Comparative Study To Determine The Efficacy, Safety, And Tolerability Of Ceftolozane-Tazobactam

Study Groups and Study Drug Administration: If participant is found to be eligible to take part in this study and participant agrees, participant will be randomly assigned (as in the flip of a coin) to either receive either the study drug (Group 1) or a standard treatment antibiotic (Group 2). This is done because no one knows if one study group is better, the same, or worse than the other group. Both participant and the study doctor will know what participant is receiving. If participant is in Group 1, participant will receive ceftolozane-tazobactam by vein over 1 hour every 8 hours. If participant is in Group 2, participant will receive a standard treatment antibiotic. This may include one of the following 3 options: cefepime by vein over about 30 minutes every 8 hours. meropenem by vein over about 30 minutes every 8 hours. piperacillin/tazobactam by vein over about 1 hour every 6 hours. Participant will receive the study drugs by vein for at least 3 days. After 3 days, if the study doctor thinks it is in participant's best interest and participant is eligible, participant may switch to receiving a different antibiotic either by mouth or by vein. The study doctor will tell participant more about what antibiotic participant may begin to receive, how it is administered, and its possible risks. If participant begins taking the study drugs by mouth, the study doctor or study staff will tell participant how and when to take each drug. If the doctor thinks it is needed, participant will be given additional standard drugs to help control the infection. Participant may ask the study staff for information about how the drugs are given and their risks. Length of Study: Participant may receive the study drugs for up to 14 days. Participant will no longer be able to receive the study drugs if the disease gets worse, if intolerable side effects occur, if participant needs treatment that is not allowed on this study, or if participant is unable to follow study directions. Participation on this study will be over after the late follow-up visit. Study Visits: Participant will have the following tests/procedures while participant is in the hospital. If participant begins to take the study drugs by mouth, participant will no longer have these study visits. Each day for up to 2 weeks, if the doctor thinks it is needed, blood (about 1 tablespoon) or urine will be collected for routine tests. Every 2 days for up to 2 weeks, blood (about 1 tablespoon) will be drawn to check for infection. Participant will stop having these blood draws when there is no longer a sign of infection and participant does not have a fever. Twice each week for up to 2 weeks, participant will have a physical exam. Follow-Up: Within 72 hours (3 days) after participant's last dose of participant's assigned study treatment and before starting the second antibiotic therapy (if applicable): Participant will have a physical exam. Blood (about 1 tablespoon) and urine will be collected for routine tests. If participant tested positive for infection at the beginning of the study, blood (about 1 tablespoon) will be drawn to check for infection. The study doctor will tell participant if participant will have this blood draw. About 21-28 days (3-4 weeks) after participant's first dose of study drug, participant will return to MD Anderson for the following tests/procedures: Participant will have a physical exam. If participant tested positive for infection at the beginning of the study, blood (about 1 tablespoon) will be drawn to check for infection. The study doctor will tell participant if participant will have this blood draw. If participant can become pregnant, blood (about 1 teaspoon) will be drawn for a pregnancy test. About 35-42 days (5-6 weeks) after participant's first dose of study drug, a member of the study staff will call participant to ask about any new drugs participant may have started and if participant is having any side effects. If participant is called, it should last about 10 minutes. If the doctor or study staff thinks it is needed, participant will be asked to come back to the clinic for the following tests/procedures: Participant will have a physical exam. If the doctor thinks it is needed, blood (about 1 tablespoon) will be drawn to check for infection. At any of these follow-up visits, if participant's doctor thinks it is needed, participant will have a chest x-ray or CT scan to check participant's lungs.