The Isolation and Identification of Salmosamonella typhi from clinical samples with molecular detection of O-antigen encoded genes


  • Huda jassim Department of Pharmaceutical Sciences, College of Pharmacy, Thi-Qar University, Iraq.




Antibiotic treatment of  S.typhi is difficult as compared to treatment of acute infection. Antibiotic resistance carried against S.typhi  by using 6 kinds of antibiotics from  different classes, their results  showed that all isolates were  high resistance to Ampicillin (99%), Gentamicin (98%), Amikacin (79%) and   less  resistances  Trimethoprim (55%) ,  Imipenem (60%)  and Ceftriaxone(66%)  .

The present study focused on the molecular detection of Wzx flippase, Wzy polymerase genes in some Salmonella typhi isolates, Samples were collected from typhoid patients by classical lab work. Antibiotics susceptibility were investigated using disc diffusion method. The DNA and molecular Wzx flippase, Wzy polymerase were implemented using specific primers. The results showed that there was 33.33% having Wzy gene. The Wzx gene didn’t observed in any Salmonella isolates. The present study concluded that there was an important of the genetic diversity of O-antigen encoded genes included Wzx and Wzy which may be effect in typhoid diagnosis and treatment types.


Falcao, D. P., Trabulsi, L. R., Hickman, F. W., & Farmer 3rd, J. J. (1975). Unusual Enterobacteriaceae: lactose-positive Salmonella typhimurium which is endemic in Sao Paulo, Brazil. Journal of clinical microbiology, 2(4), 349-353.

Ashurst JV, Truong J, Woodbury B. Salmonella typhi. (2020).In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Jan-.Available from: https:// www. ncbi. nlm. nih. gov/ books/ NBK519002/.

Tarr PI, Schoening LM, Yea YL, Ward TR, Jelacic S, et al. (2000) Acquisition of therfb-gndcluster inevolution ofEscherichia coliO55 and O157. J Bacteriol 182: 6183–6191. PMID:11029441.

Samuel G, Reeves P (2003) Biosynthesis of O-antigens: genes and pathways involved in nucleotidesugar precursor synthesis and O-antigen assembly. Carbohydr Res 338: 2503–2519. PMID:14670712.

Patel, K. B., Toh, E., Fernandez, X. B., Hanuszkiewicz, A., Hardy, G. G., Brun, Y. V., Bernards, M. A., & Valvano, M. A. (2012). Functional characterization of UDP- glucose:undecaprenyl-phosphate glucose-1-phosphate transferases of Escherichia coli and Caulobacter crescentus. Journal of bacteriology, 194(10), 2646–2657.https:// doi. Org /10.1128/JB.06052-11.

Vinés, E. D., Marolda, C. L., Balachandran, A., & Valvano, M. A. (2005). Defective O-antigen polymerization in tolA and pal mutants of Escherichia coli in response to extracytoplasmic stress. Journal of bacteriology, 187(10), 3359–3368.

Liu, D., R. A. Cole, and P. R. Reeves. (1996 ). An O-antigen processing function for Wzx (RfbX): a promising candidate for O-unit flippase. J. Bacteriol. 178:2102-2107.

Fitzgerald, C., Sherwood, R., Gheesling, L. L., Brenner, F. W., & Fields, P. I. (2003). Molecular analysis of the rfb O antigen gene cluster of Salmonella enterica serogroup O:6,14 and development of a serogroup-specific PCR assay. Applied and environmental microbiology, 69(10), 6099–6105. https:/ /doi. Org /10.1128/ aem. 69. 10. 6099-6105.2003.

Liu B, Knirel YA, Feng L, Perepelov AV, Senchenkova SN, Reeves PR, Wang L.( 2014). Structural diversity in Salmonella O antigens andits genetic basis. FEMS Microbiol. Rev. 38: 56-89.

Al-Terehi M, Khazaal S, Muhammed H, Behjet R. (2018) Molecular Detection of wzx1 and wzy Genes in Multi Drugs Resistance E. coli Isolates. International Journal of Pharmaceutical Quality Assurance 2018; 9(3); 304-307

Andualem, G., Abebe, T., Kebede, N., Gebre-Selassie, S., Mihret, A., & Alemayehu, H. (2014). A comparative study of Widal test with blood culture in the diagnosis of typhoid fever in febrile patients. BMC research notes, 7, 653.

Al-aarajy, A. Nabeel (2020). Assessment of Silver Nanoparticles as Anti- Salmonella Agent: Phenotypic, Genotypic and Histological Study .Thesis Degree of Doctorate of Philosophy of College of Science- University of Anbar

AlObaidi Ahmed Flyyih; Mohammed N. T.; Abdulrazzaq Mohammed and Basim Basima (2019) .Molecular detection of Salmonella typhi isolated from diarrheal patients in Al- Najaf governorate .Annals of Tropical Medicine & Public Health .22(9).

Olopoenia LA, King AL. Widal agglutination test - 100 years later: still plagued by controversy. Postgrad Med J( 2000) ;76:80–84. doi: 10.1136/pmj.76.892.80.

Yara Seif, Jonathan M. Monk, Henrique Machado, Erol Kavvas, Bernhard O. Palsson (2019) Systems Biology and Pangenome of Salmonella O-Antigens, Ecological and Evolutionary Science , 10 (4) e01247-19; DOI: 10.1128/mBio.01247-19.