Background: Aeromonas hydrophila is an opportunistic gram-negative bacillus that causes diseases such as gastroenteritis, muscle infections, soft tissue, sepsis, and skin diseases in humans. Today, the prevalence of antibiotic resistance in bacteria has led to treatment failure and prolonged treatment. Therefore, the aim of this study was to evaluate the level of antibiotic resistance in isolates carrying bla VIM, bla KPC, bla NDM, bla IMP, bla SHV, bla TEM, bla CTX-M and class I and II integrons in Aeromonas hydrophila.
Methods: In this cross-sectional study, Aeromonas hydrophila were collected from different clinical specimens in Hazrat Masoumeh Hospital, Qom Province, Iran, from 2018 to 2020. The collected isolates were identified by standard biochemical tests. Then, using specific primers bla VIM, bla KPC, bla NDM, bla IMP, bla SHV, bla TEM, bla CTX-M genes, and class I and II integrons were evaluated by PCR method. Then, data were analyzed using SPSS software and chi-squared tests, and the significance level was determined as p ≤ 0.05.
Results: During the sample collection period, 100 Aeromonas hydrophila were collected. Based on the results of the antibiotic resistance pattern, the highest and lowest rate of antibiotic resistance to ampicillin (92%) and azithromycin (4%) were determined for both. Among the 100 isolates, 60 isolates produced broad-spectrum beta-lactamase (ESBL) and 50 isolates produced carbapenemase. Among the studied beta-lactamase genes, the highest and lowest frequencies were related to bla CTX-M (58%) and bla TEM (1%), respectively. The frequency of class I and II integron genes was 27% and 15%, respectively.
Conclusions: The results of the study of antibiotic resistance, beta-lactamase, and carbapenemase genes showed high resistance in Aeromonas hydrophila, which raises concerns with regard to controlling infection in medical centers. Also, the study of antibiotic resistance in the presence of beta-lactamase genes showed that there was only a significant relationship between the presence of bla CTX-M gene and resistance to imipenem (p = 0.037).