Upstream region of OprD mutations in imipenem-resistant and imipenem-sensitive Pseudomonas isolates.

The current study was aimed at investigating the prevalence of the mutations upstream of the oprD coding region and its promoters among imipenem-resistant and sensitive Pseudomonas aeruginosa isolated from educational hospitals in Yazd City, Iran. All isolates were identified by the conventional biochemical tests. Then, the antibiotic resistance of these isolates was determined using the disk diffusion method according to the CLSI guidelines. Also, the E.test was performed to determine the minimum inhibitory concentrations (MIC) of imipenem. The mutations of this gene were recognized by the amplification of this region and subsequently sequenced. Sequencing of the genomic region upstream of oprD these regions were done in the 29 clinical strains. Statistical analysis was done by the statistical software SPSS-18. Seventy (77.7%) of isolates had MIC ≥ 16 and were resistant to imipenem. Mutations of the upstream of the oprD gene and its promoters were seen in 25 (86.2%) isolates and 4 isolates had no mutation. One isolate had a base substitution A→Cat nt 25 in the coding region and this isolate had a point mutation leading to an amino acid change at positions 9 (I→L). Our study results indicated that none of the strains had mutation in Shine-Dalgarno and the point mutations were the most common mutations upstream of the oprD coding region among P. aeruginosa isolates. Mutations were observed in imipenem-resistant isolates and it seems this mechanism is effective in resistance of isolates to imipenem and this confirmed that the indiscriminate use of antibiotic should be controlled.

Evaluating the effect of siRNA on SOX2OT expression in the human neuron-committed teratocarcinoma NT2 cell line.

Non-coding RNA elongated (lncRNAs) have recently attracted as molecules that regulate gene expression of the pluripotent properties (pluripotency) of stem cells. Recently our colleagues examined the role of one of these RNAs called SOX2OT in esophageal squamous cell carcinoma, and found a concomitant increase in its expression with some regulatory genes of cell proliferation. In the present study, using the design of suitable primers from SOX2OT gene, we investigated the effect of siRNA on expression of SOX2OT.