Displaying publications 201 - 220 of 223 in total

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  1. Zulkefli N, Che Zahari CNM, Sayuti NH, Kamarudin AA, Saad N, Hamezah HS, et al.
    Int J Mol Sci, 2023 Feb 27;24(5).
    PMID: 36902038 DOI: 10.3390/ijms24054607
    Wounds are considered to be a serious problem that affects the healthcare sector in many countries, primarily due to diabetes and obesity. Wounds become worse because of unhealthy lifestyles and habits. Wound healing is a complicated physiological process that is essential for restoring the epithelial barrier after an injury. Numerous studies have reported that flavonoids possess wound-healing properties due to their well-acclaimed anti-inflammatory, angiogenesis, re-epithelialization, and antioxidant effects. They have been shown to be able to act on the wound-healing process via expression of biomarkers respective to the pathways that mainly include Wnt/β-catenin, Hippo, Transforming Growth Factor-beta (TGF-β), Hedgehog, c-Jun N-Terminal Kinase (JNK), NF-E2-related factor 2/antioxidant responsive element (Nrf2/ARE), Nuclear Factor Kappa B (NF-κB), MAPK/ERK, Ras/Raf/MEK/ERK, phosphatidylinositol 3-kinase (PI3K)/Akt, Nitric oxide (NO) pathways, etc. Hence, we have compiled existing evidence on the manipulation of flavonoids towards achieving skin wound healing, together with current limitations and future perspectives in support of these polyphenolic compounds as safe wound-healing agents, in this review.
  2. Zainal Ariffin SH, Lim KW, Megat Abdul Wahab R, Zainal Ariffin Z, Rus Din RD, Shahidan MA, et al.
    PeerJ, 2022;10:e14174.
    PMID: 36275474 DOI: 10.7717/peerj.14174
    BACKGROUND: There have been promising results published regarding the potential of stem cells in regenerative medicine. However, the vast variety of choices of techniques and the lack of a standard approach to analyse human osteoblast and osteoclast differentiation may reduce the utility of stem cells as a tool in medical applications. Therefore, this review aims to systematically evaluate the findings based on stem cell differentiation to define a standard gene expression profile approach.

    METHODS: This review was performed following the PRISMA guidelines. A systematic search of the study was conducted by retrieving articles from the electronic databases PubMed and Web of Science to identify articles focussed on gene expression and approaches for osteoblast and osteoclast differentiation.

    RESULTS: Six articles were included in this review; there were original articles of in vitro human stem cell differentiation into osteoblasts and osteoclasts that involved gene expression profiling. Quantitative polymerase chain reaction (qPCR) was the most used technique for gene expression to detect differentiated human osteoblasts and osteoclasts. A total of 16 genes were found to be related to differentiating osteoblast and osteoclast differentiation.

    CONCLUSION: Qualitative information of gene expression provided by qPCR could become a standard technique to analyse the differentiation of human stem cells into osteoblasts and osteoclasts rather than evaluating relative gene expression. RUNX2 and CTSK could be applied to detect osteoblasts and osteoclasts, respectively, while RANKL could be applied to detect both osteoblasts and osteoclasts. This review provides future researchers with a central source of relevant information on the vast variety of gene expression approaches in analysing the differentiation of human osteoblast and osteoclast cells. In addition, these findings should enable researchers to conduct accurately and efficiently studies involving isolated human stem cell differentiation into osteoblasts and osteoclasts.

  3. Sayuti NH, Zulkefli N, Tan JK, Saad N, Baharum SN, Hamezah HS, et al.
    Molecules, 2023 Sep 20;28(18).
    PMID: 37764502 DOI: 10.3390/molecules28186726
    Neuronal models are an important tool in neuroscientific research. Hydrogen peroxide (H2O2), a major risk factor of neuronal oxidative stress, initiates a cascade of neuronal cell death. Polygonum minus Huds, known as 'kesum', is widely used in traditional medicine. P. minus has been reported to exhibit a few medicinal and pharmacological properties. The current study aimed to investigate the neuroprotective effects of P. minus ethanolic extract (PMEE) on H2O2-induced neurotoxicity in SH-SY5Y cells. LC-MS/MS revealed the presence of 28 metabolites in PMEE. Our study showed that the PMEE provided neuroprotection against H2O2-induced oxidative stress by activating the Nrf2/ARE, NF-κB/IκB and MAPK signaling pathways in PMEE pre-treated differentiated SH-SY5Y cells. Meanwhile, the acetylcholine (ACH) level was increased in the oxidative stress-induced treatment group after 4 h of exposure with H2O2. Molecular docking results with acetylcholinesterase (AChE) depicted that quercitrin showed the highest docking score at -9.5 kcal/mol followed by aloe-emodin, afzelin, and citreorosein at -9.4, -9.3 and -9.0 kcal/mol, respectively, compared to the other PMEE's identified compounds, which show lower docking scores. The results indicate that PMEE has neuroprotective effects on SH-SY5Y neuroblastoma cells in vitro. In conclusion, PMEE may aid in reducing oxidative stress as a preventative therapy for neurodegenerative diseases.
  4. Dapari R, Mahfot MH, Chiu Yan Yee F, Ahmad ANI, Magayndran K, Ahmad Zamzuri M'I, et al.
    PLoS One, 2023;18(11):e0293987.
    PMID: 37943862 DOI: 10.1371/journal.pone.0293987
    INTRODUCTION: Malaysia's gross domestic product is heavily influenced by the food and beverage sector and the contribution of the industry to the national economy is expected to increase in the coming years. Thus, the need for employees in the food industry will continue to rise as this sector grows. Nevertheless, employees in the food industry are exposed to various occupational hazards that can lead to occupational injuries, mainly related to kitchen work. Given the increasing number of employees in the food industry and the rising trend of occupational injuries, this study was conducted to determine the prevalence of recent occupational injuries and their associated factors and predictors among food industry workers.

    METHODS: This cross-sectional study was conducted in 2023 among food industry workers in Selangor, Malaysia. The respondents were sampled using a multistage random sampling method. Data were collected via online self-administered questionnaires and analysed using descriptive statistics and logistic regression models in the SPSS software, version 25.

    RESULTS: A total of 250 responses were received from 342 samples, with an overall response rate of 73.0%. The prevalence of recent occupational injuries among food industry workers was 44.8%. Statistically, significant associations were present between occupational injuries and alcohol consumption (p = 0.001), poor knowledge (p = 0.031), poor compliance (p = 0.021), poor safety management (p = 0.021), poor safety training (p = 0.002), poor safety culture (p = 0.003), physical exposure (p < 0.001), and ergonomic exposure (p = 0.009). The predictors for recent occupational injuries among food industry workers were Malay (adjusted Odds Ratio; aOR = 2.60, p = 0.027, 95% Confidence Interval; CI = 1.116, 6.035), alcohol consumption (aOR = 5.31, p = 0.001, 95% CI = 2.042, 13.779), poor knowledge (aOR = 1.98, p = 0.032, 95% CI = 1.059, 3.691), poor safety culture (aOR = 2.44, p = 0.002, 95% CI = 1.372, 4.342), and exposure to physical hazards (aOR = 8.88, p < 0.001, 95% CI = 3.031, 26.014).

    CONCLUSION: This study has found a high prevalence of occupational injuries among food industry workers, thereby highlighting the importance of addressing alcohol consumption, improving worker knowledge, enhancing work safety culture, and better control measures on exposure to physical hazards, especially among Malay workers. By prioritising these factors, employers can create safer work environments and minimise the risk of occupational injuries.

  5. Prasetyaningtyas N, Jatiatmaja NA, Radithia D, Hendarti HT, Parmadiati AE, Hadi P, et al.
    Eur J Dent, 2021 May;15(2):320-324.
    PMID: 33285573 DOI: 10.1055/s-0040-1721312
    OBJECTIVE:  The aim of this study is to analyze the tongue epithelial response to cigarette smoke exposure on a number of macrophages, lymphocytes, plasma cells, and matrix metalloproteinase 9 (MMP-9) expression to determine the risk factor of oral cancer development.

    MATERIALS AND METHODS:  Thirty Rattus norvegicus will be exposed to two kinds of cigarette smoke by a smoking pump for 4 and 8 weeks. The tongues were collected to analyze the number of macrophages, lymphocytes, and plasma cells with hematoxylin-eosin. The MMP-9 expression was similarly analyzed with immunohistochemical staining and then compared with the control group.

    RESULTS:  The number of macrophages, lymphocytes, and MMP-9 expression was higher in the 8-week cigarette smoke exposure compared to the 4-week cigarette smoke exposure and the control group (p < 0.000). The number of plasma cell did not differ in the 8-week cigarette smoke exposure from that of the control group (p > 0.05). The number of plasma cells in the tongue tissue during the 4-week cigarette smoke exposure was not determined.

    CONCLUSION:  Cigarette smoke exposure induces the risk of oral cancer development as a result of an increase in the number of macrophages, lymphocytes, and MMP-9 expression in the tongue epithelial.

  6. Zainol Abidin IZ, Manogaran T, Abdul Wahab RM, Karsani SA, Yazid MD, Yazid F, et al.
    Curr Stem Cell Res Ther, 2023;18(3):417-428.
    PMID: 35762553 DOI: 10.2174/1574888X17666220627145424
    BACKGROUND: Proteomic is capable of elucidating complex biological systems through protein expression, function, and interaction under a particular condition.

    OBJECTIVE: This study aimed to determine the potential of ascorbic acid alone in inducing differentially expressed osteoblast-related proteins in dental stem cells via the liquid chromatography-mass spectrometry/ mass spectrometry (LC-MS/MS) approach.

    METHODS: The cells were isolated from deciduous (SHED) and permanent teeth (DPSC) and induced with 10 μg/mL of ascorbic acid. Bone mineralisation and osteoblast gene expression were determined using von Kossa staining and reverse transcriptase-polymerase chain reaction. The label-free protein samples were harvested on days 7 and 21, followed by protein identification and quantification using LC-MS/MS. Based on the similar protein expressed throughout treatment and controls for SHED and DPSC, overall biological processes followed by osteoblast-related protein abundance were determined using the PANTHER database. STRING database was performed to determine differentially expressed proteins as candidates for SHED and DPSC during osteoblast development.

    RESULTS: Both cells indicated brownish mineral stain and expression of osteoblast-related genes on day 21. Overall, a total of 700 proteins were similar among all treatments on days 7 and 21, with 482 proteins appearing in the PANTHER database. Osteoblast-related protein abundance indicated 31 and 14 proteins related to SHED and DPSC, respectively. Further analysis by the STRING database identified only 22 and 11 proteins from the respective group. Differential expressed analysis of similar proteins from these two groups revealed ACTN4 and ACTN1 as proteins involved in both SHED and DPSC. In addition, three (PSMD11/RPN11, PLS3, and CLIC1) and one (SYNCRIP) protein were differentially expressed specifically for SHED and DPSC, respectively.

    CONCLUSION: Proteome differential expression showed that ascorbic acid alone could induce osteoblastrelated proteins in SHED and DPSC and generate specific differentially expressed protein markers.

  7. Mohamad Razif MI, Nizar N, Zainal Abidin NH, Muhammad Ali SN, Wan Zarimi WNN, Khotib J, et al.
    Expert Rev Vaccines, 2023;22(1):629-642.
    PMID: 37401128 DOI: 10.1080/14760584.2023.2232450
    INTRODUCTION: mRNA vaccines have been developed as a promising cancer management. It is noted that specification of the antigen sequence of the target antigen is necessary for the design and manufacture of an mRNA vaccine.

    AREAS COVERED: The steps involved in preparing the mRNA-based cancer vaccines are isolation of the mRNA cancer from the target protein using the nucleic acid RNA-based vaccine, sequence construction to prepare the DNA template, in vitro transcription for protein translation from DNA into mRNA strand, 5' cap addition and poly(A) tailing to stabilize and protect the mRNA from degradation and purification process to remove contaminants produced during preparation.

    EXPERT OPINION: Lipid nanoparticles, lipid/protamine/mRNA nanoparticles, and cell-penetrating peptides have been used to formulate mRNA vaccine and to ensure vaccine stability and delivery to the target site. Delivery of the vaccine to the target site will trigger adaptive and innate immune responses. Two predominant factors of the development of mRNA-based cancer vaccines are intrinsic influence and external influence. In addition, research relating to the dosage, route of administration, and cancer antigen types have been observed to positively impact the development of mRNA vaccine.

  8. Mohd-Azami SNI, Loong SK, Khoo JJ, Sahimin N, Lim FS, Husin NA, et al.
    J Vet Med Sci, 2022 Jul 01;84(7):938-941.
    PMID: 35584942 DOI: 10.1292/jvms.22-0037
    Rat bocavirus (RBoV) and rodent bocavirus (RoBoV) have previously been detected in Rattus norvegicus; however, these viruses have not been reported in rodent populations in Malaysia. We investigated the presence of RBoV and RoBoV in archived rodent specimens. DNA barcoding of the rodent cytochrome c oxidase gene identified five different species: Rattus tanezumi R3 mitotype, Rattus tiomanicus, Rattus exulans, Rattus argentiventer, and Rattus tanezumi sensu stricto. Three spleens were positive for RBoV (1.84%; 3/163), but no RoBoV was detected. Phylogenetic analyzes of the partial non-structural protein 1 gene grouped Malaysian RBoV strains with RBoV strains from China. Further studies among rats from different geographical locations are warranted for this relatively new virus.
  9. Ibrahim S, Abdul Khalil K, Zahri KNM, Gomez-Fuentes C, Convey P, Zulkharnain A, et al.
    Molecules, 2020 Aug 26;25(17).
    PMID: 32858796 DOI: 10.3390/molecules25173878
    With the progressive increase in human activities in the Antarctic region, the possibility of domestic oil spillage also increases. Developing means for the removal of oils, such as canola oil, from the environment and waste "grey" water using biological approaches is therefore desirable, since the thermal process of oil degradation is expensive and ineffective. Thus, in this study an indigenous cold-adapted Antarctic soil bacterium, Rhodococcus erythropolis strain AQ5-07, was screened for biosurfactant production ability using the multiple approaches of blood haemolysis, surface tension, emulsification index, oil spreading, drop collapse and "MATH" assay for cellular hydrophobicity. The growth kinetics of the bacterium containing different canola oil concentration was studied. The strain showed β-haemolysis on blood agar with a high emulsification index and low surface tension value of 91.5% and 25.14 mN/m, respectively. Of the models tested, the Haldane model provided the best description of the growth kinetics, although several models were similar in performance. Parameters obtained from the modelling were the maximum specific growth rate (qmax), concentration of substrate at the half maximum specific growth rate, Ks% (v/v) and the inhibition constant Ki% (v/v), with values of 0.142 h-1, 7.743% (v/v) and 0.399% (v/v), respectively. These biological coefficients are useful in predicting growth conditions for batch studies, and also relevant to "in field" bioremediation strategies where the concentration of oil might need to be diluted to non-toxic levels prior to remediation. Biosurfactants can also have application in enhanced oil recovery (EOR) under different environmental conditions.
  10. Muhammad Nadzri N, Abdul AB, Sukari MA, Abdelwahab SI, Eid EE, Mohan S, et al.
    PMID: 23737847 DOI: 10.1155/2013/810632
    Zerumbone (ZER) isolated from Zingiber zerumbet was previously encapsulated with hydroxypropyl- β -cyclodextrin (HP β CD) to enhance ZER's solubility in water, thus making it highly tolerable in the human body. The anticancer effects of this new ZER-HP β CD inclusion complex via apoptosis cell death were assessed in this study for the first time in liver hepatocellular cells, HepG2. Apoptosis was ascertained by morphological study, nuclear stain, and sub-G1 cell population accumulation with G2/M arrest. Further investigations showed the release of cytochrome c and loss of mitochondrial membrane potential, proving mitochondrial dysfunction upon the ZER-HP β CD treatment as well as modulating proapoptotic and anti-apototic Bcl-2 family members. A significant increase in caspase 3/7, caspase 9, and caspase 8 was detected with the depletion of BID cleaved by caspase 8. Collectively, these results prove that a highly soluble inclusion complex of ZER-HP β CD could be a promising anticancer agent for the treatment of hepatocellular carcinoma in humans.
  11. Anasamy T, Abdul AB, Sukari MA, Abdelwahab SI, Mohan S, Kamalidehghan B, et al.
    PMID: 23710242 DOI: 10.1155/2013/939810
    The current study was designed to evaluate the in vitro cytotoxicity effect of a phenylbutenoid dimer, cis-3-(3',4'-dimethoxyphenyl)-4-[(E)-3 (‴) ,4 (‴) -dimethoxystyryl]cyclohex-1-ene (ZC-B11) isolated from the rhizome of Zingiber cassumunar on various cancer cell line, and normal human blood mononuclear cells, and to further investigate the involvement of apoptosis-related proteins that leads, to the probable pathway in which apoptosis is triggered. Cytotoxicity test using MTT assay showed selective inhibition of ZC-B11 towards T-acute lymphoblastic leukemia cells, CEMss, with an IC50 value of 7.11 ± 0.240  μ g/mL, which did not reveal cytotoxic effects towards normal human blood mononuclear cells (IC50 > 50  μ g/mL). Morphology assessments demonstrated distinctive morphological changes corresponding to a typical apoptosis. ZC-B11 also arrested cell cycle progression at S phase and causes DNA fragmentation in CEMss cells. Decline of mitochondrial membrane potential was also determined qualitatively. In the apoptosis-related protein determination, ZC-B11 was found to significantly upregulate Bax, caspase 3/7, caspase 9, cytochrome c, and SMAC and downregulate Bcl-2, HSP70, and XIAP, but did not affect caspase 8, p53, and BID. These results demonstrated for the first time the apoptogenic property of ZC-B11 on CEMss cell line, leading to the programmed cell death via intrinsic mitochondrial pathway of apoptosis induction.
  12. Mohd Ali MR, Lih Huey L, Foo PC, Goay YX, Ismail AS, Mustaffa KMF, et al.
    Biomed Res Int, 2019;2019:9451791.
    PMID: 31355287 DOI: 10.1155/2019/9451791
    Melioidosis and leptospirosis, caused by two different bacteria, Burkholderia pseudomallei and Leptospira spp., are potentially fatal infections that share a very similar spectrum of clinical features and cause significant mortality and morbidity in humans and livestock. Early detection is important for better clinical consequences. To our knowledge, there is no diagnostic tool available to simultaneously detect and differentiate melioidosis and leptospirosis in humans and animals. In this study, we described a duplex TaqMan probe-based qPCR for the detection of B. pseudomallei and Leptospira spp. DNA. The performance of the assay was evaluated on 20 B. pseudomallei isolates, 23 Leptospira strains, and 39 other microorganisms, as well as two sets of serially diluted reference strains. The duplex qPCR assay was able to detect 0.02 pg (~ 4 copies) Leptospira spp. DNA and 0.2 pg (~ 25.6 copies) B. pseudomallei DNA. No undesired amplification was observed in other microorganisms. In conclusion, the duplex qPCR assay was sensitive and specific for the detection of B. pseudomallei & Leptospira spp. DNA and is suitable for further analytical and clinical evaluation.
  13. Asman MKA, Lutpi NA, Wong YS, Ong SA, Hanif MA, Ibrahim N, et al.
    Phys Chem Chem Phys, 2024 Jul 31;26(30):20409-20426.
    PMID: 39018044 DOI: 10.1039/d4cp01421a
    Research into the speciation of sulfur and hydrogen molecules produced through the complex process of thermophilic dark fermentation has been conducted. Detailed surface studies of solid-gas systems using real biogas (biohydrogen) streams have unveiled the mechanisms and specific interactions between these gases and the physicochemical properties of a zeolite as an adsorbent. These findings highlight the potential of zeolites to effectively capture and interact with these molecules. In this study, the hydrogen sulphide removal analysis was conducted using 0.8 g of the adsorbent and at various reaction temperatures (25-125 °C), a flow rate of 100 mL min-1, and an initial concentration of approximately 5000 ppm hydrogen sulphide. The reaction temperature has been observed to be an essential parameter of Zeolite Socony Mobil - 5 adsorption capacity. The optimum adsorption capacity attains a maximum value of 0.00890 mg g-1 at an optimal temperature of 25 °C. The formation of sulphur species resulting from the hydrogen sulphide adsorption on the zeolite determines the kinetics, thermodynamics, and mass transfer behaviours of Zeolite Socony Mobil - 5 in hydrogen sulphide removal and Zeolite Socony Mobil - 5 is found to improve the quality of biohydrogen produced in thermophilic environments. Biohydrogen (raw gas) yield was enhanced from 2.48 mol H2 mol-1 hexose consumed before adsorption to 2.59 mol H2 mol-1 hexose consumed after adsorption at a temperature of 25 °C. The Avrami kinetic model was fitted for hydrogen sulphide removal on Zeolite Socony Mobil - 5. The process is explained well and fitted using the Temkin isotherm model and the investigation into thermodynamics reveals that the adsorption behaviour is exothermic and non-spontaneous. Furthermore, the gas molecule's freedom of movement becomes random. The adsorption phase is restricted by intra-particle diffusion followed by film diffusion during the transfer of hydrogen sulphide into the pores of Zeolite Socony Mobil - 5 prior to adsorption on its active sites. The utilisation of Zeolite Socony Mobil - 5 for hydrogen sulphide removal offers the benefit of reducing environmental contamination and exhibiting significant applications in industrial operations.
  14. Tengku-Mazuki TA, Darham S, Convey P, Shaharuddin NA, Zulkharnain A, Khalil KA, et al.
    Braz J Microbiol, 2024 Mar;55(1):629-637.
    PMID: 38110706 DOI: 10.1007/s42770-023-01215-8
    Antarctica has often been perceived as a pristine continent until the recent few decades as pollutants have been observed accruing in the Antarctic environment. Irresponsible human activities such as accidental oil spills, waste incineration and sewage disposal are among the primary anthropogenic sources of heavy metal contaminants in Antarctica. Natural sources including animal excrement, volcanism and geological weathering also contribute to the increase of heavy metals in the ecosystem. A microbial growth model is presented for the growth of a bacterial cell consortium used in the biodegradation of phenol in media containing different metal ions, namely arsenic (As), cadmium (Cd), aluminium (Al), nickel (Ni), silver (Ag), lead (Pb) and cobalt (Co). Bacterial growth was inhibited by these ions in the rank order of Al 
  15. Hashim NNA, Mat S, Myint PK, Kioh SH, Delibegovic M, Chin AV, et al.
    BMJ Open, 2024 Nov 07;14(11):e087358.
    PMID: 39510770 DOI: 10.1136/bmjopen-2024-087358
    OBJECTIVE: Both changes in body composition and increased fall risk occur with increasing age. While weight management may be considered a component of falls prevention, the long-term consequences of changes in weight, however, remain uncertain. This prospective study aimed to evaluate the relationship between weight and body composition changes over 5 years with fall occurrence.

    DESIGN: Prospective cohort study.

    SETTING: Community-dwelling older adults interviewed at baseline (2013-2016) and follow-up (2020-2022) as a part of the Malaysian Elders Longitudinal Research study were included.

    PARTICIPANTS: Participants who attended face-to-face follow-up visits.

    PRIMARY AND SECONDARY OUTCOME MEASURES: Fall occurrence over 12 months preceding the follow-up visit was determined. Anthropometric, bioimpedance analysis and physical performance measurements were obtained at both time points. Participants were categorised into three groups according to changes in weight and body composition using≥5% increase or decrease in weight to determine loss or gain.

    RESULTS: Of the 225 participants, aged 71.8±6.8 years, 128 (56.9%) were women. Weight gain was associated with increased fall risk at follow-up compared with stable weight (adjusted rate ratio, aRR (95% confidence interval, CI)=2.86 (1.02-8.02)) following adjustments for age and body mass index (BMI), but this relationship was attenuated by low baseline percentage lean body mass (%LBM) in women. The association was strenghtened after adjusting for age, BMI, and low muscle strength (aRR (95% CI)=2.89 (1.01-8.28)). Weight change did not influence falls risk in men. No difference was observed with changes in percentage body fat and %LBM over time with fall occurrence for both genders.

    CONCLUSION: Lower baseline lean body mass influenced the relationship between weight gain and falls longitudinally. Interventions addressing low lean body mass should be considered in the prevention of weight-gain-related falls in older women.

  16. Azhari NN, Ramli SNA, Joseph N, Philip N, Mustapha NF, Ishak SN, et al.
    Acta Trop, 2018 Dec;188:68-77.
    PMID: 30145261 DOI: 10.1016/j.actatropica.2018.08.020
    Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32, secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans, ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus, 7/59 (11.9%) of Rattus rattus, 5/24 (20.8%) of Maxomys whiteheadi, 4/18 (22.2%) of Sundamys muelleri, 2/22 (9%), Tupaia gliss, 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures.
  17. Vincent AT, Schiettekatte O, Goarant C, Neela VK, Bernet E, Thibeaux R, et al.
    PLoS Negl Trop Dis, 2019 May;13(5):e0007270.
    PMID: 31120895 DOI: 10.1371/journal.pntd.0007270
    The causative agents of leptospirosis are responsible for an emerging zoonotic disease worldwide. One of the major routes of transmission for leptospirosis is the natural environment contaminated with the urine of a wide range of reservoir animals. Soils and surface waters also host a high diversity of non-pathogenic Leptospira and species for which the virulence status is not clearly established. The genus Leptospira is currently divided into 35 species classified into three phylogenetic clusters, which supposedly correlate with the virulence of the bacteria. In this study, a total of 90 Leptospira strains isolated from different environments worldwide including Japan, Malaysia, New Caledonia, Algeria, mainland France, and the island of Mayotte in the Indian Ocean were sequenced. A comparison of average nucleotide identity (ANI) values of genomes of the 90 isolates and representative genomes of known species revealed 30 new Leptospira species. These data also supported the existence of two clades and 4 subclades. To avoid classification that strongly implies assumption on the virulence status of the lineages, we called them P1, P2, S1, S2. One of these subclades has not yet been described and is composed of Leptospira idonii and 4 novel species that are phylogenetically related to the saprophytes. We then investigated genome diversity and evolutionary relationships among members of the genus Leptospira by studying the pangenome and core gene sets. Our data enable the identification of genome features, genes and domains that are important for each subclade, thereby laying the foundation for refining the classification of this complex bacterial genus. We also shed light on atypical genomic features of a group of species that includes the species often associated with human infection, suggesting a specific and ongoing evolution of this group of species that will require more attention. In conclusion, we have uncovered a massive species diversity and revealed a novel subclade in environmental samples collected worldwide and we have redefined the classification of species in the genus. The implication of several new potentially infectious Leptospira species for human and animal health remains to be determined but our data also provide new insights into the emergence of virulence in the pathogenic species.
  18. Ab Razak A, Rahman NA, Zulkifly MFM, Sapiai NA, Phoa PKA, Mohamed Mustafar MF, et al.
    Malays J Med Sci, 2023 Oct;30(5):1-6.
    PMID: 37928788 DOI: 10.21315/mjms2023.30.5.1
    Improving healthcare and living conditions has led to an increase in life expectancies and challenges of population aging in Malaysia. The Advanced Memory and Cognitive Service builds on integrated healthcare among multidisciplinary specialists to provide holistic and patient-centred healthcare. The service treats older adults experiencing neurocognitive impairment as well as young individuals with complex neurocognitive disorders and thoroughly screens asymptomatic individuals at high risk of developing neurocognitive disorders. This early intervention strategy is a preventive effort in the hope of reducing disease burden and improving quality of life to prepare Malaysia for the forthcoming population aging.
  19. Alkathiry H, Al-Rofaai A, Ya'cob Z, Cutmore TS, Mohd-Azami SNI, Husin NA, et al.
    Pathogens, 2022 Sep 23;11(10).
    PMID: 36297144 DOI: 10.3390/pathogens11101087
    Chigger mites are vectors of the bacterial disease scrub typhus, caused by Orientia spp. The bacterium is vertically transmitted in the vector and horizontally transmitted to terrestrial vertebrates (primarily wild small mammals), with humans as incidental hosts. Previous studies have shown that the size of the chigger populations is correlated with the density of small mammals in scrub typhus-endemic regions. Here, we explore interactions between the small mammals and chiggers in two oil palm plantations located in the Perak and Johor states of Peninsular Malaysia. The location in Perak also contained an aboriginal (Orang Asli) settlement. A ~5% sub-sample from 40,736 chigger specimens was identified from five species of small mammals (n = 217), revealing 14 chigger species, including two new records for Malaysia. The abundance and species richness of chiggers were significantly affected by habitat type (highest in forest border), state (highest in Perak), and season (highest in dry). The overall prevalence of Orientia tsutsugamushi DNA in small-mammal tissues was 11.7% and was not significantly affected by host or habitat characteristics, but in Johor, was positively associated with infestation by Leptotrombidium arenicola. These findings highlight the risk of contracting scrub typhus in oil palm plantations and associated human settlements.
  20. Badli-Sham BH, Syafiq MF, Aziz MSA, Mohd Jalil NR, Awang MT, Othman MNA, et al.
    Zookeys, 2023;1157:43-93.
    PMID: 37398628 DOI: 10.3897/zookeys.1157.95873
    Amphibians of Sekayu lowland forest have been studied more than a decade, with discoveries of new records of species showing no sign of abating between the years 2003 to 2020, indicating the remarkably rich diversity of anurans in this forest. Despite ceaseless anthropogenic activities in this area, this study successfully recorded 52 species of amphibians from 32 genera in the lowland forest of Sekayu. The species composition consisted of a single species from the family Ichthyophiidae and 51 species of anurans of 31 genera and six families. The number of species recorded has steadily increased especially during more recent surveys from 2015 to 2020. This study augments the total number of amphibian species recorded from Hulu Terengganu by ten additional species, increasing the total to 70 species for the district.
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