Patient description: The patients is a 25-year-old G1 P1 pregnant woman who is 24W3D gestational old who developed a sudden unset of fever and chills, accompany with nausea and vomiting. She also complains of dysuria, urgency and frequency. She also reports some severe pain in the flank. Her vital signs are: T = 39.7ºC, P = 117, R = 20, and BP = 113/74 mm Hg. Physical examination reveals tenderness on palpation of both costovertebral angles. She has no history of recurrent UTI prior to her pregnancy or any other underlying disease. The urine culture showed Gram-negative rod-shaped bacterial cells, leukocytes, and leukocyte casts. The blood culture is negative. A CBC shows Hb 12.9 g/dL, Hct 39%, MCV 76 fL, WBC count 14,120/µL.

Clinical trial eligibility criteria: eligible ages (years): 18.0-80.0,  Pneumonia, Bacterial Males and non-pregnant, non-lactating females, ≥ 18 years and ≤ 80 years of age Intubated and mechanically ventilated Diagnosis of pneumonia, defined as presence of a new or progressive infiltrate(s) on the most recent chest radiograph prior to screening, as determined by the treating physician Signs of infection (within 24 hours prior to screening): 1. Fever (> 38ºC or > 100.4ºF); or 2. Leukopenia (< 4,000 WBC/mm3) or leukocytosis (≥ 12,000 WBC/mm3) Impaired oxygenation (within 24 hours prior to screening): a. PaO2/FiO2 ≤ 350 mmHg Acute Physiology and Chronic Health Evaluation (APACHE) II score > 10 (within 24 hours prior to screening) Presence, or high suspicion, of Gram-negative organism(s) by either Gram stain or culture of respiratory secretions from a sample obtained within the previous 7 days (enrollment can occur before culture results are available)  History of hypersensitivity to amikacin, other aminoglycosides, fosfomycin, imipenem, meropenem, or colistin Received systemic antibiotic therapy for this episode of Gram-negative pneumonia for greater than 72 hours at the time of randomization PaO2/FiO2 ≤ 100 mmHg and diffuse infiltrates on Chest X-ray Refractory septic shock (severe sepsis plus unstable hypotension, in spite of adequate fluid resuscitation and vasopressors) Any of the following conditions that interfere with the assessment or interpretation of the diagnosis or response to therapy: 1. chest trauma with ongoing loss of stability of the thoracic cage following a fracture of the sternum, ribs, or both; 2. increased amounts of fluid in the lung cavities requiring chest tube drainage; 3. lung cancer within the last 2 years; 4. lung abscess(s); 5. anatomical bronchial obstruction; 6. suspected atypical pneumonia; 7. chemical pneumonitis (e.g., inhalation injury); 8. cystic fibrosis Immunocompromised patients, including those with neutropenia NOT due to the current infection (absolute neutrophil count < 500/mm3), leukemia, lymphoma, human immunodeficiency virus (HIV) infection with CD4 count < 200 cells/mm3, or splenectomy; those who are early post-transplantation (< 3 months post-transplant, or > 3 months post-transplant with evidence of organ rejection by clinical pathologic confirmation, or modification of immunosuppression within the past 4 weeks), are on cytotoxic chemotherapy, or are on high-dose steroids (e.g., > 40 mg of prednisone or its equivalent [> 160 mg hydrocortisone, > 32 mg methylprednisolone, > 6 mg dexamethasone, > 200 mg cortisone] daily for > 2 weeks) Evidence of significant renal impairment (serum creatinine > 4.0 mg/dL within 24 hours prior to screening). If serum creatinine is >2.0 mg/dL, site must be capable of performing continuous renal replacement therapy, if clinically indicated. Patients with serum creatinine > 4.0 mg/dL and being treated with continuous renal replacement therapy (continuous venous-venous hemofiltration or continuous venous-venous hemodialysis) or chronic hemodialysis are eligible Evidence of ototoxicity (history of hearing aid use prior to current hospitalization) Evidence of hepatotoxicity (alanine aminotransferase [ALT] or aspartate aminotransferase [AST] >3X the upper limit of normal value within 24 hours prior to screening) Positive urine and/or serum beta-hCG pregnancy test (only in women of reproductive age)