Molecular detection of shiga toxin (stx1 and stx2)‎ and intimin (eaea)‎ genes in escherichia coli isolated from fecal samples of cattle, sheep, and human in basrah governorate

Abstract EN

The present study aims to isolate and identify Escherichia coli from fecal samples of farm animals and human, also, it aims to molecular detection of shigatoxin and intimin genes in isolates.

A total of (264) fecal samples and swwere collected from different parts of Basrah in the period extending from September 2018 to January 2019.

These samples were composed of (85) samples from cows, (94) samples from humanand (85) samples from sheep.

Different techniques were used in this study to detect the presence of E.

coli; these techniques included conventional microbiological assays and molecular techniques (amplification of uidA gene by using polymerase chain reaction).

The results of these techniques indicated 50 (18.

9%) were E.

coli from the tested samples.

These isolates were subjected to PCR to detect Shiga toxins and intimin genes (stx1, stx2, and eaeA).

The results of PCR confirmed all (50) isolates were harbor at least one virulence gene.

Out of 50 isolates 20 (40%) carried stx2 gene alone, the percentages of the carrier were (66.

7 %, 41.

7% and 23.

5%) from human, sheep and cattle samples, respectively.

The genes (stx1 and stx2) were detected together in 9/50 (18%), represent (52.

9%) of cattle isolates.

The intimin gene (eaeA) alone was detected in 2/50 (4%), represent (11.

8%) of cattle isolates.

(28%) of isolates harbor (stx2 and eaeA) genes, the isolates belong to human and sheep isolates (33.

3%) and (45.

8%), respectively.

Presence of the genes (stx1, stx2, and eaeA) were discovered in (10%) of isolates, (11.

8%) of cattle and (12.

5%) of sheep.

The isolates were resistant to ampicillin, tetracycline (92%, 74%), respectively.

However, the isolates were susceptible to imipenem, gentamycin, chloramphenicol, ciprofloxacin, and cefotaxime with a ratio of 100%, 92%, 78%, 68%, and 58%, respectively.