An evaluation of methods to assess the effect of antimicrobial residues on the human gut flora

摘要: 1. Barrier effect. Relevant models should include an anaerobic dominant flora that antagonizes minor bacterial populations such as drug resistant E. coli. 2. Anaerobes vs. aerobes. Aerobe counts are more precise and much less time consuming than anaerobe counts. Minor of aerobes sensitive markers the ecosystem balance, directly relevant to potential risk antimicrobial residues. 3. MIC plate The determination minimum inhibitory concentrations (MIC) selected clones in consuming, does not detect subdominant resistance (less 1%), shift is difficult test statistically. In contrast, direct bacteria on supplemented media allows a rapid measure populations. 4. Statistics: Most published designs do adequate statistical evaluation. This critical for trials made conventional humans animals, where data highly variable. 5. Human trials: lowest concentration antibiotic tested human volunteers (2 mg oxytetracycline/d 7d 6 subjects) significantly increased proportion fecal enterobacteria (P = 0.05). However, huge day-to-day interindividual variations floras make this evidence rather weak. 6. Gnotobiotic mice inoculated with living isolated which effect any gut can be tested. vivo model barrier anaerobes. Interindividual lower those humans. 7. untreated people come from contamination raw foods. relative contribution residues selecting seems low when compared contamination.