It makes sense that you would be instructed to give enrofloxacin orally, as the injections have been proven to cause pain, inflammation, and necrosis at injection sites. Enrofloxacin is still the drug of choice for regular veterinarians who also see reptiles because they usually don't have antibiotics better suited to reptiles in stock. If your vet did a swab the first time, you should have results back by now, and you would likely remember because fo the bill. He may have taken a sample to look ta under the microscope, but he wouldn't be able to tell anything beyond what the bacteria looked like and if they were gran negative or gram positive. This information helps narrow down what antibiotic to use, but it is not even close to the same thing as identifying the specific bacteria involved and identifying what antibiotics they are sensitive to.