Research in Microbial Safety of Food and Environment

Research Highlights (summary of some recent projects):

Our interdisciplinary research program in microbial food safety runs in collaboration with US FDA, USDA, Tennessee Department of Health, Shelby County Health Department (SCHD), industry, major US and International Universities, and departments within the University of Memphis. Several MPH and doctoral students are involved in these research projects.  

Food Safety and Rapid Microbial Diagnostic Method Development

Biosensor based rapid detection of pathogens, toxins, and contaminants in food and environmental (water, soil, air) samples. (check out our relevant publication at: Toxins 2013, 5(12), 2366-2383), novel nanotechnology-based method to mitigate the “matrix effect” of foods to enable successful detection and identification of pathogens (find our work here: International Journal of Food Microbiology 2014;189:89–97). 

Application of Microbiome Research in Public Health

Dissemination of pathogens/infections and human health risks and molecular epidemiology of multi-drug resistant pathogens 

With the advent of the advanced Next Generation Sequencing (NGS) technologies, it is possible to visualize the unseen diversity of microbial pathogens inhabiting in the environment surrounding us. In one of such projects, we collaborated with a Memphis-based investigative journalist and accessed the “microbial cleanliness” of the large fitness centers around Memphis metropolitan area. Check the news coverage here: The first round of our findings including the bacterial diversity from gym surfaces is reported in International Journal of Environmental Research and Public Health 2014, 11(12), 12544-12561. In an extension of this project, Dr. Banerjee’s group has recently reported the prevalence of multi-drug resistant (MDR) methicillin-resistant Staphylococcus aureus (MRSA) in indoor surfaces, and the molecular characterization of a MRSA type (CC59) found for the first time in the US. This is reported in the American Journal of Infection Control 2016, 44(12):1681-1683.  

Microbial ecology and prevalence of multi-drug resistant organisms in in human and food environment 

In collaboration with SCHD, this project aims to assess microbiological quality and safety of retail foods commodities available in low- and high-socioeconomic neighborhoods of Memphis metropolitan. We are using conventional microbiological as well as Next Generation Sequencing-based metagenomics techniques to evaluate microbial populations of food commodities, and presence of antibiotic resistance genes in these products. The study was featured in the University of Memphis YouTube portal and can be found here: 

Haiti Drinking Water Project

In a recent project, we examined the overall bacterial diversity of selected source and point-of-use water from rural areas in Central Plateau, Haiti using NGS based metagenomics methods (pyrosequencing of 16s rRNA genes). We also evaluated the impact of interventions (filtration) in removing or reducing the overall microbial loads of drinking water in the study area. You can read the full report published in PLOS ONE 2016, 11(12): e0167353.  

Genome-wide study of pathogens - understanding factors affecting virulence and antibiotic resistance

Environment poses stress to pathogens. Recently, we have finished an extensive study where we used whole genome sequencing to understand the differential expression of virulence genes of pathogenic E. coli O157:H7 during environmental shock (such as cold temperature). The initial findings were reported in Journal of Food Protection 2016, 79(7):1259-65. Our group is also working on to understand the relationship of virulence gene expression in multi-drug resistant and drug-sensitive bacteria.