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Firearm-related deaths and injuries are a serious public health problem in California and the United States. The rate of firearm-related deaths is many times higher in the US than other democratic, industrialized nations, yet many of the deaths and injuries are preventable. The California American College of Emergency Physicians Firearm Injury Prevention Policy was approved and adopted in 2013 as an evidence-based, apolitical statement to promote harm reduction. It recognizes and frames firearm injuries as a public health epidemic requiring allocation of robust resources, including increased governmental funding of high-quality research and the development of a national database system. The policy further calls for relevant legislation to be informed by best evidence and expert consensus, and advocates for legislation regarding the following: mandatory universal background checks; mandatory reporting of firearm loss/theft; restrictions against law-enforcement or military-style assault weapons and high capacity magazines; child-protective safety and storage systems; and prohibitions for high-risk individuals. It also strongly defends the right of physicians to screen and counsel patients about firearm-related risk factors and safety. Based upon best-available evidenced, the policy was recently updated to include extreme risk protection orders, which are also known as gun violence restraining orders.

The Red Queen hypothesis proposes that coevolution of interacting species (such as hosts and parasites) should drive molecular evolution through continual natural selection for adaptation and counter-adaptation (1-3). Although the divergence observed at some host-resistance (4-6) and parasite-infectivity (7-9) genes is consistent with this, the long time periods typically required to study co-evolution have so far prevented any direct empirical test. Here we show, using experimental populations of the bacterium Pseudomonas fluorescens SBW25 and its viral parasite, phage Φ2 (refs 10, 11), that the rate of molecular evolution in the phage was far higher when both bacterium and phage coevolved with each other than when phage evolved against a constant host genotype. Coevolution also resulted in far greater genetic divergence between replicate populations, which was correlated with the range of hosts that coevolved phage were able to infect. Consistent with this, the most rapidly evolving phage genes under coevolution were those involved in host infection. These results demonstrate, at both the genomic and phenotypic level, that antagonistic coevolution is a cause of rapid and divergent evolution, and is likely to be a major driver of evolutionary change within species., According to the Red Queen hypothesis, biotic interactions are a fundamental driver of molecular evolution (2). The Red Queen hypothesis posits that for a given species, its effective environment is [...]

We studied the two mreB genes, encoding actinlike cytoskeletal elements, in the predatory bacterium Bdellovibrio bacteriovorus. This bacterium enters and replicates within other Gram-negative bacteria by attack-phase Bdellovibrio squeezing through prey outer membrane, residing and growing filamentously in the prey periplasm forming an infective 'bdelloplast,' and septating after 4 h, once the prey contents are consumed. This lifestyle brings challenges to the Bdellovibrio cytoskeleton. Both mreB genes were essential for viable predatory growth, but C-terminal green fluorescent protein tagging each separately with monomeric teal-fluorescent protein (mTFP) gave two strains with phenotypic changes at different stages in predatory growth and development. MreB1-mTFP cells arrested growth early in bdelloplast formation, despite successful degradation of prey nucleoid. A large population of stalled bdelloplasts formed in predatory cultures and predation proceeded very slowly. A small proportion of bdelloplasts lysed after several days, liberating MreB1-mTFP attack-phase cells of wild-type morphology; this process was aided by subinhibitory concentrations of an MreB-specific inhibitor, A22. MreB2-mTFP, in contrast, was predatory at an almost wild-type rate but yielded attack-phase cells with diverse morphologies, including spherical, elongated, and branched, the first time such phenotypes have been described. Wild-type predatory rates were seen for all but spherical morphotypes, and septation of elongated morphotypes was achieved by the addition of A22. doi: 10.1128/JB.01157-09

Abstract Background Evolution equipped Bdellovibrio bacteriovorus predatory bacteria to invade other bacteria, digesting and replicating, sealed within them thus preventing nutrient-sharing with organisms in the surrounding environment. Bdellovibrio were previously described as “obligate predators” because only by mutations, often in gene bd0108, are 1 in ~1x107 of predatory lab strains of Bdellovibrio converted to prey-independent growth. A previous genomic analysis of B. bacteriovorus strain HD100 suggested that predatory consumption of prey DNA by lytic enzymes made Bdellovibrio less likely than other bacteria to acquire DNA by lateral gene transfer (LGT). However the Doolittle and Pan groups predicted, in silico, both ancient and recent lateral gene transfer into the B. bacteriovorus HD100 genome. Results To test these predictions, we isolated a predatory bacterium from the River Tiber- a good potential source of LGT as it is rich in diverse bacteria and organic pollutants- by enrichment culturing with E. coli prey cells. The isolate was identified as B. bacteriovorus and named as strain Tiberius. Unusually, this Tiberius strain showed simultaneous prey-independent growth on organic nutrients and predatory growth on live prey. Despite the prey-independent growth, the homolog of bd0108 did not have typical prey-independent-type mutations. The dual growth mode may reflect the high carbon content of the river, and gives B. bacteriovorus Tiberius extended non-predatory contact with the other bacteria present. The HD100 and Tiberius genomes were extensively syntenic despite their different cultured-terrestrial/freshly-isolated aquatic histories; but there were significant differences in gene content indicative of genomic flux and LGT. Gene content comparisons support previously published in silico predictions for LGT in strain HD100 with substantial conservation of genes predicted to have ancient LGT origins but little conservation of AT-rich genes predicted to be recently acquired. Conclusions The natural niche and dual predatory, and prey-independent growth of the B. bacteriovorus Tiberius strain afforded it extensive non-predatory contact with other marine and freshwater bacteria from which LGT is evident in its genome. Thus despite their arsenal of DNA-lytic enzymes; Bdellovibrio are not always predatory in natural niches and their genomes are shaped by acquiring whole genes from other bacteria.

Abstract Background Phages are thought to play a crucial role in the maintenance of diversity in natural bacterial communities. Theory suggests that phages impose density dependent regulation on bacterial populations, preventing competitive dominants from excluding less competitive species. To test this, we constructed experimental communities containing two bacterial species (Pseudomonas fluorescens and Pseudomonas aeruginosa) and their phage parasites. Communities were propagated at two environmental temperatures that reversed the outcome of competition in the absence of phage. Results The evenness of coexistence was enhanced in the presence of a phage infecting the superior competitor and in the presence of phage infecting both competitors. This occurred because phage altered the balance of competitive interactions through reductions in density of the superior competitor, allowing concomitant increases in density of the weaker competitor. However, even coexistence was not equally stable at the two environmental temperatures. Conclusion Phage can alter competitive interactions between bacterial species in a way that is consistent with the maintenance of coexistence. However, the stability of coexistence is likely to depend upon the nature of the constituent bacteria-bacteriophage interactions and environmental conditions.

I will discuss how animal laboratory research can be ethically analyzed using Donaldson and Kymlicka's political theory of animal rights. To accomplish this, I will not presuppose their strong animal rights framework. Donaldson and Kymlicka's approach revolves around some basic human-animal relationships, reflecting the relational turn in applied ethics writ large. However, they do not discuss laboratory animal research in any detail, and so an extension to that domain of animal use is in order. Donaldson and Kymlicka's emphasis on human-animal relationships is useful for reminding ourselves that in laboratories various staff or personnel can develop bonds with captive animals that make it difficult to follow certain protocols as well as create a deep and lasting negative impression. Though, when suitably modified, Donaldson and Kymlicka's political theory can apply to animal research ethics, it can only do so if we ask more from all members of our society. [ABSTRACT FROM AUTHOR]

I will discuss how animal laboratory research can be ethically analyzed using Donaldson and Kymlicka's political theory of animal rights. To accomplish this, I will not presuppose their strong animal rights framework. Donaldson and Kymlicka's approach revolves around some basic human-animal relationships, reflecting the relational turn in applied ethics writ large. However, they do not discuss laboratory animal research in any detail, and so an extension to that domain of animal use is in order. Donaldson and Kymlicka's emphasis on human-animal relationships is useful for reminding ourselves that, in laboratories, various staff or personnel can develop bonds with captive animals that make it difficult to follow certain protocols as well as create a deep and lasting negative impression. Though, when suitably modified, Donaldson and Kymlicka's political theory can apply to animal research ethics, it can only do so if we ask more from all members of our society. [ABSTRACT FROM AUTHOR]

Bdellovibrio bacteriovorus is a bacterium which preys upon and kills Gram-negative bacteria, including the zoonotic pathogens Escherichia coli and Salmonella. Bdellovibrio has potential as a biocontrol agent, but no reports of it being tested in living animals have been published, and no data on whether Bdellovibrio might spread between animals are available. In this study, we tried to fill this knowledge gap, using B. bacteriovorus HD100 doses in poultry with a normal gut microbiota or predosed with a colonizing Salmonella strain. In both cases, Bdellovibrio was dosed orally along with antacids. After dosing non-Salmonella-infected birds with Bdellovibrio, we measured the health and well-being of the birds and any changes in their gut pathology and culturable microbiota, finding that although a Bdellovibrio dose at 2 days of age altered the overall diversity of the natural gut microbiota in 28-day-old birds, there were no adverse effects on their growth and well-being. Drinking water and fecal matter from the pens in which the birds were housed as groups showed no contamination by Bdellovibrio after dosing. Predatory Bdellovibrio orally administered to birds that had been predosed with a gut-colonizing Salmonella enterica serovar Enteritidis phage type 4 strain (an important zoonotic pathogen) significantly reduced Salmonella numbers in bird gut cecal contents and reduced abnormal cecal morphology, indicating reduced cecal inflammation, compared to the ceca of the untreated controls or a nonpredatory Δ pilA strain, suggesting that these effects were due to predatory action. This work is a first step to applying Bdellovibrio therapeutically for other animal, and possibly human, infections. [ABSTRACT FROM AUTHOR]