High prevalence and strain diversity of Melissococcus plutonius in Apis cerana in Guangxi, China
Xiaolin Cai1, Chunxiu Pang2, Fuchang Zhuo2
1Flowers Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; Key Laboratory for Insect-Pollinator Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China.
Abstract:
Melissococcus plutonius, the agent of European foulbrood (EFB), has been well studied in Apis mellifera but its epidemiology in Apis cerana remains less understood. We surveyed 37 apiaries across Guangxi, China, and detected M. plutonius in 32.4%, 10.8%, and 27.0% of larvae, adult bees, and honey samples, respectively, all originating from asymptomatic colonies. Duplex PCR revealed frequent co-detection of typical and atypical strains. Viable isolates were recovered from 58.3% of PCR-positive larval samples. Multi-locus sequence typing (MLST) showed six isolates (T1, X16, L20, Q21, Q22, L32) clustering with the atypical reference strain DAT561, and one isolate (P6) clustering with the typical reference strain ATCC 35311. Our findings highlight the high prevalence and strain diversity of M. plutonius in A. cerana in subtropical Guangxi and emphasize the need for region-specific surveillance strategies.
