Determination of multiple antibiotic resistance patterns and identification of class I and II integrons in Staphylococcus aureus isolates in Gilan.
Determination of multiple antibiotic resistance patterns and identification of class I and II integrons in Staphylococcus aureus isolates in Gilan.
Fatemeh Norouzalinia,1Leila Asadpour,2,*
1. Department of Biology, Rasht Branch, Islamic Azad University, Rasht, Iran 2. Department of Biology, Rasht Branch, Islamic Azad University, Rasht, Iran
Introduction: Studies show that several different mechanisms including mobile genetic elements consisting of plasmids, transposons and integrons play an important role in acquiring and spreading antibiotic resistance genes .
Integrons are one of the mobile genetic factors that are able to can carry and spread antibiotic resistance genes among these bacteria, and their horizontal transfer among bacteria is one of the most important ways of spreading resistance genes and creating resistant strains It is medicine.
The purpose of this study is to determine the pattern of antibiotic resistance in clinical isolates of Staphylococcus aureus in Gilan and to investigate the gene class I and II integrons in isolates with multiple antibiotic resistance.
Methods: Sampling and isolation of bacteria
Clinical isolates of Staphylococcus aureus were collected from blood, urine, joint fluid, sputum, wound, and abscess samples of patients referred to Rasht medical diagnostic laboratories and confirmed by culture and biochemical tests to identify the bacteria. To determine the antibiotic sensitivity of Staphylococcus aureus clinical isolates to aminoglycosides, an antibiogram test was performed by diffusion method.
Examining the frequency of IntI and Int II genes
Genomic DNA extraction of Staphylococcus isolates was done using a Cinagen DNA extraction kit (Cat. No. PR881614). To check the frequency of integron genes, a pair of specific primers for class 1 and 2 integrons were used in the PCR reaction.
Results: Out of the total of 66 Staphylococcus aureus isolates, 60 isolates (91%) had multiple antibiotic resistance. The highest level of resistance of isolates was against penicillin G and ampicillin antibiotics respectively, and linezolid, teicoplanin and vancomycin antibiotics were the most effective antibiotics. Also, 60 (91%) isolates had multiple antibiotic resistance. Of these, 74.5% were resistant to gentamicin and 87.2% were resistant to kanamycin.
Out of 60 isolates with multiple antibiotic resistance, in 51 isolates (85%), a fragment with an approximate length of 285 bp was produced in the PCR reaction and was found to contain the Int I gene. Also, 18 isolates (30%) were identified as positive for the presence of IntII gene by producing a fragment with an approximate length of 788 bp. 9 isolates (15%) have IntI and Int II genes at the same time
Conclusion: In the present study, the antibiotic resistance of clinical isolates of Staphylococcus aureus and class I and II integron genes in isolates with multiple antibiotic resistance were investigated. In this study, more than 90% of isolates showed multiple antibiotic resistance phenotypes. The highest level of resistance in the isolates was against beta-lactam antibiotics, and the antibiotics linezolid and teicoplanin, which have less clinical use, were the most effective antibiotics against the clinical isolates of Staphylococcus aureus studied. Also, the presence of IntI and Int II genes was detected in 51% and 30% of the isolates, respectively.
Examining the prevalence of integrons in bacterial strains isolated from each country is important as effective factors in the spread of antibiotic resistance and the emergence of multidrug resistance phenotype .
In a study conducted by Seyed Javadi et al. during a study in Tehran in 2014 on 108 isolates of Staphylococcus aureus, 3.32% of clinical samples and 67.7% of environmental isolates were classified as class I integron genes. were positive (Seyed javadi SS, 2014). In another study conducted by Yahaghi et al. on 200 strains of Staphylococcus aureus in 1992, among the 200 samples, 1% of the strains (two isolates) contained class I integron (Yahaghi E, 2014). In a study conducted by Haji Ahmadi and colleagues in Hamadan city on Staphylococcus aureus and Enterococcus spp, 68 strains of Staphylococcus aureus and 47 strains of Enterococcus resistant to antibiotics were identified. Also, 30 isolates belonged to integron class 1 (intI1) and 2 isolates belonged to integron class 2 (intI2) in Staphylococcus aureus.