Researchers in Penn State’s College of Agricultural Sciences who tested 100 whole chickens purchased from farmers markets throughout Pennsylvania found 90% tested positive for Campylobacter and 28% harbored Salmonella — two pathogens that can cause serious foodborne illnesses By comparison, just 20% of raw, whole, organic chickens purchased from grocery stores were found to contain Campylobacter bacteria, and 28% tested positive for Salmonella, the researchers said. In addition, only 8% of raw, whole, nonorganic, conventionally processed chickens from grocery stores tested positive for Campylobacter and 52% of those contained Salmonella.  Overall, the chickens purchased at the farmers markets carried higher bacterial loads than the birds purchased at grocery stores, according to the study, published online in the Journal of Food Safety.  More From NewsMax Health: These 4 Things Happen Right Before a Heart Attack  Lead researcher Catherine Cutter, professor and food safety extension specialist in the Penn State Department of Food Science, said the results challenge the widely held belief that locally bought poultry is safer.  “Some people believe that local food is safer, but we want to caution that’s not always the case,” she said. Cutter suggested concerns about antibiotic resistance and animal-welfare issues may explain why many consumers are switching to locally grown and locally processed foods.  “We hope this small study will lead to more extensive research to determine why we are seeing the levels of pathogens in these products and to find ways to mitigate them,” she said.  Cutter and her colleagues suggested antimicrobial rinses, often used by commercial farmers but not by small farm operations, can lower pathogen levels in poultry and may account for the differences. As a result, the researchers are preparing educational materials and food safety training for farmers and vendors selling poultry products at farmers markets.  More From NewsMax Health: What Your Tongue Says About Your Thyroid. See the Photo.  “We are not doing the research to scare consumers or put people out of business; we’re here to improve public health,” she said. “We can train farmers and vendors to produce a safer product that won’t make people sick. This approach also has the potential to help consumers feel more confident about buying their locally grown and processed products.” Bacteria that cause foodborne illness, such as Campylobacter and Salmonella, are destroyed by proper cooking of poultry products, but they also can cause contamination if they come in contact with other foods through contaminated cutting boards, sinks, countertops, or utensils. More From NewsMax Health: Is your carpeting making you sick?  This story originally appeared in NewsmaxHealth.com. More from Prevention:  7 Mistakes Even Safe Cooks Make  Four-Star Food Safety