Clostridium scindens ATCC 35704: Integration of Nutritional Requirements, the Complete Genome Sequence, and Global Transcriptional Responses to Bile Acids.

In the human gut, Clostridium scindens ATCC 35704 is a predominant bacterium and one of the major bile acid 7α-dehydroxylating anaerobes. While this organism is well-studied relative to bile acid metabolism, little is known about the basic nutrition and physiology of C. scindens ATCC 35704. To determine the amino acid and vitamin requirements of C. scindens, the leave-one-out (one amino acid group or vitamin) technique was used to eliminate the nonessential amino acids and vitamins. With this approach, the amino acid tryptophan and three vitamins (riboflavin, pantothenate, and pyridoxal) were found to be required for the growth of C. scindens In the newly developed defined medium, C. scindens fermented glucose mainly to ethanol, acetate, formate, and H2. The genome of C. scindens ATCC 35704 was completed through PacBio sequencing. Pathway analysis of the genome sequence coupled with transcriptome sequencing (RNA-Seq) under defined culture conditions revealed consistency with the growth requirements and end products of glucose metabolism. Induction with bile acids revealed complex and differential responses to cholic acid and deoxycholic acid, including the expression of potentially novel bile acid-inducible genes involved in cholic acid metabolism. Responses to toxic deoxycholic acid included expression of genes predicted to be involved in DNA repair, oxidative stress, cell wall maintenance/metabolism, chaperone synthesis, and downregulation of one-third of the genome. These analyses provide valuable insight into the overall biology of C. scindens which may be important in treatment of disease associated with increased colonic secondary bile acids.IMPORTANCEC. scindens is one of a few identified gut bacterial species capable of converting host cholic acid into disease-associated secondary bile acids such as deoxycholic acid. The current work represents an important advance in understanding the nutritional requirements and response to bile acids of the medically important human gut bacterium, C. scindens ATCC 35704. A defined medium has been developed which will further the understanding of bile acid metabolism in the context of growth substrates, cofactors, and other metabolites in the vertebrate gut. Analysis of the complete genome supports the nutritional requirements reported here. Genome-wide transcriptomic analysis of gene expression in the presence of cholic acid and deoxycholic acid provides a unique insight into the complex response of C. scindens ATCC 35704 to primary and secondary bile acids. Also revealed are genes with the potential to function in bile acid transport and metabolism.

The importance of water quality in classifying basic water services: The case of Ethiopia, SDG6.1, and safe drinking water.

INTRODUCTION: Sustainable Development Goal (SDG) 6 aims to coordinate international efforts toward "clean water and sanitation." However, water contaminated with pathogenic bacteria or thermotolerant coliforms (TTC) will not achieve the SDG target of clean water in the lives of people around the world. The aim of this study is to assess the water quality parameters of basic water services in Amhara and Afar regions of Ethiopia as well as the role and importance of local managerial committees in ensuring basic water functionality. METHODS: This mixed methods research, conducted in January-June 2019, sampled 22 districts from food-insecure areas in the Amhara and Afar regions of Ethiopia. From the 22 districts, which represent nearly one third of all districts in each region, 111 water services classified as "basic" were randomly selected. For each selected water service, research included: water quality sample testing, visual observation of water services, interviews and focus group discussions with the associated water managerial committee members. Descriptive statistics frequency, percent, mean, median, standard deviations, normal tables, cross-tables and graphs are used to present the data. RESULTS: Although the international water standard for thermotolerant coliform (TTC) levels is 0 CFU/100ml, in our sample of 111 water services, the maximum TTC counts were 71 CFU/100 ml and the mean was 4 CFU/100 ml. Thermotolerant coliform counts were above the permissible standard values for nearly 40% (n = 111) of the basic water services. TTC was detected in 44 (39.64%) (n = 111) basic water services. Of these, 38 (34.23%) were operationally functional while 6 (5.41%) were not functional. Approximately one third of the basic water services sampled, deemed "functional" by international standards, do not provide potable water due to thermotolerant coliform (TTC) levels. CONCLUSION: Our findings from the Amhara and Afar regions of Ethiopia demonstrate that water quality parameters are not currently considered in classifying basic water services. This suggests that international efforts to address SDG 6 should incorporate water quality as a key parameter to better track international progress toward "clean water and sanitation" efforts. We discuss two potential pathways for stronger inclusion of water quality parameters in international definitions: (1) to mandate water quality within "functional" and "non-functional" definitions or (2) to add a ladder rung titled "safe basic water services" to the international drinking water ladder. Our findings from Ethiopia suggest that additional research should be undertaken in development contexts to assess whether or not "functional" basic water services provide safe drinking water to users.

A Descriptive Study of Objectively Measured Pokémon GO Playtime in College Students.

Since its debut in July 2016, Pokémon GO has been a wildly popular mobile gaming app. In contrast to many previous apps, Pokémon GO requires the user to be physically active. However, the extent to which Pokémon GO contributes to physical activity is unknown. Therefore, the purpose of this study was to investigate the physical activity profile of playing Pokémon GO for 60 minutes in recreationally active college students. College students (n=27, n=19 female) were fitted with an accelerometer, pedometer, and heart rate monitor to assess the activity demands during a 60-min bout of Pokémon GO. Troiano accelerometer cut points were utilized to estimate time spent in sedentary, light, moderate, and vigorous-intensity physical activity. Of the 60-min allotted playtime, accelerometry indicated 82% was achieved via moderate-to vigorous-intensity physical activity. Pedometer counts indicated approximately 6000-steps/100-steps/min, indicative of moderate-intensity physical activity. Heart rates were approximately 50% of age-predicted maximum, also indicative of moderate-intensity physical activity. The results of this study provide evidence that playing one hour of Pokémon GO can be an effective means of accumulating recommended levels of daily/weekly physical activity.