Serratia marcescens is a significant opportunistic pathogen that affects a variety of hosts, including invertebrates, plants, and mammals. It is linked to a wide range of clinical illnesses, including pneumonia, keratitis, meningitis, urinary tract infections, and wound infections. The present research aimed to estimate the immune response of rabbits immunized with whole cell sonicated antigen of Serratia marcescens, killed whole cell antigen of S. marcescens and lipopolysaccharide extracted from Citrobacter freundii against Serratia marcescens infection; a challenge dose was 8x106 CFU/ml. Thirty five (35) white male rabbits aged between 6-8 weeks, were divided randomly into five groups (7 rabbits each) and ELISA test was performed. The first group received a subcutaneous (S/C) immunization with WCSAg-S and LPS-C (1000 g/mL) vaccine. The second group received KWCA-S (9 x 108 CFU/mL) and LPS-C (1000 g/mL) vaccinations. The sole vaccine given to the third group was WCSAg-S (1000 g/mL). LPS-C (1000 g/ml) was used to immunize the fourth group. 1 mL of PBS was given subcutaneously into the fifth group (the negative control) (pH 7.2). The rabbits received booster doses of the same antigens after 14 days. Following 21, 35, 49, and 53 days of vaccination, the inoculated animals demonstrated significant changes (P

<0.05) in IL-2 and IL-10 compared to the negative control group. In conclusion, the 3 rd group immunized with WCSA-S only was able to promote stronger humoral and cellular immune responses against Serratia marcescens infection in comparison with the other groups>


Serratia marcescens Citrobacter freundii antigens ELISA


How to Cite
Ikram A. A. Al-Samarraae, Roa’a N. A, & Roua J. M. (2022). The effect of Citrobacter fruendii LPS on the immune parameters of rabbits immunized with Serratia marcescens antigens. Texas Journal of Agriculture and Biological Sciences, 8, 7–12. Retrieved from https://zienjournals.com/index.php/tjabs/article/view/2288


  1. Raymann.K, Kerri L. Coon. K.L, Shafferb.Z, Salisburyb. S and Moran. N.A.(2018). Pathogenicity of Serratia marcescens Strains in Honey Bees. Host-Microbe Biology. 9 (5):1-15.
  2. Karkeya.A, Joshia.N, Chalised. S, Joshid.S and Shresthad. S. (2018).Outbreaks of Serratia marcescens and Serratia rubidaea bacteremia in a central Kathmandu hospital following the 2015 earthquakes. Trans R Soc Trop Med Hyg. (2018); 112(10): 467–472.
  3. Yimer N, Asseged B. (2018).Aerobic bacterial flora of the respiratory tract of healthy sheep slaughtered in Dessie municipal abattoir, north eastern Ethiopia. Revue de Médecine Vétérinaire.10 (10):473-78.
  4. Liu H, Zhao Z, Xue Y, Ding K, Xue Q.(2018).Fatal cases of Citrobacter freundii septicemia and encephalitis in sheep. Journal of Veterinary Diagnostic Investigation.30(2):245–248.
  5. McAleer J. P. and Vella A.T.(2008).Understanding how lipopolysaccharide impacts CD4 T cell immunity. Crit Rev Immunol. 28(4): 281–299.
  6. Sampath V. (2018).Bacterial endotoxin-lipopolysaccharide; structure, function and its role in immunity in vertebrates and invertebrates. Agriculture and Natural Resources. 52(2):115-120.
  7. Amani S.A and Lang M.L. (2020).Bacteria That Cause Enteric Diseases Stimulate Distinct Humoral Immune Responses. Front Immunol.11(565648):1-14.
  8. Levashov P. A., Matolygina D. A., Osipova H. E., Savin S. S., Zaharova G. S., Gasanova D. A., Belogurova N. G., Ovchinnikova E. D., Smirnov S. A., Tishkov V. I. and Levashov A. V.(2015).Comparison of bacteriolytic activity of human interleukin-2 and chicken egg lysozyme on Lactobacillus plantarum and Escherichia coli cells. Moscow University Chemistry Bulletin. 70(6):287–291.
  9. Walser T.C. Liclican E.L. O’Byrne K.J. William C.S. and Dubinett C.M.(2018). Microenvironment and Lung Cancer. IASLC Thoracic Oncology (Second Edition). 890(978):121-128.
  10. Nagata K. and Nishiyama C. (2021). IL-10 in Mast Cell-Mediated Immune Responses: Anti-Inflammatory and Proinflammatory Roles. International Journal of Molecular Sciences. 22(9): 4972. doi: 10.3390/ijms22094972.
  11. Mahmoud N. M.(2009). Comparative study of antigens effect prepared from Pseudomonas aeruginosa from human skin burn in immunized mice. The Iraqi Journal of Veterinary Medicine, 38(1): 1 -10.
  12. Johnson KG, Perry MB.(1976). Improved techniques for the preparation of bacterial lipopolysaccharide. Can. J. Microbiol. 22(1): 29-34.
  13. Dubois N, Cilles K.A, Hamilton J.K, Rebers P.A, Smith F. Colorimetric methods for detection of sugars and related substances. Anal. Chem. (1956); 28(3): 350-356.
  14. Bradford MM. (1976). A rapid and sensitive for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry.72: 248-254.
  15. SAS. SAS/STAT. (2012). Users Guide for Personal Computer. Release 9.13.SAS Institute, Inc., Cary, N.C., USA.2012.
  16. Aldapa-Vega, G.; Pastelín-Palacios, R.; Isibasi, A.; Moreno-Eutimio, M.; & López-Macías, C. (2016). Modulation of immune response by bacterial lipopolysaccharides. Revista Alergia Mexico, 63(3), 293-302.
  17. Mohammed R.J., Al-Samarraae I.A.A. (2021). Investigating the effect of three antigens of Citrobacter freundii on rabbit’s immune response. Iraqi J. Vet. Med. 45(1): 56-62.
  18. Fusco, Vincenzina; Abriouel, Hikmate; Benomar, Nabil; Kabisch, Jan; Chieffi, Daniele; Cho, Gyu-Sung; Franz, Charles M. A. P. (2018). Opportunistic Food-Borne Pathogens", Food Safety and Preservation, Academic Press, pp. 269–306.
  19. Choi S. Y., Lim S., Yoon K., Lee J. I., and Mitchell R. J. (2021). Biotechnological Activities and Applications of Bacterial Pigments Violacein and Prodigiosin. J Biol Eng. 15(10):1-16.
  20. Mortellaro A., Songia S and Gnocchi P. (1999). New Immunosuppressive Drug PNU156804 Blocks IL-2-Dependent Proliferation and NF-κB and AP-1 Activation. The Journal of Immunology. 162(12):710.
  21. AL-Taee H.S.R and Al-Samarraae I.A.A. (2019). Effect of crude, sonicated and P. aeruginosa liposaccharide antigens on immune markers in female albino rats. Online Journal of Veterinary Research. 9:904-908.
  22. Han S-B, Lee CW, Yoon YD, Kang JS, Lee KH, Yoon WK, Kim YK, Lee K, Park S-K, Kim HM. (2005). Effective prevention of lethal acute graft-versus-host disease by combined immunosuppressive therapy with prodigiosin and cyclosporine A. Biochem Pharmacol. 2005;70 (10):1518–1526. doi: 10.1016/j.bcp.
  23. Caradonna L., L. Amati L., Magrone T., Pellegrino N.M., Jirillo E and Caccavo D. (2000). Enteric bacteria, lipopolysaccharides and related cytokines in inflammatory bowel disease: biological and clinical significance. Journal of Endotoxin Research. 6(3): 205-214.
  24. Haan JM, Kraal G, Bevan MJ. (2007). Cutting edge: Lipopolysaccharide induces IL-10-producing regulatory CD4+ T cells that suppress the CD8+ T cell response. J Immunol. 178(9):5429–5433.
  25. Jarnicki, A.G., Conroy H., Brereton C., Donnelly G., Toomey D., Walsh K., Sweeney C., Leavy O., Fletcher J and Lavelle E.C.(2008). Attenuating regulatory T cell induction by TLR agonists through inhibition of p38 MAPK signaling in dendritic cells enhances their efficacy as vaccine adjuvants and cancer immunotherapeutics. J. Immunol.180 (6):3797–3806.
  26. Ye, Q., Shao, W. X., Xu, X. J., & Yang, Y. Z. (2014).The clinical application value of cytokines in treating infectious diseases. PloS one. 9(6): 98745.