CHEEC Seed Grants: FY 2012

Sequence analysis of transferable genes encoding bacterial attachment and multi-drug resistance
Investigators: L. Jarboe, Department of Chemical and Biological Engineering, Iowa State University (ISU); M. Soupir, Department of Agricultural and Biosystems Engineering, ISU; C. Logue, L. Nolan, Department of Veterinary Microbiology and Preventive Medicine, ISU

Functionalized magnetic mesoporous silica for adsorpsion of arsenic from water
Investigator:  S. Larsen, Department of Chemistry, University of Iowa

An investigation of carbon nanotube exposure assessment methods
Investigators:  P. O’Shaughnessy, R. Altmaier, A. Horne, Department of Occupation and Environmental Health, University of Iowa

 


Sequence analysis of transferable genes encoding bacterial attachment and multi-drug resistance
Investigators: L. Jarboe, Department of Chemical and Biological Engineering, Iowa State University (ISU); M. Soupir, Department of Agricultural and Biosystems Engineering, ISU; C. Logue, L. Nolan, Department of Veterinary Microbiology and Preventive Medicine, ISU 
The attachment of agricultural Escherichia coli isolates to environmental particles is significantly associated with multi-drug resistance. This association motivates our hypothesis that the genes responsible for bacterial attachment are encoded on a mobile genetic element that also encodes resistance and virulence. These mobile genetic elements are a group of transferable genes that can pass from one bacterium to another; plasmids are the most common form. Here, gene transfer confers not only resistance but possibly virulence. Thus, these genes are a possible environmental contaminant that could threaten human health. In this pilot-scale work we will first confirm that the genes encoding resistance and attachment can be co-transferred between bacteria. This would validate these genes as environmental contaminants. We will then sequence any plasmids transferred between bacteria during the transference of resistance and attachment. This would identify any virulence-associated genes, providing information about the threat that these plasmids present to human health.

Functionalized magnetic mesoporous silica for adsorption of arsenic from water
Investigator: S. Larsen, Department of Chemistry, University of Iowa
Access to safe drinking water is a global health issue. Human exposure to drinking water contaminants, such as arsenic, has been linked to cancer, neurological, cardiovascular and pulmonary health problems. The arsenic levels in 8% of private wells in Iowa were determined to be greater than the EPA’s drinking water standards of 10 ppb (0.01 mg/L).  Therefore, it is critical, both globally and locally, to develop improved methods for removing and analyzing arsenic in water. Mesoporous silica has well-defined pores of 1.5-10 nm and very high surface areas. Mesoporous silica can be readily modified through surface functionalization. In this study, functionalized mesoporous silica will be tailored to optimize arsenic adsorption. Specifically, mesoporous silica will be functionalized with thiol and/or amine functional groups which are expected to selectively adsorb As(III) or As(V) species, respectively. Magnetic iron oxide nanoparticles will be incorporated into the mesoporous silica to facilitate magnetic recovery from solution.                                                                                                                                                                                                                                                                                                                                                                      Publication:    Lehman SE, Larsen SC.  Zeolite and mesoporous silica nanomaterials: Greener syntheses, environmental applications and biological toxicity. Environ Sci: Nano; 2014, 1, 200-213.

An investigation of carbon nanotube exposure assessment methods
Investigators: P. O’Shaughnessy, R. Altmaier, A. Horne, Department of Occupation and Environmental Health, University of Iowa 
Carbon nanotubes (CNTs) are engineered nanoparticles (<100 nm) that have been shown to cause adverse pulmonary outcomes in test animals. As such, the National Institute for Occupational Safety and Health (NIOSH) is considering a recommended exposure level (REL) for CNTs of 7 µg/m3, which is the limit of quantification (LOQ) of a method used to measure elemental carbon (EC) in diesel particles. Such a limit presents either an under- or over-exposure scenario with no information to determine actual conditions when below the LOQ. This pilot project will seek to establish a relationship between CNT particle count concentrations given known size distributions and EC mass concentrations to guide the interpretation of environments that may become contaminated with CNTs below the LOQ. A secondary objective will be to compare EC concentrations measured using the NIOSH method with those obtained from a hand-held device suitable for personal exposure assessments.