastern U.

Bacterial bioluminescence regulates expression of a host cryptochrome gene in the squid-Vibrio symbiosis.

The symbiosis between the squid Euprymna scolopes and its luminous symbiont, Vibrio fischeri, is characterized by daily transcriptional rhythms in both partners and daily fluctuations in symbiont luminescence. In this study, we sought to determine whether symbionts affect host transcriptional rhythms. We identified two transcripts in host tissues (E.

Characterization of a Vibrio fischeri aminopeptidase and evidence for its influence on an early stage of squid colonization.

Vibrio fischeri cells are the sole colonists of a specialized light organ in the mantle cavity of the sepiolid squid Euprymna scolopes. The process begins when the bacteria aggregate in mucus secretions outside the light organ. The cells eventually leave the aggregate, enter the light organ, and encounter a rich supply of peptides.

Influence of seasonality on the genetic diversity of Vibrio parahaemolyticus in New Hampshire shellfish waters as determined by multilocus sequence analysis.

Risk of gastric infection with Vibrio parahaemolyticus increases with favorable environmental conditions and population shifts that increase prevalence of infective strains. Genetic analysis of New Hampshire strains revealed a unique population with some isolates similar to outbreak-causing strains and high-level diversity that increased as waters warmed.

Ecology and genetic structure of a northern temperate Vibrio cholerae population related to toxigenic isolates.

Although Vibrio cholerae is an important human pathogen, little is known about its populations in regions where the organism is endemic but where cholera disease is rare. A total of 31 independent isolates confirmed as V. cholerae were collected from water, sediment, and oysters in 2008 and 2009 from the Great Bay Estuary (GBE) in New Hampshire, a location where the organism has never been detected.

Comparison of the pathogenic potentials of environmental and clinical vibrio parahaemolyticus strains indicates a role for temperature regulation in virulence.

Although the presence of pathogenic Vibrio spp. in estuarine environments of northern New England has been known for some time (C. H.

Stress tolerance and environmental fitness of Pseudomonas fluorescens A506, which has a mutation in RpoS.

Establishment of suppressive populations of bacterial biological control agents on aerial plant surfaces is a critical phase in biologically based management of floral diseases. Periodically, biocontrol agents encounter inhospitable conditions for growth on plants; consequently, tolerance of environmental stresses may contribute to their fitness. In many gram-negative bacteria, including strains of Pseudomonas spp.