Identification of ESBL CTX-M-15 genes from isolates of urinary tract infections

Abstract EN

The study aimed to evaluate the distribution of CTX-M genes, which coding for ,Extended Spectrum β- lactamases (ESBLs) which hydrolyzed the extended spectrum β- lactams .

Total of 800 urine samples taken from patients suffering from urinary tract infections were collected during the period from February to September from Hospitals in Al-Najaf province.

All samples were cultured on MacConkey agar , were the results revealed that 250 isolates were lactose fermentative versus to 50 isolates were lactose non fermentative.

The isolates succumbed to conventional tests (IMVC), Indol, Methyl red , Voges- Proskauer and Citrate utilization as well as motility test.

Lactose fermentative and non motile isolates were candidate to be confirmed by Vitek2 system.

Initial screening tests by Disk Diffusion test and by MacConkey supplemented with 2 mg / liter of Ceftazidime had been conducted, the resultsof disk diffusion test revealed different resistance phenotypes as well as multi drug resistance patterns Ceftriaxone were found to be the most resistant antibiotics in our isolated bacteria with resistance of 100%.

The next most resistant antibiotics were Ceftazidime (98.11%), followed by aztreonam (90.57%); and cefotaxime (90.27%).

While the result of screening with Ceftazidime reported that 31/53(58.49%) of isolates were initially ESBLs producers.

The results of genotyping tests showed that out of 53 isolates which had been screened for the prevalence of bla CTX-M genes, 47(88.6%) were ositive.

Nucleotide sequence of bla CTX-M of amplicons (19, 20, 22, 23, 24) showed high identity (99%) with CTX-M-15 of NCBI-BLAST.

As concerning with protein sequence, the results showed high identity (98%) with reference protein of gene bank.

The results of other protein sequences revealed great degree of identity reach to (100%) of identity.