Samuel Mwakisha Mwamburi

Mr. Samuel Mwakisha Mwamburi

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 December 2024 in Microorganisms
Verified
Journal Article
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SMSamuel Mwakisha Mwamburi
Samuel Mwakisha Mwamburi
Sk Injamamul IslamSk Injamamul Islam
Sk Injamamul Islam
DNDinh-Hung Nguyen
Dinh-Hung Nguyen
ODOrathai Dangsawat
Orathai Dangsawat
RSRapeewan Sowanpreecha
Rapeewan Sowanpreecha
Linh Vu NguyenLinh Vu Nguyen
Linh Vu Nguyen
Bacillus sp. THPS1 is a novel strain isolated from a high-temperature hot spring in Thailand, exhibiting distinctive genomic features that enable adaptation to an extreme environment. This study aimed to characterize the genomic and functional attributes of Bacillus sp. THPS1 to understand its adaptation strategies and evaluate its potential for biotechnological applications. The draft genome is 5.38 Mbp with a GC content of 35.67%, encoding 5606 genes, including those linked to stress response and sporulation, which are essential for survival in high-temperature conditions. Phylogenetic analysis and average nucleotide identity (ANI) values confirmed its classification as a distinct species within the Bacillus genus. Pangenome analysis involving 19 others closely related thermophilic Bacillus species identified 1888 singleton genes associated with heat resistance, sporulation, and specialized metabolism, suggesting adaptation to nutrient-deficient, high-temperature environments. Genomic analysis revealed 12 biosynthetic gene clusters (BGCs), including those for polyketides and non-ribosomal peptides, highlighting its potential for synthesizing secondary metabolites that may facilitate its adaptation. Additionally, the presence of three Siphoviridae phage regions and 96 mobile genetic elements (MGEs) suggests significant genomic plasticity, whereas the existence of five CRISPR arrays implies an advanced defense mechanism against phage infections, contributing to genomic stability. The distinctive genomic features and functional capacities of Bacillus sp. THPS1 make it a promising candidate for biotechnological applications, particularly in the production of heat-stable enzymes and the development of resilient bioformulations.

17 October 2023 in Environmental DNA
Verified
Journal Article
Open access
SMSamuel Mwakisha Mwamburi
Samuel Mwakisha Mwamburi
JUJacqueline Uku
Jacqueline Uku
NWNina Wambiji
Nina Wambiji
JKJames Kairo
James Kairo
FOFredrick Oketch
Fredrick Oketch
NINimrod Ishmael
Nimrod Ishmael
Assessing biodiversity in marine nearshore ecosystems is crucial for effective management, especially in the context of climate change and overexploitation of marine resources. Conventional methods often fall short in providing comprehensive information for managing seagrass ecosystems. However, the emergence of environmental DNA (eDNA) techniques has transformed the field by enabling noninvasive surveys that are cost effective and provide detailed information with high resolution. In this study, we utilized eDNA to assess fish diversity and compared its effectiveness to conventional techniques such as catch assessment surveys and underwater surveys. We sampled three habitats (A: mangrove‐seagrass, B: seagrass only, and C: coral‐seagrass) with 4 replicates. Site A recorded 8 fish species, site B had 16 species, and site C, characterized by coral and seagrass habitats, exhibited the highest fish diversity with 45 species (mean H′ index = 2.455), underscoring its ecological importance. To ensure accurate taxonomic identification, we utilized an updated MiFish reference database containing a larger number of fish species compared to the initial library. This expanded reference database with 9569 fish species, facilitated more precise identification and enhanced the reliability of our findings. Notably, the eDNA technique outperformed conventional methods by detecting 23 additional fish species that went undetected using traditional surveys. Moreover, our study documented five fish species previously unknown to occur within the study region, further emphasizing the value of eDNA analysis in uncovering hidden biodiversity. These findings strongly advocate for integrating eDNA techniques into the monitoring and assessment of biodiversity in shallow tropical habitats of the Western Indian Ocean. By leveraging eDNA surveys, we can gain valuable insights into fish diversity, discover hidden species, and make informed decisions for the conservation and management of these ecologically significant areas.

1 October 2024 in Animals
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Journal Article
Open access
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DNDinh-Hung Nguyen
Dinh-Hung Nguyen
SMSamuel Mwakisha Mwamburi
Samuel Mwakisha Mwamburi
HDHa Dong
Ha Dong
Channarong RodkhumChannarong Rodkhum
Channarong Rodkhum
WMWatcharachai Meemetta
Watcharachai Meemetta
SCSatid Chauchaiphan
Satid Chauchaiphan
This study aims to genomically elucidate six isolates of rapidly growing non-tuberculous mycobacteria (RGM) derived from Siamese fighting fish (Betta splendens). These isolates had previously undergone phenotypic and biochemical characterization, antibiotic susceptibility testing, and in vivo virulence assessment. Initial DNA barcoding using the 16S rRNA sequence assigned these six isolates to five different species, namely Mycobacterium chelonae (BN1983), M. cosmeticum (BN1984 and N041), M. farcinogenes (SNSK5), M. mucogenicum (BN1956), and M. senegalense (BN1985). However, the identification relied solely on the highest percent identity of the 16S rRNA gene, raising concerns about the taxonomic ambiguity of these species. Comprehensive whole genome sequencing (WGS) and extended genomic comparisons using multilocus sequence typing (MLST), average nucleotide identity (ANI), and digital DNA–DNA hybridization (dDDH) led to the reclassification of BN1985 and SNSK5 as M. conceptionense while confirming BN1983 as M. chelonae and BN1984 and N041 as M. cosmeticum. Notably, the analysis of the BN1956 isolate revealed a potential new species that is proposed here as M. mucogenicum subsp. phocaicum sp. nov. Common genes encoding “mycobacterial” virulence proteins, such as PE and PPE family proteins, MCE, and YrbE proteins, were detected in all six isolates. Two species, namely M. chelonae and M. cosmeticum, appear to have horizontally acquired T6SS-II (clpB), catalase (katA), GroEL (groel), and capsule (rmlb) from distantly related environmental bacteria such as Klebsiella sp., Neisseria sp., Clostridium sp., and Streptococcus sp. This study provides the first draft genome sequence of RGM isolates currently circulating in B. splendens and underscores the necessity of WGS for the identification and classification of mycobacterial species.

21 November 2024 in Journal of General Virology
Verified
Journal Article
Open access
PPPattama Puttirungroj
Pattama Puttirungroj
SKSatoshi Kawato
Satoshi Kawato
SMSamuel Mwakisha Mwamburi
Samuel Mwakisha Mwamburi
MFMiho Furukawa
Miho Furukawa
RORisako Oomine
Risako Oomine
IHIkuo Hirono
Ikuo Hirono
White spot syndrome virus (WSSV) poses a significant threat to shrimp aquaculture, leading to substantial economic losses. This study aims to evaluate the virulence and evolution of recent WSSV outbreaks in Japan. Shrimp infected with WSSV were collected from Okinawa, Miyakojima and Miyazaki prefectures, yielding a total of seven isolates. Through injection and immersion tests, the lethal dose 50% endpoints were determined. Genomic analysis revealed isolates with sizes ranging from 288 to 299 kbp, sharing ~99% nucleotide identity with the reference genome (CN01: NC_003225.3). Variant analysis identified 1197 forms, primarily single-nucleotide polymorphisms, with Miyakojima isolates displaying the highest diversity. Frameshift mutations, notably in ORFs such as wsv006, wsv011, wsv091 and wsv403, were observed across all isolates. Phylogenetic analysis indicated clustering of Miyakojima isolates, suggesting similar outbreak intensities. Furthermore, isolates exhibited smaller genomic sizes compared with the reference genome, indicating ongoing WSSV evolution. Notably, a high frameshift mutation in wsv403, a viral E3 ubiquitin ligase, implies its potential role in the observed outbreaks, particularly in Miyakojima. This study addresses the research question regarding the virulence and evolutionary dynamics of WSSV outbreaks, proposing a hypothesis that genetic variations contribute to the severity and spread of WSSV in shrimp aquaculture.

1 August 2023 in Access Microbiology
Verified
Journal Article
Open access
JMJosphat Mutinda
Josphat Mutinda
SMSamuel Mwakisha Mwamburi
Samuel Mwakisha Mwamburi
KOKennedy Omondi Oduor
Kennedy Omondi Oduor
MOMaurice Vincent Omolo
Maurice Vincent Omolo
RNRegina Mongina Ntabo
Regina Mongina Ntabo
JNJames Nonoh
James Nonoh
Background. Since Anopheles mosquitoes which transmit and maintain the malaria parasite breed in the outdoor environment, there is an urgent need to manage these mosquito breeding sites. In order to elaborate more on the ecological landscape of mosquito breeding sites, the bacterial community structure and their interactions with physicochemical factors in mosquito larval habitats was characterised in Kwale County (Kenya), where malaria is endemic. Methods. The physical characteristics and water physicochemical parameters of the habitats were determined and recorded. Water samples were also collected from the identified sites for total metagenomic DNA extraction in order to characterise the bacterial communities within the breeding sites. Results and Discussion. Sites where mosquito larvae were found were described as positive and those without mosquito larvae as negative. Electrical conductivity, total dissolved solids, salinity and ammonia were lower in the rainy season than in the dry season, which also coincided with a high proportion of positive sites. Pseudomonadota was the most common phyla recovered in all samples followed by Bacteroidota and then Actinomycetota. The presence or absence of mosquito larvae in a potential proliferation site was not related to the bacterial community structure in the sampled sites, but was positively correlated with bacterial richness and evenness. Conclusion. Generally, the presence of Anopheles mosquito larvae was found to be positively correlated with rainy season, bacterial richness and evenness, and negatively correlated with electrical conductivity, total dissolved solids, salinity and ammonia. The findings of this study have implications for predicting the potential of environmental water samples to become mosquito proliferation sites.

5 May 2025 in Environmental DNA
Verified
Journal Article
Open access
Cornelius OkelloCornelius Okello
Cornelius Okello
NWNina Wambiji
Nina Wambiji
SKSusana W. Kihia
Susana W. Kihia
NONehemiah Ongeso
Nehemiah Ongeso
SMSamuel Mwakisha Mwamburi
Samuel Mwakisha Mwamburi
MOMargaret Awuor Owuor
Margaret Awuor Owuor
Restoration of degraded arid and semi‐arid lands (ASALs) dryland ecosystems gained traction globally with the enactment of the Bonn Challenge and UN Decade of Restoration. This has been domesticated in Kenya's context by The Forest and Landscape Restoration Implementation Plan (FOLAREP). However, effectively monitoring restored ecosystems is crucial but challenging because of data gaps and technical hurdles, highlighting the need for innovative approaches to assess and restore biodiversity. This study aimed to pilot soil environmental DNA (eDNA) metabarcoding to detect species compositions rapidly, evaluate population structures and abundances, and characterize taxonomic groups. The results from this study serve as a foundational step toward monitoring the impact of water bunds, a restoration approach on biodiversity conservation, in Lower Naibunga Community Conservancy in Laikipia County, Kenya. This study used 16S rDNA and rbCL metabarcoding to assess prokaryotic and plant diversity. Plant growth‐promoting rhizobacteria species attributed to enhancing nutrient availability and improving plant resilience to abiotic stress were prevalent across all six sites: Lorubai (Site 1), Burtany (Site 2), Nkirashi (Site 3), Losopukia (Site 4), Munushoi (Site 5), and Loika (Site 6). Plant species attributed to drought tolerance and rangeland rehabilitation were also identified. The study demonstrates the potential of eDNA metabarcoding as an effective tool for monitoring nature‐based solutions (NbS) interventions to enhance biodiversity and ecosystem restoration in ASALs.