Effect of quinolone treatment on selection and persistence of quinolone-resistant Escherichia coli in swine faecal flora

Abstract

Aims: To study the effect of oral administration of a quinolone on emergence of resistance in an indicator bacterial species from faecal flora. Methods and Results: Quinolone resistance was studied in Escherichia coli obtained from the faecal contents of pigs housed in nine commercial farrow-to-finish herds in France after administration of flumequine to sows. The percentage of quinolone-resistant E. coli increased in the faeces of sows after administration of flumequine (mean 21AE78% at day 7 vs 6AE42% before treatment for nalidixic acid) and then decreased (mean 12AE6 and 10AE4 at days 30 and 60, respectively for nalidixic acid), being not significantly different from initial values 1 month post-treatment. In young pigs, the proportion of resistant strains was lower and decreased over rearing period. Moreover, changes over time of both total E. coli and the proportion of resistant bacteria exhibited great inter-individual variability. Conclusions: Restoration of susceptible faecal flora occurred within 2 months after flumequine treatment. Significance and Impact of the Study: Effect of flumequine treatment of sows on the quinolone resistance of faecal E. coli of both sows and their progeny is noticeable but transitory.

Risk Factors for Community-Acquired Urinary Tract Infection Due to Quinolone-Resistant E. coli

“…Intensive use of quinolones in the treatment of infections in humans and animals has led to the spread of resistant bacteria [10,11]. The increasing prevalence of infections caused by antibiotic-resistant bacteria makes empirical treatment of these infections more difficult [12].…”

Impact of Three Ampicillin Dosage Regimens on Selection of Ampicillin Resistance in Enterobacteriaceae and Excretion of bla TEM Genes in Swine Feces

“…As indicated above, these fluctuations were correlated with counts of ampicillin-resistant Enterobacteriaceae. Similarly, Belloc et al (2) studied the effect of quinolone treatment on the selection and persistence of quinolone-resistant E. coli in swine fecal flora and observed great variability in both the percentages of resistant strains and the patterns of emergence of resistance. In the present study, despite the great variability and the small number of pigs per mode of treatment, at least two of the three modes of drug administration (i.e., the intramuscular route and the oral route in fed pigs) could be differentiated by quantifying the bla TEM genes excreted in feces, but not by phenotypic evaluation.…”

Associations Between Feed and Water Antimicrobial Use in Farrow-to-Finish Swine Herds and Antimicrobial Resistance of Fecal Escherichia coli from Grow-Finish Pigs

“…22,51 Experimentally, antimicrobial exposure increases the prevalence of resistant E. coli in healthy pigs. 7,16,30 On-farm studies have also shown antimicrobial use is associated with E. coli AMR. 2,19,21 Observational studies are ideal for investigating complex problems with many causes or hypotheses.…”