The safety profile of fluoroquinolones

The combined effects of α-tocopheryl acetate supplementation and enrofloxacin administration on oxidative stability of turkey meat

1. The combined effects of dietary supplementation of vitamin E and enrofloxacin administration on the oxidative stability of turkey meat were assessed. 2. Enrofloxacin concentrations found in muscles and liver samples from turkeys receiving 200 g/kg of alpha-tocopheryl acetate plus 50 mg/kg of enrofloxacin without a withdrawal period were higher than those of samples administered with 50 mg/kg of enrofloxacin alone. Similarly, meat samples from turkeys receiving 50 mg/kg of enrofloxacin with withdrawal plus 200 mg/kg of alpha-tocopheryl acetate showed a significantly lower vitamin E accumulation than meat samples of the treatment with enrofloxacin without withdrawal plus vitamin E. 3. The results indicated an interaction between the antioxidant and the antibiotic in their effects on oxidation susceptibility and the abiotic safety of meat from turkeys fed on supplemented diets. A mutual stabilisation of both compounds by reducing the effects of free radicals or by affecting the absorption of the compounds is suggested.

Influence of enrofloxacin administration and alpha-tocopheryl acetate supplemented diets on oxidative stability of broiler tissues

The objective of this study was to assess the oxidative stability and presence of antibiotic residues in tissues of broilers fed diets supplemented with alpha-tocopheryl acetate and treated with enrofloxacin. The activities of antioxidant enzymes and antibiotic concentrations in chicken breast, leg, and liver were determined. Iron-induced TBA-reactive substances (TBARS) and vitamin E were evaluated in muscles. The antioxidant effectiveness of vitamin E was reflected by TBARS values being lower in antioxidant-supplemented treatments than in the other dietary groups. On the other hand, antioxidant enzyme activities were not substantially affected by dietary treatments. The concentration of enrofloxacin in tissues was considerable, even after withdrawal 12 d before slaughter. Contrary to the findings in previous studies, enrofloxacin was not extensively metabolized to ciprofloxacin. Supplementation of the diet with 100 mg/kg of alpha-tocopheryl acetate did not have a significant effect on the level of antibiotic found in breast muscle samples. When comparing treatments without antibiotic withdrawal time, alpha-tocopheryl acetate supplementation led to a significant decrease in enrofloxacin level in leg and liver samples. These results showed that mutual interactions between different molecules could modify the drug residues in the tissue, which should be taken into account when considering the drug administration and the establishment of a correct withdrawal time.

Antibiotic resistance

Widespread resistance problems exist today in a global sense because of the incorporation of antibiotics with a high resistance potential into animal feeds and because of the uncontrolled use of antibiotics with a high resistance potential in the clinical setting. The only proven method of controlling nonoutbreak resistance problems in hospitals is to limit the hospital formulary to antibiotics with little or no resistance potential. The control of multiresistant organisms in outbreaks occurring in hospitals is best contained using appropriate infection control containment measures. Physicians treating infections in the community, with all other factors being equal, should preferentially select antibiotics with a low resistance potential. The titles and headings of much of the resistance literature are misleading. Articles should not contain fluoroquinolone resistant in the title when ciprofloxacin-resistant organisms are described. Many articles concerning penicillin-resistant pneumococci are entitled fluoroquinolone-resistant S. pneumoniae. These articles describe ciprofloxacin-resistant S. pneumoniae and not resistance to other fluoroquinolones. The same error is perpetuated in describing third-generation cephalosporins and carbapenems. Virtually all of the resistance problems associated with third-generation cephalosporins and carbapenems are due to ceftazidime or imipenem. More precise titling in the literature would remind physicians that antibiotic resistance is related to a specific agent and not class phenomena.