The analytic services of the Environmental Microbiology section detect potentially harmful microorganisms in many environmental matrices, including food and water. Such analyses are used in outbreak investigations to pinpoint the source of contamination and to assess the environmental impact from exposure to microbial contaminants. Culture confirmation of microorganisms is critical to perform DNA fingerprinting on food, environmental samples and clinical stool isolates to evaluate the scope of the local or national outbreak as part of remediation efforts.
Laboratory testing also supports statewide water surveillance programs to assess the overall safety of public and private drinking water supplies, surface waters (lakes and ponds), and recreational waters (pools and spas). Pathogen analyses of water, food and environmental surface samples are expanding with emphasis on Cryptosporidium, Legionella, Salmonella and Listeria.
- SDWA total coliform
- Private well total coliform and E.coli
- Private well nitrate
- Surface water E.coli
- Swimming pool total coliform
HIGHLIGHTS
- IPDP’s Center for Acute Disease Epidemiology, the Iowa Department for Inspection and Appeals (IDIA) and SHL worked together on an Iowa County outbreak investigation that was solved in one week; one of Iowa’s fastest responses from recognition to causative agent confirmation. Fifty people became ill, all reporting that they had eaten potato salad. Clinical isolates and leftover potato salad grew Salmonella Braenderup. Isolates were indistinguishable using PFGE and highly related by whole-genome sequencing, confirming the source of the outbreak. IDIA conducted environmental sampling at the implicated deli in which the same strain of Salmonella was found.
- In support of EPA’s Long Term 2 Enhanced Surface Water Treatment Rule, more than 600 surface water samples from the Midwest’s largest surface water treatment facilities were analyzed for Cryptosporidium and Giardia, double the number of the previous year.
- Before an IDIA environmental Listeria surveillance project began in Iowa retail deli facilities, a pilot project was started to validate the field test that would be used to detect Listeria species. SHL demonstrated that this field test had sensitivity and specificity issues. The manufacturer removed it from distribution, and developed a new field test. Because the new device also was unacceptable, the project was modified to have SHL test the samples in the laboratory.
- About 175 surveillance samples of hot dogs, deli meat, ground pork, and ground chicken or turkey from local stores were tested for select agent microbes or toxins through a five-year microbiology cooperative agreement grant with the USDA’s Food Safety and Inspection Service. Through this project, USDA and FDA gathered information about lab capacity and capabilities and food safety as part of preparedness planning.
