Article Published In Vol.8 (Sept-Oct 2020)

Detection of tetracycline resistance genes A and B among clinical isolates of Salmonella Typhi from blood samples in Al-Najaf hospitals

Author : Dr Fadhil Hussain Nasir Al-Muhannak and Dr Abdullah O. Mansour

The presence of Salmonella spp. antibiotic resistance genes has a significant impact on human health, especially Salmonella Typhi which causes a serious illness called typhoid fever. Therefore, the aim of this research was to detect the dissemination of tetracycline resistance genes among tetracycline-resistant S. Typhi from Al-Najaf hospitals. A total of 1743 blood samples, 2ml from infants, 5 ml from children and 10 ml from adults (according to WHO recommendations), were obtained from outpatient of the hospitals with suspected typhoid fever. 105 (6.02%) isolates were obtained as S. Typhi. Antimicrobial susceptibility tests of S. Typhi isolates were performed by disc diffusion tests and the tetracyclineresistant isolates were screened to detect the presence of tet-A, and tet-B genes by two sets of primers. The PCR products were shown by using 1.5% agarose gel in electrophoresis. Low level of resistance was observed against tetracycline 5 (4.76%). Among the 5 tetracycline-resistant Salmonella isolates, only two isolates carried tet-A gene and one of these 2 isolates carried tet-B gene also. Conclusion Resistance to Salmonella strains is arising and the two cases of tetracycline resistance are alarming.

Keywords: Salmonella Typhi; Tetracycline; tet genes; ERIC-PCR