Bacteriological and Molecular Study of Salmonella Typhi that Isolated From Typhoid Patient in Al-Muthanna City

Abstract

In this investigation, blood samples from 150 typhoid fever patients who visited Al-Hussain Teaching Hospital in Al-Muthanna City between April 2023 and February 2024 were obtained Testing for culture and biochemistry was used to identify the subject, and the Vitek2 system was used to confirm the results. The Vitek2 technique revealed that 27 (18%) of the isolates tested positive for Salmonella enteric serovar typhi. The investigation of some virulence factors were also performed of all isolated of S. typhi. All isolates have not ability to produce hemolysin in blood agar, while all isolates can produce sidrophores (100%) when investigation on M9 media supplanted with dipyridyl.

27 (100%) of the isolates under examination were positive for colonization factor antigen 3 (CFAIII). Tryptic soy broth mixed with 1 percent glucose was used in microtiter (biofilm test) experiments to measure the production of "biofilms quantitatively". The examined isolates gave positive results were 11(40.74%) were produce biofilm strongly, 9(33.33%) were minor production of biofilm, while 7(25.92%) were not produce biofilm.

The initial step of the molecular analysis process was the extraction of genomic DNA from all of the Salmonella typhi isolates using an approach that worked well for this purpose. Second, the (flicA) gene was detected by "PCR technique" and compared to an allelic ladder, yielding a (578 bp) result. It was discovered that 25 (92.59%) isolates of the positive sample contained the (flicA) gene. Also, molecular method showed Wzy gene detected with product molecular weight (451bp) the result showed that 19(70.37%) isolates were positive for this gene.