Comparison of the expression of small regulatory RNAs AS1974, AS2779, IGR2780 and the Hfq gene in carbapenem-resistant and susceptible clinical isolates of Pseudomonas aeruginosa.

Abstract

Background: Small regulatory RNAs regulate many physiological processes, such as quorum sensing, iron homeostasis, and biofilm formation in Pseudomonas aeruginosa. This study aimed to investigate the expressions of sRNAs AS1974, AS2779, IGR2780, and Hfq in carbapenem-resistant and susceptible clinical isolates of P. aeruginosa.

Methods: Clinical isolates of P. aeruginosa were inoculated onto cetrimide agar and incubated for 24 h, and were identified using standard microbiology tests. Final confirmation of the bacteria was performed using PCR amplification of gyrB. The antibiotic resistance pattern was evaluated using disk diffusion method. The expressions of sRNAs AS1974, AS2779, IGR2780, and Hfq were assessed by real-time reverse transcription polymerase chain reaction.

Results: Overall, 80 isolates of P. aeruginosa were confirmed by phenotypic tests and PCR of gyrB. The results showed that 25% (N = 20) and 75% (N = 60) isolates of P. aeruginosa were carbapenem-susceptible and carbapenem-resistant, respectively. The presence of sRNAs AS1974, AS2779, IGR2780, and Hfq genes were confirmed in 80 clinical isolates of P. aeruginosa using PCR. The expressions of sRNAs AS1974, AS2779, and IGR2780 were decreased in carbapenem-resistant isolates compared to susceptible isolates of P. aeruginosa. hfq had significant increase in expression in carbapenem-resistant isolates compared to susceptible isolates of P. aeruginosa.

Conclusions: The results of our study confirmed the regulatory role of sRNAs in antibiotic resistance among clinical isolates of P. aeruginosa. Further studies are needed to verify and determine the details of this regulatory role.