did not find these effects associated with fluoroquinolone-resistant Campylobacter infections. In Campylobacter, resistance to GSK2118436 mw quinolones and macrolides is primarily associated with mutations in the gyrA and 23S rRNA genes, respectively [20, 25]. The involvement of the CmeABC multidrug efflux pump in resistance to both classes of antimicrobials
has also been recognized [26, 27]. Information about antimicrobial resistance of Campylobacter at different levels of production is important for the development of control strategies for this pathogen. In addition, differentiation of antimicrobial-resistant strains is necessary to investigate the epidemiology of resistance. Restriction fragment length polymorphism (RFLP) analysis of the flaA gene (fla typing) and pulsed-field gel electrophoresis (PFGE) are two genotyping methods used to successfully differentiate Campylobacter strains [28, 29]. This study was conducted to assess the ciprofloxacin and erythromycin resistance in Campylobacter isolated from turkey at the processing level. Fla typing, PFGE, and antimicrobial susceptibility testing were used to characterize a subset of ciprofloxacin- and/or erythromycin-resistant and susceptible Campylobacter isolates obtained from pre and post chill turkey carcasses and chill water. Results Antimicrobial susceptibility testing Figure 1A and 1B shows
the MICs of 801 Campylobacter isolates to ciprofloxacin and erythromycin. Few isolates were co-resistant to both antimicrobials (2 from plant A [0.45% of plant A isolates] and 9 from plant B [2.5% of plant B isolates]). Resistant isolates were recovered from carcasses at pre chill and buy Palbociclib post chill at both plants. No significant difference (P > 0.01) was observed between the number ADAMTS5 of ciprofloxacin-resistant or erythromycin-resistant isolates obtained from either process stage at plant A (Table 1). Figure 1 Antimicrobial susceptibility profiles of Campylobacter isolates (n = 801).
Isolates from plant A (n = 439; open bars) and plant B (n = 362; black bars) were tested for antimicrobial susceptibility using agar dilution. A. The frequency of MICs obtained for ciprofloxacin. The arrow denotes the breakpoint of ≥ 4 μg/ml. B. The frequency of MICs obtained for erythromycin. The arrow denotes the breakpoint of ≥ 32 μg/ml. Table 1 Antimicrobial resistance and sampling stage distribution of Campylobacter isolates (n = 801). Plant A Plant B Sampling Stage Total Isolates Ciprofloxacin Resistance Erythromycin Resistance Total Isolates Ciprofloxacin Resistance Erythromycin Resistance Pre Chill 225 a (51) b 7 c (3.1) d 46 c (20) d 242 a (67) b 99 c (41) d 6 c (2.5) d Post Chill 209 (48) 16 (7.7) 35 (17) 119 (33) 37 (31) 4 (3.4) Chill Water 5 (1.1) 1 (20) 1 (20) 1 (0.3) 1 (100) 0 (0) Total 439 24 c (5.5) e 82 c (19) e 362 137 c (38) e 10 c (2.8) e a Number of total isolates tested. b Percentage of total isolates tested. c Number of isolates resistant.