Effect of gentamicin and doxycycline on expression of relB and relE genes in Klebsiella pneumonia

Abstract

The goal of study was determined that Klebsiella pneumoniae isolates possessed Toxin-Antitoxin II genes such as relE and relB, other than if there was a correlation between the expression of these two genes and antibiotics, and they may participate in increasing the resistance to antibiotics in K. pneumoniae. Fifty-seven urine samples were collected, from Baghdad s’ hospitals, diagnosed and identified by phenotype and biochemical tests, and confirmed with VITEK 2 compact system. Only fifteen isolates which were identified as K. pneumoniae. Antibiotic sensitivity was identified by using twelve antibiotics discs and K. pneumoniae were resisted in 100% to Ceftriaxone, Amoxicillin, Ticarcillin, Ticarcillin+Clavulanic acid, Ceftazidime, Tetracycline, while other antibiotics were showed less percent of resistant. Minimum inhibitory concentrations (MICs) of antibiotics detected by using macro tube dilution method to identify the antimicrobial activity for K. pneumoniae, the MIC of Gentamicin and Doxycycline antibiotics was 1024 Mg/ml, 512 Mg/ml respectively. By polymerase chain reaction detected genes of relB, relE with 115bp. and 136pb. respectively, then gene expression of relB, relE was conducted by using (RT-qPCR) technique with treated sub MIC concentration of (Gentamicin and Doxycycline) antibiotics. This study was found only ten isolates harbored the two genes as well as, value of folding was increased expression fold of relB gene, but in the same time relE gene was decreased its fold change according to control infB1 gene expression results. This means the bacterial cell tolerance antibiotics sub MIC concentrations by maintaining the number of bacteria under stress of antibiotics. Finally, these findings suggest the potential of relB to give K. pneumoniae resistant to antibiotics in their infections when it was being under stress of antibiotics by toxin-antitoxin II system to stay life.