Therapeutic use of antibiotics

The committee recommended a comparison of subtherapeutic with therapeutic use of antibiotics on the prevalence of resistant transfer factors in meat animals. Also recommended was a study comparing the enteric flora of vegetarians and meat-eaters. A third study would involve workers in abattoirs and their contacts. These studies are in progress under the direction of Dr. Edward Kass at Harvard University and investigators at the Loma Linda Medical School. The committee also recommended further research on the mechanisms of the antibiotic growth effect. The report (7) said there is little indication that sale of antibiotics, including penicillin and tetracyclines, for feed and veterinary use, "has decreased as a result of the Swann Report."... 

Animals are treated routinely with antibiotics to prevent, treat, or control disease. Even under the best conditions of agricultural management, crowding and stress can lead to disease. While historically there have also been non-therapeutic uses of antibiotics, typically as production tools to improve endpoints such as feed efficiency and weight gain, there is a call to diminish these uses worldwide, and concern for the development of resistance to antibiotics used in human medicine as a result of their use in animal agriculture has led to international efforts to evaluate that risk. The results of the therapeutic uses are healthy animals that contribute to a healthful and plentiful food supply. 

Many of these enzyme inhibitors are important as therapeutic agents. Enzyme inhibitors serve as antibiotics, lower our plasma cholesterol and blood pressure, relieve pain and inflammation, help heal our ulcers, reduce our fevers, and treat cancer, among many other uses. Many examples of the therapeutic uses of enzyme inhibitors follow in later chapters. 

In organic farming, the sub-therapeutic application of antibiotics and the use of growth-promoting hormones is strictly forbidden and adequately controlled. Thus the resulting risks are not associated with animal produce from organic... 

Exposure of animals to therapeutic levels of antibiotics will markedly raise the level of resistance and a long period of time is required for the resistance levels to return to the pre-treatment level In an experiment replicated five times (Lang lo is et al ifi.) we found that exposure of animals to subtherapeutic levels of gram-positive spectrum antibiotics also resulted in increased levels of tetracycline resistance During the course of our study we have sampled pigs on two separate occasions (1974 and 1985) from another research herd in which antibiotics have never been used as feed additives but only for therapeutic purposes Of the 100 pigs sampled in 1974 only one had been... 

This incident and concerns that resistance to antibiotics was increasing led to the formation of the Swann Committee, which examined the use of antibacterials in feeds in England. In 1969, the Committee issued its report ( ) on the use of antibiotics in veterinary medicine and animal husbandry. It recommended that antibiotics and other antibacterials be divided into a "feed class and a "therapeutic class which would be used only by issuance of a veterinary prescription. The British government accepted the Swann Commmttee recommendations in 1971. 

NRDC contended that the suspension of these subtherapeutlc uses of penicillin and the tetracyclines In animal feeds poses no human health problem. No potential human health problem has been Identified In the literature. Any risk of eating meat from an animal that becomes 111, because penicillin and the tetracyclines were not available, could be alleviated by using substitute antibiotics and better farming practices to prevent or reduce the Incidence of disease. Moreover, there would be an Increased probability of effectively treating the diseases with therapeutic levels of antibiotics If they were not used at subtherapeutlc levels. 

Typical classes and examples within these categories as they apply to what is currently most prescribed on the U.S. market are summarized in Table 1.8. The targets in groups 1 and 4 are unique in bacteria and absent in humans and other animals, whereas groups 2, 3, and 5 have human counterparts that are structurally different between prokaryotes and eukaryotes. These differences in targets make the use of antibiotics selective for bacteria with little or no effect on eukaryotic cells from a therapeutic perspective. However, that does not mean that antimicrobial compounds are completely inert to eukaryotes. The mechanisms that block bacterial protein synthesis, block DNA replication, and those that disrupt membrane integrity affect membrane pores. 

New vancomycin-type glycopeptide antibiotics are in clinical trials to combat methicillin-resistant bacteria (2612, 2613) such as the deadly Staphylococcus aureus (2614). For the first time, extracts of marine algae indigenous to Japan have shown activity against methicillin-resistant Staphylococcus aureus bacteria (2615, 2661). The therapeutic use of iodine has been rejuvenated (2616). For example, in the treatment of cyclic mastalgia (2617). 

In the very important therapeutic class of antibiotics, both 6-AP A (6-amino-penicillinic acid) and 7-ADC A (7-aminodeacetoxycephalosporanic acid) are being produced today on multi-ton scale using the cross-linked crystal form of peni-cillin-G amidase (SynthaCLEC -PA) (P. Lanciano, President, Altus Biologies,... 

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