An Evaluation of Presence and Source of Fecal Contamination at Golden Gardens Park

Golden Gardens is an 87.8 acre Park in Seattle, WA that has come under recent scrutiny over concerns about water quality in the streams and at the beach. Located just north of Shillshole marina in Seattle it has a swimming beach which is 1439 m in length, as well as a forested region directly east of the beach on a relatively steep hill with several drainages flowing into the sound. The purpose of this study was to assess the levels of indicator bacteria in beach water and in the fresh water drainages and to determine if the bacterial contamination is related to human or animal inputs. Specifically, we were interested in determining if the off-leash area for dogs, located on the hill above the beach, was contributing to the contamination. Water was collected five times from June-August 2010 at 4 locations at two depths along the beach and as many as 20 locations in the drainages on the hill. One-hundred ml aliquots of water were analyzed in duplicate for each site sampled via membrane filtration for fecal coliforms, and enterococci. DNA from Enterococci isolates were amplified by PCR targeting the esp gene in enterococci and DNA extracted from 200ml of fresh water was amplified for the 16S rRNA gene in Bacteroides to determine the source of contamination. Fecal coliform levels for marine beach water at Golden Gardens typically meet WA State bacteriological criteria for secondary contact recreation. The stream water frequently exceeded the USEPA recommended level of 33 enteroccoci per 100ml. Preliminary PCR results showed that two of 24 samples from one sampling period were positive for human specific Enterococcus. PCR analysis for human specific Enterococcus and for human and canine specific Bacteroides is still underway for the other sampling period

Temporal and Spatial Impact of Human Cadaver Decomposition on Soil Bacterial and Arthropod Community Structure and Function

As vertebrate carrion decomposes, there is a release of nutrient-rich fluids into theunderlying soil, which can impact associated biological community structure andfunction. How these changes alter soil biogeochemical cycles is relatively unknown and may prove useful in the identification of carrion decomposition islands that have long lasting, focal ecological effects. This study investigated the spatial (0, 1, and 5 m) and temporal (3–732 days) dynamics of human cadaver decomposition on soil bacterial and arthropod community structure and microbial function. We observed strong evidence of a predictable response to cadaver decomposition that varies over space for soil bacterial and arthropod community structure, carbon (C) mineralization and microbial substrate utilization patterns. In the presence of a cadaver (i.e., 0 m samples), the relative abundance of Bacteroidetes and Firmicutes was greater, while the relative abundance of Acidobacteria, Chloroflexi, Gemmatimonadetes, and Verrucomicrobia was lower when compared to samples at 1 and 5 m. Micro-arthropods were more abundant (15 to 17-fold) in soils collected at 0 m compared to either 1 or 5 m, but overall, micro-arthropod community composition was unrelated to either bacterial community composition or function. Bacterial community structure and microbial function also exhibited temporal relationships, whereas arthropod community structure did not. Cumulative precipitation was more effective in predicting temporal variations in bacterial abundance and microbial activity than accumulated degree days. In the presence of the cadaver (i.e., 0 m samples), the relative abundance of Actinobacteria increased significantly with cumulative precipitation. Furthermore, soil bacterial communities and C mineralization were sensitive to the introduction of human cadavers as they diverged from baseline levels and did not recover completely in approximately 2 years. These data are valuable for understanding ecosystem function surrounding carrion decomposition islands and can be applicable to environmental bio-monitoring and forensic sciences

Tetrahydropyrazolo[1,5-a]Pyrimidine-3-Carboxamide and N-Benzyl-6′,7′-Dihydrospiro[Piperidine-4,4′-Thieno[3,2-c]Pyran] analogues with bactericidal efficacy against Mycobacterium tuberculosis targeting MmpL3

Mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (TB). Current treatment programs to combat TB are under threat due to the emergence of multi-drug and extensively-drug resistant TB. As part of our efforts towards the discovery of new anti-tubercular leads, a number of potent tetrahydropyrazolo[1,5-a]pyrimidine-3-ca​rboxamide(THPP) and N-benzyl-6′,7′-dihydrospiro[piperidine-4,​4′-thieno[3,2-c]pyran](Spiro) analogues were recently identified against Mycobacterium tuberculosis and Mycobacterium bovis BCG through a high-throughput whole-cell screening campaign. Herein, we describe the attractive in vitro and in vivo anti-tubercular profiles of both lead series. The generation of M. tuberculosis spontaneous mutants and subsequent whole genome sequencing of several resistant mutants identified single mutations in the essential mmpL3 gene. This ‘genetic phenotype’ was further confirmed by a ‘chemical phenotype’, whereby M. bovis BCG treated with both the THPP and Spiro series resulted in the accumulation of trehalose monomycolate. In vivo efficacy evaluation of two optimized THPP and Spiro leads showed how the compounds were able to reduce >2 logs bacterial cfu counts in the lungs of infected mice

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Not AvailableNitrogen (N) fertilization and soil redox potential influence N cycling processes in forested ecosystems. Gross N transformations are indicators of NH4+ and NO3 − production and consumption within soil. Furthermore, dissimilatory nitrate reduction to ammonium (DNRA), a typically overlooked process in terrestrial N cycling, can conserve N within soil by reducing losses of soil N via NO3 − leaching and denitrification. We tested the effects of urea fertilization and soil redox on microbial N cycling processes and N2O fluxes using a 15N tracer experiment in soils from loblolly pine plantations located in different physiographical regions (i.e., Coastal Plain of North Carolina and Piedmont of Virginia). Mineral soils (0– 15 cm) from fertilized and unfertilized plots were incubated at high (Eh, 200 to 400 mV) and low redox potential (Eh, −100 to 100 mV). Site differences were limited primarily to edaphic factors, although gross N mineralization was higher in NC. Gross nitrification, DNRA, and NO3– −–N concentrations were higher in soils from fertilized plots. DNRA was higher at high compared to low redox potential, while N2O fluxes were higher at low redox potential. Fluxes of N2O were further enhanced in fertilized treatments incubated at low redox potential. DNRA was positively correlated with NO3 − availability, but not to soil C pools. Furthermore, DNRA was negatively correlated with C/NO3 − ratio, implying that NO3 − pool size was the primary factor influencing DNRA. These results suggest N fertilization has alleviated limitations to nitrification, DNRA, and N2O production processes and that gaseous losses of N will prevail over N conservation pathways at low soil redox potentials.Not Availabl