20.500.12556/RUL-176796 European human granulocytic anaplasmosis is caused by a subcluster of Anaplasma phagocytophilum Ecotype I Anaplasma phagocytophilum causes human granulocytic anaplasmosis. However, despite its ubiquitous presence in animals and ticks, human cases are rarely reported in Europe. We generated genetic data from A. phagocytophilum from patients and compared them with sequences from wild and domestic animals to assess the zoonotic potential of the respective genotypes. The genomic sequence of an A. phagocytophilum isolate obtained from a Slovenian patient was determined. We also sequenced a groEL-gene fragment of eight isolates from human patients from France and Poland. The A. phagocytophilum genome from the Slovenian patient was more closely related to isolates from dogs than from sheep. Using groEL-based typing, isolates from humans were found within a distinct subcluster of A. phagocytophilum Ecotype I. This subcluster was defined as zoonotic. Strains from dogs, horses, cats, foxes, wolves, and wild boar were significantly overrepresented in this branch. Variants outside this subcluster were more abundant and found in a wider variety of domestic and wild animals, most notably ruminants. A similar pattern was observed for the MLST analyses targeting seven housekeeping genes. Human anaplasmosis in Europe is associated with a specific subcluster of A. phagocytophilum Ecotype I, which is not primarily associated with ruminants, but rather with dogs, horses, cats, carnivores, wild boar and hedgehogs. Our findings provide a reasonable explanation for the discrepancy between the omnipresence of A. phagocytophilum in the environment and the limited number of reported human cases. We recommend taking this genetic sub-clustering into account for future risk assessments. anaplasma phagocytophilum groEL human granulocytic anaplasmosis Ixodes ricinus multilocus sequence typing ecotypes whole genome sequence ticks true false true Angleški jezik Ni določen Članek v reviji 2025-12-11 04:25:25 2025-12-16 07:50:52 2026-07-23 11:56:45 0000-00-00 00:00:00 2025 0 0 8 str. art. 100324 Vol. 8 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616.98 2667-114X 10.1016/j.crpvbd.2025.100324 252191747 RAZ_Lesiczka_Paulina_M._2025.pdf RAZ_Lesiczka_Paulina_M._2025.pdf 1 87780C1374C02731D1054BE409808DEC 064ee53450a8d1a257c1cf60521be5fbf304ab88cabbe8340603b69f1a8f1a5e 80462cac-da45-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=223764 https://www.sciencedirect.com/science/article/pii/S2667114X25000846?via%3Dihub 1 9f7da011-d640-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=223368 Medicinska fakulteta 0 0 0