Fluoroquinolone resistance detection in Campylobacter coli and Campylobacter jejuni by Luminex xMAP technology.

The proportion of Campylobacter spp. isolates that are resistant to fluoroquinolones, the drugs of choice for campylobacteriosis, has been increasing worldwide. We developed an innovative method based on a Luminex xMAP DNA suspension array that allows the identification of Campylobacter species and, simultaneously, the detection of the most common point mutation in the gyrA gene (substitution from threonine 86 to isoleucine 86) that is responsible for fluoroquinolone resistance. Ninety-six Campylobacter coli and Campylobacter jejuni isolates collected from turkeys were first investigated by microdilution test to characterize the antimicrobial resistance patterns. The isolates, amplified for the quinolone resistance determining region of the gyrA gene, were then tested using Luminex suspension array. The reliability of the method was demonstrated by the total concordance between the results obtained using Luminex and those of the sequencing of gyrA polymerase chain reaction products. The genotypic characterization of fluoroquinolone resistance using Luminex was also consistent with the data on phenotypical resistance obtained by microdilution test. The results of this study strongly support the potential of Luminex xMAP technology as an efficient molecular method for the rapid and accurate identification of C. coli and C. jejuni isolates and the characterization of the major determinant of fluoroquinolone resistance.