Molecular Study of Multidrug-Resistant Integrons Associated with Acinetobacter baumannii Isolated from Clinical Samples

Abstract

The study investigated the prevalence of class one, two, and three integrons in A. baumannii isolates obtained from patients admitted to government hospitals in Diwaniyah (General Diwaniyah, Women and Children, al Hussein, and Burns Hospital) in Al-Qadisiyah Governorate, Iraq. From September 2024 to January 2025, 150 non-duplicate samples were collected, including 21 (14%) wound swabs, 36 (24%) burn swabs, 32 (21.33%) blood samples, 34 (22.66%) urine samples, and 27 (18%) tracheal swabs. After initial identification on MacConkey agar, blood agar, and chromium agar, the samples were chemically tested and Gram-stained. The VITEK2 compact system was used to confirm the diagnosis. This study showed that 117 (78%) of the samples showed bacterial growth, of which 40 (34.18%) were confirmed as A. baumannii, distributed as follows: 3 isolates (14.28%) from wounds, 6 isolates (16.66%) from burn swabs, 13 isolates (40.62%) from blood, 6 isolates (17.64%) from urine samples, and 12 isolates (44.44%) from tracheal swabs. The data indicated that tracheal swabs had the highest percentage of A. baumannii isolation, followed by blood, urine, burns, and wounds (44.44%, 40.62%, 17.64%, 16.66%, and 14.28%, respectively). Antibiotic susceptibility testing was performed using the Vitek device for 20 antibiotics. The purity and concentration of genomic DNA were measured using a Nanodrop instrument, and a conventional PCR reaction was set up to detect integrons using specific primers provided by Promega. The products were analyzed by agarose gel electrophoresis. The highest prevalence was found for class I integrons (23 samples, 57.5%), followed by class III (9 samples, 22.5%), and class II (6 samples, 15%) out of the 40 A. baumannii-positive samples