biostudies-literatureSchroeder SBundesministerium für Bildung und Forschung (Federal Ministry of Education and Research)Bundesministerium für Bildung und Forschung5324https://www.ebi.ac.uk/biostudies/studies/S-EPMC8423819biostudies-literatureUnknown12(1)Middle East respiratory syndrome coronavirus (MERS-CoV) is enzootic in dromedary camels across the Middle East and Africa. Virus-induced pneumonia in humans results from animal contact, with a potential for limited onward transmission. Phenotypic changes have been suspected after a novel recombinant clade (lineage 5) caused large nosocomial outbreaks in Saudi Arabia and South Korea in 2016. However, there has been no functional assessment. Here we perform a comprehensive in vitro and ex vivo comparison of viruses from parental and recombinant virus lineages (lineage 3, n = 7; lineage 4, n = 8; lineage 5, n = 9 viruses) from Saudi Arabia, isolated immediately before and after the shift toward lineage 5. Replication of lineage 5 viruses is significantly increased. Transcriptional profiling fNature communicationsFunctional comparison of MERS-coronavirus lineages reveals increased replicative fitness of the recombinant lineage 5.PMC842381901KI1723ABoulant SEggeling SWolff THippenstiel SMache CDijkman RThiel VSchroeder SKleine-Weber HMuth DGultom MPohlmann SMuller MAFatykhova DCorman VMHocke ADrosten CMemish ZAStanifer MLRichter AfalseFunctional comparison of MERS-coronavirus lineages reveals increased replicative fitness of the recombinant lineage 5.Middle East respiratory syndrome coronavirus (MERS-CoV) is enzootic in dromedary camels across the Middle East and Africa. Virus-induced pneumonia in humans results from animal contact, with a potential for limited onward transmission. Phenotypic changes have been suspected after a novel recombinant clade (lineage 5) caused large nosocomial outbreaks in Saudi Arabia and South Korea in 2016. However, there has been no functional assessment. Here we perform a comprehensive in vitro and ex vivo comparison of viruses from parental and recombinant virus lineages (lineage 3, n = 7; lineage 4, n = 8; lineage 5, n = 9 viruses) from Saudi Arabia, isolated immediately before and after the shift toward lineage 5. Replication of lineage 5 viruses is significantly increased. Transcriptional profiling f2021-01-01T00:00:00Z2021 Sep2026-05-09T05:46:36.906Z2022-02-11T15:00:09.679ZS-EPMC84238193449373010.1038/s41467-021-25519-1