seminar about antibiotics
Answers
Explanation:
Bacitracin is an antibiotic produced by a strain of B. subtilis recovered from the débrided tissue removed from a compound fracture. It has a wide antibacterial spectrum and is not inhibited by the penicillinase producers.
2.2. Bacitracin has been produced commercially and is available as a lyophilized powder which has been accepted by the Food and Drug Administration for local use in the treatment of infections. These infections have responded favorably in the great majority of cases when the drug was applied locally in the form of a solution or in an ointment base, or when the solution was injected locally into the inflamed tissues or instilled after the aspiration of a purulent exudate from an abscess cavity.
3.3. Many patients with surgical, dermatologic and ophthalmologic infections have been reported successfully treated in this manner without any evidence of toxicity and with minimal allergenicity.
4.4. Bacitracin has been found to be lethal for Endameba histolytica and has been effective by oral administration in the treatment of amebiasis. It is not toxic when given by mouth and is not readily absorbed.
5.5. Bacitracin is retained in the alimentary tract and acts upon many of the intestinal bacterial species.
6.6. Bacitracin has been administered by intramuscular injection in the systemic treatment of various types of infections in 270 cases, with a favorable response in about two-thirds of the patients. More than half of this series had failed to respond previously to other methods of antibacterial therapy, and more than half of these responded favorably to bacitracin.
7.7. Some of the patients treat intramuscularly with bacitracin showed disturbing symptoms and signs of kidney irritation but these can be reduced to a minimum if the commercial product can consistently meet a specification of LD-50 of 500 units for a 20-gram mouse.
8.8. There is evidence that there is a synergistic action between penicillin and bacitracin in the control of infections.
9.9. Chemical studies are being pursued in an effort to purify this drug further, to identify the active principle and to separate it if possible from the toxic factor so that it may be administered in large quantities as safely as is penicillin.
☆Part of this work was done under a contract between Columbia University and the Office of Scientific Research and Development of the United States and the Medical Research and Development Board of the Surgeon General of the Army, and part was done under grants in aid from the United States Public Health Service.