【Animal modeling】-Changes of biological characteristics of black-lined hamsters infected with Babesia

  OBJECTIVE: To establish a black-lined hamster model infected with babesiosis, to clarify the changes of biological characteristics of black-lined hamsters after infection, and to provide basic data for the detection and prevention of babesiosis.

  METHODS: Black-lined hamsters were infected by intraperitoneal injection of blood containing Babesia. On the 0th, 2nd, 4th, 6th, 8th, 10th, 12th, 14th, 16th, 23rd, 30th and 37th days of infection, 5 animals were collected each time. Anticoagulation and whole blood were used to prepare blood smears, and Giemsa staining was used to detect the reproduction of parasites; total blood DNA was isolated, and REAL-TIME PCR was used to detect the reproduction rules of Babesia in the host; The blood physiological and biochemical indexes were measured by the detector; the heart, liver, spleen, lung, kidney and other organs were collected after the animals were sacrificed, and the organ coefficients were determined by weighing; the IL-2 concentration in the serum of the infected animals was detected by ELISA.

  RESULTS: The number of Babesia in black-lined hamsters was the largest on the 4th day after infection, and then showed a downward trend as a whole, with a brief increase on the 12th day. The liver and spleen had the largest changes in the organ coefficients of infected animals, and the heart, lung and kidney coefficients showed slight fluctuations throughout the infection period, all within the normal range. The blood cells of the infected animals fluctuated, and peaked twice on the 10th and 23rd days, among which the white blood cells changed the most; the blood biochemical indexes that detected changes reached their peak on the 12th day. IL-2 in the serum of infected animals peaked on the 10th day, and then decreased continuously.

  Conclusion: Babesia-infected black-lined hamsters have typical characteristics of tick-borne parasitic diseases. The pathogens reach the peak of reproduction within one week of invasion, and the pathogens can be latent in the host for a long time. The host immune response peaked in the second week, and the immune-related organs and blood cells had obvious stress responses. Accordingly, the diagnosis and prevention of babesiosis can be carried out in a targeted manner.