Physical Signs and Hematological and Biochemical Alterations in Salmonella-Plasmodium Sequentially Coinfected Albino Wistar Rats.

BACKGROUND

In endemic countries, people remain at risk of contracting both malaria and typhoid concurrently. Though experimental animal models are very reliable for understanding human diseases, the rat model for Plasmodium-Salmonella coinfection remains underresearched.

OBJECTIVES

The present study was performed to characterize the rat model of malaria-typhoid coinfection focusing on physical, hematological, and biochemical parameters.

METHODS

Thirty-four Wistar rats were distributed into five groups including normal control, immunosuppressed, Salmonella-infected, Plasmodium-infected, and Salmonella-Plasmodium-coinfected. Physical signs, mobility, and the fecal appearance of animals were observed. Plasmodium load was monitored through microscopic Giemsa-staining thin blood smears. Concurrently, Salmonella load was evaluated after feces culture in Shigella-Salmonella agar medium based on the McFarland turbidity to determine the number of colony-forming units. Hematological and biochemical parameters were assessed using an automatic hematology analyzer and a spectrophotometer, respectively.

RESULTS

All the infected animals exhibited at least one clinical sign including piloerection, eye depigmentation, or hyperthermia. Coinfected animals showed severe anemia, leukocytosis, and thrombocytosis compared with monoinfected animals. A significant (p < 0.001) drop in total blood proteins and cholesterol levels was observed in infected rats, with a remarkable decrease in Salmonella-Plasmodium-coinfected rats, whereas transaminase levels significantly (p < 0.001) increased in the same coinfected group.

CONCLUSION

This model provides many important features of Salmonella and Plasmodium sequential coinfection and therefore may be used as a tool to better understand, diagnose, and care for human malaria and/or typhoid pathogenesis.