Background: The current study was conducted to investigate the frequency of resistance in the bacteria isolated from various sources, in Shiraz, Iran. Acquisition of new resistance genes is an important factor in the increasing incidence of resistant strains. A critical feature of resistance gene transfer is their stability to adapt rapidly to a new host and make serious consequences. Methods: A total of 520 samples were chosen from human and animal sources in order to investigate the frequency of antibiotics resistance mobile genes using PCR assay. Results: The rates of 70%, 52%, 16.5%, 8.5%, 8%, 4%, 9.2% and 6.8% were confirmed for several genes including tetO, tetA, tetB, tetM, tetR, gyrA, blaz, and blaSHV, respectively. Our results have revealed a pool of mobile genetic elements in the bacteria isolated from various sources in Iran. Conclusion: Our findings indicated un-regulated use of antibiotics in the food production chains which require more investigation
