Evaluation of bacteria in the mouth and throat before study drug ( Levofloxacin, floroquinolone antibiotic and Azithromycin, a macrolide antibiotic) is started and then periodically for 6 weeks after the last dose of study drug is taken

This is a randomized, open-label, single center, exploratory, Phase 1 study to explore changes and resistance patterns of bacteria in the oral flora of healthy male and female adult subjects. The study is to enroll approximately 140 healthy subjects. Approximately 70 subjects are to receive levofloxacin once daily for 5 days and 70 are to receive azithromycin once daily for 5 days. Male or female healthy subjects, 18 years or older may participate. Subjects will be treated on an outpatient basis at a Phase 1 facility. Laboratory testing (blood and urine collection) and microbiologic testing (throat swab) will be performed before dosing with study drug at the Study Entry (Visit 1). Subjects will return daily to the testing facility for their once-daily dosing of study drug for Visits 2 through 5 for a total of 5 consecutive days. At Visit 5 laboratory and microbiologic testing will be performed. Subjects will again return to the testing facility for the 2-Week (Visit 6), 4-Week (Visit 7) and 6-Week (Visit 8) Post-Therapy Visits to undergo microbiologic testing (throat swab). The primary endpoint is the emergence of bacterial resistance in the oropharyngeal flora starting prior to the initiation of study drug through a 6-week observation period. Microbiologic testing (throat swab) will be conducted prior to dosing on Day 1 and following dosing on Days 5, 19, 33, and 47. Safety assessments will be conducted prior to drug administration, during study drug treatment, and at the end-of-therapy visit. These included clinical laboratory evaluations, vital signs, physical examinations, pregnancy testing, and collection of adverse events. Serious adverse events will be collected for 30 days following the last dose of study drug. Levofloxacin Once-Daily 750 mg PO For 5 Days And Azithromycin Once-Daily 500 mg PO On Day One And Then 250 mg On Days 2 Through 5

Inclusion Criteria:

• Male or female
• Healthy on the basis of a pre-study physical examination, medical history, and the laboratory results of blood hematology, biochemistry, and urinalysis performed within 24 hours before the first dose
• Renal function tests must be within the normal laboratory reference ranges
• Normotensive with sitting (5 minutes) blood pressure between the range of 90 to 140 mmHg systolic, inclusive, and 50-90 mmHg diastolic, inclusive
• Normal temperature for at least 72 hours. Normal defined as >36.0 C (96.8 F) to <37.5 C (99.5 F)
• Weight as defined by BMI range of 18 to 32 kg/m2, inclusive
• Must have read and signed the informed consent document before the first study-related procedure indicating that they understand the purpose of and procedures required for the study and are willing to participate in the study.

Exclusion Criteria:

• History of allergy or serious adverse reaction to levofloxacin or any other quinolone or to azithromycin or any other macrolide
• Clinically significant abnormal laboratory values
• Previous systemic antimicrobial therapy within 3 months of Study Entry for any reason
• Hospitalized for any cause within 3 months prior to Study Entry
• Current drug abuse, alcohol abuse, or homelessness
• Requirement for any prescription or non-prescription medication or supplements such as vitamins and herbal supplements, except for paracetamol (acetaminophen) for the treatment of headache and other pain, hormone replacement therapy, and birth control medication upon study entry and during study conduct
• Pregnancy or breastfeeding
• Has received an experimental drug or medical device within the previous 3 months or involvement in any other experimental protocol.