Inclusion Criteria:

• To be eligible for this study, a patient must provide informed consent and must meet all of the following criteria. No study procedures, including any baseline tests, should be performed until the patient (or parent/legally acceptable representative, if appropriate) legally signs the informed consent form.
• Male or female, 18 years of age or older and >= 40 kg body weight
• End-stage renal disease patients on hemodialysis with: A) Signs and symptoms of a localized catheter-related infection (eg tenderness and/or pain, erythema, swelling, purulent exudates within 2 cm of entry site); OR B) A body temperature of >= 38.0 C or < 36.0 C (oral equivalent); OR C) A Gram-positive blood culture. If the Gram-positive isolate is S. aureus, it must be cultured from at least 1 culture bottle from either the peripheral set or the catheter set of culture bottles. For all other Gram-positive pathogens (eg, coagulase-negative staphylococci), isolates need to be cultured from at least 2 culture bottles of which one must be from the peripheral set. There must be no other obvious source of the bacteremia
• Presence of at least one of the following systemic signs of infection (may be obtained up to 24 hours prior to baseline): *Hypotension, defined as systolic blood pressure <90 mmHg or its reduction by >= 40 mmHg from the patient's baseline, in the absence of other causes for hypotension; *Tachycardia defined as a pulse rate > 90 beats per minute; *Tachypnea defined as a respiratory rate > 20 breaths per minute or PACO2 <32 torr; *White blood count >10,000 cells/mm3 or < 4,000 cells/mm3, or with a differential count showing >10% band neutrophil forms.
• Patients on hemodialysis with tunneled or nontunneled catheters including antibiotic coated hemodialysis catheters. Patients may have more than one concurrent catheter.
• Patients who are willing and able to comply with scheduled visits, treatment plan, laboratory tests and other study procedures

Exclusion Criteria:

• Patients presenting with any of the following will not be included in this study:
• Catheter-related bloodstream infections caused by Gram-negative bacteria, fungi, mixed cultures of Gram negative bacteria and Gram positive bacteria or mixed cultures of Gram positive/negative bacteria and fungi
• Patients with evidence of other infections resulting in bacteremia, such as clinical or radiographic signs of osteomyelitis, endocarditis, skin/skin structure infection, pneumonia, urinary tract infection, joint infection, intraabdominal infection, septic thrombophlebitis or other infection
• Patients in whom the infected catheter cannot be removed
• Patients with permanent intravascular devices such as artificial vascular grafts, implantable pacemakers or defibrillators; intra-aortic balloon pumps, and left ventricular assist device; intravascular transplants such as prosthetic cardiac valves; or non-intravascular devices such as peritoneal dialysis catheters; or neurosurgical devices such as ventriculo-peritoneal shunts, intra-cranial pressure monitors, or epidural catheters, prosthetic cardiac valves, prosthetic vascular grafts, or other internal prosthesis
• Females of child-bearing potential who are unable or unwilling to take adequate contraceptive precautions, have a positive pregnancy result within 24 hours prior to study entry, are known to be pregnant, or are currently breastfeeding an infant
• Identification of a pathogen resistant to linezolid or vancomycin
• Patients who are unlikely to survive through the treatment period and evaluation
• Administration of a glycopeptide antibiotic within 5 days prior to enrollment. Administration of other potentially effective systemic Gram-positive antibiotics for more than 48 hours within 72 hours prior to enrollment unless the pathogen showed drug resistance
• Previous enrollment in this protocol
• Hypersensitivity to linezolid, vancomycin, gentamicin or one of their excipients (or aztreonam if non-bacteremic Gram-negative coverage is required)
• Concurrent use of another investigational medication or use within 30 days of study entry
• Patients with pressor and fluid-resistant hemodynamic compromise or pulmonary embolism