In vitro cultivation of Babesia bigemina.
Level 5 - mechanism / opinion, no new human data
Bench in vitro culture and single-animal inoculation study
What was done
A strain of Babesia bigemina isolated from an infected calf was propagated in vitro using washed normal and infected bovine erythrocytes (5% to 10% v/v suspension) in medium 199 with 20% to 50% fresh normal bovine serum at a depth of 4 mm under a 5% CO2, 2% O2, and 93% N2 atmosphere. After 36 days in vitro and 9 subcultures, cultured parasites were inoculated into a susceptible calf to assess infectivity and pathogenicity, followed by treatment with 1% trypan blue and subsequent re-isolation.
What was found
The original isolate was maintained in continuous in vitro cultivation for more than 99 days. Parasites maintained in culture for 36 days produced clinical disease upon inoculation into a susceptible calf, from which the strain was successfully re-isolated after recovery following 1% trypan blue treatment.
Why it matters
This demonstrated a continuous in vitro propagation method for Babesia bigemina that preserves the parasite's viability and pathogenicity in bovine hosts.
Limits
The abstract describes an in vitro protocol with testing in only a single recipient calf, lacks quantitative growth or parasitemia metrics, and does not evaluate multiple distinct strains.
Cited by
- contradicts Babesia parasites inhabit red blood cells and proliferate in high-oxygen environments.