The study will evaluate the efficacy and safety of Meropenem and Pralurbactam versus Best Available Therapy in the treatment of Carbapenem-Resistant Enterobacteriaceae Infections. Infections evaluated in the study will be hospital-acquired bacterial pneumonia (HABP), ventilator-associated bacterial pneumonia (VABP), complicated intra-abdominal infection (cIAI), complicated urinary tract infection (cUTI), and Bloodstream Infection (BSI).

Inclusion Criteria:

• Hospitalized male or female≥18 and ≤80 years of age，
• Participant must have a diagnosis of an infection (HABP/VABP, cUTI, cIAI, BSI) due to confirmed Carbapenem-Resistant Enterobacteriaceae infection, requiring administration of IV antibacterial therapy
• Participant who had received appropriate prior empiric antibacterial therapy for a carbapenem-resistant pathogen must meet at least 1 of the following criteria: no or no more than 24h; worsening of objective symptoms or signs after at least 48 hours of antibacterial therapy; no change of objective symptoms or signs after at least 72 hours of antibacterial therapy
• The estimated survival time is more than 28 days
• Understand and abide by the research procedures and methods, voluntarily participate in this research, and sign an informed consent form

Exclusion Criteria:

• Participants who need more than 3 systemic antibiotics as part of best available treatment (BAT)
• Participant is expected to require more than 21 days of treatment
• Acute Physiology and Chronic Health Evaluation (APACHE) II score >30 using the most recent available data
• Other medical or psychiatric condition may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• Those who participated in other clinical trials within 28 days before randomization and used any test drugs or medical devices