first detection of nosema ceranae, a microsporidian protozoa of european honey­bees (apis mellifera) in iran

background : nosemosis of european honey bee (apis mellifera ) is present in bee colonies world­wide. until recently, nosema apis had been regarded as the causative agent of the disease, that causes heavy economic losses in apicultures. nosema ceranae is an emerging microsporidian para­site of european honeybees, a. mellifera , but its distribution is not well known. previously, nosemosis in honeybees in iran was attributed exclusively to n. apis . methods : six nosema positive samples (determined from light microscopy of spores) of adult worker bees from one province of iran (savadkouh- mazandaran, northern iran) were tested to determine nosema species using previously- developed pcr primers of the 16 s rrna gene. as it is difficult to distinguish n. ceranae and n. apis morphologically, a pcr assay based on 16 s ribosomal rna has been used to differentiate n. apis and n. ceranae . results : only n. ceranae was found in all samples, indicating that this species present in iran apiar­ies. conclusion : this is the first report of n. ceranae in colonies of a. mellifera in iran. it seems that intensive surveys are needed to determine the distribution and prevalence of n. ceranae in differ­ent regions of iran.