Recent research has debunked the myth that urine is sterile, having uncovered bacteria within the bladders of healthy individuals. However, the identity, diversity, and putative roles of bacteriophages in the bladder are unknown. We report the draft genome sequences of seven bacteriophages isolated from microbial communities from adult female bladders.

Advances in bioinformatics and sequencing technologies have allowed for the analysis of complex microbial communities at an unprecedented rate. While much focus is often placed on the cellular members of these communities, viruses play a pivotal role, particularly bacteria-infecting viruses (bacteriophages); phages mediate global biogeochemical processes and drive microbial evolution through bacterial grazing and horizontal gene transfer. Despite their importance and ubiquity in nature, very little is known about the diversity and structure of viral communities. Though the need for culture-based methods for viral identification has been somewhat circumvented through metagenomic techniques, the analysis of metaviromic data is marred with many unique issues. In this review, we examine the current bioinformatic approaches for metavirome analyses and the inherent challenges facing the field as illustrated by the ongoing efforts in the exploration of freshwater phage populations.

BackgroundGrowth cone navigation across the vertebrate midline is critical in the establishment of nervous system connectivity. While midline crossing is achieved through coordinated signaling of attractive and repulsive cues, this has never been demonstrated at the single cell level. Further, though growth cone responsiveness to guidance cues changes after crossing the midline, it is unclear whether midline crossing itself is required for subsequent guidance decisions in vivo. In the zebrafish, spinal commissures are initially formed by a pioneer neuron called CoPA (Commissural Primary Ascending). Unlike in other vertebrate models, CoPA navigates the midline alone, allowing for single-cell analysis of axon guidance mechanisms.ResultsWe provide evidence that CoPA expresses the known axon guidance receptors dcc, robo3 and robo2. Using loss of function mutants and gene knockdown, we show that the functions of these genes are evolutionarily conserved in teleosts and that they are used consecutively by CoPA neurons. We also reveal novel roles for robo2 and robo3 in maintaining commissure structure. When midline crossing is prevented in robo3 mutants and dcc gene knockdown, ipsilaterally projecting neurons respond to postcrossing guidance cues. Furthermore, DCC inhibits Robo2 function before midline crossing to allow a midline approach and crossing.ConclusionsOur results demonstrate that midline crossing is not required for subsequent guidance decisions by pioneer axons and that this is due, in part, to DCC inhibition of Robo2 function prior to midline crossing.

In comparison to the oceans, freshwater environments represent a more diverse community of microorganisms, exhibiting comparatively high levels of variability both temporally and spatially Maranger and Bird, Microb. Ecol. 31 (1996) 141–151. This level of variability is likely to extend to the world of viruses as well, in particular bacteria-infecting viruses (bacteriophages). Phages are known to influence bacterial diversity, and therefore key processes, in environmental niches across the globe Clokie et al., Bacteriophage 1 (2011) 31–45; Jacquet et al., Adv. Ocean Limn. 1 (2010) 97–141; Wilhelm and Suttle, Bioscience 49 (1999) 781–788; Bratback et al., Microb. Ecol. 28 (1994) 209–221. Despite their prevalence and likely critical role in freshwater environments, very few viral species have been characterized. Metagenomic approaches, however, have allowed for a glimpse into phage diversity. We collected surface water samples from four Chicago area beaches – Gillson Park, Montrose Beach, 57th Street Beach, and Calumet Beach – every two weeks from May 13 through August 5, 2014. Sampling was conducted with four biological replicates for each sampling date and location, resulting in 112 samples. DNA isolated from each of the individual samples for a given collection date/location was pooled together, with one exception – Calumet Beach on August 5, 2014 – in which each biological replicate was sequenced individually. Raw sequence data is available via NCBI’s SRA database (part of BioProject PRJNA248239).

Freshwater lakes are home to bacterial communities with 1000s of interdependent species. Numerous high-throughput 16S rRNA gene sequence surveys have provided insight into the microbial taxa found within these waters. Prior surveys of Lake Michigan waters have identified bacterial species common to freshwater lakes as well as species likely introduced from the urban environment. We cultured bacterial isolates from samples taken from the Chicago nearshore waters of Lake Michigan in an effort to look more closely at the genetic diversity of species found there within. The most abundant genus detected was Pseudomonas , whose presence in freshwaters is often attributed to storm water or runoff. Whole genome sequencing was conducted for 15 Lake Michigan Pseudomonas strains, representative of eight species and three isolates that could not be resolved with named species. These genomes were examined specifically for genes encoding functionality which may be advantageous in their urban environment. Antibiotic resistance, amidst other known virulence factors and defense mechanisms, were identified in the genome annotations and verified in the lab. We also tested the Lake Michigan Pseudomonas strains for siderophore production and resistance to the heavy metals mercury and copper. As the study presented here shows, a variety of pseudomonads have inhabited the urban coastal waters of Lake Michigan.