Spore-forming bacteria Paenibacillus spp. were isolated from spoiled corn paste stored below 10℃. Spoilage associated with pH decrease was reproduced by inoculating isolated strains to normal corn paste. To obtain insights to prevent recurrence of Paenibacillus-mediated spoilage, we further characterized the growth temperature, drug sensitivity, and heat resistance of the isolated strains. The isolated Paenibacillus strains could grow at as low as 2.5℃, suggesting that contamination by these strains can cause spoilage during cold chain transport and storage. We also report that these strains can be controlled by heat treatment such as 140℃ for 8 sec, and by treatment with cleaning reagent containing sodium dichloroisocyanurate.
Food borne outbreaks by norovirus caused more than 10,000 acute gastroenteritis patients every year in Japan. Food handler with norovirus infection often contaminates food with the virus. Monitoring norovirus infection in food handlers is thus critical. A small number of norovirus particles are sufficient to establish infection in humans. If a food handler is infected with norovirus, co-workers are at high risk of norovirus infection. Norovirus establishes asymptomatic infection. It is recommended to implement a highly sensitive norovirus testing to every food handlers regardless of gastrointestinal symptoms to reduce the risk of norovirus contamination in food. To do this, the cost and the rapidness of the laboratory test are concerned. In this study, we evaluated a novel nucleic acid-based diagnostic kit for norovirus infection free from standard nucleic acid purification. This was shown to have sensitivity and specificity comparable to the conventional diagnostic procedures employing two-step real-time PCR, suggesting that the new kit offers a rapid and inexpensive laboratory test of norovirus infection. This kit should be able to contribute to the periodic norovirus monitoring of food handlers, leading to the prevention of food poisoning by norovirus.