Predator-Prey Interactions between and Pathogenic Vibrio parahaemolyticus Strains: Geographical Considerations and Influence of Hemolysins.

is a genus of naturally occurring marine predatory bacteria that attack, replicate within, and lyse vibrios and other bacteria. This study evaluated the specificity of four strains against important sequence types (STs) of clinically relevant Vibrio parahaemolyticus, including pandemic strains ST3 and ST36. The bacteria were previously isolated from seawater from the Mid-Atlantic, Gulf of Mexico, and Hawaiian coasts of the United States.

Environmental Regulation of the Distribution and Ecology of and Like Organisms.

The impact of key environmental factors, salinity, prey, and temperature, on the survival and ecology of and like bacteria (BALOs), including the freshwater/terrestrial, non-halotolerant group and the halophilic strains, has been assessed based on a review of data in the literature. These topics have been studied by numerous investigators for nearly six decades now, and much valuable information has been amassed and reported. The collective data shows that salinity, prey, and temperature play a major role in, not only the growth and survival of BALOs, but also the structure and composition of BALO communities and the distribution of the predators.

Relative Contributions of and Bacteriophage to Bacterial Cell Death under Various Environmental Conditions.

The role of protists and bacteriophages in bacterial predation in the microbial food web has been well studied. There is mounting evidence that and like organisms (BALOs) also contribute to bacterial mortality and, in some cases, more so than bacteriophages. A full understanding of the ecologic function of the microbial food web requires recognition of all major predators and the magnitude of each predator's contribution.

Analysis of gene gain and loss in the evolution of predatory bacteria.

Predatory bacteria are ubiquitously distributed in nature in including in aquatic environments, sewage, intestinal tracts of animals and humans, rhizophere and, soils. However, our understanding of their evolutionary history is limited. Results of recent studies have shown that acquiring novel genes is a major force driving bacterial evolution.

Halobacteriovorax, an underestimated predator on bacteria: potential impact relative to viruses on bacterial mortality.

Predation on bacteria and accompanying mortality are important mechanisms in controlling bacterial populations and recycling of nutrients through the microbial loop. The agents most investigated and seen as responsible for bacterial mortality are viruses and protists. However, a body of evidence suggests that predatory bacteria such as the Halobacteriovorax (formerly Bacteriovorax), a Bdellovibrio-like organism, contribute substantially to bacterial death.

Draft genome sequences for the obligate bacterial predators Bacteriovorax spp. of four phylogenetic clusters.

Bacteriovorax is the halophilic genus of the obligate bacterial predators, Bdellovibrio and like organisms. The predators are known for their unique biphasic life style in which they search for and attack their prey in the free living phase; penetrate, grow, multiply and lyse the prey in the intraperiplasmic phase. Bacteriovorax isolates representing four phylogenetic clusters were selected for genomic sequencing.

Genome-wide comparative analysis of ABC systems in the Bdellovibrio-and-like organisms.

Bdellovibrio-and-like organisms (BALOs) are gram-negative, predatory bacteria with wide variations in genome sizes and GC content and ecological habitats. The ATP-binding cassette (ABC) systems have been identified in several prokaryotes, fungi and plants and have a role in transport of materials in and out of cells and in cellular processes. However, knowledge of the ABC systems of BALOs remains obscure.

Reclassification of Bacteriovorax marinus as Halobacteriovorax marinus gen. nov., comb. nov. and Bacteriovorax litoralis as Halobacteriovorax litoralis comb. nov.; description of Halobacteriovoraceae fam. nov. in the class Deltaproteobacteria.

The taxonomic status of saltwater Bdellovibrio-like prokaryotic predators has been revised to assign species to Halobacteriovorax gen. nov. A reclassification of Bacteriovorax marinus as Halobacteriovorax marinus comb.

454 Pyrosequencing reveals diversity of Bdellovibrio and like organisms in fresh and salt water.

Bdellovibrio-and-like organisms (BALOs) are Gram-negative, predatory bacteria that inhabit terrestrial, freshwater and saltwater environments. They have been detected primarily by culture-dependent methods which have limitations. In this study, diversity and community structure of BALOs in freshwater and saltwater samples were characterized by 16S rRNA gene pyrosequencing with specific BALO group primers.

Differences in bacterial community structure on Hydrilla verticillata and Vallisneria americana in a freshwater spring.

The phylogenetic composition of the epiphytic bacterial community of an invasive aquatic plant (Hydrilla verticillata) and a native species (Vallisneria americana [eelgrass]) of the Wakulla Spring (Florida) was investigated, along with the water column bacterial composition, using clone libraries of the 16S rRNA genes. The bacterial clones from three clone libraries were classified into 182 operational taxonomic units (OTUs), most of which were affiliated with bacterial divisions commonly found in freshwater ecosystems. Based on the identified classes, the bacterial communities on eelgrass and Hydrilla were distinct, such that Planctomycetes, Cyanobacteria, Bacilli and Actinobacteria were found on eelgrass and in the water column but not on Hydrilla.

Functional diversity of bacterioplankton in three North Florida freshwater lakes over an annual cycle.

The phylogenetic diversity of freshwater bacterioplankton is widely known; however, there is minimal information on the functional diversity of the bacterial communities in these systems. Understanding the functional diversity of freshwater bacterial communities is important because heterotrophic bacteria can be impacted by anthropogenic perturbation, which in turn can alter biogeochemical cycling. The objective of this study was to use Biolog EcoPlates to acquire spatial and temporal community-level physiological profiles (CLPPs) for three freshwater lakes of different trophic levels and to assess the phylogenetic affiliation of the bacteria responsible for utilizing the various carbon guilds within them by denaturing gradient gel electrophoresis (DGGE).

Niche partition of Bacteriovorax operational taxonomic units along salinity and temporal gradients in the Chesapeake Bay reveals distinct estuarine strains.

The predatory Bacteriovorax are Gram-negative bacteria ubiquitous in saltwater systems that prey upon other Gram-negative bacteria in a similar manner to the related genus Bdellovibrio. Among the phylogenetically defined clusters of Bacteriovorax, cluster V has only been isolated from estuaries suggesting that it may be a distinct estuarine phylotype. To assess this hypothesis, the spatial and temporal distribution of cluster V and other Bacteriovorax phylogenetic assemblages along the salinity gradient of Chesapeake Bay were determined.

A small predatory core genome in the divergent marine Bacteriovorax marinus SJ and the terrestrial Bdellovibrio bacteriovorus.

Bacteriovorax marinus SJ is a predatory delta-proteobacterium isolated from a marine environment. The genome sequence of this strain provides an interesting contrast to that of the terrestrial predatory bacterium Bdellovibrio bacteriovorus HD100. Based on their predatory lifestyle, Bacteriovorax were originally designated as members of the genus Bdellovibrio but subsequently were re-assigned to a new genus and family based on genetic and phenotypic differences.

Sharing of prey: coinfection of a bacterium by a virus and a prokaryotic predator.

Unlabelled: Rarely, if ever, has a single bacterial cell been confirmed to simultaneously host two fundamentally different predators. Two such predators are viruses and the predatory prokaryotes known as Bdellovibrio and like organisms. Viruses or bacteriophage are particles requiring prey cells in an active metabolic state to complete their life cycle.

Predatory Bacteriovorax communities ordered by various prey species.

The role of predation in altering microbial communities has been studied for decades but few examples are known for bacterial predators. Bacteriovorax are halophilic prokaryotes that prey on susceptible gram-negative bacteria. We recently reported novel observations on the differential selection of Bacteriovorax phylotypes by two different prey, Vibrio parahaemolyticus and Vibrio vulnificus.

Prey bacteria shape the community structure of their predators.

Although predator-prey interactions among higher organisms have been studied extensively, only few examples are known for microbes other than protists and viruses. Among the bacteria, the most studied obligate predators are the Bdellovibrio and like organisms (BALOs) that prey on many other bacteria. In the macroscopical world, both predator and prey influence the population size of the other's community, and may have a role in selection.

Soil functional diversity analysis of a bauxite-mined restoration chronosequence.

Soil microorganisms are sensitive to environmental perturbations such that changes in microbial community structure and function can provide early signs of anthropogenic disturbances and even predict restoration success. We evaluated the bacterial functional diversity of un-mined and three chronosequence sites at various stages of rehabilitation (0, 10, and 20 years old) located in the Mocho Mountains of Jamaica. Samples were collected during the dry and wet seasons and analyzed for metal concentrations, microbial biomass carbon, bacterial numbers, and functional responses of soil microbiota using community-level physiological profile (CLPP) assays.

Increased diversity of predacious Bdellovibrio-like organisms (blos) as a function of eutrophication in Kumaon Lakes of India.

Predation by Bdellovibrio-like organisms (BLOs) results in bacterial community succession in aquatic ecosystems. The effects of nutrient loading on the distribution and phylogeny of BLOs remain largely unknown. To this end, we present our findings on BLO diversity from four north-Indian lakes that are variable in their trophic status; Nainital is eutrophic, both, Bhimtal and Naukuchiatal are mesotrophic and Sattal remains oligotrophic, respectively.

Survival response of Bacteriovorax in surface biofilm versus suspension when stressed by extremes in environmental conditions.

The Bacteriovorax, previously in the genus Bdellovibrio, are prokaryotes that prey upon many Gram-negative bacteria. They are ubiquitous in salt-water environments and have been reported to have a strong association with biofilms. The purpose of this study was to test the hypothesis that this association affords protection for the Bacteriovorax and enhances their survival in nature when exposed to extreme environmental conditions.

Impact of sideways and bottom-up control factors on bacterial community succession over a tidal cycle.

In aquatic systems, bacterial community succession is a function of top-down and bottom-up factors, but little information exists on "sideways" controls, such as bacterial predation by Bdellovibrio-like organisms (BLOs), which likely impacts nutrient cycling within the microbial loop and eventual export to higher trophic groups. Here we report transient response of estuarine microbiota and BLO spp. to tidal-associated dissolved organic matter supply in a river-dominated estuary, Apalachicola Bay, Florida.

Development and evaluation of a quantitative real-time PCR assay for the detection of saltwater Bacteriovorax.

Bdellovibrio-and-like-organisms (BALOs) are small, Gram-negative predatory bacteria with the ability to prey on a wide variety of Gram-negative bacteria, and which may have a significant ecological role. Detection and quantification of BALOs by culture-dependent methods are complicated, as their reproduction is dependent upon the use of appropriate prey. For this reason, a sensitive and specific molecular detection method was developed.

Phylogenetic relationships amongst the saltwater members of the genus Bacteriovorax using rpoB sequences and reclassification of Bacteriovorax stolpii as Bacteriolyticum stolpii gen. nov., comb. nov.

Members of the saltwater genus Bacteriovorax, formerly known as the marine Bdellovibrio, are obligate predatory bacteria that prey selectively on other Gram-negative bacteria. Previous phylogenetic analysis based on the 16S rRNA genes of saltwater Bacteriovorax isolates from environmental samples revealed 11 distinct phylogenetic clusters based on > or =96.5 % gene sequence similarity.

Biostimulation of estuarine microbiota on substrate coated agar slides: a novel approach to study diversity of autochthonous Bdellovibrio- and like organisms.

Characterization of Bdellovibrio- and like organisms (BALOs) from environmental samples involves growing them in the presence of Gram-negative prey bacteria and isolation of BALO plaques. This labor-intensive enrichment and isolation procedure may impede the detection and phylogenetic characterization of uncultivable BALOs. In this article, we describe a simple slide biofilm assay to improve detection and characterization of BALO microbiota.

Global survey of diversity among environmental saltwater Bacteriovoracaceae.

Halophilic Bacteriovorax (Bx), formerly known as the marine Bdellovibrio, are Gram-negative, predatory bacteria found in saltwater systems. To assess their genetic diversity and geographical occurrence, the small subunit rRNA (ssu-rRNA) gene sequences were analysed from 111 marine, salt lake and estuarine isolates recovered from 27 locations around the world. Phylogenetic analysis of these isolates using Geobacter as the outgroup revealed eight distinct ribotype clusters each with at least two isolates.

Response of Bdellovibrio and like organisms (BALOs) to the migration of naturally occurring bacteria to chemoattractants.

A dual culture-based and non-culture-based approach was applied to characterize predator bacterial groups in surface water samples collected from Apalachicola Bay, Florida. Chemotaxis drop assays were performed on concentrated samples in an effort to isolate predator bacteria by their chemotactic ability. Yeast extract (YE) and casamino acids (CA) proved to be strong chemoattractants and resulted in three visibly distinct bands; however, dextrose, succinate, pyruvate, and concentrated cells of Vibrio parahaemolyticus P5 as prey did not elicit any response.