Background: Exist of folate pathway inhibitor genes among Acinetobacter spp. isolates are regarded as a significant mechanism of resistance for sulfa drugs in this pathogen. Objective: This study aimed to investigate genes associated with sulfa drugs resistance among Acinetobacter spp. using Polymerase Chain Reaction (PCR). Patients and Methods: This study included 928 specimens from patients who visited the main hospitals and private clinic laboratories of Al-Najaf City-Iraq. All specimens were cultivated and bacterial diagnosis was done according to standard methods. Antibiotics susceptibility and molecular investigation for sul-1, sul-2, sul-3, dfr-A, dfr-B, dfr-G and dfr-K for  all Acinetobacter spp. isolates were done. Results:The rate of Acinetobacter spp. isolates were 28 (5.4%). Results showed a high resistance towards antibiotics classes, 28 (100%) of isolates were resistance to piperacillin, cefotaxime, ceftriaxone, ceftazidime and cefepime, while the lowest resistance rate was against minocycline reached 42.85. PCR showed 28 (100%) of Acinetobacter spp isolates were harbored sul-1 and drf-G genes. 25 (89.29%) and 21 (75%) of isolates were positive for sul-2 and drf-A genes respectively, while sul-3, drf-B and drf-K genes were not detected.
Conclusion: There is a great deal of concern about antimicrobial agent resistance and also about the number of drug-associated resistance genes contained in Acinetobacter spp. isolates especially sul-1, sul-2, dfr-A, and dfr-G, which have a significant role in sulfa drug resistance.