Phylogenetic relationship of Citrobacter spp. and Other Enterobacteriaceae Isolated from Stool Samples of Healthy and Patients with Colorectal Cancer in Al-Najaf Al-Ashraf/Iraq

Abstract

    The current study aimed to detect phylogenetic relationships among enterobacteriaceae isolates. A total of 110 stool samples were collected from healthy and patients with coleractal cancer during the period 2016-2017. The results of PCR technique for amplification of tuf showed that 55 isolate (55%) were belong to Enterobacteriaceae (suspected Citrobacter) by appearance amplicon with molecular weight 871 bp while 45 isolate (45%) were belong to E.coli by appearance of amplicon with molecular wight 884 bp. Also, the results of electrophoresis of atpD1 and atpD2 showed that 36 isolates (56%) and 24 (42.8%) isolates were belong to E.coli by appearance of amplicon with molecular weight 884 bp while 32 isolates (57.1%) were belong to other Enterobacteriaceae (suspected Citrobacter) by appearance amplicon with molecular weight 871 bp. DNA sequencing of amplicon resulted from amplification of tuf, atpD1 and atpD2 was carried out to confirmed identification of Citrobacter spp as well as to evaluate the phylogenetic  relationship among bacterial isolates. Thirty isolates were selected for DNA sequencing depending one presence and absence of tuf, atpD1 and atpD2. The results of DNA sequencing and alignment with other enterobacterial sequences available in public database using MEGA 7 and BLAST showed that 4, 2 and 1 isolates gave strong alignment with E. coli, Klebseilla and Citrobacter.