Tigecycline is being developed as an agent that overcomes tetracycline-resistance mechanisms and provides activity against emerging multi-drug resistant pathogens. The purpose of this protocol is to determine the linkage between time related clinical measures of infection response and time to bacterial eradication in patients with intravascular catheter infections caused by Staphylococcus epidermidis and other coagulase negative staphylococci.

Tigecycline, a glycylcycline antibiotic and an analog of the tetracycline minocycline, demonstrates a broad spectrum of antibacterial activity by inhibiting multiply resistant gram-positive, gram-negative, anaerobic, and "atypical" bacteria. It is being developed as an agent that overcomes tetracycline-resistance mechanisms and provides activity against emerging multi-drug resistant pathogens. These attributes may provide clinicians with a valuable therapeutic alternative. The purpose of this protocol is to determine the linkage between time related clinical measures of infection response and time to bacterial eradication in patients with intravascular catheter infections caused by Staphylococcus epidermidis and other coagulase negative staphylococci. The study is being conducted in two phases. The first treats patients who have removal of the catheter at the time of treatment, and the second treats patients who have the catheter remaining in situ during tigecycline treatment.

Inclusion Criteria:

• Male or female patients, 18-85 years of age and a weight of > 45 kilograms.
• Patients with intravascular catheters and a blood culture that is positive for gram-positive cocci in clusters. Patients will be subsequently excluded from the study analysis if they do not have a culture-positive infection with S. epidermidis or other coagulase negative staphylococci, expected to be susceptible to tigecycline.
• Patients in whom the bacteremia can be cultured daily by the site investigator.
• Patients who have failed other available antibiotic therapies may be enrolled with positive blood cultures and organism susceptibility to tigecycline.

Exclusion Criteria:

• Patients that cannot be cultured daily by the site investigator.
• Intravascular catheter infections known to be caused by bacteria other than a coagulase negative staphylococci, for example, Staphylococcus aureus.
• Any patient who has received more than 24 hrs of vancomycin.
• Any patient who has received any antibiotic active against S. epidermidis other than vancomycin.
• Patients who are moribund with an expected survival of less than 2 weeks.
• Patients who are neutropenic (ANC <500) at the time of bacteremia
• Patients who have been designated as "Do Not Resuscitate", unless it is anticipated within a reasonable degree of medical certainty that they can achieve benefit from tigecycline therapy.
• Known or suspected hypersensitivity to tigecycline, tetracyclines, or other compounds related to this class of antibacterial agents.
• Pregnant women or nursing mothers.
• Female patients of childbearing potential who do not agree to use a medically acceptable method of contraception throughout the duration of the study and for at least 1 month after the last dose of tigecycline.
• Patients with suspected or proven endocarditis or osteomyelitis
• Patients with suspected or proven mycobacterial infections