High Level of Chromosomal Quinolone Resistance in Commensal Escherichia coli from Chicken

Kmet V.¹, Kmetova M.²,

¹Institute of Animal Physiology, Slovak Academy of Sciences, Soltesovej 4, 040 01 Kosice
²Institute of Medical Microbiology and Clinical Microbiology, Faculty of Medicine, University P. J. Safarik, Kosice

The aim of study was to investigate the development of resistance to quinolones (enrofloxacin, ciprofloxacin and nalidixic acid) during years 2005-2007 in 346 strains of Escherichia coli isolated from healthy chicken broilers of various Slovak farms. People who consume chicken contaminated with fluoroquinolone-resistant E.coli are at risk of becoming infected with a bacteria that current drugs can't easily kill. Phenotype interpretation of chromosomal quinolone resistance mechanisms was performed with modification of method according Lee et al. (2005). Nalidix acid resistant isolates with low level of MIC for ciprofloxacin (0.1 to 0.5 mg/L) and enrofloxacin (1 to 4 mg/L) represented a single mutation; intermediary MIC for ciprofloxacin (1-2 mg/L) and enrofloxacin (4-8 mg/L) related with two mutations (one gyrA and one parC) and full resistance MIC for ciproflaxin (>=4 mg/ml) and enrofloxacin (>=16 mg/L) represented three mutations (two in gyrA and one in parC). Three hundred and forty-six E. coli chicken isolates (2005/2006/2007) showed a high resistance to nalidixic acid (87/85/67 %), ciprofloxacin (49/54/29 %) and enrofloxacin (52/42/22 %). There was correlation between phenotype reading of full resistance and mutations in gyrA (Ser83Leu, Asp87Tyr or Asp87Asn) and parC (Ser80Ile) gene. High occurrence of full resistant strains was recorded. This is the first report of quantitative antimicrobial resistance in commensal E. coli isolated from chicken broilers in Slovakia.
This study was supported by Slovak VEGA grants No. 2/0012/08 and No. 1/4254/07.

Kmet V, Kmetova M. High level of chromosomal quinolone resistance in commensal Escherichia coli from chicken. Abstrakta XII. česko–slovenského kongresu o infekčních nemocech, Ústí nad Labem, 11.– 13. 6. 2008. [CD-ROM] Klin mikrobiol inf lék. 2008;14(Suppl 1):Abstr #49