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First Report of Podosphaera fusca Causing Powdery Mildew of Cosmos caudatus in Malaysia

Siddiqui Y, Sariah M, Kausar H

Plant Dis, 2011 Apr;95(4):495.
PMID: 30743349 DOI: 10.1094/PDIS-12-10-0866

Cosmos caudatus Kunth. (Asteraceae), commonly known as ulam raja, is widely grown as an herbal aromatic shrub. In Malaysia, its young leaves are popularly eaten raw as salad with other greens and have been reported to possess extremely high antioxidant properties, which may be partly responsible for some of its believed medicinal functions. In early 2010, a suspected powdery mildew was observed on ulam raja plants at the Agricultural Park of Universiti Putra Malaysia. Initially, individual, white, superficial colonies were small and almost circular. Later, they enlarged and coalesced to cover the whole abaxial leaf surface. With development of the disease, all green parts (leaves, stems, and petioles) became covered with a continuous mat of mildew, giving a dusty appearance. Newly emerged leaves rapidly became infected. Diseased leaves ultimately senesced and dried up, making them aesthetically unattractive and unmarketable. The pathogen produced conidia in short chains (four to six conidia) on erect conidiophores. Conidiophores were unbranched, cylindrical, 125 to 240 μm long, with a slightly swollen foot cell. Individual conidia were hyaline, ellipsoid, and 25 to 30 (27.5) × 15 to 20 (17.5) μm with fibrosin inclusions. Morphological descriptions were consistent with those described for Sphaerotheca fuliginea or S. fusca, which has lately been reclassified as Podosphaera fusca (1). From extracted genomic DNA of P. fusca UPM UR1, the internal transcribed spacer (ITS) region was amplified with ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'). A BLAST search of GenBank with an ITS rDNA sequence of this fungus (GenBank Accession No. HQ589357) showed a maximum identity of 98% to the sequences of two P. fusca isolates (GenBank Accession Nos. AB525915.1 and AB525914.1). To satisfy Koch's postulates, the pathogenicity of fungal strain UPM UR1 was verified on 4-week-old plants. Inoculation was carried out by gently rubbing infected leaves onto healthy plants of C. caudatus. Ten pots of inoculated plants were kept under a plastic humid chamber and 10 pots of noninoculated plants, placed under another chamber, served as controls. After 48 h, the plants were then placed under natural conditions (25 to 28°C). Powdery mildew symptoms, similar to those on diseased field plants, appeared after 7 days on all inoculated plants. The white, superficial colonies enlarged and merged to cover large areas within 2 weeks. The infected leaf tissues became necrotic 6 to 8 days after the appearance of the first symptoms. Sporulation of P. fusca was observed on all infected leaves and stems. No symptoms were seen on the control plants. To our knowledge, this is the first report of P. fusca causing powdery mildew on C. caudatus in Malaysia. This pathogen has also been reported previously to be economically important on a number of other hosts. With ulam raja plants, more attention should be given to prevention and control measures to help manage this disease. Reference: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000.

Matched MeSH terms: DNA, Ribosomal
A new black fly species of Simulium (Nevermannia) (Diptera: Simuliidae) from Vietnam

Takaoka H, Low VL, Tan TK, Sofian-Azirun M, Chen CD, Lau KW, et al.

Acta Trop, 2019 Feb;190:320-328.
PMID: 30496721 DOI: 10.1016/j.actatropica.2018.11.025

Simulium pumatense sp. nov. is described from Vietnam, and is placed in the Simulium feuerborni species-group of the subgenus Simulium (Nevermannia) Enderlein. Its morphological characteristics include the relatively smaller numbers of the following three numerical features: inner teeth of the female mandible (15-18), minute conical processes (16) on the female cibarium, and male upper-eye facets (in 15 vertical columns and 16 horizontal rows). Keys are constructed to distinguish this species from four species of the same group in Vietnam. Our molecular analysis of the DNA barcoding COI gene shows that this species is most closely related to cytoform A of the S. feuerborni complex from Thailand.

Matched MeSH terms: DNA Barcoding, Taxonomic
First Report of Rubber Tree Stem Rot Caused by Fusarium oxysporum in China

Li BX, Shi T, Liu XB, Lin CH, Huang GX

Plant Dis, 2014 Jul;98(7):1008.
PMID: 30708897 DOI: 10.1094/PDIS-01-14-0004-PDN

Rubber tree (Hevea brasiliensis) is an important crop in tropical regions of China. In October 2013, a new stem rot disease was found on cv. Yunyan77-4 at a rubber tree plantation in Hekou, Yunnan Province. There were about 100 plants, and diseased rubber trees accounted for 30% or less. Initially, brown-punctuate secretion appeared on the stem, which was 5 to 6 cm above the ground. Eventually, the secretion became black and no latex produced from the rubber tree bark. After removing the secretion, the diseased bark was brown putrescence, but the circumambient bark was normal. Upon peeling the surface bark, the inner bark and xylem had brown rot and was musty. The junction between health and disease was undulate. On the two most serious plants, parts of leaves on the crown were yellow, and the root near the diseased stem was dry and puce. The pathogen was isolated and designated HbFO01; the pathogenicity was established by following Koch's postulates. The pathogen was cultivated on a potato dextrose agar (PDA) plate at 28°C for 4 days. Ten plants of rubber tree cv. Yunyan77-4 were selected from a disease-free plantation in Haikou, Hainan Province, and the stem diameter was about 7 cm. The bark of five plants was peeled, and one mycelium disk with a diameter of 1 cm was inserted into the cut and covered again with the bark. The other five plants were treated with agar disks as controls. The inoculation site was kept moist for 2 days, and then the mycelium and agar disk were removed. On eighth day, symptoms similar to the original stem lesions were observed on stems of inoculated plants, while only scars formed on stems of control plants. The pathogen was re-isolated from the lesions of inoculated plants. On PDA plates, the pathogen colony was circular and white with tidy edges and rich aerial hyphae. Microscopic examination showed microconidia and chlamydospores were produced abundantly on PDA medium. The falciform macroconidia were only produced on lesions and were slightly curved, with a curved apical cell and foot shaped to pointed basal cell, usually 3-septate, 16.2 to 24.2 × 3.2 to 4.0 μm. Microconidia were produced in false heads, oval, 0-septate, 6.2 to 8.2 × 3.3 to 3.8 μm, and the phialide was cylindrical. Chlamydospores were oval, 6.4 to 7.2 × 3.1 to 3.8 μm, alone produced in hypha. Morphological characteristics of the specimen were similar to the descriptions for Fusarium oxysporum (2). Genomic DNA of this isolate was extracted with a CTAB protocol (4) from mycelium and used as a template for amplification of the internal transcribed spacer (ITS) region of rDNA with primer pair ITS1/ITS4 (1). The full length of this sequence is 503 nt (GenBank Accession No. KJ009335), which exactly matched several sequences (e.g., JF807394.1, JX897002.1, and HQ451888.1) of F. oxysporum. Williams and Liu had listed F. oxysporum as the economically important pathogen of Hevea in Asia (3), while this is, to our knowledge, the first report of stem rot caused by F. oxysporum on rubber tree in China. References: (1) D. E. L. Cooke et al. Fungal Genet. Biol. 30:17, 2000. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual, 2006. (3) T. H. Williams and P. S. W. Liu. A host list of plant diseases in Sabah, Malaysia, 1976. (4) J. R. Xu et al. Genetics 143:175, 1996.

Matched MeSH terms: DNA, Ribosomal
Occurrence of Anthracnose Caused by Colletotrichum truncatum on Chickpea (Cicer arietinum) in Malaysia

Mahmodi F, Kadir JB, Nasehi A, Puteh A, Soleimani N

Plant Dis, 2013 Nov;97(11):1507.
PMID: 30708462 DOI: 10.1094/PDIS-03-13-0231-PDN

At least nine Colletotrichum species, particularly Colletotrichum truncatum, have been recorded on legumes worldwide (1). In June 2010, samples of chickpea leaflets showing leaf spot disease symptoms were collected from experimental farms in Ladang Dua, Selangor state of Malaysia. Tan lesions with darker brown borders were observed on leaflets and were associated with premature leaf drop. Stem lesions initially appeared on the lower parts of stems and later progressed higher in the plant. Lesions often girdled the stem and caused severe dieback. Abundant acervuli developed in the lesions visible as black dots. Foliar lesions were removed, surface sterilized in 1% sodium hypochlorite for 2 min, rinsed twice with distilled water, dried on sterilized tissue paper, plated on PDA plates, and incubated at 25°C (3). Three isolates of the fungus were obtained and identified as C. truncatum on the basis of morphological characteristics (2). The isolates were deposited in the University Putra of Malaysia Culture Collection (UPMCC). Colony characteristics on PDA varied from greyish white to dark in color and exhibited mycelial growth with sparse acervuli. The isolates produced both sclerotia and setae in culture. Conidia (mean ± SD = 22 ± 0.83 × 3.6 ± 0.08 μm, L/W ratio = 6.1) produced in acervuli were falcate, hyaline, and aseptate, with tapering towards the acute and greatly curved apex. The conidial mass color varied from pale buff to saffron. Isolates produced simple to slightly lobed, mainly short clavate appressoria (mean ± SD = 9.60 ± 0.36 × 6.67 ± 0.29 μm, L/W ratio = 1.45). Amplification and sequence analysis of coding and none-coding regions of the ITS-rDNA (GenBank Accession JX971160), actin (JX975392), β-tubulin (KC109495), histone (KC109535), chitin synthase (KC109575), and glyceraldehyde-3-phosphate dehydrogenase (KC109615) obtained from the representative isolate, CTM37, aligned with deposited sequences from GenBank and revealed 99 to 100% sequence identity with C. truncatum strains (AJ301945, KC110827, GQ849442, GU228081, GU228359, and HM131501 from GenBank). Isolate CTM37 was used to test pathogenicity in the greenhouse. Five chickpea seeds of cultivar ILC-1929 were sown per pot in four replications. Ten days after seedling emergence, plants were inoculated with a spore suspension (concentration = 106 conidia ml-1) and check pots were sprayed with distilled water. After inoculation, the plants were covered with plastic bags for 48 h and kept at 28 to 33°C and >90% RH. After incubation, the plastic bags were removed and the plants were placed on greenhouse benches and monitored daily for symptom development (3). One week after inoculation, typical anthracnose symptoms developed on the leaves and stems of inoculated plants including acervuli formation, but not on the checks. A fungus with the same colony and conidial morphology as CTM37 was recovered from the lesions on the inoculated plants. The experiment was repeated twice. The ability to accurately diagnose Colletotrichum species is vital for the implementation of effective disease control and quarantine measures. We believe this is the first report of C. truncatum causing anthracnose on chickpea in Malaysia. References: (1) B. D. Gossen et al. Can. J. Plant Pathol. 31:65, 2009. (2) B. C. Sutton. The Genus Glomerella and its anamorph Colletotrichum. CAB International, Wallingford. UK. 1992. (3) P. P. Than et al. Plant Pathol. 57:562, 2008. ERRATUM: A correction was made to this Disease Note on May 19, 2014. The author N. Soleimani was added.

Matched MeSH terms: DNA, Ribosomal
Fulltext First record of Phyllorhiza sp. (Cnidaria: Scyphozoa) in a Chinese coastal aquaculture pond

Dong Z, Morandini AC, Schiariti A, Wang L, Sun T

PeerJ, 2019;7:e6191.
PMID: 30643699 DOI: 10.7717/peerj.6191

Background: It has been suggested that aquaculture ponds on the Chinese coast could act as breeding grounds for scyphozoans. Here, we present the first record of the scyphomedusa Phyllorhiza sp. in an aquaculture pond on the coast of the southern Yellow Sea, based on a combination of morphological characteristics and mitochondrial 16S DNA sequence data.
Methods: A field survey was performed on June 29, 2017 in a pond used for culturing the shrimp Penaeus japonicus, located in the southern Yellow Sea, China. Jellyfish specimens were collected for morphological and genetic analysis. The morphological characters of the jellyfish specimens were compared to taxonomic literature. Additionally, phylogenetic analysis of the mitochondrial 16S fragments of these specimens were also conducted.
Results: These specimens had the following morphological characters: hemispherical umbrella without scapulets; J-shaped oral arms; a single larger terminal club on each arm; bluish colored with a slightly expanded white tip; and mouthlets present only in the lower half to one-third of each arm. These morphological features of the medusae indicated that the specimens found in the shrimp culture ponds belong to the genus Phyllorhiza Agassiz, 1862, but did not match with the description of any of the known species of the genus Phyllorhiza. Phylogenetic analyses of the mtDNA 16S regions revealed that these specimens, together with Phyllorhiza sp. from Malaysian coastal waters, belong to a sister group of Phyllorhiza punctata. Juveniles and ephyrae of Phyllorhiza sp. were observed in the aquaculture pond. The mean density of Phyllorhiza sp. medusa in the surface water within the pond was estimated to be 0.05 individuals/m2.
Discussion: Based on our observations of the gross morphology and molecular data, we state that the specimens collected in the aquaculture pond can be identified as Phyllorhiza sp. This is the first record of Phyllorhiza sp. in Chinese seas. Large scale dispersal through ballast water or the expansion of jellyfish aquarium exhibitions are possible pathways of invasion, but this needs to be confirmed in further studies.

Matched MeSH terms: DNA, Mitochondrial
Phyla nodiflora L. Extracts Induce Apoptosis and Cell Cycle Arrest in Human Breast Cancer Cell Line, MCF-7

Teoh PL, Liau M, Cheong BE

Nutr Cancer, 2019;71(4):668-675.
PMID: 30663402 DOI: 10.1080/01635581.2018.1559942

Phyla nodiflora L. has been used as medicinal remedies for various ailments due to its antioxidant, anti-inflammatory, anti-bacterial, anti-tumor activity. Previously, we found that the plant extracts induced DNA fragmentation in MCF-7. This study was to investigate the modes of action of P. nodiflora in inhibiting breast cancer cells using leaf ethyl acetate (EA leaf), stem ethyl acetate (EA stem) and stem methanol (Met stem) extracts. The MTT assay showed that the anti-proliferative effects of P. nodiflora extracts were selective towards MCF-7 with a minimal effect on MCF10A. Morphological changes such as cell shrinkage and nuclear condensation were observed in treated cells. We found that induction of apoptosis by EA leaf and EA stem was mitochondrial-dependent while loss of mitochondrial membrane potential was not found in Met stem-treated cells. In addition, the expression levels of AIFM1, CASP9, CFLAR, and IGF1R were altered after treatment. Decreased BCL-2 expression was found in treated cells while BAX and caspases' expression was upregulated or maintained. All extracts caused perturbation of cell cycle at S phase by dysregulating the expression of cell cycle regulators such as CDKs and cyclins. Our findings indicate that P. nodiflora inhibits MCF-7 cells by inducing apoptosis and perturbing cell cycle.

Matched MeSH terms: DNA Fragmentation
Ultrastructural aspects of sylvatic dengue virus infection in Vero cell

Fish-Low CY, Abubakar S, Othman F, Chee HY

Malays J Pathol, 2019 Apr;41(1):41-46.
PMID: 31025636

INTRODUCTION: Dengue virus (DENV), the causative agent of dengue disease exists in sylvatic and endemic ecotypes. The cell morphological changes and viral morphogenesis of two dengue ecotypes were examined at the ultrastructural level to identify potential similarities and differences in the surrogate model of enzootic host.
MATERIALS AND METHODS: Vero cells were inoculated with virus at a multiplicity of infection (MOI) of 0.1. Cell cultures were harvested over a time course and processed for transmission electron microscopic imaging.
RESULTS: The filopodia protrusions on cell periphery preceded virus entry. Additionally, sylvatic DENV infection was found spreading slower than the endemic DENV. Morphogenesis of both dengue ecotypes was alike but at different level of efficiency in the permissive cells.
CONCLUSIONS: This is the first ultrastructural study on sylvatic DENV and this comparative study revealed the similarities and differences of cellular responses and morphogenesis of two dengue ecotypes in vitro. The study revealed the weaker infectivity of sylvatic DENV in the surrogate model of enzootic host, which supposed to support better replication of enzootic DENV than endemic DENV.

Matched MeSH terms: DNA Replication
Fulltext Overview of safety and efficacy of non-viral gene transfer in cartilage tissue engineering from the worldview of Islam

Noorhidayah Md Nazir, Munirah Sha’ban

International Medical Journal Malaysia, 2018;17(101):115-123.
MyJurnal

This paper examines the safety and efficacy of non-viral gene transfer in cartilage tissue engineering (TE) from the worldview of Islam. The first clinical trial treating adenosine deaminase deficient patients conducted in 1990 has triggered the development of gene transfer technology. The potential of gene transfer is further explored in TE field with the hope that it could prosper the regenerative medicine application. However, ethical issues become important when it comes to application of new treatment modalities, primarily in gene transfer because of genetic modification influences the basis of life - the DNA. Besides ethical issue, the application of gene transfer in treating diseases also attract views from religious context. The questions on the techniques to administer the gene in human, social acceptance of genetically modified cell and adverse effects from it are still debatable and unresolved. Apart from that dilemma, both safety and efficacy issues are raised due to the scientific uncertainty and social perception of the technology. Despite countless number of encouraging findings and recommendations by the proponents of
the technology, gene transfer is currently available only in the research setting. The established guidelines are used to complement and provide the necessary foundations in discussing the aspects involved in the incorporation of gene transfer with cartilage TE. Relevant Islamic input are identified and aligned to those particular guidelines. It is hoped that the integration of Islamic inputs in the existing guidelines could suggest the safest approach in treating cartilage degenerative disease through gene transfer and TE.

Matched MeSH terms: DNA
Fulltext Chromosome Arm Locations of Barley Sucrose Transporter Gene in Transgenic Winter Wheat Lines

Takenaka S, Weschke W, Brückner B, Murata M, Endo TR

Front Plant Sci, 2019;10:548.
PMID: 31114602 DOI: 10.3389/fpls.2019.00548

Three transgenic HOSUT lines of winter wheat, HOSUT12, HOSUT20, and HOSUT24, each harbor a single copy of the cDNA for the barley sucrose transporter gene HvSUT1 (SUT), which was fused to the barley endosperm-specific Hordein B1 promoter (HO; the HOSUT transgene). Previously, flow cytometry combined with PCR analysis demonstrated that the HOSUT transgene had been integrated into different wheat chromosomes: 7A, 5D, and 4A in HOSUT12, HOSUT20, and HOSUT24, respectively. In order to confirm the chromosomal location of the HOSUT transgene by a cytological approach using wheat aneuploid stocks, we crossed corresponding nullisomic-tetrasomic lines with the three HOSUT lines, namely nullisomic 7A-tetrasomic 7B with HOSUT12, nullisomic 5D-tetrasomic 5B with HOSUT20, and nullisomic 4A-tetrasomic 4B with HOSUT24. We examined the resulting chromosomal constitutions and the presence of the HOSUT transgene in the F2 progeny by means of chromosome banding and PCR. The chromosome banding patterns of the critical chromosomes in the original HOSUT lines showed no difference from those of the corresponding wild type chromosomes. The presence or absence of the critical chromosomes completely corresponded to the presence or absence of the HOSUT transgene in the F2 plants. Investigating telocentric chromosomes occurred in the F2 progeny, which were derived from the respective critical HOSUT chromosomes, we found that the HOSUT transgene was individually integrated on the long arms of chromosomes 4A, 7A, and 5D in the three HOSUT lines. Thus, in this study we verified the chromosomal locations of the transgene, which had previously been determined by flow cytometry, and moreover revealed the chromosome-arm locations of the HOSUT transgene in the HOSUT lines.

Matched MeSH terms: DNA, Complementary
Selective inhibition of genes in methicillin resistant Staphylococcus aureus (MRSA) treated with Melastoma malabathricum methanol extract

Zulaikah Mohamed, Nazlina Ibrahim, Ismail Ahmad

Sains Malaysiana, 2008;37(1):107-113.

Methanol extract of Melastoma malabathricum leaves inhibited the growth of Staphylococcus aureus and six clinical isolates of Methicilin Resistant Stapyhlococcus aureus (MRSA 1-6). The minimum inhibitory concentration (MIC) of test substance was 1.565mg/ml and the minimum bacteriocidal concentration (MBC) was 3.125 mg/ml. The methanol extract suppressed RNA synthesis at 10 mg/ml as shown by RNA profile which was devoid of three bands compared to the control. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis using seven primer pairs was only successful in amplifying four cDNA amplicons. The failure to amplify three cDNA amplicons for three primer pairs corresponding to gyrA, femA and nuc genes, implied the possibility of suppression of the corresponding mRNA. Electrophoretic separation of endogenous and exogenuos bacterial proteins showed that three and five protein, respectively were not expressed. One endogenous and three exogenous proteins were over-expressed in treated MRSA compared with untreated control. The results of the molecular and proteomic analyses are in agreement, and based on primers being used, methanol extract of M. malabathricum leaves possibly inhibits MRSA growth through inhibition of DNA synthesis, peptidoglycan production, and nuclease production.
Keywords: Methicillin resistant Staphylococcus aureus; Melastoma malabathricum; gene expression; protein production

Matched MeSH terms: DNA, Complementary
Comparison between Pork and wild Boar meat (Sus Scrofa ) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)

Sahilah Abu Mutalib, Wan Sakeenah Wan Nazari, Safiyyah Shahimi, Norhayati Yaakob, Norrakiah Abdullah Sani, Aminah Abdullah, et al.

Sains Malaysiana, 2012;41:199-204.

A method of PCR-restriction fragment length polymorphism (RFLP) has been utilized to differentiate the mitochondrial genes of pork and wild boar meat (Sus scrofa). The amplification PCR products of 359 bp and 531 bp were successfully amplified from the cyt b gene of these two meats. The amplification product of pork and wild boar using mt-12S rRNA gene successfully produced a single band with molecular size of 456 bp. Three restriction endonucleases (AluI, HindIII and BsaJI) were used to restrict the amplification products of the mitochondrial genes. The restriction enzymes of AluI and BsaJI were identified as potential restriction endonucleases to differentiate those meats. HindIII enzyme was unable to restrict the PCR product of both meats. The genetic differences within the cyt b gene among the two meats were successfully confirmed by PCR-RFLP analysis.

Matched MeSH terms: DNA Restriction Enzymes
Pengesahan bagi mengesan bakteria patogen makanan menggunakan teknologi mikroaturan DNA

SAWEI J, NORRAKIAH ABDULLAH SANI, AMINAH ABDULLAH, SAHILAH ABD. MUTALIB

Sains Malaysiana, 2013;42:1715-1720.

Kajian ini dijalankan untuk mengesahkan kemampuan teknologi DNA mikroaturan cip gen OliproTM FoodPATH bagi mengesan bakteria patogen makanan. Sebanyak 9 jenis DNA bakteria patogen makanan telah digunakan iaitu Bacillus cereus, Escherichia coli O157:H7, Staphylococcus aureus, Vibrio cholerae, Vibrio parahaemolyticus, Listeria monocytogenes, Salmonella spp., Shigella spp. dan Campylobacter spp. Sebanyak 36 kombinasi templat DNA bakteria patogen makanan telah digunakan. Pengesahan bagi mengesan bakteria patogen makanan dilakukan dengan menggunakan kaedah reaksi berantai polimerase (PCR) dan penghibridan Southern-blotting di atas cip gen untuk mengesahkan kemampuannya. Keputusan daripada analisis hibridasi di atas cip gen telah dibandingkan dengan hasil gel elektroforesis 2.0% (w/v). Lima saringan diperlukan untuk menghabiskan 36 kombinasi templat DNA bakteria patogen makanan. Setiap saringan, satu cip gen telah digunakan sebagai kawalan negatif tidak diinokulasikan dengan sebarang kombinasi DNA bakteria patogen makanan. Daripada hasil kajian, didapati bahawa semua kombinasi templat DNA bakteria patogen makanan telah dapat dikesan. Cip yang digunakan sebagai kawalan negatif tidak menunjukkan kehadiran DNA. Oleh itu, daripada kajian ini cip gen OliproTM FoodPATH didapati memberikan keputusan yang lebih baik berbanding dengan 2.0% (w/v) gel elektroforesis.

Matched MeSH terms: DNA
Fulltext Serological evidence and experimental infection of cynomolgus macaques with pteropine orthoreovirus reveal monkeys as potential hosts for transmission to humans

Tan CW, Wittwer K, Lim XF, Uehara A, Mani S, Wang LF, et al.

Emerg Microbes Infect, 2019;8(1):787-795.
PMID: 31132935 DOI: 10.1080/22221751.2019.1621668

Pteropine orthoreoviruses (PRV) are emerging bat-borne viruses with proven zoonotic transmission. We recently demonstrated human exposure to PRV in Singapore, which together with previous reports from Malaysia and Vietnam suggest that human infection of PRV may occur periodically in the region. This raises the question whether bats are the only sources of human infection. In this study, we screened 517 cynomolgus macaques caught in Singapore for evidence of exposure to PRV3M (also known as Melaka virus), which was first isolated from human patients in Melaka, Malaysia. We found that 67 serum samples were PRV3M positive by ELISA and 34 were also positive by virus neutralization assay. To investigate whether monkeys could act as hosts for PRV transmission, we experimentally infected cynomolgus macaques with PRV3M and housed these animals with uninfected monkeys. Although no clinical signs of infection were observed in infected animals, viral RNA was detected in nasal and rectal swabs and all infected macaques seroconverted. Additionally, one of the uninfected animals seroconverted, implying active shedding and transmission of PRV3M. We provide evidence that PRV exposure in the macaque population in Singapore occurs at a relatively high prevalence and this study suggests that cynomolgus macaques may be an intermediate or reservoir host for PRVs.

Matched MeSH terms: DNA Viruses
DNA polymorphism of D1S80 locus in modern Malay sample population of Sarawak

Hairul Azman Roslan, Nur Hafizah Azizan, Rosmawati Saat

Sains Malaysiana, 2009;38.

The molecular genetic marker, minisatellite locus D1S80 (1p35-p36), is a highly polymorphic variable number of tandem repeats (VNTR). Its polymorphic nature allows for phylogenetic studies, forensic analysis, genetic maps construction and paternity testing to be performed. A study of the hypervariable locus D1S80 was conducted to determine the allele frequency and distribution of this locus in modern Malay in Sarawak population. The polymerase chain reaction technique was employed and results were analysed on polyacrylamide gel. A total of seventy-six DNA samples of unrelated Malay individuals in UNIMAS were collected and examined. The VNTR analysis of the D1S80 locus demonstrated the presence of 17 alleles in the Malay population. Allele with the size of 577 bp (27 repeats) was determined to be the most common in the sample population with the frequency of 0.1641, followed by allele with the size of 561 bp (26 repeats) and 529 bp (24 repeats) whose frequency is 0.1172 and 0.1094, respectively. The smallest allele is allele with the size of 465 bp (20 repeats) whereas the largest is allele with the size of 753 bp (38 repeats). The sample population exhibited 57.8% heterozygosity.

Matched MeSH terms: DNA
Fulltext Detection of malaria parasites in Sabah by nested polymerase chain reaction: a focus of naturally acquired Plasmodium knowlesi infections

Anderios F, Zulaikah Mohamed, Ratnam S, Mohd Yusof Ibrahim, Tajul Ariffin Mohd Awang

Sains Malaysiana, 2008;37(2).

The emergence of primate malaria known as Plasmodium knowlesi in humans, which is always misdiagnosed by microscopy as P. malariae, has contribute to the needs of nucleic acid based technology to be applied in detection and differentiation of malaria parasites. The target DNA sequence of the 18SrRNA gene was amplified by a nested PCR assay for detection and identification of Plasmodium species in 31 Giemsa-stained blood smears examined as P. malariae. The assay demonstrated three samples identified as positive to genus-specific primers but negative to all species-specific primers. Three cases of misdiagnosed species were detected. The samples were diagnosed as P. malariae microscopically, but detected as P. falciparum by PCR assay. Twenty five out of 31 samples were detected as P. knowlesi. None of the samples diagnosed microscopically as P. malariae were identified as P. malariae with the nested PCR assay. Over 80.6% of all malaria cases in this study showed naturally acquired P. knowlesi infections.

Matched MeSH terms: DNA Primers
Phylogeny of sea cucumber (Echinodermata: Holothuroidea) as inferred from 16S mitochondrial rRNa gene sequences

Kamarul Rahim Kamarudin, Ridzwan Hashim, Usup G

Sains Malaysiana, 2010;39:209-218.

This study aimed to determine phylogenetic relationship between and among selected species of sea cucumbers (Echinodermata: Holothuroidea) using 16S mitochondrial ribosomal RNA (rRNA) gene. Phylogenetic analyses of 37 partial sequences of 16S mitochondrial rRNA gene using three main methods namely neighbour joining (NJ), maximum parsimony (MP) and maximum likelihood (ML) showed the presence of five main genera of sea cucumbers: Molpadia from order Molpadiida and four genera of order Aspidochirotida namely Holothuria, Stichopus, Bohadschia and Actinopyga. All of the 17 species obtained from Malaysia distributed among the main genera except within Actinopyga. Interestingly, Holothuria excellens was out of Holothuria group causing Holothuria to be paraphyletic. High bootstrap value and consistent clustering made Molpadia, Stichopus, Bohadschia and Actinopyga monophyletic. The relationship of Actinopyga with the other genera was unclarified and Stichopus was sister to Molpadia. The latter finding caused the resolution at order level unclear. The pairwise genetic distance calculated using Kimura 2-parameter model further supported and verified findings from the phylogenetic trees. Further studies with more samples and different mitochondrial DNA genes need to be done to get a better view and verification on the molecular phylogeny of sea cucumbers.

Matched MeSH terms: DNA, Mitochondrial
Molecular phylogeny of holothuria (mertensiothuria) leucospilota (Brandt 1835) as inferred from cytochrome C oxidase I mitochondrial DNA gene sequences

Hajar Fauzan Ahmad, Mohd Hanafi Anua, Mohd Yaman Idris, Aisyah Mohamed Rehan, Ridzwan Hashim, Usup G, et al.

Sains Malaysiana, 2011;40.

Holothuria (Mertensiothuria) leucospilota (Brandt 1835), white threads fish or locally known as bat puntil is currently considered as the most abundant sea cucumber species in Malaysia. This study aimed to generate the genetic profile of H. leucospilota from Malaysia and then to determine the phylogenetic relationship between H. leucospilota and other members of genus Holothuria using partial sequences of cytochrome c oxidase I (COI) mitochondrial DNA (mtDNA) gene. In this study, specimens of H. leucospilota were collected from Intan Besar Island, Langkawi, Kedah Darul Aman in the west coast of Peninsular Malaysia. Three main methods namely neighbour joining, maximum parsimony and maximum likelihood were used for the phylogenetic tree reconstruction. Tree topologies showed that H. leucospilota has its own monophyletic clade clearly distinct from the other species. The pairwise genetic distance calculated further supported these findings. In addition, the results also should that the COI mtDNA gene is capable to unravel the phylogenetic relationship of H. leucospilota.

Matched MeSH terms: DNA, Mitochondrial
Molecular Mitochondrial DNA and radiographic approaches for human archaeology identification

Rus Dina Rus Din, Shahrul Hisham Zainal Ariffin, Sahidan Senafi, Rohaya Megat Abdul Wahab, Intan Zarina Zainol Abidin

Sains Malaysiana, 2014;43:1523-1535.

Ancient remains are considered very valuable artefacts, as they allow for the study of ancient cultures, phylogeny, evolution and the reconstruction of demographic history. To obtain all the information contained within remains, the investigation of such samples requires the expertise and various techniques from multiple fields of study. The present review focuses on the molecular biology and radiographic approaches used to identify ancient samples. Studies of ancient remains face various limitations; for example, the quality and quantity of the ancient samples can affect the difficulty of the investigations. Due to these limitations, new sophisticated techniques are being introduced to replace the earlier conventional techniques. A search was conducted using PubMed, Scopus, Science Direct and Science Finder to provide a new and timely review on the molecular mitochondrial DNA and radiographic analysis for human archaeology identification. The present review has determined that molecular biological approaches are very accurate and useful for the use in the ancestral determination of incomplete specimens, whereas observations of the dental pulp chamber are suitable for age at death estimations in both adults and children. However, these techniques are expensive and require expert personnel. Therefore, conventional approaches remain the favourite methods of most institutions, especially in Asia.

Matched MeSH terms: DNA, Mitochondrial
Hydrops fetalis: a simple novel screen for the rapid identification of haemoglobin Bart's syndrome

George-Kodiseri E, Faridah K

Family Physician, 1991;3(1):25-27.

Haemoglobin Bart's hydrops fetalis syndrome is totally lethal. Globin chain electrophoresis on mylar backed cellulose acetate strips, by a method modified from Ueda and Schneider has been established to demonstrate total absence of alpha chains in this syndrome. This simple test can identify fetuses, stillbirths and newborns with homozygous Î±o-thalassaemia. In this region where DNA studies are limited, and prenatal diagnosis is unavailable, this test which describes the phenotypic expression of Hb Bart's syndrome will improve genetic counselling of women at risk of homozygous Î±o-thalassaemia.

Matched MeSH terms: DNA
Fulltext Resting Cyst Distribution and Molecular Identification of the Harmful Dinoflagellate Margalefidinium polykrikoides (Gymnodiniales, Dinophyceae) in Lampung Bay, Sumatra, Indonesia

Thoha H, Muawanah, Bayu Intan MD, Rachman A, Sianturi OR, Sidabutar T, et al.

Front Microbiol, 2019;10:306.
PMID: 30846977 DOI: 10.3389/fmicb.2019.00306

Margalefidinium polykrikoides, an unarmored dinoflagellate, was suspected to be the causative agent of the harmful algal blooms - associated with massive fish mortalities - that have occurred continually in Lampung Bay, Indonesia, since the first bloom event in October 2012. In this study, after examination of the morphology of putative M. polykrikoides-like cysts sampled in bottom sediments, cyst bed distribution of this harmful species was explored in the inner bay. Sediment samples showed that resting cysts, including several morphotypes previously reported as M. polykrikoides, were most abundant on the northern coast of Lampung Bay, ranging from 20.6 to 645.6 cysts g-1 dry sediment. Molecular phylogeny inferred from LSU rDNA revealed that the so-called Mediterranean ribotype was detected in the sediment while M. polykrikoides motile cells, four-cell chain forming in bloom conditions, belonged to the American-Malaysian ribotype. Moreover, hyaline cysts, exclusively in the form of four-cell chains, were also recorded. Overall, these results unequivocally show that the species M. polykrikoides is abundantly present, in the form of vegetative cells, hyaline and resting cysts in an Indonesian area.

Matched MeSH terms: DNA, Ribosomal

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