Molecular detection of Lotmaria passim in honeybees in Japan

The trypanosomatid (Kinetoplastida: Trypanosomatidae) parasites in bees: A review on their environmental circulation, impacts and implications

Trypanosomatids, obligate parasites capable of impacting insects' hindgut, have recently obtained considerable attention, especially about their effects on bees. While Crithidia mellificae and C. bombi were initially discovered and studied in honey bees and bumblebees, respectively, molecular techniques revealed Lotmaria passim as the predominant trypanosomatid in honey bees globally. New species like C. expoeki and C. acanthocephali have also been identified. These parasites have complex life cycles involving various host developmental stages and are transmitted horizontally within and outside colonies through direct contact, oral interactions, and contaminating flowers with infected faeces. The impact of trypanosomatids on honey bee colony health remains uncertain. In bumblebees, studies highlighted the widespread presence of C. bombi, affecting colony and individual fitness, development, and foraging behaviour. Bee trypanosomatids have been detected in various species, including other insects, and mammals, suggesting diverse epidemiological pathways and potential effects that warrant further investigation. Biotic factors, including co-infections, gut microbiota, food contamination, and abiotic factors like environmental conditions, pesticides, and urbanization, play crucial roles in infection dynamics. This review aimed to summarise key research on trypanosomatid transmission and infection in both managed and wild bees, focusing on the influence of biotic and abiotic factors. The work highlights significant gaps in current knowledge and provides a valuable foundation for future studies. Understanding the pathogenicity and infection dynamics of trypanosomatids, along with the impact of environmental factors, is essential for developing effective conservation strategies that support pollinator health and overall ecosystem resilience.

Occurrence of Nosema ceranae, Ascosphaera apis and trypanosomatids in Vespa orientalis linneus 1771

Vespa orientalis is spreading across the Italian and European territories leading to new interactions among species, which could lead to the transmission of pathogens between species. Detection of honey bee viruses in V. orientalis has already been revealed in both adults and larvae, while no information is available regarding parasitic occurrence. Sixty adult hornets collected across apiaries in the South of Italy were subjected to cytological, histopathological and biomolecular examination to evaluate the occurrence of Nosema ceranae, Ascosphaera apis, Lotmaria passim, Crithidia mellificae, and Crithidia bombi. Cytological examination revealed the presence of Nosema spores in 38.33% of individuals while histopathological analysis showed the presence of L. passim-like elements in the rectum of two examined specimens and the presence of fungal hyphae in the small intestine of another hornet. Biomolecular investigation revealed that N. ceranae was the most prevalent pathogen (50.0%), followed by A. apis (6.66%), L. passim (6.66%) and C. bombi (6.0%).

Phylogenetic analysis of the trypanosomatid parasite Lotmaria passim in honey bees (Apis mellifera) in Poland

Introduction

Lotmaria passim (L. passim) is a single-celled flagellate which colonises the bee gastrointestinal tract and is highly prevalent in honey bees. This parasite is associated with colony losses. Honey bee (Apis mellifera) colonies were sampled from five apiaries in the north-eastern part of Poland for the phylogenetic analysis of L. passim.

Material and Methods

Each apiary consisted of approximately 60 bee colonies, of which 20 were randomly selected. Samples of 60 differently aged worker bees were collected from each colony and pooled. A total of 100 bee colonies from five apiaries were examined. Protozoa of the Trypanosomatidae family were identified by PCR. L. passim was detected in 47 (47%) of the samples. The 18S ribosomal (r) RNA amplicons of L. passim were sequenced by a commercial service. Their sequences were analysed with BLASTN and noted to be compatible with the GenBank sequences of this region of the organism's genome. A sequence analysis was performed using the BioEdit Sequence Alignment Editor and Clustal W software.

Results

The amplicon sequences of L. passim were 100% homologous with the sequences deposited in GenBank under accession numbers KM066243.1., KJ684964.1 and KM980181.1.

Conclusion

This is the first study to perform a phylogenetic analysis of L. passim in Polish honey bees. The analysis demonstrated high levels of genetic similarity between isolates of L. passim colonising apiaries in the north-eastern region of Poland.

Frequent Parasitism of Apis mellifera by Trypanosomatids in Geographically Isolated Areas with Restricted Beekeeping Movements

Trypanosomatids form a group of high prevalence protozoa that parasitise honey bees, with Lotmaria passim as the predominant species worldwide. However, the knowledge about the ecology of trypanosomatids in isolated areas is limited. The Portuguese archipelagos of Madeira and Azores provide an interesting setting to investigate these parasites because of their geographic isolation, and because they harbour honey bee populations devoid of two major enemies: Varroa destructor and Nosema ceranae. Hence, a total of 661 honey bee colonies from Madeira and the Azores were analysed using different molecular techniques, through which we found a high prevalence of trypanosomatids despite the isolation of these islands. L. passim was the predominant species and, in most colonies, was the only one found, even on islands free of V. destructor and/or N. ceranae with severe restrictions on colony movements to prevent the spread of them. However, islands with V. destructor had a significantly higher prevalence of L. passim and, conversely, islands with N. ceranae did not shown any significant correlation with the trypanosomatid. Crithidia bombi was detected in Madeira and on three islands of the Azores, almost always coincident with L. passim. By contrast, Crithidia mellificae was not detected in any sample. A high-throughput sequencing analysis distinguished two main haplotypes of L. passim, which accounted for 98% of the total sequence reads. This work suggests that L. passim and C. bombi are parasites that have been associated with honey bees predating the spread of V. destructor and N. ceranae.