Browsing by Author "Beti, Melkiory"

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    Genomic characterization of a novel human astrovirus MLB1 variant from Tanzania
    (Elsevier B.V., 2026-03-03) Shayo, Mariana; Kuchaka, Davis; Beti, Melkiory; Mwing'a, Gerald; Kimu, Patrick; Wadugu, Boaz; Juma, Masoud; Kumburu, Happiness; Kiwelu, Ireen; Ali, Mohamed; Kazyoba, Paul; Clausen, Philip; Muro, Florida; Mmbaga, Blandina; Alifrangis, Michael; Aarestrup, Frank; Sonda, Tolbert
    Human astroviruses (HAstV) are emerging viral pathogens responsible for gastroenteritis worldwide, but whole-genome data from Africa, including from Tanzania, remains scarce. A genomic analysis of stools of children with diarrhea was performed using nanopore sequencing. We successfully assembled HAstV-MLB1 complete genomes from two different stool samples, achieving high sequence coverage of 354.75x and 769.94x, respectively. Analyses included phylogeny, synteny, comparative genomics, and structural characterization of the capsid protein. The two Tanzanian HAstV-MLB1 strains showed high genetic similarity to each other and clustered within the Melbourne-like virus (MLB1) clade and were most closely related (96% similarity) to the Australian reference strain. Both synteny and capsid structure analysis confirmed their conserved nature. This study presents the first whole-genome data from Tanzania. Our findings align with the previously reported genetic stability of HAstV, regional variability, and potential functional variation of the capsid protein, emphasizing the need for surveillance and functional characterization.
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    Genomic characterization of methicillin-resistant Staphylococcus aureus isolated from patients attending regional referral hospitals in Tanzania
    (BioMed Central, 2024-08-14) Geofrey, Mujungu; Sauli, Elingarami; Kanje, Livin; Beti, Melkiory; Shayo, Mariana; Kuchaka, Davis; Zwetselaar, Marco; Wadugu, Boaz; Mmbaga, Blandina; Mkumbaye, Sixbert; Kumburu, Happiness; Sonda, Tolbert
    Background Methicillin-resistant Staphylococcus aureus (MRSA) colonization increases the risk of subsequent infection by MRSA strain complex interlinking between hospital and community-acquired MRSA which increases the chance of drug resistance and severity of the disease. Objective Genomic characterization of Staphylococcus aures strains isolated from patients attending regional referral hospitals in Tanzania. Methodology A laboratory-based cross-sectional study using short read-based sequencing technology, (Nextseq550,Illumina, Inc. San diego, California, USA). The samples used were collected from patients attending selected regional referral hospitals in Tanzania under the SeqAfrica project. Sequences were analyzed using tools available in the center for genomic and epidemiology server, and visualization of the phylogenetic tree was performed in ITOL 6.0. SPSS 28.0 was used for statistical analysis. Results Among 103 sequences of S. aureus, 48.5% (50/103) carry the mecA gene for MRSA. High proportions of MRSA were observed among participants aged between 18 and 34 years (52.4%), in females (54.3%), and among outpatients (60.5%). The majority of observed MRSA carried plasmids rep5a (92.0%), rep16 (90.0%), rep7c (90.0%), rep15 (82.0%), rep19 (80.0%) and rep10 (72.0%). Among all plasmids observed rep5a, rep16, rep20, and repUS70 carried the blaZ gene, rep10 carried the erm(C) gene and rep7a carried the tet(K) gene. MLST and phylogeny analysis reveal high diversity among MRSA. Six different clones were observed circulating at selected regional hospitals and MRSA with ST8 was dominant. Conclusion The study reveals a significant presence of MRSA in Staphylococcus aureus strains from Tanzanian regional hospitals, with nearly half carrying the mecA gene. MRSA is notably prevalent among young adults, females, and outpatients, showing high genetic diversity and dominance of ST8. Various plasmids carrying resistance genes indicate a complex resistance profile, highlighting the need for targeted interventions to manage MRSA infections in Tanzania.
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    Genomic diversity of human adenoviruses in Tanzanian children under five: Insights into F40, F41, B, and rare A18 genotypes
    (Elsevier B.V., 2026-01-23) Shayo, Mariana; Kuchaka, Davis; Beti, Melkiory; Kimu, Patrick; Wadugu, Boaz; Jensen, Emilie; Kumburu, Happiness; Kazyoba, Paul; Ali, Mohamed; Consortium, SeqTZ; Clausen, Philip; Muro, Florida; Mmbaga, Blandina; Alifrangis, Michael; Aarestrup, Frank; Sonda, Tolbert
    Human adenoviruses (HAdVs) are important pathogens that are associated with a wide array of clinical diseases, particularly in the pediatric population. Despite numerous reports of HAdV infections in Tanzania, there are currently no whole genome sequences from this region available in global public databases. This gap presents challenges to our efforts to understand their dissemination and evolution over time. This study employed nanopore-based metagenomic sequencing to detect and sequence the whole genomes of HAdV strains in Tan zanian infants with diarrhea. We present the first whole genome of HAdV-A18 from Africa, representing only the third worldwide. Additionally, it includes the first complete genomes of HAdV-F40, HAdV-F41, and HAdV-B3 obtained from Tanzania. In addition, this study provides information on the enteric adenovirus lineages circu lating in Tanzania. These findings provide crucial genomic insights into the diversity of viruses in sub-Saharan Africa and underscore the importance of genomic surveillance to deepen our understanding of adenovirus transmission and evolution.