Arctic fleas are not fussy eaters: Bartonella bacteria may hitchhike between birds and mammals in a tundra ecosystem

Within the terrestrial Arctic ecosystem at Karrak Lake, Nunavut, Bartonella bacteria (B. vinsonii subsp. berkhoffii and B. henselae) have been detected in avian nest fleas (Ceratophyllus vagabundus vagabundus) and the blood of Arctic foxes (Vulpes lagopus). We further investigate the transmission dynamics at Karrak Lake by identifying Bartonella present in rodents, migratory geese upon arrival to nesting grounds, and rodent and avian fleas. Conventional PCR targeting the 16S-23S rRNA intergenic transcribed spacer region revealed DNA of B. vinsonii subsp. berkhoffii and B. rochalimae in 42% of 24 nest flea pools, B. rochalimae and B. grahamii in 70% of 10 rodent flea pools (Amalaraeus dissimilis), B. grahamii, B. vinsonii subsp. berkhoffii, and Bartonella sp. BvS12 in 20% of 20 red-backed voles (Myodes rutilus), and B. vinsonii subsp. berkhoffii in 2% of 42 Ross’s geese (Anser rossii). These findings suggest that geese and their associated fleas serve as migratory hosts and vectors. Detection of the same or similar species of Bartonella in rodent fleas, nest fleas and foxes proposes that transmission may occur during predation and detection of B. rochalimae (a Bartonella species commonly detected in rodents) in nest fleas, may suggest that these fleas have generalist feeding tendencies, acquiring Bartonella from rodents or foxes as they visit nests.