Study participants will be admitted to the hospital for 2 to 4 days. On day 1, they will receive the first dose of VNP0009, infused over a 30-minute period through an intravenous catheter (a small plastic tube inserted into a vein). Blood will be drawn every day to determine if the bacteria are still in the body. After discharge, patients will return to the hospital on days after approximately 1-2 weeks and again after 4-5 weeks for additional blood tests to measure levels of the bacteria and for collection of blood, urine and stool samples. Patients whose tumors are on or just beneath the skin may be asked to have one or two tumors removed surgically.