MyMedR

Displaying publications 1 - 20 of 21 in total

Abstract:

Sort:

Fulltext Escherichia coli strain INF32/16/A: Dataset of raw reads and assembled draft genome

Mat-Sharani S, Sulaiman S, Yusof NY

Data Brief, 2021 Dec;39:107640.
PMID: 34901351 DOI: 10.1016/j.dib.2021.107640

Escherichia coli strain INF32/16/A is a gram-negative bacteria which is an extended-spectrum beta-lactamases (ESBL). ESBL is an enzyme that is produced by bacteria to become resistant to existing antibiotic such as extended-spectrum penicillin, cephalosporins, and have been threatening the ability to treat an infection. Therefore, genome analysis will provide an insight of how this bacteria able to evolve and the information obtained will able to facilitate in designing new antibiotics. The genome of E. coli strain was sequenced using Illumina MiSeq and raw genome sequence have been submitted into NCBI SRA database (SRR15334628) under Bioproject accession number PRJNA726861.
Investigation of highly unsaturated fatty acid metabolism in the Asian sea bass, Lates calcarifer

Mohd-Yusof NY, Monroig O, Mohd-Adnan A, Wan KL, Tocher DR

Fish Physiol Biochem, 2010 Dec;36(4):827-43.
PMID: 20532815 DOI: 10.1007/s10695-010-9409-4

Lates calcarifer, commonly known as the Asian sea bass or barramundi, is an interesting species that has great aquaculture potential in Asia including Malaysia and also Australia. We have investigated essential fatty acid metabolism in this species, focusing on the endogenous highly unsaturated fatty acid (HUFA) synthesis pathway using both biochemical and molecular biological approaches. Fatty acyl desaturase (Fad) and elongase (Elovl) cDNAs were cloned and functional characterization identified them as ∆6 Fad and Elovl5 elongase enzymes, respectively. The ∆6 Fad was equally active toward 18:3n-3 and 18:2n-6, and Elovl5 exhibited elongation activity for C18-20 and C20-22 elongation and a trace of C22-24 activity. The tissue profile of gene expression for ∆6 fad and elovl5 genes, showed brain to have the highest expression of both genes compared to all other tissues. The results of tissue fatty acid analysis showed that the brain contained more docosahexaenoic acid (DHA, 22:6n-3) than flesh, liver and intestine. The HUFA synthesis activity in isolated hepatocytes and enterocytes using [1-(14)C]18:3n-3 as substrate was very low with the only desaturated product detected being 18:4n-3. These findings indicate that L. calcarifer display an essential fatty acid pattern similar to other marine fish in that they appear unable to synthesize HUFA from C18 substrates. High expression of ∆6 fad and elovl5 genes in brain may indicate a role for these enzymes in maintaining high DHA levels in neural tissues through conversion of 20:5n-3.
Fulltext A Review on the Development of Gold and Silver Nanoparticles-Based Biosensor as a Detection Strategy of Emerging and Pathogenic RNA Virus

Ibrahim N, Jamaluddin ND, Tan LL, Mohd Yusof NY

Sensors (Basel), 2021 Jul 28;21(15).
PMID: 34372350 DOI: 10.3390/s21155114

The emergence of highly pathogenic and deadly human coronaviruses, namely SARS-CoV and MERS-CoV within the past two decades and currently SARS-CoV-2, have resulted in millions of human death across the world. In addition, other human viral diseases, such as mosquito borne-viral diseases and blood-borne viruses, also contribute to a higher risk of death in severe cases. To date, there is no specific drug or medicine available to cure these human viral diseases. Therefore, the early and rapid detection without compromising the test accuracy is required in order to provide a suitable treatment for the containment of the diseases. Recently, nanomaterials-based biosensors have attracted enormous interest due to their biological activities and unique sensing properties, which enable the detection of analytes such as nucleic acid (DNA or RNA), aptamers, and proteins in clinical samples. In addition, the advances of nanotechnologies also enable the development of miniaturized detection systems for point-of-care (POC) biosensors, which could be a new strategy for detecting human viral diseases. The detection of virus-specific genes by using single-stranded DNA (ssDNA) probes has become a particular interest due to their higher sensitivity and specificity compared to immunological methods based on antibody or antigen for early diagnosis of viral infection. Hence, this review has been developed to provide an overview of the current development of nanoparticles-based biosensors that target pathogenic RNA viruses, toward a robust and effective detection strategy of the existing or newly emerging human viral diseases such as SARS-CoV-2. This review emphasizes the nanoparticles-based biosensors developed using noble metals such as gold (Au) and silver (Ag) by virtue of their powerful characteristics as a signal amplifier or enhancer in the detection of nucleic acid. In addition, this review provides a broad knowledge with respect to several analytical methods involved in the development of nanoparticles-based biosensors for the detection of viral nucleic acid using both optical and electrochemical techniques.
Rapid and sensitive detection of Salmonella in agro-Food and environmental samples: A review of advances in rapid tests and biosensors

Oslan SNH, Yusof NY, Lim SJ, Ahmad NH

J Microbiol Methods, 2024 Apr;219:106897.
PMID: 38342249 DOI: 10.1016/j.mimet.2024.106897

Salmonella is as an intracellular bacterium, causing many human fatalities when the host-specific serotypes reach the host gastrointestinal tract. Nontyphoidal Salmonella are responsible for numerous foodborne outbreaks and product recalls worldwide whereas typhoidal Salmonella are responsible for Typhoid fever cases in developing countries. Yet, Salmonella-related foodborne disease outbreaks through its food and water contaminations have urged the advancement of rapid and sensitive Salmonella-detecting methods for public health protection. While conventional detection methods are time-consuming and ineffective for monitoring foodstuffs with short shelf lives, advances in microbiology, molecular biology and biosensor methods have hastened the detection. Here, the review discusses Salmonella pathogenic mechanisms and its detection technology advancements (fundamental concepts, features, implementations, efficiency, benefits, limitations and prospects). The time-efficiency of each rapid test method is discussed in relation to their limit of detections (LODs) and time required from sample enrichment to final data analysis. Importantly, the matrix effects (LODs and sample enrichments) were compared within the methods to potentially speculate Salmonella detection from environmental, clinical or food matrices using certain techniques. Although biotechnological advancements have led to various time-efficient Salmonella-detecting techniques, one should consider the usage of sophisticated equipment to run the analysis by moderately to highly trained personnel. Ultimately, a fast, accurate Salmonella screening that is readily executed by untrained personnels from various matrices, is desired for public health procurement.
Identification and analysis of a prepro-chicken gonadotropin releasing hormone II (preprocGnRH-II) precursor in the Asian seabass, Lates calcarifer, based on an EST-based assessment of its brain transcriptome

Tan SL, Mohd-Adnan A, Mohd-Yusof NY, Forstner MR, Wan KL

Gene, 2008 Mar 31;411(1-2):77-86.
PMID: 18280674 DOI: 10.1016/j.gene.2008.01.008

Using a novel library of 5637 expressed sequence tags (ESTs) from the brain tissue of the Asian seabass (Lates calcarifer), we first characterized the brain transcriptome for this economically important species. The ESTs generated from the brain of L. calcarifer yielded 2410 unique transcripts (UTs) which comprise of 982 consensi and 1428 singletons. Based on database similarity, 1005 UTs (41.7%) can be assigned putative functions and were grouped into 12 functional categories related to the brain function. Amongst others, we have identified genes that are putatively involved in energy metabolism, ion pumps and channels, synapse related genes, neurotransmitter and its receptors, stress induced genes and hormone related genes. Subsequently we selected a putative preprocGnRH-II precursor for further characterization. The complete cDNA sequence of the gene obtained was found to code for an 85-amino acid polypeptide that significantly matched preprocGnRH-II precursor sequences from other vertebrates, and possesses structural characteristics that are similar to that of other species, consisting of a signal peptide (23 residues), a GnRH decapeptide (10 residues), an amidation/proteolytic-processing signal (glycine-lysine-argine) and a GnRH associated peptide (GAP) (49 residues). Phylogenetic analysis showed that this putative L. calcarifer preprocGnRH-II sequence is a member of the subcohort Euteleostei and divergent from the sequences of the subcohort Otocephalan. These findings provide compelling evidence that the putative L. calcarifer preprocGnRH-II precursor obtained in this study is orthologous to that of other vertebrates. The functional prediction of this preprocGnRH-II precursor sequence through in silico analyses emphasizes the effectiveness of the EST approach in gene identification in L. calcarifer.
Fulltext Draft Genome Sequence of the Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolate INF13/18/A, Recovered from Kelantan, Malaysia

Wan Makhtar WR, Mohd Azlan M, Hassan NH, Aziah I, Samsurizal NH, Yusof NY

Microbiol Resour Announc, 2020 Aug 13;9(33).
PMID: 32817162 DOI: 10.1128/MRA.01497-19

We describe here the draft genome sequence and basic characteristics of Escherichia coli isolate INF13/18/A, which was isolated from Universiti Sains Malaysia (USM) Hospital. This isolate was identified as an extended-spectrum β-lactamase-producing Escherichia coli strain harboring the antimicrobial resistance genes TEM, CTX-M-1, and CTX-M-9.
Fulltext Inadequate health literacy on childhood immunization and its predictors among antenatal mothers

Mohamad Yusof NY, Mohd Zulkefli NA, Ismail S, Abd Rashid MF

Malaysian Journal of Medicine and Health Sciences, 2017;13(3):51-59.
MyJurnal

Introduction: Outbreak of vaccine preventable disease still persists despite good coverage of immunization in Malaysia. Health literacy on childhood immunization is one of essential factor for the outbreak to happen. Thus, this study determined the predictors of health literacy on childhood immunization among antenatal mother in Seremban, Negeri Sembilan.
Methodology: A cross sectional study was conducted among 424 antenatal women using a cluster sampling approach. Antenatal women who were Malaysian and not illiterate were chosen in this study. A selfadministered, validated and pretested questionnaire was used to collect data on sociodemographic, socio economic, awareness on immunization, utilization of health care services and health literacy on childhood immunization. The data was analyzed using SPSS version 22.0. Chi Square test was used in bivariate analysis and multiple logistic regression was used to determine the predictors of inadequate health literacy on childhood immunization.
Result: Out of 362 respondents, 81.2% were inadequate health literacy. The predictors were maternal education (AOR= 2.608, 95% CI 1.477-4.604), parity (AOR= 1.067, 95% CI 1.103-3.876), residential area (AOR= 2.344, 95% CI 1.184-4.641) and utilization of government hospital (AOR= 2.344, 95% CI 1.184-4.641).
Conclusion: Accessibility of health education with regard to immunization need to be strengthen among primigravida, low education and those staying in rural area. In addition, health education also needs to emphasize on the individual that is employed and low economic status with underutilization of government hospital. A simplified education material with interesting pictures and using visual aids help illiterate people for better understanding.
Study site: Klinik Kesihatan, Seremban district, Negeri Sembilan, Malaysia
Fulltext Biosynthesis of Saxitoxin in Marine Dinoflagellates: An Omics Perspective

Akbar MA, Mohd Yusof NY, Tahir NI, Ahmad A, Usup G, Sahrani FK, et al.

Mar Drugs, 2020 Feb 05;18(2).
PMID: 32033403 DOI: 10.3390/md18020103

Saxitoxin is an alkaloid neurotoxin originally isolated from the clam Saxidomus giganteus in 1957. This group of neurotoxins is produced by several species of freshwater cyanobacteria and marine dinoflagellates. The saxitoxin biosynthesis pathway was described for the first time in the 1980s and, since then, it was studied in more than seven cyanobacterial genera, comprising 26 genes that form a cluster ranging from 25.7 kb to 35 kb in sequence length. Due to the complexity of the genomic landscape, saxitoxin biosynthesis in dinoflagellates remains unknown. In order to reveal and understand the dynamics of the activity in such impressive unicellular organisms with a complex genome, a strategy that can carefully engage them in a systems view is necessary. Advances in omics technology (the collective tools of biological sciences) facilitated high-throughput studies of the genome, transcriptome, proteome, and metabolome of dinoflagellates. The omics approach was utilized to address saxitoxin-producing dinoflagellates in response to environmental stresses to improve understanding of dinoflagellates gene-environment interactions. Therefore, in this review, the progress in understanding dinoflagellate saxitoxin biosynthesis using an omics approach is emphasized. Further potential applications of metabolomics and genomics to unravel novel insights into saxitoxin biosynthesis in dinoflagellates are also reviewed.
Fulltext Isolation of Leptospira kmetyi from residential areas of patients with leptospirosis in Kelantan, Malaysia

Mohd Ali MR, Mohamad Safiee AW, Yusof NY, Fauzi MH, Yean Yean C, Ismail N

J Infect Public Health, 2017 12 23;11(4):578-580.
PMID: 29277333 DOI: 10.1016/j.jiph.2017.12.008

BACKGROUND: Environmental sampling provides important information that enhances the understanding of the leptospiral human-environment-animal relationship. Several studies have described the distribution of Leptospira in the environment. However, more targeted sites, that is, areas surrounding leptospirosis patients' houses, remain under-explored. Therefore, this study aims to detect the presence of Leptospira spp. in the residential areas of patients with leptospirosis.
METHODS: Soil and water samples near leptospirosis patients' residences were collected, processed and cultured into EMJH media. Partial 16S rRNA gene sequencing was performed to confirm the identity of Leptospira.
RESULTS: EMJH culture and partial 16S rRNA gene sequencing revealed predominant growth of pathogenic Leptospira kmetyi (17%, n=7/42). All tested locations had at least one Leptospira sp., mostly from the soil samples.
CONCLUSION: More than one species of Leptospira may be present in a sampling area. The most common environmental isolates were pathogenic L. kmetyi.
Fulltext Sequence, Secondary Structure, and Phylogenetic Conservation of MicroRNAs in Arabidopsis thaliana

Mazhar MW, Yusof NY, Shaheen T, Saif S, Raza A, Mazhar F

Bioinform Biol Insights, 2022;16:11779322221142116.
PMID: 36570328 DOI: 10.1177/11779322221142116

MicroRNAs are small non-coding RNA molecules that are produced in a cell endogenously. They are made up of 18 to 26 nucleotides in strength. Due to their evolutionary conserved nature, most of the miRNAs provide a logical basis for the prediction of novel miRNAs and their clusters in plants such as sunflowers related to the Asteraceae family. In addition, they participate in different biological processes of plants, including cell signaling and metabolism, development, growth, and tolerance to (biotic and abiotic) stresses. In this study profiling, conservation and characterization of novel miRNA possessing conserved nature in various plants and their targets annotation in sunflower (Asteraceae) were obtained by using various computational tools and software. As a result, we looked at 152 microRNAs in Arabidopsis thaliana that had already been predicted. Drought tolerance stress is mediated by these 152 non-coding RNAs. Following that, we used local alignment to predict novel microRNAs that were specific to Helianthus annuus. We used BLAST to do a local alignment, and we chose sequences with an identity of 80% to 100%. MIR156a, MIR164a, MIR165a, MIR170, MIR172a, MIR172b, MIR319a, MIR393a, MIR394a, MIR399a, MIR156h, and MIR414 are the new anticipated miRNAs. We used MFold to predict the secondary structure of new microRNAs. We used conservation analysis and phylogenetic analysis against a variety of organisms, including Gossypium hirsutum, H. annuus, A. thaliana, Triticum aestivum, Saccharum officinarum, Zea mays, Brassica napus, Solanum tuberosum, Solanum lycopersicum, and Oryza sativa, to determine the evolutionary history of these novel non-coding RNAs. Clustal W was used to analyze the evolutionary history of discovered miRNAs.
Electrochemical genosensor based on RNA-responsive human telomeric G-quadruplex DNA: A proof-of-concept with SARS-CoV-2 RNA

Ibrahim N, Gan KB, Mohd Yusof NY, Goh CT, Krupa B N, Tan LL

Talanta, 2024 Jul 01;274:125916.
PMID: 38547835 DOI: 10.1016/j.talanta.2024.125916

In this report, a facile and label-free electrochemical RNA biosensor is developed by exploiting methylene blue (MB) as an electroactive positive ligand of G-quadruplex. The electrochemical response mechanism of the nucleic acid assay was based on the change in differential pulse voltammetry (DPV) signal of adsorbed MB on the immobilized human telomeric G-quadruplex DNA with a loop that is complementary to the target RNA. Hybridization between synthetic positive control RNA and G-quadruplex DNA probe on the transducer platform rendered a conformational change of G-quadruplex to double-stranded DNA (dsDNA), and increased the redox current of cationic MB π planar ligand at the sensing interface, thereby the electrochemical signal of the MB-adsorbed duplex is proportional to the concentration of target RNA, with SARS-CoV-2 (COVID-19) RNA as the model. Under optimal conditions, the target RNA can be detected in a linear range from 1 zM to 1 μM with a limit of detection (LOD) obtained at 0.59 zM for synthetic target RNA and as low as 1.4 copy number for positive control plasmid. This genosensor exhibited high selectivity towards SARS-CoV-2 RNA over other RNA nucleotides, such as SARS-CoV and MERS-CoV. The electrochemical RNA biosensor showed DPV signal, which was proportional to the 2019-nCoV_N_positive control plasmid from 2 to 200000 copies (R2 = 0.978). A good correlation between the genosensor and qRT-PCR gold standard was attained for the detection of SARS-CoV-2 RNA in terms of viral copy number in clinical samples from upper respiratory specimens.
Fulltext Complete Genome Sequence of Leptospira kmetyi LS 001/16, Isolated from a Soil Sample Associated with a Leptospirosis Patient in Kelantan, Malaysia

Yusof NY, Muhammad Yusoff F, Muhammad Harish S, Ahmad MN, Khalid MF, Mohd Nor F, et al.

Microbiol Resour Announc, 2019 Jul 11;8(28).
PMID: 31296668 DOI: 10.1128/MRA.00015-19

The Gram-negative pathogenic spirochetal bacteria Leptospira spp. cause leptospirosis in humans and livestock animals. Leptospira kmetyi strain LS 001/16 was isolated from a soil sample associated with a leptospirosis patient in Kelantan, which is among the states in Malaysia with a high reported number of disease cases. Here, we report the complete genome sequence of Leptospira kmetyi strain LS 001/16.
Fulltext Sandwich-Type DNA Micro-Optode Based on Gold-Latex Spheres Label for Reflectance Dengue Virus Detection

Jeningsih, Tan LL, Ulianas A, Heng LY, Mazlan NF, Jamaluddin ND, et al.

Sensors (Basel), 2020 Mar 25;20(7).
PMID: 32218202 DOI: 10.3390/s20071820

A DNA micro-optode for dengue virus detection was developed based on the sandwich hybridization strategy of DNAs on succinimide-functionalized poly(n-butyl acrylate) (poly(nBA-NAS)) microspheres. Gold nanoparticles (AuNPs) with an average diameter of ~20 nm were synthesized using a centrifugation-based method and adsorbed on the submicrometer-sized polyelectrolyte-coated poly(styrene-co-acrylic acid) (PSA) latex particles via an electrostatic method. The AuNP-latex spheres were attached to the thiolated reporter probe (rDNA) by Au-thiol binding to functionalize as an optical gold-latex-rDNA label. The one-step sandwich hybridization recognition involved a pair of a DNA probe, i.e., capture probe (pDNA), and AuNP-PSA reporter label that flanked the target DNA (complementary DNA (cDNA)). The concentration of dengue virus cDNA was optically transduced by immobilized AuNP-PSA-rDNA conjugates as the DNA micro-optode exhibited a violet hue upon the DNA sandwich hybridization reaction, which could be monitored by a fiber-optic reflectance spectrophotometer at 637 nm. The optical genosensor showed a linear reflectance response over a wide cDNA concentration range from 1.0 × 10-21 M to 1.0 × 10-12 M cDNA (R2 = 0.9807) with a limit of detection (LOD) of 1 × 10-29 M. The DNA biosensor was reusable for three consecutive applications after regeneration with mild sodium hydroxide. The sandwich-type optical biosensor was well validated with a molecular reverse transcription polymerase chain reaction (RT-PCR) technique for screening of dengue virus in clinical samples, e.g., serum, urine, and saliva from dengue virus-infected patients under informed consent.
Fulltext Colorimetric Approach for Nucleic Acid Salmonella spp. Detection: A Systematic Review

Ahmad Faris AN, Ahmad Najib M, Mohd Nazri MN, Hamzah ASA, Aziah I, Yusof NY, et al.

Int J Environ Res Public Health, 2022 Aug 25;19(17).
PMID: 36078284 DOI: 10.3390/ijerph191710570

Water- and food-related health issues have received a lot of attention recently because food-poisoning bacteria, in particular, are becoming serious threats to human health. Currently, techniques used to detect these bacteria are time-consuming and laborious. To overcome these challenges, the colorimetric strategy is attractive because it provides simple, rapid and accurate sensing for the detection of Salmonella spp. bacteria. The aim of this study is to review the progress regarding the colorimetric method of nucleic acid for Salmonella detection. A literature search was conducted using three databases (PubMed, Scopus and ScienceDirect). Of the 88 studies identified in our search, 15 were included for further analysis. Salmonella bacteria from different species, such as S. Typhimurium, S. Enteritidis, S. Typhi and S. Paratyphi A, were identified using the colorimetric method. The limit of detection (LoD) was evaluated in two types of concentrations, which were colony-forming unit (CFU) and CFU per mL. The majority of the studies used spiked samples (53%) rather than real samples (33%) to determine the LoDs. More research is needed to assess the sensitivity and specificity of colorimetric nucleic acid in bacterial detection, as well as its potential use in routine diagnosis.
Biochemical and gene expression studies reveal the potential of Aspergillus oryzae-fermented broken rice and brewers' rice water extracts as anti-photoageing agents

Jamaluddin A, Mohd Abd Rahman SM, Abd Manan M, Abd Razak DL, Abd Rashid NY, Abd Ghani A, et al.

Cell Mol Biol (Noisy-le-grand), 2023 Nov 15;69(11):9-16.
PMID: 38015547 DOI: 10.14715/cmb/2023.69.11.2

In this study, UVA- and UVB-irradiated human fibroblasts were used to investigate the anti-photoaging efficacy of two aqueous extracts from Aspergillus oryzae-fermented broken rice (FBR) and brewers' rice (FBrR). As UVA and UVB can damage the dermal and epidermal layers, respectively, two UV radiation approaches were utilised: i) direct UVA irradiation on fibroblasts, and ii) UVB-irradiated keratinocytes indirectly co-cultured with fibroblasts to observe their epithelial-mesenchymal interaction during UVB-induced photoaging. The anti-photoaging properties were tested utilising biochemical tests and quantitative polymerase chain reaction (qPCR). The treatment of UV-irradiated human fibroblasts with FBR and FBrR dramatically downregulates MMP-1 and SFE gene expression. Nonetheless, MMP-1 secretion was inhibited by FBR and FBrR, with more substantial decreases in UVB-treated co-cultures, ranging from 0.76- to 1.89-fold relative to the untreated control. In UVA-treated fibroblasts, however, the elastase-inhibiting activity of FBR and FBrR is up to 1.63-fold and 2.13-fold more potent, respectively. In addition, post-UV irradiation treatment with FBR and FBrR was able to repair and enhance collagen formation in UVA-irradiated fibroblasts. Both FBR and FBrR were able to upregulate elastin gene expression in fibroblasts under both culture conditions, especially at 50 µg/mL. The pro-inflammatory cytokines TNF-, IL-1ß, and IL-6 were likewise lowered by FBR and FBrR, which may have contributed to the anti-photoaging effect of the UVB-treated co-culture. These results reveal that FBR and FBrR inhibit photoaging in human fibroblasts under both UV induction conditions. In conclusion, FBR and FBrR may be attractive bio-ingredients for usage in the cosmetic sector as cosmeceuticals.
Enhancing early warning: A DNA biosensor with polyaniline/graphene nanocomposite for label-free voltammetric detection of saxitoxin-producing harmful algae

Chwan Chuong Chin JJ, Akbar MA, Mohd Yusof NY, Pike A, Goh CT, Mustapha S, et al.

Chemosphere, 2024 Aug 20;364:143114.
PMID: 39154772 DOI: 10.1016/j.chemosphere.2024.143114

Yearly reports of detrimental effects resulting from harmful algal blooms (HAB) are still received in Malaysia and other countries, particularly concerning fish mortality and seafood contamination, both of which bear consequences for the fisheries industry. The underlying reason is the absence of a dependable early warning system. Hence, this research aims to develop a single DNA biosensor that can detect a group of HAB species known for producing saxitoxin (SXT), which is commonly found in Malaysian waters. The screen-printed carbon electrode (SPCE)-based DNA biosensor was fabricated by covalent grafting of the 3' aminated DNA probe of the sxtA4 conserved domain in SXT-producing dinoflagellates on the reverse-phase polymerized polyaniline/graphene (PGN) nanocomposite electrode via carbodiimide linkage. The introduction of a carboxyphenyl layer to the PGN nanotransducing element was essential to augment the carboxylic groups on the graphene (RGO), facilitating attachment with the aminated DNA. The synergistic effect of the asynthesized nanocomposite of PANI and RGO, tremendously enhanced the electron transfer rate of the ferri/ferrocyanide redox probe at the SPCE transducer surface, allowing for the label-free bioanalytical assay of complementary DNA targets. The developed DNA biosensor featuring the capacity to detect a broad range of Alexandrium minutum (A. minutum) cell concentrations, ranging from 10 to 10,000,000 cells L-1. The quantification of A. minutum cells from pure algal culture by the electrochemical DNA biosensor has been well-validated with traditional microscopic techniques. Furthermore, Alexandrium tamiyavanichii, another toxigenic HAB species, exhibited a similar electrochemical characteristic signal to those observed with A. minutum, whilst the biosensor yielded appreciably distinctive results when subjected to a non-toxigenic microalgae species as a negative control, i.e. Isochrysis galbana. A compendium DNA biosensor design and electrochemical detection strategy at laboratory scale serves as a precursor to the potential development of portable device for on-site detection, thus expanding the utility and scope of biosensor technology.
Fulltext A Global Mutational Profile of SARS-CoV-2: A Systematic Review and Meta-Analysis of 368,316 COVID-19 Patients

Yusof W, Irekeola AA, Wada Y, Engku Abd Rahman ENS, Ahmed N, Musa N, et al.

Life (Basel), 2021 Nov 11;11(11).
PMID: 34833100 DOI: 10.3390/life11111224

Since its first detection in December 2019, more than 232 million cases of COVID-19, including 4.7 million deaths, have been reported by the WHO. The SARS-CoV-2 viral genomes have evolved rapidly worldwide, causing the emergence of new variants. This systematic review and meta-analysis was conducted to provide a global mutational profile of SARS-CoV-2 from December 2019 to October 2020. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA), and a study protocol was lodged with PROSPERO. Data from 62 eligible studies involving 368,316 SARS-CoV-2 genomes were analyzed. The mutational data analyzed showed most studies detected mutations in the Spike protein (n = 50), Nucleocapsid phosphoprotein (n = 34), ORF1ab gene (n = 29), 5'-UTR (n = 28) and ORF3a (n = 25). Under the random-effects model, pooled prevalence of SARS-CoV-2 variants was estimated at 95.1% (95% CI; 93.3-96.4%; I2 = 98.952%; p = 0.000) while subgroup meta-analysis by country showed majority of the studies were conducted 'Worldwide' (n = 10), followed by 'Multiple countries' (n = 6) and the USA (n = 5). The estimated prevalence indicated a need to continuously monitor the prevalence of new mutations due to their potential influence on disease severity, transmissibility and vaccine effectiveness.
A review on current diagnostic tools and potential optical absorption spectroscopy for HFMD detection

Mustafa FH, Ismail I, Ahmad Munawar AAZ, Abdul Basir B, Shueb RH, Irekeola AA, et al.

Anal Biochem, 2023 Dec 15;683:115368.
PMID: 37890549 DOI: 10.1016/j.ab.2023.115368

Hand, Foot, and Mouth Disease (HFMD) is an outbreak infectious disease that can easily spread among children under the age of five. The most common causative agents of HFMD are enterovirus 71 (EV71) and coxsackievirus A16 (CVA16), but infection caused by EV71 is more associated with fatalities due to severe neurological disorders. The present diagnosis methods rely on physical examinations by the doctors and further confirmation by laboratories detection methods such as viral culture and polymerase chain reaction. Clinical signs of HFMD infection and other childhood diseases such as chicken pox, and allergies are similar, yet the genetics and pathogenicity of the viruses are substantially different. Thus, there is an urgent need for an early screening of HFMD using an inexpensive and user-friendly device that can directly detect the causative agents of the disease. This paper reviews current HFMD diagnostic methods based on various target types, such as nucleic acid, protein, and whole virus. This was followed by a thorough discussion on the emerging sensing technologies for HFMD detection, including surface plasmon resonance, electrochemical sensor, and surface enhanced Raman spectroscopy. Lastly, optical absorption spectroscopic method was critically discussed and proposed as a promising technology for HFMD screening and detection.
Biochemical and in silico structural characterization of a cold-active arginase from the psychrophilic yeast, Glaciozyma antarctica PI12

Yusof NY, Quay DHX, Kamaruddin S, Jonet MA, Md Illias R, Mahadi NM, et al.

Extremophiles, 2024 Feb 01;28(1):15.
PMID: 38300354 DOI: 10.1007/s00792-024-01333-7

Glaciozyma antarctica PI12 is a psychrophilic yeast isolated from Antarctica. In this work, we describe the heterologous production, biochemical properties and in silico structure analysis of an arginase from this yeast (GaArg). GaArg is a metalloenzyme that catalyses the hydrolysis of L-arginine to L-ornithine and urea. The cDNA of GaArg was reversed transcribed, cloned, expressed and purified as a recombinant protein in Escherichia coli. The purified protein was active against L-arginine as its substrate in a reaction at 20 °C, pH 9. At 10-35 °C and pH 7-9, the catalytic activity of the protein was still present around 50%. Mn2+, Ni2+, Co2+ and K+ were able to enhance the enzyme activity more than two-fold, while GaArg is most sensitive to SDS, EDTA and DTT. The predicted structure model of GaArg showed a very similar overall fold with other known arginases. GaArg possesses predominantly smaller and uncharged amino acids, fewer salt bridges, hydrogen bonds and hydrophobic interactions compared to the other counterparts. GaArg is the first reported arginase that is cold-active, facilitated by unique structural characteristics for its adaptation of catalytic functions at low-temperature environments. The structure and function of cold-active GaArg provide insights into the potentiality of new applications in various biotechnology and pharmaceutical industries.
Fulltext Global Prevalence of Nosocomial Multidrug-Resistant Klebsiella pneumoniae: A Systematic Review and Meta-Analysis

Mohd Asri NA, Ahmad S, Mohamud R, Mohd Hanafi N, Mohd Zaidi NF, Irekeola AA, et al.

Antibiotics (Basel), 2021 Dec 08;10(12).
PMID: 34943720 DOI: 10.3390/antibiotics10121508

The emergence of nosocomial multidrug-resistant Klebsiella pneumoniae is an escalating public health threat worldwide. The prevalence of nosocomial infections due to K. pneumoniae was recorded up to 10%. In this systematic review and meta-analysis, which were conducted according to the guidelines of Preferred Reporting Items for Systematic Review and Meta-Analysis, 1092 articles were screened from four databases of which 47 studies fulfilled the selected criteria. By performing a random-effect model, the pooled prevalence of nosocomial multidrug-resistant K. pneumoniae was estimated at 32.8% (95% CI, 23.6-43.6), with high heterogeneity (I2 98.29%, p-value < 0.001). The estimated prevalence of this pathogen and a few related studies were discussed, raising awareness of the spread of multidrug-resistant K. pneumoniae in the healthcare setting. The emergence of nosocomial multidrug-resistant K. pneumoniae is expected to increase globally in the future, and the best treatments for treating and preventing this pathogen should be acknowledged by healthcare staff.

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links