Prevalence of

Honey bees (Apis mellifera) are among the most crucial pollinators, significantly contributing to the growth of flowers and wild plants within ecosystems. Extensive epidemiological studies have been undertaken to identify and mitigate bacterial, fungal, and viral diseases affecting these insects. American foulbrood (AFB) is a particularly severe and highly contagious bacterial disease that impacts honey bee (Apis mellifera) larvae. This disease is caused by a gram-positive bacterium known as Paenibacillus larvae. This bacterium has the capacity to produce resilient spores that possess the ability to survive for extended periods under conducive environmental conditions. In the absence of a timely diagnosis and subsequent treatment, Africanized honey bees (AFB) have the potential to infect the entire hive and disseminate the infection to neighboring hives. The objective of this research was to assess the prevalence of AFB disease in apiaries nationwide. From autumn to winter of 2022, the study entailed the sampling of adult bees and honey from 266 apiaries dispersed across various regions of the country, encompassing 31 provinces. The preparation of the 532 samples was carried out in accordance with established protocols, and the subsequent DNA extraction process was executed. Two sets of specific primers were employed to identify the P. larvae using PCR and nested-PCR methods. Subsequently, the selected samples that were positive for PCR were subjected to sequencing, and a phylogenetic tree was constructed. The findings indicate that, among the 266 honeybee samples, 14 (5.26%) were positive, and among the 266 honey samples, 42 (15.78%) were positive. Among the 31 provinces that were investigated, P. larvae infection was detected in 18 provinces (61%). The highest incidence of AFB disease was documented in the Northern Provinces (28.78%) and the central regions of the country (25.35%). In contrast, the Eastern Provinces demonstrated the lowest infection rate (5.71%), a finding that was statistically significant. The majority of positive honeybee samples were sourced from the Central Provinces, while the majority of honey samples were from the Northern Provinces. The findings of this study suggest that Afipobacterial fever (AFB) is a prevalent bacterium in apiaries throughout Iran.