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Updated: Nov 19, 2025
Preparation of Virus-Enriched Inoculum for Oral Infection of Honey Bees Apis mellifera
Published on: August 26, 2020
Workflow of Lotmaria passim isolation: Experimental infection with a low-passage strain causes higher honeybee
María Buendía-Abad1, Mariano Higes1, Raquel Martín-Hernández1,2
1IRIAF - Regional Institute for Agrifood and Forestry Research and Development, Laboratory of Bee Pathology, Center for Beekeeping and Agro-environmental Research (CIAPA), Community of Castilla-La Mancha, Marchamalo, Spain.
Abstract:
The impact of trypanosomatid parasites on honeybee health may represent a major threat to bee colonies worldwide. However, few axenic isolates have been generated to date and with no details on cell culture passages, a parameter that could influence parasite virulence. To address this question, a trypanosomatid isolation protocol was developed and a new strain was obtained, named L. passim C1. Using experimental infection of worker honeybees, we compared the virulence and mortality rates of the ATCC PRA-403 reference strain and C1 strain, the latter showing higher virulence from 10 days post-infection onward. This study highlights the impact of cell culture passages on the pathogenicity of L. passim in honeybees, providing new evidence of its negative effects on honeybee health.
Insights
Trypanosomatid parasites threaten honeybees globally. This study reveals that cell culture passages significantly impact the virulence of *L. passim*, a parasite affecting bee health.
Area of Science:
- Veterinary Parasitology
- Apiculture Science
- Microbial Pathogenesis
Background:
- Honeybee colonies face global threats from trypanosomatid parasites.
- Limited availability of axenic isolates and lack of passage information hinder virulence studies.
- Parasite cell culture passages may influence virulence and pathogenicity.
Purpose of the Study:
- To develop a trypanosomatid isolation protocol and obtain a new *L. passim* strain.
- To compare the virulence and mortality rates of a new *L. passim* strain (C1) with a reference strain (ATCC PRA-403).
- To investigate the impact of cell culture passages on *L. passim* pathogenicity in honeybees.
Main Methods:
- Development of a novel trypanosomatid isolation protocol.
- Isolation and characterization of a new *L. passim* C1 strain.
- Experimental infection of worker honeybees with *L. passim* strains.
- Comparison of virulence and mortality rates between C1 and ATCC PRA-403 strains.
Main Results:
- A new *L. passim* strain, C1, was successfully isolated.
- The C1 strain exhibited significantly higher virulence than the ATCC PRA-403 reference strain from 10 days post-infection.
- Increased pathogenicity was observed in honeybees infected with the C1 strain.
Conclusions:
- Cell culture passages critically influence the virulence of *L. passim* in honeybees.
- The study provides new evidence for the negative impact of *L. passim* on honeybee health.
- Understanding passage effects is crucial for accurate assessment of parasite virulence and its threat to bee colonies.
