A nurse of the kindergarten was taken to the hospital with complaints of accute pain in parumbilical region, convulsions of lower limbs, multiple bile vomiting, frequent watery foul feces of green colour in huge amounts. At the same time all the staff in the kindergarden got ill. Two days ago all of them ate cottage cheese with sour cream. General condition of patients is of moderate severity. Temperature 38,2°C. Heart tones: rhythmic and muted. Heart rate 95/min, arterial pressure: 160 mm/Hg. Abdomen is slightly swollen, painful. Liver 2 cm. What is the most likely diagnosis?