20.500.12556/RUL-183193 Emerging human pathogen identifying Spiroplasma ixodetis as a frequent cause of unlocalised febrile illness Objectives: Febrile illness without clear localisation presents a significant diagnostic challenge due to nonspecific symptoms and diverse aetiologies. Spiroplasma ixodetis, an emerging tick-associated pathogen previously linked mainly to congenital cataracts, has not been well characterised in adults. We investigated the prevalence and clinical features of S. ixodetis infection in adults with acute febrile illness without localisation. Methods: Shotgun metagenomic sequencing identified S. ixodetis in the initial 209 patient cohort and the sequences were used to developed a novel real-time PCR assay targeting the 23S rRNA gene. Initial cohort screening was followed by testing 128 patients from an additionally selected targeted cohort. Positive results were confirmed by sequencing of 16S and 23S rRNA genes. Results: S. ixodetis DNA was confirmed in 7.2% patients from the initial and in 35.2% patients from the additional cohort (60 in total). All were identified in the period from April to October and 57% reported a recent tick-bite. Clinical presentation was homogenous, characterised by fever, headache, bicytopenia and liver enzyme abnormalities. Outcomes were favourable, with 15% requiring hospitalisation. Conclusion: This study identifies S. ixodetis as a previously unrecognised cause of adult febrile illness without localisation, bridging the gap between previously published data between tick studies and isolated human case reports. 23S rRNA PCR fever metagenomics patients Spiroplasma ixodetis tick-borne diseases 23S rRNA PCR vročina metagenomika bolniki Spiroplasma ixodetis klopne bolezni true false true Angleški jezik Slovenski jezik Članek v reviji 2026-06-07 07:36:24 2026-06-07 07:36:24 2026-06-08 08:23:41 0000-00-00 00:00:00 2026 0 0 9 str. iss. 1, art. 106776 Vol. 93 May 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616.9 0163-4453 10.1016/j.jinf.2026.106776 280582403 RAZ_Korva_Misa_2026.pdf RAZ_Korva_Misa_2026.pdf 1 F2AEAB5B95B375117C32DA71FEA95D2C 8eb20af8b9f05d8ef4f56e517b87245576d65ec0b8ac0838d74a77aa33d14f68 98735e8e-6233-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=235062 https://www.journalofinfection.com/article/S0163-4453(26)00101-5/fulltext 1 7338a774-6232-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=235061 Medicinska fakulteta 0 0 0