Publications, Posters and Talks
As main author:
As Co-Author:
- Owen, C., Wright-Foulkes, D., Alvarez, P., Delgado, H., Durance, E. C., Wells, G. F., Poretsky, R. & Shrestha, A. (2022). Reduction and discharge of SARS-CoV-2 RNA in Chicago-area water reclamation plants. FEMS Microbes, 3, xtac015. https://doi.org/10.1093/femsmc/xtac015
- Owen, C., Edwardson, C., Oliaro, F., Cabay, C., Van Bonn, W., & Rose, J. (2018). Analysis of proposed water quality indicators for marine mammal enclosures (poster presentation). ASM Microbe 2018, Atlanta, GA.
- Owen, C. (2018). Assessment of Proposed Marine Mammal Water Quality Indicator Organisms in a Recirculating Artificial Seawater System (spoken presentation). 13th Annual Michigan State University Fisheries and Wildlife Graduate Student Research Symposium, East Lansing, MI.
ABSTRACT: Institutions that house marine mammals are required by law to monitor total coliform counts in enclosure waters and maintain counts ≤ 1,000 colony-forming units (CFU) per 100 mL. There is also a proposal to reduce the limit to 500 CFU/100 mL and additionally require one of the following: Enterococci ≤ 35 CFU/100 mL, b) Pseudomonas ≤ 10 CFU/100 mL, or c) Staphylococcus ≤ 10 CFU/100 mL. In a recirculating artificial seawater system, baseline concentrations of these organisms were assessed using culture-dependent methods and compared between exhibit water and system plumbing immediately upstream and downstream of ozone contact. In addition, the feces and chuff of Pacific white-sided dolphins housed in the system were tested for the presence or absence of the proposed organisms. Finally, colony counts were analyzed in conjunction with 16S rRNA gene sequence data to determine whether the proposed water quality indicator organisms are able to predict aspects of the broader microbial community composition. - Owen, C. (2017). Evaluating Bacterial Indicators of Marine Mammal Water Quality (spoken presentation). 12th Annual Michigan State University Fisheries and Wildlife Graduate Student Research Symposium, East Lansing, MI.
ABSTRACT: Bacteriological assays are used to assess water quality in all facilities that maintain captive marine mammals in the United States. The United States Department of Agriculture (USDA) currently requires systems housing marine mammals to maintain coliform bacteria levels below 1000 CFU/100 mL. In addition, the USDA has published a proposed rule that would limit coliform bacteria to 500 CFU/100mL (or alternatively, limit fecal coliform bacteria to 400 CFU/100mL). In addition, the new rule would require the systems to maintain at least one of the following: a) Enterococcus spp. below 35 CFU/100 mL, b) Staphylococcus spp. below 10 CFU/100 mL, or c) Pseudomonas spp. below 10 CFU/100 mL. Some members of the newly proposed genera are opportunistic pathogens of marine mammals, however it is not known whether their presence at the taxonomic level of screening, along with the presence of coliforms or fecal coliforms, indicates health risk for marine animals. In order to help assess these organisms as indicators, I am currently conducting two preliminary studies. The first involves performing 16s rRNA gene surveys on filtered water samples from the Shedd Aquarium’s Sea Lion systems, in association with coliform counts conducted from subsamples of the same water. From this data, I will be able to evaluate whether coliform numbers predict properties of the water’s microbiome. Second, I will be performing whole-genome sequencing on isolates from culture-based counting assays of Staphylococcus, Enterococcus, and Pseudomonas in order to determine the population dynamics of individual benign and potentially pathogenic strains.
As Co-Author:
- William G. Van Bonn, Christopher N. Owen, Christian F. Edwardson, Allen E. LaPointe, Frank J. Oliaro, Chrissy S. Cabay, Shannon D. Manning, Joan B. Rose (2017). Preliminary Assessment of Proposed Marine Mammal Water Quality Indicator Organisms (spoken presentation). IAAAM 2017, Cancun, Mexico.
ABSTRACT: The United States Department of Agriculture, Animal and Plant Health Inspection Service recently proposed to amend the Animal Welfare Act regulations concerning the humane handling, care, treatment and transportation of marine mammals in captivity. Included in the proposed changes is "reducing allowable bacteria counts in water to improve water quality." Specifically, the proposed "bacterial standards" regarding water quality are:
"...that the coliform count can be either a total coliform count or a fecal coliform count. In the case of a total coliform count, we propose that the coliform count shall not exceed 500 colonies per 100 mL. If a fecal coliform test is used, we propose that the fecal count shall not exceed 400 colonies per 100 mL."
"...in addition to a total coliform or fecal coliform test... ...require that one of the following tests also be conducted on a weekly basis:
Enterococci count (count shall not exceed 35 colonies per 100 mL); or
Pseudomonas count (count shall not exceed 10 colonies per 100 mL); or
Staphylococcus count (count shall not exceed 10 colonies per 100 mL)."
The aim of this study is to evaluate ecological relationships of the proposed indicator organisms to total coliform bacterial counts, to overall microbial community structure in sampled waters and using whole genome sequencing, any indicators of potential pathogenicity in these communities. We share our observations with culture dependent and culture independent assessments of the proposed indicator organisms and a dose-response to ozone exposure.