Investigating the prevalence of class 1, 2, and 3 integrons in carbapenem-resistant Acinetobacter baumannii isolated...

Acinetobacter baumannii is a significant antibiotic-resistant pathogen with high morbidity and mortality in hospitalized patients, especially in burn units. Acquiring mobile genetic elements, such as integrons, is significant in developing multidrug-resistant (MDR) hospital isolates. Therefore, this study aimed to determine the prevalence of class 1, 2, and 3 integrons in A. baumannii. The clinical isolates were collected from burned patients with wound infections. The isolates were identified using standard biochemical and microbiological tests and were confirmed by detecting the bla_oxa-51 gene. The antibiotic resistance pattern of the isolates was evaluated using the disk agar diffusion method. The genomic DNAs were extracted using the boiling method. Finally, the presence of integrons was assessed using the PCR test. One hundred non-repeated clinical isolates of A. baumannii were collected from 75 males and 25 females. The mean age of the patients was 45.03 ± 24.35 years, while patients aged from 1-85 years. The highest antibiotic resistance (100%) was observed against ciprofloxacin, ceftriaxone, and cefepime. Besides, doxycycline was the most effective drug with a 88% resistance rate. However, all A. baumannii isolates were multidrug-resistant (MDR). The intI1 gene was presented in 74% of the isolates, and 45% carried the intI3 gene, while no isolates had the intI2 gene. High-level antibiotic resistance and MDR frequency in burned patients indicate the inappropriate use of broad-spectrum antibiotics for the initial treatment of infections in these patients. This incorrect policy has caused the rapid spread of integrons among the isolates. The high frequency of class 3 integron is a new concern because this high rate has never been observed before in this area. So, further investigation and rapid change in antibiotic prescription policies is required in this hospital.