Check our collaborative poster presented at ICAAC on Sept 20, 2011!

Check our collaborative poster presented at ICAAC on Sept 20, 2011!


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Check our collaborative poster presented at ICAAC on Sept 20, 2011!

The poster (see ref. below) presented novel data showing a clear link between intestinal concentrations of ciprofloxacin and the amount of ciprofloxacin-resistant enterobacteria excreted by the animals.

This may be of utmost importance in the current context of the spread of bacterial resistance. This link supports the development of novel strategies to capture residual antibiotics that reach the colon before they negatively affect the colonic flora. If such a removal could be obtained in animals or humans receiving therapeutic doses of quinolones without impairing the blood pharmacokinetics of the drug, such as what Da Volterra develops with DAV-132,  this would open new avenues to help control of the emergence and spread of quinolone resistance in gut-originating Gram-negative bacteria.

Background: Colonic flora is where antibiotic residues select resistant commensal bacteria during treatments. We assessed here the relationship between fecal concentrations of ciprofloxacin and levels of ciprofloxacin resistant Enterobacteriaceae (EB) in piglets.
Methods: 30 piglets were randomly assigned to placebo (10 piglets, group 1), oral ciprofloxacin, 1.5 mg/kg/d (10 piglets, group 2) or 15 mg/kg/d (10 piglets, group 3) for 5 days. Fecal ciprofloxacin resistant EB were counted on selective agar with 2 µg/ml of ciprofloxacin before, during and after treatment. Fecal concentrations of ciprofloxacin were measured using a microbiological assay at D1, D3 and D5 of treatment and at D7 and D9 after it. Individual area under the curve (AUC) of bacteria log counts and ciprofloxacin concentrations in feces were computed from D1 to D9 by trapezoidal approach.

Results: Fecal concentrations of ciprofloxacin peaked respectively at D5 at 11.6±12.6 and 84.8±57.9 µg/g of feces for groups 2 and 3 versus < 0.1 µg/g for group 1. Mean counts of ciprofloxacin resistant EB before treatment were similar in the 3 groups at 2.5±0.7 log CFU/ g of feces and on D5, at 2.4±0.9, 3.4±1.1 and 5.6±1.3 log CFU/g of feces in groups 1, 2 and 3 respectively. There was a significant correlation between AUC of ciprofloxacin fecal concentrations and AUC of fecal counts of ciprofloxacin resistant EB (s=0.71, p<0.0001, Spearman correlation test).

Conclusion: Concentrations of fecal ciprofloxacin increase sharply with the dose taken and correlate positively with levels of ciprofloxacin resistant Enterobacteriaceae excreted.

Reference of the poster: Nguyen TT; Chachaty E; Huy C; Mentre F; de Gunzburg J; Andremont A (2011), Correlation between counts of ciprofloxacin resistant enterobacteriaceae and ciprofloxacin concentrations in feces during treatment, Poster ICAAC Chicago, A1-1749.