PCR mapping of integrons is an effective epidemiological tool for studying the plasmids and transposons that mobilize antibiotic resistance determinants in Salmonella. Integrons play a crucial role in the dissemination of antimicrobial resistance among Salmonella species. This study investigated the occurrence and diversity of integron classes in isolates from broiler chickens in Jordan. A total of 185 isolates were screened by PCR and sequenced for integron-associated genes. The overall prevalence of the three integron classes was 87.56%, and only 23 out of 185 samples were negative for all three tested classes. Class 1 was detected in 81.1% of samples, while classes 2 and 3 were found at lower frequencies. Gene cassette arrays of class 1 integrons were detected in nearly all integron-positive isolates (93.8%). Sequence analysis identified several resistance cassettes, including aadA1, aadA15, (aadA2–dfrA12), dfrA5, and dfrA15. Class 2 integrons were less frequent, found in only three isolates carrying cassette combinations of (dfrA1+sat2+aadA1) and (dfrA1+sat2). Phenotypically, the highest resistance rates were observed against tetracycline, ampicillin, amoxicillin, chloramphenicol, and nalidixic acid. PCR screening also revealed a high prevalence of resistance genes, particularly aadA, tet(A), and floR.  Overall, these findings indicate an alarming level of multidrug resistance among Salmonella isolates from broiler chickens in Jordan, underscoring the widespread presence of integrons and resistance gene cassettes, and highlighting the urgent need to regulate antimicrobial use in poultry production.

To Cite This Article: Etoom EM and Gharaibeh MH, 2025. Investigation and molecular assessment of integron-mediated resistance determinants in salmonella species from broiler chickens in jordan. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2025.316