Abstract:
The presence of extended spectrum β-lactamase (ESBL) - producing organisms significantly
affects the course and outcome of an infection and poses a challenge to infection management
worldwide.
ESBL producing bacteria may not be detected by routine disc susceptibility, lead to
inappropriate use of drug, hence treatment failure. In this study polymerase chain reaction
technique was used to detect the plasmid genes which encoded for ESBLs enzymes producing
by Salmonella typhi in Khartoum State.
This study was carried out in the Research Laboratory of the Sudan University of Science and
Technology in period Between Decembers 2009 and May 2010. The targeted strains were
obtained from same Laboratory, they were isolated from Khartoum State hospitals, were
identified as Salmonella typhi, and were tested for sensitivity to third generation of
cephalosporin by E.test, which revealed that resistance was 100% to ceftazidime and the
isolates were storged in glycerol media at -20C ̊ in research lab (Hassan, 2009).
In this study the 12 targeted strains were reactivated on Nutirent agar,6 straine were obtained
from this reactivation and they were tested for purity by colonial morphology, Gram stain and
APIE, aftar that DNA was extracted from each pure strain of Salmonella typhi by boiling
method. Polymerase chain reaction was adopted with specific primers to detect presence of bla
TEM, bla SHV and bla CTX-M genes (Patrson, 2003).
The results revealed that all strains showed presence of bla CTX-M gene, where in the
blaTEM and bla SHV genes showed Negative result in strain number 2 in Salmonella typhi
isolates. It is concluded that the bla CTX-M gene, blaTEM and bla SHV genes are the
excistant genes in Salmonella typhi isolates in this study. Further studies with large number of
isolates are required to validate this research results.
