Displaying publications 1 - 20 of 24 in total

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  1. Chin SW, Azman AS, Tan JW
    Health Sci Rep, 2024 Jul;7(7):e2251.
    PMID: 39015423 DOI: 10.1002/hsr2.2251
    BACKGROUND AND AIMS: The difficulty in treating chronic wounds due to the prolonged inflammation stage has affected a staggering 6.5 million people, accompanied by 25 billion USD annually in the United States alone. A 1.9% rise in chronic wound prevalence among Medicare beneficiaries was reported from 2014 to 2019. Besides, the global wound care market values were anticipated to increase from USD 20.18 billion in 2022 to USD 30.52 billion in 2030, suggesting an expected rise in chronic wounds financial burdens. The lack of feasibility in using traditional dry wound dressings sparks hydrogel development as an alternative approach to tackling chronic wounds. Since ancient times, honey has been used to treat wounds, including burns, and ongoing studies have also demonstrated its wound-healing capabilities on cellular and animal models. However, the fluidity and low mechanical strength in honey hydrogel necessitate the incorporation of other polymers. Therefore, this review aims to unravel the characteristics and feasibility of natural (chitosan and gelatin) and synthetic (polyvinyl alcohol and polyethylene glycol) polymers to be incorporated in the honey hydrogel.

    METHODS: Relevant articles were identified from databases (PubMed, Google Scholar, and Science Direct) using keywords related to honey, hydrogel, and polymers. Relevant data from selected studies were synthesized narratively and reported following a structured narrative format.

    RESULTS: The importance of honey's roles and mechanisms of action in wound dressings were discussed. Notable studies concerning honey hydrogels with diverse polymers were also included in this article to provide a better perspective on fabricating customized hydrogel wound dressings for various types of wounds in the future.

    CONCLUSION: Honey's incapability to stand alone in hydrogel requires the incorporation of natural and synthetic polymers into the hydrogel. With this review, it is hoped that the fabrication and commercialization of the desired honey composite hydrogel for wound treatment could be brought forth.

  2. Azman AS, Mawang CI, Khairat JE, AbuBakar S
    Int Microbiol, 2019 Dec;22(4):403-409.
    PMID: 30847714 DOI: 10.1007/s10123-019-00066-4
    A biofilm is a community of microorganisms attached to a surface and embedded in a matrix of extracellular polymeric substances. Biofilms confer resistance towards conventional antibiotic treatments; thus, there is an urgent need for newer and more effective antimicrobial agents that can act against these biofilms. Due to this situation, various studies have been done to investigate the anti-biofilm effects of natural products including bioactive compounds extracted from microorganisms such as Actinobacteria. This review provides an insight into the anti-biofilm potential of Actinobacteria against various pathogenic bacteria, which hopefully provides useful information, guidance, and improvements for future antimicrobial studies. Nevertheless, further research on the anti-biofilm mechanisms and compound modifications to produce more potent anti-biofilm effects are required.
  3. Mawang CI, Azman AS, Fuad AM, Ahamad M
    Biotechnol Rep (Amst), 2021 Dec;32:e00679.
    PMID: 34660214 DOI: 10.1016/j.btre.2021.e00679
    Over the past two decades, various eco-friendly approaches utilizing microbial species to clean up contaminated environments have surfaced. In this aspect, actinobacteria have demonstrated their potential in contaminant degradation. The members of actinobacteria phylum exhibits a cosmopolitan distribution, which means that they can be found widely in both aquatic and terrestrial ecosystems. Actinobacteria play important ecological roles in the environment, such as degrading complex polymers, recycling compounds, and producing bioactive molecules. Hence, using actinobacteria to clean up contaminants is an attractive method in the field of biotechnology. This can be achieved through the green technology of bioaugmentation, whereby the degradative capacity of contaminated areas can be greatly improved through the introduction of specific microorganisms. This review describes actinobacteria as an eco-friendly and a promising technology for the bioaugmentation of contaminants, with focus on pesticides and heavy metals.
  4. Zainuddin MS, Bhuvanendran S, Radhakrishnan AK, Azman AS
    J Alzheimers Dis Rep, 2023;7(1):1335-1350.
    PMID: 38143777 DOI: 10.3233/ADR-230065
    BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease that is characterized as rapid and progressive cognitive decline affecting 26 million people worldwide. Although immunotherapies are ideal, its clinical safety and effectiveness are controversial, hence, treatments are still reliant on symptomatic medications. Concurrently, the Streptomyces genus has attracted attention given its pharmaceutically beneficial secondary metabolites to treat neurodegenerative diseases.

    OBJECTIVE: To present secondary metabolites from Streptomyces sp. with regulatory effects on proteins and identified prospective target proteins for AD treatment.

    METHODS: Research articles published between 2010 and 2021 were collected from five databases and 83 relevant research articles were identified. Post-screening, only 12 research articles on AD-related proteins were selected for further review. Bioinformatics analyses were performed through the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) network, PANTHER Go-Slim classification system (PANTHER17.0), and Kyoto Encyclopedia of Genes and Genomes (KEGG) Mapper.

    RESULTS: A total of 20 target proteins were identified from the 12 shortlisted articles. Amyloid-β, BACE1, Nrf-2, Beclin-1, and ATG5 were identified as the potential target proteins, given their role in initiating AD, mitigating neuroinflammation, and autophagy. Besides, 10 compounds from Streptomyces sp., including rapamycin, alborixin, enterocin, bonnevillamides D and E, caniferolide A, anhydroexfoliamycin, rhizolutin, streptocyclinone A and B, were identified to exhibit considerable regulatory effects on these target proteins.

    CONCLUSIONS: The review highlights several prospective target proteins that can be regulated through treatments with Streptomyces sp. compounds to prevent AD's early stages and progression. Further identification of Streptomyces sp. compounds with potential anti-AD properties is recommended.

  5. Tang MC, Wong KH, Azman AS, Lani R
    Animal Model Exp Med, 2024 Jul 10.
    PMID: 38987937 DOI: 10.1002/ame2.12471
    Vector-borne diseases caused by arthropod-borne viruses (arboviruses) are a considerable challenge to public health globally. Mosquito-borne arboviruses, such as Chikungunya, Dengue, and Zika viruses, cause a range of human illnesses and may be fatal. Currently, efforts to control these diseases still face challenges due to growing vector resistance towards insecticides, urbanization, and limited effective antiviral treatments and vaccines. Animal models are crucial in antiviral research on mosquito-borne arboviruses, playing a role in understanding disease mechanisms, vaccine development, and toxicity testing, but the application of animal models still faces the challenges of ethical considerations and animal-to-human translational success. Genetically engineered mouse models, hamster models and non-human primate (NHP) are currently used in arbovirus research, but new models such as tree shrews and novel humanized mice are emerging. In the context of Malaysian research, the use of long-tailed macaques as potential NHP models for arbovirus research is possible; however, it faces the ethical dilemma of using an endangered species for scientific purposes. Overall, animal models play a crucial role in advancing infectious disease research, but a balance between medical research and species conservation must be upheld.
  6. Lee LH, Azman AS, Zainal N, Yin WF, Mutalib NA, Chan KG
    Int J Syst Evol Microbiol, 2015 Mar;65(Pt 3):996-1002.
    PMID: 25563924 DOI: 10.1099/ijs.0.000053
    Strain MUSC 117(T) was isolated from mangrove soil of the Tanjung Lumpur forest in Pahang, Malaysia. This bacterium was yellowish-white pigmented, Gram-staining-positive, rod-coccus shaped and non-motile. On the basis of 16S rRNA gene sequence, strain MUSC 117(T) exhibited highest sequence similarity to Sinomonas atrocyanea DSM 20127(T) (98.0 %), Sinomonas albida LC13(T) (97.9 %) and Sinomonas soli CW 59(T) (97.8 %), and lower (<97.6 %) sequence similarity to other species of the genus Sinomonas. DNA-DNA hybridization experiments revealed a low level of DNA-DNA relatedness (less than 27 %) between strain MUSC 117(T) and closely related species. Chemotaxonomically, the peptidoglycan type was A3α, containing the amino acids lysine, serine, glycine, alanine, glutamic acid and muramic acid. The whole-cell sugars detected were rhamnose, ribose, glucose, galactose and a smaller amount of mannose. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and five unidentified glycolipids. The major fatty acids (>10.0 %) of the cell membrane were anteiso-C15 : 0 (39.4 %), C18 : 1ω7c (17.7 %), anteiso-C17 : 0 (17.2 %) and iso-C16 : 0 (11.4 %). The predominant respiratory quinones detected were MK-9(H2) and MK-9. The DNA G+C content was 67.3 mol%. A comparison of BOX-PCR fingerprints indicated that strain MUSC 117(T) represented a unique DNA profile. Results based on a polyphasic approach showed that strain MUSC 117(T) represents a novel species of the genus Sinomonas, for which the name Sinomonas humi sp. nov. is proposed. The type strain of Sinomonas humi sp. nov. is MUSC 117(T) ( = DSM 29362(T) = MCCC 1K00410(T) = NBRC 110653(T)).
  7. Lee LH, Azman AS, Zainal N, Eng SK, Mutalib NA, Yin WF, et al.
    Int J Syst Evol Microbiol, 2014 Oct;64(Pt 10):3513-3519.
    PMID: 25056298 DOI: 10.1099/ijs.0.062414-0
    Strain MUSC 115(T) was isolated from mangrove soil of the Tanjung Lumpur river in the state of Pahang, Peninsular Malaysia. Cells of this strain stained Gram-positive and were non-spore-forming, short rods that formed yellowish-white colonies on different agar media. The taxonomy of strain MUSC 115(T) was studied by a polyphasic approach, and the organism showed a range of phylogenetic and chemotaxonomic properties consistent with those of the genus Microbacterium. The cell-wall peptidoglycan was of type B2β, containing the amino acids ornithine, alanine, glycine, glutamic acid and homoserine. The muramic acid was of the N-glycolyl form. The predominant menaquinones detected were MK-12, MK-13 and MK-11. The polar lipids consisted of phosphatidylglycerol, phosphoglycolipid, diphosphatidylglycerol, two unidentified lipids, three unidentified phospholipids and four unidentified glycolipids. The major fatty acids of the cell membrane were anteiso-C15:0 and anteiso-C17:0. The whole-cell sugars detected were ribose, glucose, mannose and galactose. Based on the 16S rRNA gene sequence, strain MUSC 115(T) showed the highest sequence similarity to Microbacterium immunditiarum SK 18(T) (98.1%), M. ulmi XIL02(T) (97.8%) and M. arborescens DSM 20754(T) (97.5%) and lower sequence similarity to strains of other species of the genus Microbacterium. DNA-DNA hybridization experiments revealed a low level of DNA-DNA relatedness (less than 24%) between strain MUSC 115(T) and the type strains of closely related species. Furthermore, BOX-PCR fingerprint comparison also indicated that strain MUSC 115(T) represented a unique DNA profile. The DNA G+C content determined was 70.9 ± 0.7 mol%, which is lower than that of M. immunditiarum SK 18(T). Based on the combination of genotypic and phenotypic data, it is proposed that strain MUSC 115(T) represents a novel species of the genus Microbacterium, for which the name Microbacterium mangrovi sp. nov. is proposed. The type strain is MUSC 115(T) ( = MCCC 1K00251(T) = DSM 28240(T) = NBRC 110089(T)).
  8. Lee LH, Zainal N, Azman AS, Eng SK, Ab Mutalib NS, Yin WF, et al.
    Int J Syst Evol Microbiol, 2014 Sep;64(Pt 9):3297-306.
    PMID: 24994773 DOI: 10.1099/ijs.0.065045-0
    Two novel actinobacteria, strains MUSC 135(T) and MUSC 137, were isolated from mangrove soil at Tanjung Lumpur, Malaysia. The 16S rRNA gene sequence similarity and DNA-DNA relatedness between strains MUSC 135(T) and MUSC 137 were 100 % and 83±3.2 %, confirming that these two strains should be classified in the same species. Strain MUSC 135(T) exhibited a broad-spectrum bacteriocin against the pathogens meticillin-resistant Staphylococcus aureus (MRSA) strain ATCC BAA-44, Salmonella typhi ATCC 19430(T) and Aeromonas hydrophila ATCC 7966(T). A polyphasic approach was used to study the taxonomy of MUSC 135(T), and it showed a range of phylogenetic and chemotaxonomic properties consistent with those of the genus Streptomyces. The diamino acid of the cell-wall peptidoglycan was ll-diaminopimelic acid. The predominant menaquinones were MK-9(H6), MK-9(H4) and MK-9(H8). Polar lipids detected were a lipid, an aminolipid, a phospholipid, phosphatidylinositol, phosphatidylethanolamine and two glycolipids. The predominant cellular fatty acids (>10.0 %) were anteiso-C15 : 0 (20.8 %), iso-C16 : 0 (18.0 %), iso-C15 : 0 (12.2 %) and anteiso-C17 : 0 (11.6 %). The whole-cell sugars were ribose, glucose and mannose. These results suggested that MUSC 135(T) should be placed within the genus Streptomyces. Phylogenetic analysis based on the 16S rRNA gene sequence exhibited that the most closely related strains were Streptomyces cinereospinus NBRC 15397(T) (99.18 % similarity), Streptomyces mexicanus NBRC 100915(T) (99.17 %) and Streptomyces coeruleofuscus NBRC 12757(T) (98.97 %). DNA-DNA relatedness between MUSC 135(T) and closely related type strains ranged from 26.3±2.1 to 49.6±2.5 %. BOX-PCR fingerprint comparisons showed that MUSC 135(T) exhibited a unique DNA profile. The DNA G+C content determined was 70.7±0.3 mol%. Based on our polyphasic study of MUSC 135(T), the strain merits assignment to a novel species, for which the name Streptomyces pluripotens sp. nov. is proposed. The type strain is MUSC 135(T) ( = MCCC 1K00252(T) = DSM 42140(T)).
  9. Lee LH, Azman AS, Zainal N, Eng SK, Fang CM, Hong K, et al.
    Int J Syst Evol Microbiol, 2014 Apr;64(Pt 4):1194-201.
    PMID: 24408529 DOI: 10.1099/ijs.0.059014-0
    A novel bacterium, strain MUSC 273(T), was isolated from mangrove sediments of the Tanjung Lumpur river in the state of Pahang in peninsular Malaysia. The bacterium was yellow-pigmented, Gram-negative, rod-shaped and non-spore-forming. The taxonomy of strain MUSC 273(T) was studied by a polyphasic approach and the organism showed a range of phenotypic and chemotaxonomic properties consistent with those of the genus Novosphingobium. The 16S rRNA gene sequence of strain MUSC 273(T) showed the highest sequence similarity to those of Novosphingobium indicum H25(T) (96.8 %), N. naphthalenivorans TUT562(T) (96.4 %) and N. soli CC-TPE-1(T) (95.9 %) and lower sequence similarity to members of all other species of the genus Novosphingobium. Furthermore, in phylogenetic analyses based on the 16S rRNA gene sequence, strain MUSC 273(T) formed a distinct cluster with members of the genus Novosphingobium. DNA-DNA relatedness of strain MUSC 273(T) to the type strains of the most closely related species, N. indicum MCCC 1A01080(T) and N. naphthalenivorans DSM 18518(T), was 29.2 % (reciprocal 31.0 %) and 17 % (reciprocal 18 %), respectively. The major respiratory quinone was ubiquinone Q-10, the major polyamine was spermidine and the DNA G+C content was 63.3±0.1 mol%. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine and sphingoglycolipid. The major fatty acids were C18 : 1ω7c, C17 : 1ω6c, C16 : 0, C15 : 0 2-OH and C16 : 1ω7c. Comparison of BOX-PCR fingerprints indicated that strain MUSC 273(T) represented a unique DNA profile. The combined genotypic and phenotypic data showed that strain MUSC 273(T) represents a novel species of the genus Novosphingobium, for which the name Novosphingobium malaysiense sp. nov. is proposed. The type strain is MUSC 273(T) ( = DSM 27798(T) = MCCC 1A00645(T) = NBRC 109947(T)).
  10. Lee LH, Zainal N, Azman AS, Mutalib NA, Hong K, Chan KG
    Int J Syst Evol Microbiol, 2014 May;64(Pt 5):1461-1467.
    PMID: 24449791 DOI: 10.1099/ijs.0.058701-0
    A novel actinobacterial strain, designated MUSC 201T, was isolated from a mangrove soil collected from Kuantan, the capital city of Pahang State in Malaysia. The taxonomic status of this strain was determined using a polyphasic approach. Comparative 16S rRNA gene sequence analysis revealed that strain MUSC 201T represented a novel lineage within the class Actinobacteria. Strain MUSC 201T formed a distinct clade in the family Nocardioidaceae and was most closely related to the members of the genera Nocardioides (16S rRNA gene sequence similarity, 91.9-95.1%), Aeromicrobium (92.7-94.6%), Marmoricola (92.5-93.1%) and Kribbella (91.5-92.4%). The cells of this strain were irregular coccoid to short rod shaped. The peptidoglycan contained ll-diaminopimelic acid as diagnostic diamino acid and the peptidoglycan type was A3γ. The peptidoglycan cell wall contained ll-diaminopimelic acid, glycine, glutamic acid and alanine in a molar ratio of 1.5:0.9:1.0:1.5. The cell-wall sugars were galactose and rhamnose. The predominant menaquinone was MK-9(H4). The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, glycolipid and four unknown phospholipids. The major cellular fatty acids were C18:1ω9c (30.8%), C16:0 (24.1%), and 10-methyl C18:0 (13.9%). The DNA G+C content was 72.0±0.1 mol%. On the basis of phylogenetic and phenotypic differences from members of the genera of the family Nocardioidaceae, a novel genus and species, Mumia flava gen. nov., sp. nov. are proposed. The type strain of Mumia flava is MUSC 201T (=DSM 27763T=MCCC 1A00646T=NBRC 109973T).
  11. Azman AS, Othman I, Velu SS, Chan KG, Lee LH
    Front Microbiol, 2015;6:856.
    PMID: 26347734 DOI: 10.3389/fmicb.2015.00856
    Actinobacteria are one of the most important and efficient groups of natural metabolite producers. The genus Streptomyces have been recognized as prolific producers of useful natural compounds as they produced more than half of the naturally-occurring antibiotics isolated to-date and continue as the primary source of new bioactive compounds. Lately, Streptomyces groups isolated from different environments produced the same types of compound, possibly due to frequent genetic exchanges between species. As a result, there is a dramatic increase in demand to look for new compounds which have pharmacological properties from another group of Actinobacteria, known as rare actinobacteria; which is isolated from special environments such as mangrove. Recently, mangrove ecosystem is becoming a hot spot for studies of bioactivities and the discovery of natural products. Many novel compounds discovered from the novel rare actinobacteria have been proven as potential new drugs in medical and pharmaceutical industries such as antibiotics, antimicrobials, antibacterials, anticancer, and antifungals. This review article highlights the latest studies on the discovery of natural compounds from the novel mangrove rare actinobacteria and provides insight on the impact of these findings.
  12. Azman AS, Zainal N, Mutalib NA, Yin WF, Chan KG, Lee LH
    Int J Syst Evol Microbiol, 2016 Feb;66(2):554-561.
    PMID: 26556816 DOI: 10.1099/ijsem.0.000753
    A novel actinobacterial strain, MUSC 78T, was isolated from a mangrove soil collected from Peninsular Malaysia. The taxonomic status of this strain was determined using a polyphasic approach. Comparative 16S rRNA gene sequence analysis revealed that strain MUSC 78T represented a novel lineage within the class Actinobacteria. Strain MUSC 78T formed a distinct clade in the family Intrasporangiaceae and was related most closely to members of the genera Terrabacter (98.3-96.8 % 16S rRNA gene sequence similarity), Intrasporangium (98.2-96.8 %), Humibacillus (97.2 %), Janibacter (97.0-95.3 %), Terracoccus (96.8 %), Kribbia (96.6 %), Phycicoccus (96.2-94.7 %), Knoellia (96.1-94.8 %), Tetrasphaera (96.0-94.9 %) and Lapillicoccus (95.9 %). Cells were irregular rod-shaped or cocci and stained Gram-positive. The cell-wall peptidoglycan type was A3γ, with ll-diaminopimelic acid as the diagnostic diamino acid. The main cell-wall sugar was mannose and lower amounts of galactose and rhamnose were present. The predominant menaquinone was MK-8(H4). The polar lipid profile consisted of phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, diphosphatidylglycerol and phosphoglycolipid. The predominant fatty acids were iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0. The DNA G+C content was 73.1 mol%. Based on this polyphasic study, MUSC 78T exhibited phylogenetic and phenotypic differences from members of the genera of the family Intrasporangiaceae, and therefore a novel species of a new genus, Monashia flava gen. nov., sp. nov., is proposed. The type strain of Monashia flava is MUSC 78T ( = DSM 29621T = MCCC 1K00454T = NBRC 110749T).
  13. Chaudhary MN, Lim VC, Sahimin N, Faller EM, Regmi P, Aryal N, et al.
    Travel Med Infect Dis, 2023;54:102620.
    PMID: 37487946 DOI: 10.1016/j.tmaid.2023.102620
    BACKGROUND: Annually, 600 million individuals are affected by food-borne diseases (FBD), alongside 425,000 fatalities. Improving the general public knowledge of, attitudes towards, and practices in, (KAP) food safety is necessary for minimizing FBD transmission. In Malaysia, migrant workers account for 11.1% of the workforce, with a high proportion involved in food and beverage services. Therefore, this study aimed (i) to evaluate the current food safety KAP, and (ii) to identify the strategies to promote food safety awareness, among migrant workers across occupational sectors in Klang Valley.

    METHOD: A survey was conducted with 403 migrant workers through phone interviews and online self-administered questionnaires. Piecewise structural equation modelling and multinomial regression were applied to identify predictor variables for food safety KAP and to explore differences across nationalities.

    RESULTS: The respondents were Nepalese, Filipino and Indonesian. The majority were male, working in the services industry, had completed high school, aged between 30 and 39 years and had worked in Malaysia for less than ten years. Knowledge was significantly correlated with attitudes and practices. Female respondents had lower knowledge and attitude scores while younger respondents had lower knowledge scores. Indonesian and Filipino respondents had lower knowledge and attitudes scores than Nepalese respondents. Understanding food safety information from social media was positively correlated with the respondents' food safety knowledge and practices.

    CONCLUSION: These findings highlighted: (i) the need to target female, younger, Indonesian and Filipino migrant workers, and (ii) the potential of social media to improve public awareness of food safety and hygienic practices.

  14. Mohd Putera NWS, Azman AS, Mohd Zain SN, Yahaya H, Lewis JW, Sahimin N
    Trop Biomed, 2023 Jun 01;40(2):138-151.
    PMID: 37650399 DOI: 10.47665/tb.40.2.003
    The mass movement of migrants to Malaysia for employment is one of the factors contributing to the emergence and re-emergence of infectious diseases in this country. Despite mandatory health screening for migrants seeking employment, prevalence records of infectious diseases amongst migrant populations in Malaysia are still within negligible proportions. Therefore, the present review highlights the incidence, mortality and overall status of infectious diseases amongst migrants' populations in Malaysia, which maybe be useful for impeding exacerbation of inequalities among them and improving our national health system thru robust and effective emergency responses in controlling the prevalent diseases found among these populations and maybe, Malaysian citizens too. Peer-reviewed articles from January 2016 to December 2020 were searched through online platform including SCOPUS, PubMed, Science Direct, and Google Scholar. Non-peer-reviewed reports and publications from ministry and government websites including data from related agencies were also scoured from in order to ensure that there are no cases being overlooked, as most published articles did not have migrants as the research subjects. A total of 29 studies had been selected in the final analysis. Migrants in Malaysia were at higher risk for tuberculosis, malaria, lymphatic filariasis, cholera, leprosy and leptospirosis. Lymphatic filariasis was still endemic among this population while thousand cases of TB and cholera had been reported among them due to cramp living conditions and poor sanitation in their settlements respectively. While malaria had gradually decreased and become sporadic, the influx of migrant workers had led to the rising of imported malaria cases. Low cases of leprosy had been recorded in Malaysia but a significant proportion of it was contributed by migrant workers. As for leptospirosis, studies found that there are prominent cases among migrant workers, which particularly highest within workers with lower educational attainment. Infectious diseases are still prevalent among migrants in Malaysia due to various interplay factors including their working sectors, country of origin, immunization status, type of settlement, impoverished living conditions, and language and cultural barriers that impeding access to health facilities.
  15. Tan KS, Azman AS, Hassandarvish P, Amelia-Yap ZH, Tan TK, Low VL
    Int J Mol Sci, 2023 Aug 03;24(15).
    PMID: 37569772 DOI: 10.3390/ijms241512398
    The insecticidal activity of Streptomyces sp. KSF103 ethyl acetate (EA) extract against mosquitoes is known; however, the underlying mechanism behind this activity remains elusive. In this study, liquid chromatography with tandem mass spectrometry (LC-MS/MS) was employed to investigate changes in the protein profile of Aedes aegypti larvae and adults treated with lethal concentrations of 50 (LC50) EA extract. By comparing the treated and untreated mosquitoes, this study aimed to identify proteins or pathways that exhibit alterations, potentially serving as targets for future insecticide development. Treatment with a lethal concentration of EA extract upregulated 15 proteins in larvae, while in adults, 16 proteins were upregulated, and two proteins were downregulated. These proteins were associated with metabolism, protein regulation/degradation, energy production, cellular organization and structure, enzyme activity, and catalysis, as well as calcium ion transport and homeostasis. Notably, ATP synthase, fructose-bisphosphate aldolase (FBA), and ATP citrate synthase were significantly expressed in both groups. Gene ontology analysis indicated a focus on energy metabolic processes. Molecular docking revealed a strong interaction between dodemorph, selagine (compounds from the EA extract), and FBA, suggesting FBA as a potential protein target for insecticide development. Further studies such as Western blot and transcriptomic analyses are warranted to validate the findings.
  16. Azman AS, Othman I, Fang CM, Chan KG, Goh BH, Lee LH
    Indian J Microbiol, 2017 Jun;57(2):177-187.
    PMID: 28611495 DOI: 10.1007/s12088-016-0627-z
    Mangrove is a complex ecosystem that contains diverse microbial communities, including rare actinobacteria with great potential to produce bioactive compounds. To date, bioactive compounds extracted from mangrove rare actinobacteria have demonstrated diverse biological activities. The discovery of three novel rare actinobacteria by polyphasic approach, namely Microbacterium mangrovi MUSC 115T, Sinomonas humi MUSC 117T and Monashia flava MUSC 78T from mangrove soils at Tanjung Lumpur, Peninsular Malaysia have led to the screening on antibacterial, anticancer and neuroprotective activities. A total of ten different panels of bacteria such as Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300, ATCC 70069, Pseudomonas aeruginosa NRBC 112582 and others were selected for antibacterial screening. Three different neuroprotective models (hypoxia, oxidative stress, dementia) were done using SHSY5Y neuronal cells while two human cancer cells lines, namely human colon cancer cell lines (HT-29) and human cervical carcinoma cell lines (Ca Ski) were utilized for anticancer activity. The result revealed that all extracts exhibited bacteriostatic effects on the bacteria tested. On the other hand, the neuroprotective studies demonstrated M. mangrovi MUSC 115T extract exhibited significant neuroprotective properties in oxidative stress and dementia model while the extract of strain M. flava MUSC 78T was able to protect the SHSY5Y neuronal cells in hypoxia model. Furthermore, the extracts of M. mangrovi MUSC 115T and M. flava MUSC 78T exhibited anticancer effect against Ca Ski cell line. The chemical analysis of the extracts through GC-MS revealed that the majority of the compounds present in all extracts are heterocyclic organic compound that could explain for the observed bioactivities. Therefore, the results obtained in this study suggested that rare actinobacteria discovered from mangrove environment could be potential sources of antibacterial, anticancer and neuroprotective agents.
  17. Khairat JE, Hatta MNA, Abdullah N, Azman AS, Calvin SYM, Syed Hassan S
    Biosci Rep, 2024 Mar 29;44(3).
    PMID: 38372298 DOI: 10.1042/BSR20231827
    Septin proteins are a subfamily of closely related GTP-binding proteins conserved in all species except for higher plants and perform essential biological processes. Septins self-assemble into heptameric or octameric complexes and form higher-order structures such as filaments, rings, or gauzes by end-to-end binding. Their close association with cell membrane components makes them central in regulating critical cellular processes. Due to their organisation and properties, septins function as diffusion barriers and are integral in providing scaffolding to support the membrane's curvature and stability of its components. Septins are also involved in vesicle transport and exocytosis through the plasma membrane by co-localising with exocyst protein complexes. Recently, there have been emerging reports of several human and animal diseases linked to septins and abnormalities in their functions. Most of our understanding of the significance of septins during microbial diseases mainly pertains to their roles in bacterial infections but not viruses. This present review focuses on the known roles of septins in host-viral interactions as detailed by various studies.
  18. Lee LH, Zainal N, Azman AS, Eng SK, Goh BH, Yin WF, et al.
    ScientificWorldJournal, 2014;2014:698178.
    PMID: 25162061 DOI: 10.1155/2014/698178
    The aim of this study was to isolate and identify Actinobacteria from Malaysia mangrove forest and screen them for production of antimicrobial secondary metabolites. Eighty-seven isolates were isolated from soil samples collected at 4 different sites. This is the first report to describe the isolation of Streptomyces, Mycobacterium, Leifsonia, Microbacterium, Sinomonas, Nocardia, Terrabacter, Streptacidiphilus, Micromonospora, Gordonia, and Nocardioides from mangrove in east coast of Malaysia. Of 87 isolates, at least 5 isolates are considered as putative novel taxa. Nine Streptomyces sp. isolates were producing potent antimicrobial secondary metabolites, indicating that Streptomyces isolates are providing high quality metabolites for drug discovery purposes. The discovery of a novel species, Streptomyces pluripotens sp. nov. MUSC 135(T) that produced potent secondary metabolites inhibiting the growth of MRSA, had provided promising metabolites for drug discovery research. The biosynthetic potential of 87 isolates was investigated by the detection of polyketide synthetase (PKS) and nonribosomal polyketide synthetase (NRPS) genes, the hallmarks of secondary metabolites production. Results showed that many isolates were positive for PKS-I (19.5%), PKS-II (42.5%), and NRPS (5.7%) genes, indicating that mangrove Actinobacteria have significant biosynthetic potential. Our results highlighted that mangrove environment represented a rich reservoir for isolation of Actinobacteria, which are potential sources for discovery of antimicrobial secondary metabolites.
  19. Yap PC, Ayuhan N, Woon JJ, Teh CSJ, Lee VS, Azman AS, et al.
    Molecules, 2021 Mar 19;26(6).
    PMID: 33808805 DOI: 10.3390/molecules26061727
    A total of 20 of isolates of lactic acid bacteria (LAB) were selected and screened for antagonistic activity against clinical strains of 30 clinical isolates of extremely drug-resistant (XDR) Acinetobacter baumannii using the well diffusion assay method. Results showed that 50% of the highly LAB strains possessed inhibitory activity against (up to 66%) of the XDR A. baumannii strains tested. The supernatant of the twenty LAB strains was subjected to gas chromatography mass spectrometry (GCMS) revealed that the common compound found in the active isolates against XDR A. baumannii was 3-Isobutyl-2,3,6,7,8,8a-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione, a known potential diketopiperazine group. The molecular docking study against potential antibacterial targets with selected ligands was performed to predict the binding mode of interactions, which is responsible for antibacterial activity. The docking analysis of the potent compounds supported the potential antibacterial activity exhibiting high inhibition constant and binding affinity in silico.
  20. Amelia-Yap ZH, Low VL, Saeung A, Ng FL, Chen CD, Hassandarvish P, et al.
    Sci Rep, 2023 Jan 02;13(1):4.
    PMID: 36593229 DOI: 10.1038/s41598-022-25387-9
    A potentially novel actinobacterium isolated from forest soil, Streptomyces sp. KSF103 was evaluated for its insecticidal effect against several mosquito species namely Aedes aegypti, Aedes albopictus, Anopheles cracens and Culex quinquefasciatus. Mosquito larvae and adults were exposed to various concentrations of the ethyl acetate (EA) extract for 24 h. Considerable mortality was evident after the EA extract treatment for all four important vector mosquitoes. Larvicidal activity of the EA extract resulted in LC50 at 0.045 mg/mL and LC90 at 0.080 mg/mL for Ae. aegypti; LC50 at 0.060 mg/mL and LC90 at 0.247 mg/mL for Ae. albopictus; LC50 at 2.141 mg/mL and LC90 at 6.345 mg/mL for An. cracens; and LC50 at 0.272 mg/mL and LC90 at 0.980 mg/mL for Cx. quinquefasciatus. In adulticidal tests, the EA extract was the most toxic to Ae. albopictus adults (LD50 = 2.445 mg/mL; LD90 = 20.004 mg/mL), followed by An. cracens (LD50 = 5.121 mg/mL; LD90 = 147.854 mg/mL) and then Ae. aegypti (LD50 = 28.873 mg/mL; LD90 = 274.823 mg/mL). Additionally, the EA extract exhibited ovicidal activity against Ae. aegypti (LC50 = 0.715 mg/mL; LC90 = 6.956 mg/mL), Ae. albopictus (LC50 = 0.715 mg/mL; LC90 = 6.956 mg/mL), and An. cracens (LC50 = 0.715 mg/mL; LC90 = 6.956 mg/mL), evaluated up to 168 h post-treatment. It displayed no toxicity on the freshwater microalga Chlorella sp. Beijerinck UMACC 313, marine microalga Chlorella sp. Beijerinck UMACC 258 and the ant Odontoponera denticulata. In conclusion, the EA extract showed promising larvicidal, adulticidal and ovicidal activity against Ae. aegypti, Ae. albopictus, An. cracens, and Cx. quinquefasciatus (larvae only). The results suggest that the EA extract of Streptomyces sp. KSF103 has the potential to be used as an environmental-friendly approach in mosquito control. The current study would serve as an initial step toward complementing microbe-based bioinsecticides for synthetic insecticides against medically important mosquitoes.
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