Evaluation of low-cost phage-based Microbial Source Tracking tools for elucidating human fecal contamination pathways in Kolkata, India

Phages, such as those infecting Bacteroides spp., have been proven to be reliable indicators of human fecal contamination in microbial source tracking (MST) studies, and the efficacy of these MST markers found to vary geographically. This study reports the application and evaluation of candidate MST methods (phages infecting previously isolated B. fragilis strain GB-124, newly isolated Bacteroides strains (K10, K29, and K33) and recently isolated Kluyvera intermedia strain ASH-08), along with non-source specific somatic coliphages (SOMCPH infecting strain WG-5) and indicator bacteria (Escherichia coli) for identifying fecal contamination pathways in Kolkata, India. Source specificity of the phage-based methods was first tested using 60 known non-human fecal samples from common animals, before being evaluated with 56 known human samples (municipal sewage) collected during both the rainy and dry season. SOMCPH were present in 40-90% of samples from different animal species and in 100% of sewage samples. Phages infecting Bacteroides strain GB-124 were not detected from the majority (95%) of animal samples (except in three porcine samples) and were present in 93 and 71% of the sewage samples in the rainy and dry season (Mean = 1.42 and 1.83 log(10)PFU/100mL, respectively), though at lower levels than SOMCPH (Mean = 3.27 and 3.02 log(10)PFU/100mL, respectively). Phages infecting strain ASH-08 were detected in 89 and 96% of the sewage samples in the rainy and dry season, respectively, but were also present in all animal samples tested (except goats). Strains K10, K29, and K30 were not found to be useful MST markers due to low levels of phages and/or co-presence in non-human sources. GB-124 and SOMCPH were subsequently deployed within two low-income neighborhoods to determine the levels and origin of fecal contamination in 110 environmental samples. E. coli, SOMCPH, and phages of GB-124 were detected in 68, 42, and 28% of the samples, respectively. Analyses of 166 wastewater samples from shared community toilets and 21 samples from sewage pumping stations from the same districts showed that SOMCPH were present in 100% and GB-124 phages in 31% of shared toilet samples (Median = 5.59 and <1 log(10) PFU/100 mL, respectively), and both SOMCPH and GB-124 phages were detected in 95% of pumping station samples (Median = 5.82 and 4.04 log(10) PFU/100 mL, respectively). Our findings suggest that GB-124 and SOMCPH have utility as low-cost fecal indicator tools which can facilitate environmental surveillance of enteric organisms, elucidate human and non-human fecal exposure pathways, and inform interventions to mitigate exposure to fecal contamination in the residential environment of Kolkata, India

The State of the Region: Hampton Roads 2016

This is Old Dominion University\u27s 17th annual State of the Region report. While it represents the work of many people connected in various ways to the university, the report does not constitute an official viewpoint of Old Dominion or it\u27s president, John R. Broderick. The report maintains the goal of stimulating thought and discussion that ultimately will make Hampton Roads an even better place to live. We are proud of our region\u27s many successes, but realize that it is possible to improve our performance. In order to do so, we must have accurate information about where we are and a sound understanding of the policy options open to us.https://digitalcommons.odu.edu/economics_books/1002/thumbnail.jp

2016 State of the Commonwealth Report

This is the second State of the Commonwealth Report produced by the Center for Economic Analysis and Policy at Old Dominion University. It is jointly sponsored by ODU\u27s Strome College of Business and the Virginia Chamber of Commerce. While the report represents the work of many people connected in various ways to the university, it does not constitute an official viewpoint of Old Dominion, or it\u27s president, John R. Broderick. Similarly, it does not represent the views of the Virginia Chamber of Commerce or it\u27s president, Barry DuVal. The report maintains the goal of stimulating thought and discussion that ultimately will make Virginia an even better place to live, work, and do business. We are proud of the Commonwealth\u27s many successes, but realize that it is possible to improve our performance. In order to do so, we must have accurate information about where we are and a sound understanding of the policy options open to us.https://digitalcommons.odu.edu/economics_books/1019/thumbnail.jp

2015 State of the Commonwealth Report

This is the first State of the Commonwealth Report. It is jointly sponsored by the Strome College of Business at Old Dominion University and the Virginia Chamber Foundation. While the report represents the work of many people connected in various ways to the university, it does not constitute an official viewpoint of Old Dominion or it\u27s president, John R. Broderick. Similarly, it does not represent the views of the Virginia Chamber of Commerce or it\u27s president and CEO, Barry DuVal. The goal of the report is to stimulate thought and discussion that ultimately will make Virginia an even better place to live, work, and do business. We are proud of the Commonwealth\u27s many successes, but realize that it is possible to improve our performance. In order to do so, we must have accurate information about where we are and a sound understanding of the policy options open to us.https://digitalcommons.odu.edu/economics_books/1020/thumbnail.jp

The State of the Region: Hampton Roads 2015

This is Old Dominion University\u27s 16th annual State of the Region report. While it represents the work of many people connected in various ways to the university, the report does not constitute an official viewpoint of Old Dominion or it\u27s president, John R. Broderick. The report maintains the goal of stimulating thought and discussion that ultimately will make Hampton Roads an even better place to live. We are proud of our region\u27s many successes, but realize that it is possible to improve our performance. In order to do so, we must have accurate information about where we are and a sound understanding of the policy options open to us.https://digitalcommons.odu.edu/economics_books/1003/thumbnail.jp

Comparison of fully-automated radiosyntheses of [11C]erlotinib for preclinical and clinical use starting from in target produced [11C]CO2 or [11C]CH4

Abstract Background [11C]erlotinib has been proposed as a PET tracer to visualize the mutational status of the epidermal growth factor receptor (EGFR) in cancer patients. For clinical use, a stable, reproducible and high-yielding radiosynthesis method is a prerequisite. In this work, two production schemes for [11C]erlotinib applied in a set of preclinical and clinical studies, starting from either [11C]CH4 or [11C]CO2, are presented and compared in terms of radiochemical yields, molar activities and overall synthesis time. In addition, a time-efficient RP-HPLC method for quality control is presented, which requires not more than 1 min. Results [11C]erlotinib was reliably produced applying both methods with decay-corrected radiochemical yields of 13.4 ± 6.2% and 16.1 ± 4.9% starting from in-target produced [11C]CO2 and [11C]CH4, respectively. Irradiation time for the production of [11C]CO2 was higher in order to afford final product amounts sufficient for patient application. Overall synthesis time was comparable, mostly attributable to adaptions in the semi-preparative HPLC protocol. Molar activities were 1.8-fold higher for the method starting from [11C]CH4 (157 ± 68 versus 88 ± 57 GBq/μmol at the end of synthesis). Conclusions This study compared two synthetic protocols for the production of [11C]erlotinib with in-target produced [11C]CO2 or [11C]CH4. Both methods reliably yielded sufficiently high product amounts for preclinical and clinical use

Factors Governing P‑Glycoprotein-Mediated Drug–Drug Interactions at the Blood–Brain Barrier Measured with Positron Emission Tomography

The adenosine triphosphate-binding cassette transporter P-glycoprotein (ABCB1/Abcb1a) restricts at the blood–brain barrier (BBB) brain distribution of many drugs. ABCB1 may be involved in drug–drug interactions (DDIs) at the BBB, which may lead to changes in brain distribution and central nervous system side effects of drugs. Positron emission tomography (PET) with the ABCB1 substrates (<i>R</i>)-[¹¹C]­verapamil and [¹¹C]-<i>N</i>-desmethyl-loperamide and the ABCB1 inhibitor tariquidar has allowed direct comparison of ABCB1-mediated DDIs at the rodent and human BBB. In this work we evaluated different factors which could influence the magnitude of the interaction between tariquidar and (<i>R</i>)-[¹¹C]­verapamil or [¹¹C]-<i>N</i>-desmethyl-loperamide at the BBB and thereby contribute to previously observed species differences between rodents and humans. We performed <i>in vitro</i> transport experiments with [³H]­verapamil and [³H]-<i>N</i>-desmethyl-loperamide in ABCB1 and Abcb1a overexpressing cell lines. Moreover we conducted <i>in vivo</i> PET experiments and biodistribution studies with (<i>R</i>)-[¹¹C]­verapamil and [¹¹C]-<i>N</i>-desmethyl-loperamide in wild-type mice without and with tariquidar pretreatment and in homozygous <i>Abcb1a/1b^(−/−)</i> and heterozygous <i>Abcb1a/1b^(+/−)</i> mice. We found no differences for <i>in vitro</i> transport of [³H]­verapamil and [³H]-<i>N</i>-desmethyl-loperamide by ABCB1 and Abcb1a and its inhibition by tariquidar. [³H]-<i>N</i>-Desmethyl-loperamide was transported with a 5 to 9 times higher transport ratio than [³H]­verapamil in ABCB1- and Abcb1a-transfected cells. <i>In vivo</i>, brain radioactivity concentrations were lower for [¹¹C]-<i>N</i>-desmethyl-loperamide than for (<i>R</i>)-[¹¹C]­verapamil. Both radiotracers showed tariquidar dose dependent increases in brain distribution with tariquidar half-maximum inhibitory concentrations (IC₅₀) of 1052 nM (95% confidence interval CI: 930–1189) for (<i>R</i>)-[¹¹C]­verapamil and 1329 nM (95% CI: 980–1801) for [¹¹C]-<i>N</i>-desmethyl-loperamide. In homozygous <i>Abcb1a/1b^(−/−)</i> mice brain radioactivity distribution was increased by 3.9- and 2.8-fold and in heterozygous <i>Abcb1a/1b^(+/−)</i> mice by 1.5- and 1.1-fold, for (<i>R</i>)-[¹¹C]­verapamil and [¹¹C]-<i>N</i>-desmethyl-loperamide, respectively, as compared with wild-type mice. For both radiotracers radiolabeled metabolites were detected in plasma and brain. When brain and plasma radioactivity concentrations were corrected for radiolabeled metabolites, brain distribution of (<i>R</i>)-[¹¹C]­verapamil and [¹¹C]-<i>N</i>-desmethyl-loperamide was increased in tariquidar (15 mg/kg) treated animals by 14.1- and 18.3-fold, respectively, as compared with vehicle group. Isoflurane anesthesia altered [¹¹C]-<i>N</i>-desmethyl-loperamide but not (<i>R</i>)-[¹¹C]­verapamil metabolism, and this had a direct effect on the magnitude of the increase in brain distribution following ABCB1 inhibition. Our data furthermore suggest that in the absence of ABCB1 function brain distribution of [¹¹C]-<i>N</i>-desmethyl-loperamide but not (<i>R</i>)-[¹¹C]­verapamil may depend on cerebral blood flow. In conclusion, we have identified a number of important factors, i.e., substrate affinity to ABCB1, brain uptake of radiolabeled metabolites, anesthesia, and cerebral blood flow, which can directly influence the magnitude of ABCB1-mediated DDIs at the BBB and should therefore be taken into consideration when interpreting PET results