Miss Gopika Kottantharayil Bhasi1, Professor Travis Beddoe1, Dr Gemma Zerna1
1La Trobe University
Biography:
Gopika Kottantharil Bhasi is a dedicated third-year PhD student at the Animal, Plant, and Soil Sciences Department of La Trobe University, where she works under the guidance of Professor Travis Beddoe and Dr. Gemma Zerna. Gopika is distinguished as the inaugural recipient of the prestigious Shah Rukh Khan La Trobe University PhD Fellowship, awarded in 2020. The onset of the COVID-19 pandemic delayed the start of her research, leading her to begin her studies in 2022.
Gopika's research is at the cutting edge of honey bee health, focusing on the detection of honey bee pathogens using environmental DNA (eDNA) extracted from honey samples. Her work involves a comprehensive approach to understanding the prevalence and diversity of these pathogens, crucial for the health and sustainability of bee populations. As part of her research, Gopika conducted a national survey across Australia, meticulously collecting 135 honey samples to investigate common bee pathogens.
Beyond studying well-known pathogens, Gopika's research extends to the exploration of less-studied pathogenic species in honey bees, such as trypanosomatids and other opportunistic pathogens. Additionally, she is engaged in the innovative application of metabarcoding analysis of honey eDNA, which shows significant potential as a tool for the authentication and quality control of honey, contributing to the broader field of apiculture and environmental science.
Abstract:
Honey bee populations are currently experiencing a rapid decline in many parts of the world posing a formidable threat to both managed and natural ecosystems. This decline is driven by a complex interplay of environmental stressors and the increasing prevalence of chronic diseases, highlighting the need for effective disease monitoring and pathogen identification methods. Monitoring diseases in adult bees is difficult due to the high costs and resource demands of sampling individual bees, providing limited snapshots of disease prevalence. Alternatively, hive materials like honey offer a more practical source of environmental DNA (eDNA), allowing for the detection of multiple pathogens and providing a broader, more continuous picture of hive health. Honey eDNA has thus emerged as a practical method for monitoring honey bee pathogens and parasites. This is due to the potential transfer of pathogens and pathogen material during the production of hive substances following the acquisition of a pathogen while foraging.
We collected 135 honey samples from diverse botanical and geographical regions across Australia. These samples were utilised to isolate eDNA using a modified in-house extraction protocol, a bead-beating-silica DNA extraction. Single-plex and multiplex PCR techniques were employed to identify key pathogens and parasites known to affect honey bee populations, including bacterial, fungal, and arthropod species. Trypanosomatids infecting honey bees are also being assessed using the extracted DNA.
Our findings revealed that Nosema ceranae emerged as the most prevalent pathogen, detected in 57.03% of samples, followed by Aethina tumida (40%), Galleria mellonella (37.03%), Paenibacillus larvae (20.74%), Nosema apis (18.51%), and Mellisococcus plutonius (17.77%). Ascosphaera apis was detected in 5.18% of the samples, while 25 samples (18.52%) tested negative for all the pathogens analysed. This study highlights honey eDNA as a valuable tool for non-invasive pathogen monitoring, offering insights into the health and disease dynamics of honey bee populations.