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Apis mellifera filamentous virus (AmFV) is a double-stranded DNA virus that infects Apis mellifera bees. To our knowledge, this is the first comprehensive study aiming to detect and analyse the genetic diversity and prevalence of AmFV in Korean honeybee colonies. Phylogenetic analysis based on baculovirus repeat open reading frame–N gene (Bro–N) sequences revealed that AmFV isolates from the Republic of Korea (ROK) fell into two distinct lineages, with genetic origins in Switzerland and China, with nucleotide similarities of 98.3% and 98.2%, respectively. Our prevalence analysis demonstrated a noteworthy infection rate of AmFV in 545 honeybee colonies, reaching 33.09% in 2022 and increasing to 44.90% by 2023. Intriguingly, we also detected AmFV in Varroa destructor mites, highlighting their potential role as vectors and carriers of AmFV. The presence of AmFV was correlated with an increased infection rate of sacbrood virus, deformed wing virus, Lake Sinai virus 2, black queen cell virus, and Nosema ceranae in honeybee colonies. These findings provide valuable insight into the prevalence and potential transmission mechanisms of AmFV in honeybee colonies in the ROK. The results of this study may be instrumental in the effective management of viral infections in honeybee apiaries. [ABSTRACT FROM AUTHOR]

Mites of the genus Tyrophagus (Acari: Acaridae) are among the most widely distributed mites. The species in this genus cause damage to stored products and crops, and pose a threat to human health. However, the influence of Tyrophagus spp. in apiculture remains unknown. In 2022, a study focusing on the identification of Tyrophagus species within five apiaries was conducted in Chungcheongnam Province, Republic of Korea. Its specific objective was to investigate the presence of Tyrophagus mites in response to the reported high mortality of honey bee colonies in this area. Morphological identification and phylogenetic analysis using the mitochondrial gene cytochrome-c oxidase subunit 1 (CO1) confirmed for the first time the presence of the mite species Tyrophagus curvipenis in a honey bee colony in the Republic of Korea. Two honey bee pathogens were detected in the mite, a viral pathogen (deformed wing virus, DWV) and a protozoal pathogen (Trypanosoma spp.). The presence of the two honey bee pathogens in the mite suggests that this mite could contribute to the spread of related honey bee diseases. However, the direct influence of the mite T. curvipenis on honey bee health remains unknown and should be further investigated. [ABSTRACT FROM AUTHOR]

Migratory birds disperse ticks and associated tick-borne pathogens along their migratory routes. Four selected pathogens of medical importance (Coxiella burnetii, Rickettsia spp., Francisella tularensis, and Toxoplasma gondii) were targeted for detection in 804 ticks (365 pools) collected from migratory birds at Hong and Heuksan Islands in the Republic of Korea (ROK) from 2010 to 2011 and 2016. Toxoplasma gondii and Rickettsia spp., were detected in 1/365 (0.27%) and 34/365 (9.32%) pools of ticks, respectively. T. gondii and five rickettsial species were recorded in ticks collected from migratory birds for the first time in ROK. The five rickettsial species (R. monacensis, Candidatus Rickettsia longicornii, R. japonica, R. raoultii, and R. tamurae) were identified using sequence and phylogenetic analysis using ompA and gltA gene fragments. Rickettsia spp. are important pathogens that cause rickettsiosis in humans, with cases recorded in the ROK. These results provide important evidence for the potential role of migratory birds in the introduction and dispersal of T. gondii and Rickettsia spp. along their migratory routes and raise awareness of potential transmission of zoonotic tick-borne pathogens associated with migratory birds in the ROK. [ABSTRACT FROM AUTHOR]

Honey bees are important pollinators for the conservation of the ecosystem and agricultural products and provide a variety of products important for human use, such as honey, pollen, and royal jelly. Sacbrood disease (SD) is a devastating viral disease in Apis cerana; an effective preventive measure for SD is urgently needed. In this study, the relationship between the gut microbiome of honey bees and SD was investigated by pyrosequencing. Results revealed that sacbrood virus (SBV)-resistant A. cerana strains harbour a unique acetic acid bacterium, Bombella intestini, and the lactic acid bacteria (LAB) Lactobacillus (unclassified)_uc, Bifidobacterium longum, B. catenulatum, Lactococcus lactis, and Leuconostoc mesenteroides in larvae and Hafnia alvei, B. indicum, and the LAB L. mellifer and Lactobacillus HM215046_s in adult bees. Changes in the gut microbiome due to SBV infection resulted in loss of bacteria that could affect host nutrients and inhibit honey bee pathogens, such as Gilliamella JFON_s, Gilliamella_uc, Pseudomonas putida, and L. kunkeei in A. cerana larvae and Frischella_uc, Pantoea agglomerans, Snodgrassella_uc, and B. asteroides in adult bees. These findings provide important information for the selection of probiotics for A. cerana larvae and adults to prevent pathogenic infections and keep honey bees healthy. [ABSTRACT FROM AUTHOR]

Objectives: In this study, the gut microbiome of healthy adult honeybees, Apis cerana, was investigated by sequencing the V3 – V4 region in 16S rRNA gene using Illumina Miseq platform. Results: The total of 37,853 reads for 16S rRNA gene were obtained and 30,121 (79.6%) reads were valid with 25,291 (84.0%) reads that were classified into 116 species belonging to four major phyla. The relative abundances of the bacterial isolates in honeybee samples were phylum Proteobacteria (70.7%), Actinobacteria (10.7%), Firmicutes (10.3%), and Bacteroidetes (8.4%), respectively. Lactic acid bacteria comprised 18.95% with 10 groups including Bifidobacterium asteroides, B. indicum, Fructobacillus fructosus, Lactobacillus apinorum, L. apis, L. helsingborgensis, L. kimbladii, L. kullabergensis, and L. kunkeei. Conclusions: The presence of beneficial bacteria in the gut highlighted their role in the honeybee and suggested that they can be promising candidates for the development of probiotics for health improvement, infection control and disease management of honeybees. [ABSTRACT FROM AUTHOR]

Kashmir bee virus (KBV) is one of the most common viral infections in honeybees. In this study, a phylogenetic analysis was performed using nine partial nucleotide sequences of RdRp and the structural polyprotein regions of South Korean KBV genotypes, as well as nine previously reported KBV genotypes from various countries and two closely related genotypes of Israeli acute paralysis virus (IAPV) and Acute bee paralysis virus (ABPV). The Korean KBV genotypes were highly conserved with 94-99 % shared identity, but they also shared 88-95 % identity with genotypes from various countries, and they formed a separate KBV cluster in the phylogenetic tree. The complete genome sequence of Korean KBV was also determined and aligned with previously reported complete reference genome sequences of KBV, IAPV, and ABPV to compare different genomic regions. The complete Korean KBV genome shared 93, 79, and 71 % similarity with the complete reference genomes of KBV, IAPV, and ABPV, respectively. The Korean KBV was highly conserved relative to the reference KBV genomes in the intergenic and 3′ untranslated region (UTR), but it had a highly variable 5′ UTR, whereas there was little divergence in the helicase and 3C-protease of the nonstructural protein, and the external domains of the structural polyprotein region. Thus, genetic recombination and geographical distance may explain the genomic variations between the Korean and reference KBV genotypes. [ABSTRACT FROM AUTHOR]