Jenny Fisher portrait

Jenny Fisher

Assistant Professor - Biology

Marram Hall 304

Research and Publications

Prevalence of Antibiotic-Resistant Bacteria in Sanitary Sewage

Widespread use and misuse of antibiotics has created a global health crisis, with antibiotic-resistant bacteria occurring more frequently and often exhibiting resistance to multiple drugs. Previous research on antibiotic resistance has focused mainly on pathogenic (disease-causing) organisms, but harmless bacteria (commensal organisms) found in the human microbiome can also acquire and share antibiotic resistance genes. Sewage provides an integrated signal of human populations and has the potential to be used as a tool for assessment of the human-associated microbiome of entire communities. My previous work has shown that certain human commensal bacteria selectively grow in sewer systems, suggesting that the sewer environment may act as both a reservoir and an incubator for antibiotic-resistant bacteria originally associated with humans. The goal of this study is to conduct a population-level assessment of antibiotic-resistant commensal bacteria by using sewage as a proxy for bacteria derived from the human microbiome. This work will provide insight into which commonly used antibiotics are most and least effective for treatment of Enterobacterial infections.

Biological Activity of Metal-Binding Ligands

Faculty from the IUN Chemistry Department have synthesized new types of ligands that will bind silver and copper ions. Heavy metals like Ag and Cu are known to have biological toxicity, but the degree to which that toxicity is dampened or enhanced by chelation with novel ligands is currently unknown. We will analyze the effects of the metal+ligand complexes on two typical lab strains, Escherichia coli and Staphylococcus aureus (a Gram negative and a Gram positive) using methods similar to those for testing antibiotic resistance. This study will determine what biological effects, if any, the ligand itself or the metal+ligand complexes may have on bacteria, and may provide options for new types of antibiotic treatment. Resistance to both metals and antibiotics can be acquired by bacteria through the transfer of resistance plasmids. Future studies will investigate the degree of metal resistance in antibiotic-resistant organisms isolated from sewage and the presence of plasmids that confer both/either metal resistance and antibiotic resistance.

Microbial source tracking of septic pollution

Save the Dunes organization has recently launched a septic system awareness campaign to educate the public on the potential environmental and public health risks associated with poorly maintained septic tanks. Several lakefront communities in NWI (Miller Beach, Ogden Dunes, and Beverly Shores) have many older homes with septic tanks in poor repair. Leaks or overflows coming from septic tanks can result in direct human fecal inputs to the beaches and Lake Michigan. Our work will include sampling beach sand, nearshore lake water, and small creeks and tributaries in areas with high densities of septic systems. We will use a three-pronged approach to tracking and identifying sources of fecal pollution: 1) collection of source samples (septic tank samples, wildlife fecal samples), 2) monitoring water samples for elevated concentrations of fecal indicator bacteria, 3) using DNA-based methods (qPCR and whole community sequencing) to identify instances of human fecal pollution. (Pending grant funding).

Recent Publications

Green HC, Fisher JC, McLellan, SL, Sogin ML, Shanks OC. 2016. Identification of specialists and an abundance-occupancy relationship among intestinal bacteria of Aves, Mammalia, and Actinopterygii. Applied and Environmental Microbiology 82(5):1496-1503. doi:10.1128/AEM.02456-15.

McLellan SL, Fisher JC, Newton RJ. 2015. The microbiome of urban waters. International Microbiology 18(3):141-149. doi:10.2436/20.1501.01.244. (Invited review)

Fisher JC, Eren AM, Green HC, Shanks OC, Morrison HG, Vineis JH, Sogin ML, and McLellan SL. 2015. Comparison of the microbiomes of sewage and animal feces by oligotyping reveals potential human fecal indicators in multiple taxonomic groups. Applied and Environmental Microbiology 81:7023-7033. doi:10.1128/AEM.01524-15. (Featured in Spotlight)

Fisher JC, Newton RJ, Dila DK, and McLellan SL. 2015. Urban microbial ecology in a freshwater estuary of Lake Michigan. Elementa: Science of the Anthropocene 3: 000064. doi: 10.12952/journal.elementa.000064. (Invited contribution to special issue on Urban Aquatic Ecosystems).

Eren AM, Sogin ML, Morrison HG, Vineis JH, Fisher JC, Newton RJ, McLellan SL. 2015. A single genus in the gut microbiome reflects host preference and specificity. ISME Journal 9:90-100. doi: 101038/ismej201497.

Koskey AM, Fisher JC, Eren AM, Ponce Terashima R, Reis MG, Blanton RE, and Mclellan SL. 2014. Blautia and Prevotella sequences distinguish human and animal fecal pollution in Brazil surface waters. Environmental Microbiology Reports 6(6):696-704. doi: 101111/1758-222912189.

Fisher JC, Levican A, Figueras MJ, McLellan SL. 2014. Population dynamics and ecology of Arcobacter in sewage. Frontiers in Microbiology 5:525. doi: 10.3389/fmicb.2014.00525.

Koskey AM, Fisher JC, Traudt MF, Newton RJ, McLellan SL. 2014. Analysis of the gull fecal microbial community reveals the dominance of Catellicoccus marimammalium in relation to culturable enterococci Applied and Environmental Microbiology 80(2):757-765.