Year: 2026
Type: preprint
Abstract: Background Staphylococcus aureus is a leading cause of hospital and community-associated human infections. Despite its clinical importance, molecular epidemiology data in Nigeria are limited. This study characterized bloodstream S. aureus isolates submitted to the Nigerian Antimicrobial Resistance Surveillance System. Methods Bloodstream S. aureus isolates from six tertiary healthcare institutions in Nigeria collected between 2016 and 2021 were characterized by antimicrobial susceptibility testing and whole-genome sequencing. Bioinformatic analyses were conducted using publicly available pipelines in addition to contextualization with publicly available sequences. Results Of 138 isolates, 85 (61.6%) were methicillin-resistant S. aureus (MRSA). A total of 31 spa types, 14 sequence types (STs), eight clonal complexes (CCs) - CC1, CC5, CC8, CC15, CC30, CC45, CC88, CC121 - and two singletons (ST152 and ST11258) were identified. ST152 (n = 48, 35%) was the predominant lineage, followed by ST772 (n = 21, 15%), ST8 (n = 16, 12%) and ST789 (n = 13, 9%). These lineages were detected across sentinel sites, indicating widespread geographic dissemination. ST772-MRSA isolates possessed the highest number of antimicrobial (AMR) and virulence genes. ST789 was characterized by numerous AMR genes in both MRSA and MSSA backgrounds, whereas ST8 and ST152-MRSA isolates demonstrated abundant virulence genes, with comparatively few AMR genes. ST152, ST772, and ST789 genomes generally clustered together relative to publicly available genomes of the corresponding STs, with lineage-specific subclades differentiated by AMR profiles. Conclusion Predominance of ST152-MRSA, ST772-MRSA, and ST789-MRSA among bloodstream S. aureus isolates in Nigeria is a significant public health concern. Sustained genomic surveillance is critical to inform infection prevention and control in Nigeria.
Source: Research Square
Authors: Anderson O. Oaikhena, Ifeanyi E. Mba, Gabriel T. Sunmonu, Dorothy Cyril-Okoh, Odion O. Ikhimiukor, Ayorinde O. Afolayan, Erkison Ewomazino Odih, Aaron O. Aboderin, Veronica O. Ogunleye, Bashirat A. Olanipekun, Rasaki A. Raheem, Oyinlola O. Oduyebo, Ifeoluwa Komolafe, Aderemi Kehinde, Adewale A. Amupitan, Oyekola V. Abiri, Temitope O. Obadare, Olatunde F. Olabisi, Charles J. Elikwu, Abayomi Fadeyi, Josephine F. Ojo, Abolaji T. Adeyemo, Philip O. Oshun, Victoria A. Aikhomu, Anthony Underwood, Silvia Argimón, Mihir Kekre, Abiodun Egwuenu, Tochi Okwor, Chikwe Ihekweazu, Adebayo O. Shittu, David M. Aanensen, Iruka N. Okeke
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7225755865