The first report of the prevalence of <i>Nosema ceranae</i> in Bulgaria

Abstract

<i>Nosema apis</i> and <i>Nosema ceranae</i> are the two main microsporidian parasites causing nosematosis in the honey bee <i>Apis mellifera</i>. The aim of the present study is to investigate the presence of <i>Nosema apis</i> and <i>Nosema ceranae</i> in the area of Bulgaria. The 16S (SSU) rDNA gene region was chosen for analysis. A duplex PCR assay was performed on 108 honey bee samples from three different parts of the country (South, North and West Bulgaria). The results showed that the samples from the northern part of the country were with the highest prevalence (77.2%) for <i>Nosema ceranae</i> while those from the mountainous parts (the Rodopa Mountains, South Bulgaria) were with the lowest rate (13.9%). Infection with <i>Nosema apis</i> alone and co-infection <i>N. apis/N. ceranae</i> were not detected in any samples. These findings suggest that <i>Nosema ceranae</i> is the dominant species in the Bulgarian honey bee. It is not known when the introduction of <i>Nosema ceranae</i> in Bulgaria has occurred, but as in the rest of the world, this species has become the dominant one in Bulgarian <i>Apis mellifera</i>. In conclusion, this is the first report for molecular detection of <i>Nosema</i> infection of honey bee in Bulgaria. The results showed that <i>N. ceranae</i> is the main <i>Nosema</i> species in Bulgaria.