Characterization of the facial microbiome in twins discordant for rosacea.

Previously, we determined that genetic and environmental factors contributed equally towards rosacea in twins. To assess an environmental factor, we characterized the malar cheek bacterial microbiome from twins discordant for rosacea. We found no significant difference in facial microbiome alpha and beta diversity between related twins discordant for rosacea. However, the relative percentage abundance of Gordonia and Geobacillus, low-abundant genera, was positively and negatively associated with rosacea severity, respectively. Our data demonstrate a significant correlation between facial microbiome and severity of rosacea in genetically matched twins and importantly that overall microbiome composition is largely unchanged.

Use of 16S rRNA sequencing and quantitative PCR to correlate venous leg ulcer bacterial bioburden dynamics with wound expansion, antibiotic therapy, and healing.

Clinical diagnosis of infection in chronic wounds is currently limited to subjective clinical signs and culture-based methods that underestimate the complexity of wound microbial bioburden as revealed by DNA-based microbial identification methods. Here, we use 16S rRNA next generation sequencing and quantitative polymerase chain reaction to characterize weekly changes in bacterial load, community structure, and diversity associated with a chronic venous leg ulcer over the 15-week course of treatment and healing. Our DNA-based methods and detailed sampling scheme reveal that the bacterial bioburden of the wound is unexpectedly dynamic, including changes in the bacterial load and community structure that correlate with wound expansion, antibiotic therapy, and healing. We demonstrate that these multidimensional changes in bacterial bioburden can be summarized using swabs taken prior to debridement, and therefore, can be more easily collected serially than debridement or biopsy samples. Overall, this case illustrates the importance of detailed clinical indicators and longitudinal sampling to determine the pathogenic significance of chronic wound microbial dynamics and guide best use of antimicrobials for improvement of healing outcomes.

Crystal Diagnostics MultiPath System™.

The Crystal Diagnostics MultiPath System™ provides rapid detection of Escherichia coli O157 in fresh raw ground beef, raw beeftrim, and spinach. The Crystal Diagnostics system combines patented Liquid Crystal technology with antibody-coated paramagnetic microspheres to selectively capture and detect E. coli O157 in food matrixes. This is the only liquid crystal-based biosensor commercially available for the detection of pathogens. The Crystal Diagnostics system expeditiously provides the sensitivity and accuracy of the U.S. Department of Agriculture Food Safety Inspection Service (USDA-FSIS) and the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA-BAM) methods for detecting as low as one CFU of E. coli O157 per 375 g of raw ground beef and raw beef trim, or 200 g of raw spinach. An internal inclusivity validation demonstrated detection of all 50 tested strains of . coli O157. The internal and independent laboratory tests demonstrate that the method is rapid and sensitive for detecting of E. coli O157 in fresh raw ground beef, beef trim, and spinach.

Utilization of DNA as a sole source of phosphorus, carbon, and energy by Shewanella spp.: ecological and physiological implications for dissimilatory metal reduction.

The solubility of orthophosphate (PO4(3-)) in iron-rich sediments can be exceedingly low, limiting the bioavailability of this essential nutrient to microbial populations that catalyze critical biogeochemical reactions. Here we demonstrate that dissolved extracellular DNA can serve as a sole source of phosphorus, as well as carbon and energy, for metal-reducing bacteria of the genus Shewanella. Shewanella oneidensis MR-1, Shewanella putrefaciens CN32, and Shewanella sp. strain W3-18-1 all grew with DNA but displayed different growth rates. W3-18-1 exhibited the highest growth rate with DNA. While strain W3-18-1 displayed Ca2+-independent DNA utilization, both CN32 and MR-1 required millimolar concentrations of Ca2+ for growth with DNA. For S. oneidensis MR-1, the utilization of DNA as a sole source of phosphorus is linked to the activities of extracellular phosphatase(s) and a Ca2+-dependent nuclease(s), which are regulated by phosphorus availability. Mass spectrometry analysis of the extracellular proteome of MR-1 identified one putative endonuclease (SO1844), a predicted UshA (bifunctional UDP-sugar hydrolase/5' nucleotidase), a predicted PhoX (calcium-activated alkaline phosphatase), and a predicted CpdB (bifunctional 2',3' cyclic nucleotide 2' phosphodiesterase/3' nucleotidase), all of which could play important roles in the extracellular degradation of DNA under phosphorus-limiting conditions. Overall, the results of this study suggest that the ability to use exogenous DNA as the sole source of phosphorus is widespread among the shewanellae, and perhaps among all prokaryotes, and may be especially important for nutrient cycling in metal-reducing environments.