Genome Comparison of Erythromycin Resistant from Turkeys Identifies Hosts and Pathways for Horizontal Spread of (B) Genes.

Pathogens in the genus are the most common cause of food-borne bacterial gastro-enteritis. Campylobacteriosis, caused principally by and , is transmitted to humans by food of animal origin, especially poultry. As for many pathogens, antimicrobial resistance in is increasing at an alarming rate. Erythromycin prescription is the treatment of choice for clinical cases requiring antimicrobial therapy but this is compromised by mobility of the erythromycin resistance gene (B) between strains. Here, we evaluate resistance to six antimicrobials in 170 isolates (133 and 37 ) from turkeys. Erythromycin resistant isolates ( = 85; 81 and 4 ) were screened for the presence of the (B) gene, that has not previously been identified in isolates from turkeys. The genomes of two positive isolates were sequenced and in both isolates the (B) gene clustered with resistance determinants against aminoglycosides plus tetracycline, including , and (O) genes. Comparative genomic analysis identified identical (B) sequences among from turkeys, from pigs and and from humans. This is consistent with multiple horizontal transfer events among different bacterial species colonizing turkeys. This example highlights the potential for dissemination of antimicrobial resistance across bacterial species boundaries which may compromise their effectiveness in antimicrobial therapy.