Predatory bacteria prevent the proliferation of intraocular and fluoroquinolone-resistant .

Endogenous endophthalmitis caused by Gram-negative bacteria is an intra-ocular infection that can rapidly progress to irreversible loss of vision. While most endophthalmitis isolates are susceptible to antibiotic therapy, the emergence of resistant bacteria necessitates alternative approaches to combat intraocular bacterial proliferation. In this study the ability of predatory bacteria to limit intraocular growth of , , and was evaluated in a New Zealand white rabbit endophthalmitis prevention model.

Intra-ocular Predation of Fluoroquinolone-Resistant and by Predatory Bacteria.

Endogenous endophthalmitis caused by Gram-negative bacteria is an intra-ocular infection that can rapidly progress to irreversible loss of vision. While most endophthalmitis isolates are susceptible to antibiotic therapy, the emergence of resistant bacteria necessitates alternative approaches to combat intraocular bacterial proliferation. In this study the ability of predatory bacteria to limit intraocular growth of , , and was evaluated in a New Zealand White rabbit endophthalmitis prevention model.

Predatory bacteria can reduce Pseudomonas aeruginosa induced corneal perforation and proliferation in a rabbit keratitis model.

Purpose: Pseudomonas aeruginosa keratitis is a severe ocular infection that can lead to perforation of the cornea. In this study we evaluated the role of bacterial quorum sensing in generating corneal perforation and bacterial proliferation and tested whether co-injection of the predatory bacteria Bdellovibrio bacteriovorus could alter the clinical outcome. P.

Predatory Bacteria can Reduce Induced Corneal Perforation and Proliferation in a Rabbit Keratitis Model.

Purpose: keratitis is a severe ocular infection that can lead to perforation of the cornea. In this study we evaluated the role of bacterial quorum sensing in generating corneal perforation and bacterial proliferation and tested whether co-injection of the predatory bacteria could alter the clinical outcome. with mutations were observed among keratitis isolates from a study collecting samples from India, so an isogenic mutant strain of was included.

Breakdown of clonal cooperative architecture in multispecies biofilms and the spatial ecology of predation.

Biofilm formation, including adherence to surfaces and secretion of extracellular matrix, is common in the microbial world, but we often do not know how interaction at the cellular spatial scale translates to higher-order biofilm community ecology. Here we explore an especially understudied element of biofilm ecology, namely predation by the bacterium . This predator can kill and consume many different Gram-negative bacteria, including and .

Clearance of Gram-Negative Bacterial Pathogens from the Ocular Surface by Predatory Bacteria.

It was previously demonstrated that predatory bacteria are able to efficiently eliminate Gram-negative pathogens including antibiotic-resistant and biofilm-associated bacteria. In this proof-of-concept study we evaluated whether two species of predatory bacteria, and , were able to alter the survival of Gram-negative pathogens on the ocular surface. Clinical keratitis isolates of (strain PAC) and (strain K904) were applied to the ocular surface of NZW rabbits followed by application of predatory bacteria.

Bacterial predation transforms the landscape and community assembly of biofilms.

The bacterium Bdellovibrio bacteriovorus attaches to the exterior of a Gram-negative prey cell, enters the periplasm, and harvests resources to replicate before lysing the host to find new prey. Predatory bacteria such as this are common in many natural environments, as are groups of matrix-bound prey cell clusters, termed biofilms. Despite the ubiquity of both predatory bacteria and biofilm-dwelling prey, the interaction between B.

Effects of the prey landscape on the fitness of the bacterial predators Bdellovibrio and like organisms.

Bdellovibrio and like organisms (BALOs) are obligate predatory bacteria commonly encountered in the environment. In dual predator-prey cultures, prey accessibility ensures optimal feeding and replication and rapid BALO population growth. However, the environmental prey landscape is complex, as it also incorporates non-prey cells and other particles.

To hunt or to rest: prey depletion induces a novel starvation survival strategy in bacterial predators.

The small size of bacterial cells necessitates rapid adaption to sudden environmental changes. In Bdellovibrio bacteriovorus, an obligate predator of bacteria common in oligotrophic environments, the non-replicative, highly motile attack phase (AP) cell must invade a prey to ensure replication. AP cells swim fast and respire at high rates, rapidly consuming their own contents.

Characterizing species interactions that contribute to biofilm formation in a multispecies model of a potable water bacterial community.

Microbial biofilms are ubiquitous in drinking water systems, yet our understanding of drinking water biofilms lags behind our understanding of those in other environments. Here, a six-member model bacterial community was used to identify the interactions and individual contributions of each species to community biofilm formation. These bacteria were isolated from the International Space Station potable water system and include , , , ( and , but all six species are common members of terrestrial potable water systems.

High-Throughput Analysis of Gene Function in the Bacterial Predator Bdellovibrio bacteriovorus.

is a bacterial predator capable of killing and replicating inside most Gram-negative bacteria, including antibiotic-resistant pathogens. Despite growing interest in this organism as a potential therapeutic, many of its genes remain uncharacterized. Here, we perform a high-throughput genetic screen with using transposon sequencing (Tn-seq) to explore the genetic requirements of predation.

Bacterial predation under changing viscosities.

Bdellovibrio and like organisms (BALOs) are largely distributed in soils and in water bodies obligate predators of gram-negative bacteria that can affect bacterial communities. Potential applications of BALOs include biomass reduction, their use against pathogenic bacteria in agriculture, and in medicine as an alternative against antibiotic-resistant pathogens. Such different environments and uses mean that BALOs should be active under a range of viscosities.

The anti-nociceptive effects of Porphyromonas gingivalis lipopolysaccharide.

Objective: The objective of this study was to assess the effect of Porphyromonas gingivalis lipopolysaccharide (PG LPS) on acute pain-related behaviour induced in rats and to measure its impact on the levels of pro-inflammatory cytokines (IL-1β, IL-6) and anti-inflammatory (IL-10) cytokines.

Design: The Brennan model was used to induce acute pain like signs in rats' hind paw. Twenty-four hours following the surgery the rats were divided into 5 groups and the affected paws were injected with 0.

Susceptibility of Virulent Bacteria to Predator Bacteria in the Lungs of Mice.

Multi-drug resistant bacterial infections are a serious threat to global public health. Changes in treatment modalities and prudent use of antibiotics can assist in reducing the threat, but new approaches are also required for untreatable cases. The use of predatory bacteria, such as , is among the novel approaches being considered as possible therapeutics for antibiotic resistant and/or unidentified bacterial infections.

Vibrio cholerae motility exerts drag force to impede attack by the bacterial predator Bdellovibrio bacteriovorus.

The bacterial predator Bdellovibrio bacteriovorus is evolved to attack and kill other bacteria, including the human intestinal pathogen Vibrio cholerae. Although B. bacteriovorus exhibit a broad prey range, little is known about the genetic determinants of prey resistance and sensitivity.

Serralysin family metalloproteases protects Serratia marcescens from predation by the predatory bacteria Micavibrio aeruginosavorus.

Micavibrio aeruginosavorus is an obligate Gram-negative predatory bacterial species that feeds on other Gram-negative bacteria by attaching to the surface of its prey and feeding on the prey's cellular contents. In this study, Serratia marcescens with defined mutations in genes for extracellular cell structural components and secreted factors were used in predation experiments to identify structures that influence predation. No change was measured in the ability of the predator to prey on S.

Keeping it together: absence of genetic variation and DNA incorporation by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus during predation.

The use of predatory bacteria as a potential live therapeutic to control human infection is gaining increased attention. Earlier work with Micavibrio spp. and Bdellovibrio spp.

Susceptibility of colistin-resistant pathogens to predatory bacteria.

The increase in multidrug-resistant Gram-negative bacterial infections has forced the reintroduction of antibiotics such as colistin. However, the spread of the plasmid-borne mcr-1 colistin resistance gene have moved us closer to an era of untreatable Gram-negative infections. To evaluate whether predatory bacteria could be used as a potential therapeutic to treat this upcoming threat, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on several clinically relevant mcr-1-positive, colistin-resistant isolates was evaluated.

Examining the efficacy of intravenous administration of predatory bacteria in rats.

The proteobacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are obligate predators of Gram-negative bacteria, and have been proposed to be used to treat multidrug-resistant bacterial infections. The ability of predatory bacteria to reduce bacterial burden in vivo within the lungs of rats has been demonstrated, but it was unknown if predatory bacteria can attenuate systemic bacterial burden administered intravenously. In this study, we first assessed the safety of intravenous inoculation of predatory bacteria in rats.

Effect of predatory bacteria on the gut bacterial microbiota in rats.

Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are Gram-negative proteobacteria that are obligate predators of other Gram-negative bacteria and are considered potential alternatives to antibiotics. Most studies focusing on predatory bacteria have been performed in vitro, thus the effect of predatory bacteria on a live host, including the impact on the ecology of the native microbiota, has yet to be fully examined. In this study, intrarectal inoculations of Sprague-Dawley rats with predatory bacteria were performed.

Modelling and parameter inference of predator-prey dynamics in heterogeneous environments using the direct integral approach.

Most bacterial habitats are topographically complex in the micro scale. Important examples include the gastrointestinal and tracheal tracts, and the soil. Although there are myriad theoretical studies that explore the role of spatial structures on antagonistic interactions (predation, competition) among animals, there are many fewer experimental studies that have explored, validated and quantified their predictions.

Evaluating the Effect of Oxygen Concentrations on Antibiotic Sensitivity, Growth, and Biofilm Formation of Human Pathogens.

Standard antimicrobial susceptibility tests are performed in vitro under normal room oxygen conditions to predict the in vivo effectiveness of antimicrobial therapy. The aim of this study was to conduct a comprehensive analysis of the effect of different oxygen levels on the antibiotic susceptibility of two strains of , , and . It was found that anoxic conditions caused reduced sensitivity of bacteria to aminoglycoside antibiotics in four of six bacteria used in the study.

Predatory Bacteria Attenuate Klebsiella pneumoniae Burden in Rat Lungs.

Unlabelled: Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are predatory bacteria that naturally-and obligately-prey on other Gram-negative bacteria, and their use has been proposed as a potential new approach to control microbial infection. The ability of predatory bacteria to prey on Gram-negative human pathogens in vitro is well documented; however, the in vivo safety and efficacy of predatory bacteria have yet to be fully assessed. In this study, we examined whether predatory bacteria can reduce bacterial burden in the lungs in an in vivo mammalian system.

Effect of Predatory Bacteria on Human Cell Lines.

Predatory bacteria are Gram-negative bacteria that prey on other Gram-negative bacteria and have been considered as potential therapeutic agents against multi-drug resistant pathogens. In vivo animal models have demonstrated that predatory bacteria are non-toxic and non-immunogenic in rodents. In order to consider the use of predatory bacteria as live antibiotics, it is important to investigate their effect on human cells.