Returning to his lab one morning in 1928 after a two-week vacation, Scottish microbiologist Sir Alexander Fleming realized that one petri dish inoculated with staphylococcus bacteria had been accidentally left open. About to dispose of the moldy dish, he noticed a clear halo devoid of any bacterial overgrowth surrounding each mold colony. For some reason, the bacteria did not grow in these small halos of agar surrounding the greenish mold. Instead of discarding the sample, he explored the antibacterial properties of the unusual mold, called Penicillium notatum, and the rest is history.
Since Fleming’s discovery of penicillin, wide varieties of antimicrobial chemicals have been developed, and researchers continue to seek newer, safer, and more effective methods of interfering with bacterial and other microorganism replication. One of the greatest challenges veterinarians and human doctors face is to make appropriate antibiotic selections that help the patient recover from bacterial, yeast, and fungal infections – and at the same time not harm the patient.
How would the patient be harmed by antibiotics? One example is over-prescribing them. Recently, a young Wire Fox Terrier was presented to me because of sudden onset of loose, foul-smelling stool. There was no history of the dog having eaten anything un-usual, the diet was excellent, no intestinal parasites were evident on the fecal analysis, and the patient was not dehydrated, vomiting, or acting de-pressed. The dog’s temperature was normal and abdominal palpation revealed a loose, gassy, and non-painful character. My diagnosis was viral enteritis – intestinal flu. After discussing my diagnosis and my preferred treatment of withholding all dog food for 24 hours, allowing plenty of fresh water, and allowing the dog to eat small amounts of yogurt every two hours until the following day, the owner asked, “Aren’t you going to give him some antibiotics?”
I had to convince the concerned and skeptical owner that if my diagnosis was correct, this patient did not need antibiotics and in fact might develop a much worse diarrhea if we went that route. Plus, once an antibiotic is used in a patient, there is potential for that patient to develop a resistant population of bacteria. And someday, when antibiotics are truly needed, if that antibiotic is chosen as a treatment the infection may be resistant to the drug. What this patient needed was to have “good” bacteria reintroduced into the gastrointestinal tract so that the correct balance of bacterial flora could be re-established. Antibiotic administration should be reserved for patients who truly need them. Indiscriminate or casual use of antibiotics may lead to bacterial resistance in a patient, as well as set up the potential for a future allergic reaction to the drug.Page 1 | 2 | 3