Abstract
Multiantimicrobial-resistant
isolates are a global human health problem causing increasing morbidity and mortality. Genes encoding antimicrobial resistance are mainly harbored on mobile genetic elements (MGEs) such as transposons and plasmids as well as integrons, which enhance their rapid spread. The aim of this study was to characterize 83 multiantimicrobial-resistant
isolates recovered from healthy broiler chickens. Among 78 tetracycline-resistant isolates, the
,
, and
genes were detected in 59 (75.6%), 14 (17.9%), and one (1.2%) isolates, respectively. The
,
, and
genes were detected 31 (46.2%), 16 (23.8%), and 6 (8.9%) isolates, respectively, among 67 sulfonamide-resistant isolates. The PCR-based replicon typing method showed plasmids in 29 isolates, IncFIB (19), IncI1-I
(17), IncF (14), IncK (14), IncFIC (10), IncP (8), IncY (3), IncHI2 (1), and IncX (1). The class 1 and 2 integrons were detected in 57 and 2 isolates, respectively; one isolate harbored both integrons. Seven and one gene cassette arrays were identified in class 1 and class 2 integrons, respectively. Our findings show that multiantimicrobial-resistant
isolates from chickens serve as reservoirs of highly diverse and abundant
and
genes and plasmid replicons. Such isolates and MGEs pose a potential health threat to the public and animal farming.