Dissemination of Class 1 Integron among Different Multidrug Resistant Pseudomonas aeruginosa Strains

Abstract

Background and objectives: The present study was conducted to detect class 1 integrons and evaluate antibiotic susceptibility patterns among clinical isolates of P. aeruginosa. Methods: Sixty clinical samples from blood, tracheal wounds, burns and urinary tract infections were collected from three general hospitals in Tehran, Iran. Culture of specimens was performed on common bacteriological culture media. Bacteria were identified based on mobility, pigment production, growth at 42 o C, and oxidase and catalase tests. Overall, 21 P. aeruginosa strains were isolated. Antimicrobial susceptibility of was evaluated via the disk diffusion method (Kirby-Bauer) according to the CLSI guidelines. Presence of the intI1, sul1, aadA2 and aadB gene cassettes was investigated using PCR. The collected data were analyzed using SPSS software (version 21). Results: The most effective antimicrobial agents against P. aeruginosa isolates were tetracycline and gentamicin. All P. aeruginosa isolates were multidrug resistant. Moreover, the intI1, sul1, aadA2 and aadB genes were found in 90.5%, 90.5%, 47.6% and 19% of the P. aeruginosa isolates, respectively. Conclusion: The results indicate that the presence of aadB, aadA2 and sul1 gene cassetes may play an important role in the dissemination of antimicrobial resistance determinants.

<p>Distribution and Molecular Characterization of Resistance Gene Cassettes Containing Class 1 Integrons in Multi-Drug Resistant (MDR) Clinical Isolates of <em>Pseudomonas aeruginosa</em></p>

“…6 All integrons have at least three essential regions between two conserved ends (5′CS and 3′CS) including intI, a gene encoding integrase enzymes, attI, a site which recognizes by integrases for the integration of the integron cassettes, and a pc promoter which leads to the transcription of encoded genes. 7 Also, there is an internal variable region (IVR) between these conserved sections containing antibiotic or disinfectant resistance genes, called gene cassettes. 4 Integrons can divide into five classes based on differences in amino acid sequences and relative homology of intI, which class 1 integrons are the most prevalent and clinically significant in P. aeruginosa.…”

“…6 These elements probably play a key role in the dissemination of multi-drug resistance (MDR) genes among the strains of P. aeruginosa or other bacteria. 7,8 Among various known sub-classes, the class 1 integrons are well known and are the most prevalent among MDR P. aeruginosa clinical isolates. 7 Dissemination of antimicrobial resistance genes by the class 1 integrons is a growing health concern, especially among Gram-negative bacteria.…”

“…7,8 Among various known sub-classes, the class 1 integrons are well known and are the most prevalent among MDR P. aeruginosa clinical isolates. 7 Dissemination of antimicrobial resistance genes by the class 1 integrons is a growing health concern, especially among Gram-negative bacteria. 4 The present study aimed to investigate the frequency of class 1 integrons and characterization of resistance gene cassettes in clinical isolates as well as multidrug resistant P. aeruginosa collected from patients admitted to educational and therapeutic hospitals of Mazandaran province, north of Iran.…”

Frequency of Aminoglycoside Resistance Genes in Clinical Isolates of Pseudomonas aeruginosa from Sistan, Iran

“…Furthermore, 16S RMTase genes are linked to mobile genetic elements such as transposons and plasmids, which makes it easier for them to spread through horizontal gene transfer. 29 In the present study, for the first time after the COVID-19 pandemic, the frequency of AME genes in clinical isolates of P. aeruginosa from southeastern Iran was evaluated. 33 This significant difference may also be due to geographical factors.…”

“…This differs from other aminoglycoside resistance mechanisms, which require multiple genes to reach the same resistance level. 29 There have been global reports of 16S RMTase genes such as armA, rmtA, rmtH, and npmA. Their appearance is a public health concern because 16S RMTase genes are linked to other genes that make bacteria resistant to antibiotics.…”