Evidence of Apis cerana Sacbrood virus Infection in Apis mellifera

Abstract

bSacbrood virus (SBV) is one of the most destructive viruses in the Asian honeybee Apis cerana but is much less destructive in Apis mellifera. In previous studies, SBV isolates infecting A. cerana (AcSBV) and SBV isolates infecting A. mellifera (AmSBV) were identified as different serotypes, suggesting a species barrier in SBV infection. In order to investigate this species isolation, we examined the presence of SBV infection in 318 A. mellifera colonies and 64 A. cerana colonies, and we identified the genotypes of SBV isolates. We also performed artificial infection experiments under both laboratory and field conditions. The results showed that 38 A. mellifera colonies and 37 A. cerana colonies were positive for SBV infection. Phylogenetic analysis based on RNA-dependent RNA polymerase (RdRp) gene sequences indicated that A. cerana isolates and most A. mellifera isolates formed two distinct clades but two strains isolated from A. mellifera were clustered with the A. cerana isolates. In the artificial-infection experiments, AcSBV negative-strand RNA could be detected in both adult bees and larvae of A. mellifera, although there were no obvious signs of the disease, demonstrating the replication of AcSBV in A. mellifera. Our results suggest that AcSBV is able to infect A. mellifera colonies with low prevalence (0.63% in this study) and pathogenicity. This work will help explain the different susceptibilities of A. cerana and A. mellifera to sacbrood disease and is potentially useful for guiding beekeeping practices.

A comparison of biological characteristics of three strains of Chinese sacbrood virus in Apis cerana

“…In group I, although SXYL-2015, SXnor1–2012, and BJ-2012 were isolated from the Chinese honeybee A. cerana , those strains formed a closely related cluster with the strains originating overseas, such as AcSBV-IndK1A, AcSBV-IndII-2 (GenBank: JX270795), AmSBV-Australia (GenBank: KJ629183), AmSBV-Kor21, and SBV-UK. We deduced that SXYL-2015, SXnor1-2012, and BJ-2012 probably originated from SBV infecting Apis mellifera , and then infected A. cerana , indicating that SBV can cause interspecies infections, and these data are consistent with Gong’s results28. By contrast, HBQHD-2012, LNSZ-2011, GZ-2000, and GZ-2002 form a closely related cluster with groups II and III; this finding shows that these isolates originated from GZ-2000, which was first isolated from the Chinese honeybee A. cerana in Guangzhou in 2000.…”

“…Ma et al predicted and identified four major CSBV structural proteins by means of bioinformatics and mass spectrometry12. There are reported differences between CSBV and SBV in their physicochemical characteristics, pathogenicity, and immunogenicity131415; however, it is unknown whether these differences exist between CSBVs of different genotypes.…”

Visualizing Sacbrood Virus of Honey Bees via Transformation and Coupling with Enhanced Green Fluorescent Protein

“…Sacbrood virus (SBV) is a common virus belonging to the genus Iflavirus and causes failure to pupate and subsequent death in Apis mellifera [1][2][3]. It was the first identified iflavirus in European honey bees and a strain has evolved that also infects Asian honey bees, Apis cerana [4,5]. The A. cerana strain (Ac-SBV) shares more than 97% similarity with A. mellifera SBV isolates and causes more losses in A. cerana colonies than SBV in A. mellifera [4].…”

“…It was the first identified iflavirus in European honey bees and a strain has evolved that also infects Asian honey bees, Apis cerana [4,5]. The A. cerana strain (Ac-SBV) shares more than 97% similarity with A. mellifera SBV isolates and causes more losses in A. cerana colonies than SBV in A. mellifera [4]. A. cerana is naturally resistant to Varroa mites and less prone to some common virus diseases found in A. mellifera; however, A. cerana apiaries in China were reporting serious losses caused by SBV [6].…”

Ecological and evolutionary approaches to managing honeybee disease

“…In addition, buttressing the health of managed pollinators must not be done at the expense of native pollinators, as honeybees can serve as reservoirs of diseases that threaten wild bees 201 – 203 and other managed bees 204 . More than 20,000 species of wild bees play critical roles in agriculture and native ecosystems, and disease risk is a threat to this critical component of biodiversity 10 , 186 .…”