Valerie Harwood
Valerie Harwood
Associate Professor
Contact
Office: BSF 203
Phone: 813/974-1524
Email:
Links
Education
Ph.D., Old Dominion University and Eastern Virginia Medical School: Biomedical Sciences, 1992.
Research
Water quality microbiology and microbial ecology
My laboratory works on several facets of environmental microbiology and microbial water quality analysis. One of the main emphases is microbial (bacterial) source tracking (called MST or BST). The goal of MST is identification of the source of indicator bacteria (E. coli or Enterococcus) isolated from natural waters. Alternatively, other organisms such as coliphages or Bacteroides may be targeted to identify the source of fecal pollution in water. Fecal coliforms, E. coli and Enterococcus are used extensively in the US and throughout the world as indicator organisms to signal fecal contamination in water, yet these organisms can enter the water in the feces of animals as diverse as birds and humans. In subtropical waters such as those found in Florida, there is potential for growth of these indicator organisms. If growth occurs after indicator organisms enter water, sediments and soil, the indicator organism will tend to be present at high levels in the absence of pathogens, nullifying its use as an indicator of water quality and its predictive value for risk to human health.
We employ several MST methods and have performed studies in many states including Florida, California, Colorado, New Mexico and Virginia. Antibiotic resistance analysis, ribotyping, other genomic methods of DNA fingerprinting, and PCR amplification of source-specific genes are utilized in our environmental microbiology lab. We are also investigating the potential for growth of E. coli, Enterococcus and other indicator organisms in Florida sediments and waters, and the stability of genomic fingerprints for these organisms under environmental conditions.
Other research interests include investigation of the incidence of antibiotic resistance in Vibrio species isolated from Tampa Bay, and the fundamental importance to human health of antibiotic-resistant bacteria humans and animals. Rapid detection, including biosensor and real-time PCR, and subtyping of Vibrio vulnificus, an important human pathogen that naturally occurs in estuarine waters, is also being explored. Community structure and indicator diversity in anthropogenically impacted vs. disturbed environments constitutes another area of ongoing research.
Current Courses
Recent Publications
2007. Brownell, M.B., V.J. Harwood , R.C. Kurz, S.M. McQuaig, J. Lukasik, and T.M. Scott . Confirmation of putative stormwater impact on water quality at a Florida beach by microbial source tracking methods and structure of indicator organism populations. Water Research 41: 3747-3457.
2007. Stoeckel, D.M. and V.J. Harwood. Performance, design, and analysis in microbial source tracking studies. Appl. Environ. Microbiol. 73:2405-2415.
2006. Shannon M. McQuaig, Troy M. Scott, Valerie J. Harwood, Samuel R. Farrah and Jerzy O. Lukasik. Novel method for the detection of human derived fecal pollution in environmental waters using a PCR based human polyomavirus assay. App. Environ. Microbiol. 72: 7567-7564.
2006. M. A. Anderson, J.E. Whitlock and V.J. Harwood. Diversity and Distribution of Escherichia coli Genotypes and Antibiotic-Resistant Phenotypes in Feces of Humans, Cattle and Horses Appl. Environ Microbiol. 72: 6914-6922.
2006. M. Chatzidaki-Livanis, M. A. Hubbard, K.V. Gordon, V. J. Harwood, and A.C. Wright. Genetic distinctions among clinical and environmental strains of Vibrio vulnificus. Appl. Environ. Microbiol. 72:6136-6141.
2006. A Cardoso, A.D. Levine, B.S. Nayak and V.J. Harwood. Lysimeter comparison of the role of waste characteristics in the formation of mineral deposits in leachate drainage systems. Waste Management Res. 24:560-572.