Antimicrobial resistance and molecular characterization of gene cassettes from class 1 integrons in strains.

The emergence of antibiotic-resistant isolates is a global concern and has been attributed to the indiscriminate use of antibiotics in humans and animals. Integrons are mobile gene elements closely related to bacterial drug resistance. Among them, class 1 integrons containing various resistance gene cassettes could play an important role in disseminating and maintaining antibiotic resistance in isolates.. class 1 integrons have a relationship with drug resistance.. This study aims to investigate the distribution of class 1 integrons and their variable regional molecular characteristics, as well as the diversity of the promoters and drug sensitivity among strains.. A total of 111 strains, collected between 2018 and 2020, underwent fully automated bacterial identification using the VITEK 2 Compact system and an antibiotic sensitivity test. PCR was employed to screen class 1 integrase genes () and integron variable regions, while promoter type and variable region gene cassette characteristics were determined using sequencing analysis.. A total of 24 -positive strains were detected in 111 strains. Moreover, -positive strains exhibited statistically significant resistance to ceftazidime, ciprofloxacin, levofloxacin ceftriaxone, trimethoprim/sulfamethoxazole and azithromycin compared to integron-negative strains (<0.05). The multidrug resistance rate of -positive strains was significantly higher than that of negative strains. Variable regions were observed in 6 of the 24 -positive strains. Four gene cassettes were detected, namely , , and . Finally, 3 types of class 1 integron variable region promoters were identified in 24 strains, including PcW, PcH1 and PcW; they are all relatively weak promoters.. The integron and the drug resistance genes carried by integron have a certain relationship with drug resistance.