Molecular study of Shigella dysenteriae Aminoglycoside Resistance Genes Isolated from Children and its Expression Under the Influence of Curcumin Nanoparticle

 Shigella is the causative agent of shigellosis in the world. Antibiotic treatment is important in this bacterium, but recently Shigella species containing the aph, aadE, aacA-aphD genes have shown resistance to aminoglycosides and have hampered the treatment process. Therefore, the aim of this study is a molecular investigation of Shigella dysenteriae aminoglycoside resistance genes isolated from children and its expression under the influence of curcumin nanoparticles.

 In this study, 60 diarrhea samples collected from Tehran hospitals in 2022 were used. Shigella dysenteriae isolates were identified by biochemical and microbial tests. The presence of aadE, aacA-aphD, and aph genes was confirmed by the Multiplex-PCR method. Then, real-time PCR was used to investigate the expression of aadE gene in the presence of curcumin nanoparticles.

From the 60 diarrhea samples examined, 12 strains (40%) of Shigella dysentery were identified by biochemical tests. Ten isolates (83.3%) carried the aadE gene, six isolates carried the aacA_aphD gene, and one isolate carried the aph gene. The Sub MIC value of curcumin nanoparticles on aadE gene expression is 128 µg/mL, and the Fold Change for this gene is -1.03.

 Considering the presence of aadE gene in 83.3% of Shigella dysenteriae isolates, it is important to investigate the presence of this gene in providing a suitable treatment model for patients infected with this bacterium, as well as the expression of aadE gene as the most common one. The expression of the aminoglycoside resistance gene was reduced to a relative amount in the presence of curcumin nanoparticles. Therefore, curcumin nanoparticles can be a suitable alternative for the treatment of strains carrying aminoglycoside resistance genes.