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Recent advances in DNA-based electrochemical biosensors for heavy metal ion detection: A review

Saidur MR, Aziz AR, Basirun WJ

Biosens Bioelectron, 2017 Apr 15;90:125-139.
PMID: 27886599 DOI: 10.1016/j.bios.2016.11.039

The presence of heavy metal in food chains due to the rapid industrialization poses a serious threat on the environment. Therefore, detection and monitoring of heavy metals contamination are gaining more attention nowadays. However, the current analytical methods (based on spectroscopy) for the detection of heavy metal contamination are often very expensive, tedious and can only be handled by trained personnel. DNA biosensors, which are based on electrochemical transduction, is a sensitive but inexpensive method of detection. The principles, sensitivity, selectivity and challenges of electrochemical biosensors are discussed in this review. This review also highlights the major advances of DNA-based electrochemical biosensors for the detection of heavy metal ions such as Hg(2+), Ag(+), Cu(2+) and Pb(2+).

Matched MeSH terms: DNA/chemistry*
Development of a thermostabilised triplex LAMP assay with dry-reagent four target lateral flow dipstick for detection of Entamoeba histolytica and non-pathogenic Entamoeba spp

Foo PC, Chan YY, Mohamed M, Wong WK, Nurul Najian AB, Lim BH

Anal Chim Acta, 2017 May 08;966:71-80.
PMID: 28372729 DOI: 10.1016/j.aca.2017.02.019

This study highlighted the development of a four target nitrocellulose-based nucleic acid lateral flow immunoassay biosensor in a dry-reagent strip format for interpretation of double-labelled double-stranded amplicons from thermostabilised triplex loop-mediated isothermal amplification assay. The DNA biosensor contained two test lines which captured biotin and texas red labelled amplicons; a LAMP internal amplification control line that captured digoxigenin labelled amplicon; and a chromatography control line that validated the functionality of the conjugated gold nanoparticles and membrane. The red lines on detection pad were generated when the gold nanoparticles conjugated antibody bound to the fluorescein labelled amplicons, and the capture agents bound to their specific hapten on the other 5' end of the double-stranded amplicon. The applicability of this DNA biosensor was demonstrated using amoebiasis-causing Entamoeba histolytica simultaneously with the non-pathogenic but morphologically identical Entamoeba dispar and Entamoeba moshkovskii. The biosensor detection limit was 10 E. histolytica trophozoites, and revealed 100% specificity when it was evaluated against 3 medically important Entamoeba species and 75 other pathogenic microorganisms. Heat stability test showed that the biosensor was stable for at least 181 days at ambient temperature. This ready-to-use and cold-chain-free biosensor facilitated the post-LAMP analysis based on visualisation of lines on strip instead of observation of amplicon patterns in agarose gel.

Matched MeSH terms: DNA, Protozoan/analysis
Mutations in mitochondrial complex I assembly factor NDUFAF3 cause Leigh syndrome

Baertling F, Sánchez-Caballero L, Timal S, van den Brand MA, Ngu LH, Distelmaier F, et al.

Mol Genet Metab, 2017 03;120(3):243-246.
PMID: 27986404 DOI: 10.1016/j.ymgme.2016.12.005

NDUFAF3 is an assembly factor of mitochondrial respiratory chain complex I. Variants in NDUFAF3 have been identified as a cause of severe multisystem mitochondrial disease. In a patient presenting with Leigh syndrome, which has hitherto not been described as a clinical feature of NDUFAF3 deficiency, we identified a novel homozygous variant and confirmed its pathogenicity in patient fibroblasts studies. Furthermore, we present an analysis of complex I assembly routes representative of each functional module and, thereby, link NDUFAF3 to a specific step in complex I assembly. Therefore, our report expands the phenotype of NDUFAF3 deficiency and further characterizes the role of NDUFAF3 in complex I biogenesis.

Matched MeSH terms: Sequence Analysis, DNA/methods*
Fulltext Three members of Opisthomonorcheides Parukhin, 1966 (Digenea: Monorchiidae) from carangid fishes (Perciformes) from Indonesia, with a review of the genus

Bray RA, Palm HW, Cutmore SC, Cribb TH

Syst Parasitol, 2017 05;94(4):443-462.
PMID: 28337682 DOI: 10.1007/s11230-017-9717-5

Three species of Opisthomonorcheides Parukhin, 1966 are reported for the first time from Indonesian waters: O. pampi (Wang, 1982) Liu, Peng, Gao, Fu, Wu, Lu, Gao & Xiao, 2010 and O. ovacutus (Mamaev, 1970) Machida, 2011 from Parastromateus niger (Bloch), and O. decapteri Parukhin, 1966 from Atule mate (Cuvier). Both O. pampi and O. ovacutus can now be considered widespread in the Indo-Pacific region, with earlier records of these species being from Fujian Province, China and Penang, Malaysia, respectively. We redescribe O. decapteri from one of its original hosts, Atule mate, off New Caledonia, and report this species from Jakarta Bay, Indonesia, extending its range throughout the Indian Ocean into the south-western Pacific. All three species possess a genital atrium that is long, sometimes very long, and a genital pore that is located in the forebody. This validates the interpretation that the original description was erroneous in reporting the genital pore in the hindbody, well posterior to the ventral sucker. These observations verify the synonymy of Retractomonorchis Madhavi, 1977 with Opisthomonorcheides. A major discrepancy between the species of Opisthomonorcheides is that some are described with the uterus entering the terminal organ laterally and some with it entering terminally; this feature needs further analysis. Based on the length of the genital atrium and the posterior extent of the vitellarium, the 27 species of Opisthomonorcheides considered valid can be divided into four groups. Among the 53 host records analysed, the families Carangidae (53% of records), Stromateidae (17%) and Serranidae (5.7%) are the most common; the reports are overwhelmingly from members of the Perciformes (91%), with further records in the Clupeiformes (5.7%), Gadiformes (1.9%) and Pleuronectiformes (1.9%). Two fish genera (Parastromateus Bleeker and Pampus Bonaparte) dominate the recorded hosts, with the black pomfret Parastromateus niger harbouring six species, the silver pomfret Pampus argenteus (Euphrasen) harbouring six, and the Chinese silver pomfret P. chinensis (Euphrasen) two. A host-parasite checklist is presented. We discuss the host-specificity of members of the genus, questioning some records such as that of O. decapteri in a deep-sea macrourid. We also comment on the morphological similarity, but phylogenetic distance, between the various Pomfret species, advancing the possibility that a series of host misidentifications has occurred. Sequences of the ITS2 rDNA gene generated for O. pampi and O. ovacutus are briefly discussed and molecular data are lodged in the GenBank database.

Matched MeSH terms: DNA, Ribosomal Spacer/genetics
Fulltext Cellular Homeostasis and Antioxidant Response in Epithelial HT29 Cells on Titania Nanotube Arrays Surface

Smn Mydin RB, Sreekantan S, Hazan R, Farid Wajidi MF, Mat I

Oxid Med Cell Longev, 2017;2017:3708048.
PMID: 28337249 DOI: 10.1155/2017/3708048

Cell growth and proliferative activities on titania nanotube arrays (TNA) have raised alerts on genotoxicity risk. Present toxicogenomic approach focused on epithelial HT29 cells with TNA surface. Fledgling cell-TNA interaction has triggered G0/G1 cell cycle arrests and initiates DNA damage surveillance checkpoint, which possibly indicated the cellular stress stimuli. A profound gene regulation was observed to be involved in cellular growth and survival signals such as p53 and AKT expressions. Interestingly, the activation of redox regulator pathways (antioxidant defense) was observed through the cascade interactions of GADD45, MYC, CHECK1, and ATR genes. These mechanisms furnish to protect DNA during cellular division from an oxidative challenge, set in motion with XRRC5 and RAD50 genes for DNA damage and repair activities. The cell fate decision on TNA-nanoenvironment has been reported to possibly regulate proliferative activities via expression of p27 and BCL2 tumor suppressor proteins, cogent with SKP2 and BCL2 oncogenic proteins suppression. Findings suggested that epithelial HT29 cells on the surface of TNA may have a positive regulation via cell-homeostasis mechanisms: a careful circadian orchestration between cell proliferation, survival, and death. This nanomolecular knowledge could be beneficial for advanced medical applications such as in nanomedicine and nanotherapeutics.

Matched MeSH terms: DNA Damage/drug effects; DNA-Binding Proteins/genetics; DNA-Binding Proteins/metabolism; DNA Repair Enzymes/genetics; DNA Repair Enzymes/metabolism
Cytochrome c oxidase subunit I haplotype reveals high genetic diversity of Angiostrongylus malaysiensis (Nematoda: Angiostrongylidae)

Eamsobhana P, Yong HS, Song SL, Prasartvit A, Boonyong S, Tungtrongchitr A

J Helminthol, 2018 Mar;92(2):254-259.
PMID: 28330511 DOI: 10.1017/S0022149X17000244

The rat lungworm Angiostrongylus malaysiensis is a metastrongyloid nematode parasite. It has been reported in Malaysia, Thailand, Laos, Myanmar, Indonesia and Japan. In this study, A. malaysiensis adult worms recovered from the lungs of wild rats in different geographical regions/provinces in Thailand were used to determine their haplotype by means of the mitochondrial partial cytochrome c oxidase subunit I (COI) gene sequence. The results revealed high COI haplotype diversity of A. malaysiensis from Thailand. The geographical isolates of A. malaysiensis from Thailand and other countries formed a monophyletic clade distinct from the closely related A. cantonensis. In the present study, five new haplotypes were identified in addition to the four haplotypes reported in the literature. Phylogenetic analysis revealed that four of these five new haplotypes - one from Mae Hong Song (northern region), two from Tak (western region) and one from Phang Nga (southern region) - formed a distinct clade with those from Phatthalung (southern region) and Malaysia. The haplotype from Malaysia was identical to that of Phatthalung (haplotype AM1). In general, the COI sequences did not differentiate unambiguously the various geographical isolates of A. malaysiensis. This study has confirmed the presence of high COI genetic diversity in various geographical isolates of A. malaysiensis. The COI gene sequence will be suitable for studying genetic diversity, population structure and phylogeography.

Matched MeSH terms: DNA, Helminth/genetics
Draft genome sequence of multidrug-resistant Salmonella enterica serovar Brancaster strain PS01 isolated from chicken meat, Malaysia

Chin PS, Yu CY, Ang GY, Yin WF, Chan KG

J Glob Antimicrob Resist, 2017 06;9:41-42.
PMID: 28300643 DOI: 10.1016/j.jgar.2016.12.017

OBJECTIVES: Salmonella spp. represent one of the main diarrhoeal pathogens that are transmitted via the food supply chain. Here we report the draft genome sequence of a multidrug-resistant Salmonella enterica serovar Brancaster (PS01) that was isolated from poultry meat in Malaysia.
METHODS: Genomic DNA was extracted from Salmonella strain PS01 and was sequenced using an Illumina HiSeq 2000 platform. The generated reads were de novo assembled using CLC Genomics Workbench. The draft genome was annotated and the presence of antimicrobial resistance genes was identified.
RESULTS: The 5 036 442bp genome contains various antimicrobial resistance genes conferring resistance to aminoglycosides, fluoroquinolones, fosfomycin, macrolides, phenicols, sulphonamides, tetracyclines and trimethoprim. The β-lactamase gene blaTEM-176 encoding TEM-176 was also found in this strain.
CONCLUSIONS: The genome sequence will aid in the understanding of drug resistance mechanisms in foodborne Salmonella Brancaster and highlights the need to ensure the judicious use of antibiotics in animal husbandry as well as the importance of implementing proper food handling and preparation practices.

Matched MeSH terms: Sequence Analysis, DNA*
Habitat segregation and cryptic adaptation of species of Periophthalmus (Gobioidei: Gobiidae)

Polgar G, Zaccara S, Babbucci M, Fonzi F, Antognazza CM, Ishak N, et al.

J Fish Biol, 2017 May;90(5):1926-1943.
PMID: 28239874 DOI: 10.1111/jfb.13276

A study was conducted on the habitat distribution of four sympatric species of Periophthalmus (the silver-lined mudskipper Periophthalmus argentilineatus, the slender mudskipper Periophthalmus gracilis, the kalolo mudskipper Periophthalmus kalolo and the Malacca mudskipper Periophthalmus malaccensis) from northern Sulawesi. Molecular phylogenetic reconstructions based on one mtDNA marker (16S) were used to validate the morphological taxa, identifying five molecular clades. Periophthalmus argentilineatus includes two molecular species, which are named Periophthalmus argentilineatus clades F and K. Multivariate direct gradient analysis show that these species form three distinct ecological guilds, with the two molecular species occurring in different guilds. Periophthalmus clade F is ecologically eurytypic; Periophthalmus clade K and P. kalolo are prevalent in ecosystems isolated by strong oceanic currents and at shorter distances from the sea; P. gracilis plus P. malaccensis are prevalent in ecosystems connected by shallow coastal waters, in vegetated habitats at larger distances from the sea. This indicates for the first time that mudskipper species exhibit a range of adaptations to semiterrestrialism not only within genera, but even within morphospecies, delineating a much more complex adaptive scenario than previously assumed.

Matched MeSH terms: DNA, Mitochondrial/genetics
Fulltext Three Divergent Subpopulations of the Malaria Parasite Plasmodium knowlesi

Divis PC, Lin LC, Rovie-Ryan JJ, Kadir KA, Anderios F, Hisam S, et al.

Emerg Infect Dis, 2017 04;23(4):616-624.
PMID: 28322705 DOI: 10.3201/eid2304.161738

Multilocus microsatellite genotyping of Plasmodium knowlesi isolates previously indicated 2 divergent parasite subpopulations in humans on the island of Borneo, each associated with a different macaque reservoir host species. Geographic divergence was also apparent, and independent sequence data have indicated particularly deep divergence between parasites from mainland Southeast Asia and Borneo. To resolve the overall population structure, multilocus microsatellite genotyping was conducted on a new sample of 182 P. knowlesi infections (obtained from 134 humans and 48 wild macaques) from diverse areas of Malaysia, first analyzed separately and then in combination with previous data. All analyses confirmed 2 divergent clusters of human cases in Malaysian Borneo, associated with long-tailed macaques and pig-tailed macaques, and a third cluster in humans and most macaques in peninsular Malaysia. High levels of pairwise divergence between each of these sympatric and allopatric subpopulations have implications for the epidemiology and control of this zoonotic species.

Matched MeSH terms: DNA, Protozoan/genetics
Association of ARID5B gene variants with acute lymphoblastic leukemia in Yemeni children

Al-Absi B, Noor SM, Saif-Ali R, Salem SD, Ahmed RH, Razif MF, et al.

Tumour Biol., 2017 Apr;39(4):1010428317697573.
PMID: 28381164 DOI: 10.1177/1010428317697573

Studies have shown an association between ARID5B gene polymorphisms and childhood acute lymphoblastic leukemia. However, the association between ARID5B variants and acute lymphoblastic leukemia among the Arab population still needs to be studied. The aim of this study was to investigate the association between ARID5B variants with acute lymphoblastic leukemia in Yemeni children. A total of 14 ARID5B gene single nucleotide polymorphisms (SNPs) were genotyped in 289 Yemeni children, of whom 136 had acute lymphoblastic leukemia and 153 were controls, using the nanofluidic Dynamic Array (Fluidigm 192.24 Dynamic Array). Using logistic regression adjusted for age and gender, the risks of acute lymphoblastic leukemia were presented as odds ratios and 95% confidence intervals. We found that nine SNPs were associated with acute lymphoblastic leukemia under additive genetic models: rs7073837, rs10740055, rs7089424, rs10821936, rs4506592, rs10994982, rs7896246, rs10821938, and rs7923074. Furthermore, the recessive models revealed that six SNPs were risk factors for acute lymphoblastic leukemia: rs10740055, rs7089424, rs10994982, rs7896246, rs10821938, and rs7923074. The gender-specific impact of these SNPs under the recessive genetic model revealed that SNPs rs10740055, rs10994982, and rs6479779 in females, and rs10821938 and rs7923074 in males were significantly associated with acute lymphoblastic leukemia risk. Under the dominant model, SNPs rs7073837, rs10821936, rs7896246, and rs6479778 in males only showed striking association with acute lymphoblastic leukemia. The additive model revealed that SNPs with significant association with acute lymphoblastic leukemia were rs10821936 (both males and females); rs7073837, rs10740055, rs10994982, and rs4948487 (females only); and rs7089424, rs7896246, rs10821938, and rs7923074 (males only). In addition, the ARID5B haplotype block (CGAACACAA) showed a higher risk for acute lymphoblastic leukemia. The haplotype (CCCGACTGC) was associated with protection against acute lymphoblastic leukemia. In conclusion, our study has shown that ARID5B variants are associated with acute lymphoblastic leukemia in Yemeni children with several gender biases of ARID5B single nucleotide polymorphisms reported.

Matched MeSH terms: DNA-Binding Proteins/genetics*
Complete Genome Sequence of Proteus mirabilis Phage pPM_01 Isolated from Raw Sewage

Wirjon IA, Lau NS, Arip YM

Intervirology, 2016;59(5-6):243-253.
PMID: 28384626 DOI: 10.1159/000468987

OBJECTIVES: Phage pPM_01 was previously isolated from a raw sewage treatment facility located in Batu Maung, Penang, Malaysia, and it was highly lytic against Proteus mirabilis, which causes urinary tract infections in humans. In this paper, we characterize the biology and complete genome sequence of the phage.
METHODS AND RESULTS: Transmission electron microscopy revealed phage pPM_01 to be a siphovirus (the first reported virus to infect P. mirabilis), with its complete genome sequence successfully determined. The genome was sequenced using Illumina technology and the reads obtained were assembled using CLC Genomic Workbench v.7.0.3. The whole genome contains a total of 58,546 bp of linear double-stranded DNA with a G+C content of 46.9%. Seventy putative genes were identified and annotated using various bioinformatics tools including RAST, Geneious v.R7, National Center for Biotechnology Information (NCBI) BLAST, and tRNAscan-SE-v1.3 Search. Functional clusters of related potential genes were defined (structural, lytic, packaging, replication, modification, and modulatory). The whole genome sequence showed a low similarity to known phages (i.e., Enterobacter phage Enc34 and Enterobacteria phage Chi). Host range determination and SDS-PAGE analysis were also performed.
CONCLUSIONS: The inability to lysogenize a host, the absence of endotoxin genes in the annotated genome, and the lytic behavior suggest phage pPM_01 as a possible safe biological candidate to control P. mirabilis infection.

Matched MeSH terms: DNA; DNA Replication
Fulltext Extraction of mitochondrial DNA from tooth dentin: application of two techniques

Ahmad Azlina, Berahim Zurairah, Sidek Mohamad Ros, Mokhtar Khairani Idah, Samsudin Abdul Rani

Archives of Orofacial Sciences, 2011;6(1):9-14.
MyJurnal

Mitochondrial DNA (mtDNA) is a hereditary material located in mitochondria and is normally maternally inherited. Mutational analysis performed on mtDNA proved that the mutations are closely related with a number of genetic illnesses, besides being exploitable for forensic identification. Those findings imply the importance of mtDNA in the scientific field. MtDNA can be found in abundance in tooth dentin where it is kept protected by the enamel, the hardest outer part of the tooth. In this study, two techniques of mtDNA extraction were compared to determine the efficacy between the two techniques. Teeth used for the study was collected from Dental Clinic, Hospital Universiti Sains Malaysia. After the removal of tooth from the tooth socket of the patient, the tooth was kept at -20C until use. Later, pulp tissue and enamel was excised using dental bur and only the root dentin was utilized for the isolation of mtDNA by crushing it mechanically into powdered form. MtDNA was extracted using the two published methods, Pfeifer and Budowle and then subjected to spectrophotometry DNA quantification and purity, Polymerase chain reaction (PCR) amplification of hypervariable-two region of mtDNA, followed by DNA sequencing to analyze the reliability of the extraction techniques. In conclusion, both techniques proved to be efficient and capable for the extraction of mtDNA from tooth dentin.

Matched MeSH terms: DNA, Mitochondrial; Sequence Analysis, DNA
Fulltext Enhancers of Agrobacterium-mediated transformation of Tibouchina semidecandra selected on the basis of GFP expression

Thau, Wilson Lym Yon, Henry, Erle Stanley, Janna Ong Abdullah

Trop Life Sci Res, 2010;21(2):-.
MyJurnal

Genetic engineering is a powerful tool for the improvement of plant traits. Despite reported successes in the plant kingdom, this technology has barely scratched the surface of the Melastomataceae family. Limited studies have led to some optimisation of parameters known to affect the transformation efficiency of these plants. The major finding of this study was to optimise the presence of selected enhancers [e.g., monosaccharides (D-glucose, D-galactose and D-fructose), tyrosine, aluminium chloride (AICI3) and ascorbic
acid] to improve the transformation efficiency of Tibouchina semidecandra. Agrobacterium tumefaciens strain LBA4404 harbouring the disarmed plasmid pCAMBIA1304 was used to transform shoots and nodes of T. semidecandra. Different concentrations of the transformation enhancers were tested by using green fluorescent protein (GFP) as a reporter. The results obtained were based on the percentage of GFP expression, which was observed 14 days post-transformation. A combination of 120 µM galactose and 100
µM tyrosine supplemented with 600 µM AICI3 in the presence of 15 mg/l ascorbic acid gave the highest percentage of positive transformants for T. semidecandra shoots. Whereas 60 µM galactose and 50 µM tyrosine with 200 µM AICI3 in the presence of 15 mg/l ascorbic acid was optimum for T. semidecandra nodes. The presence of the hygromycin phosphotransferase II (hptII) transgene in the genomic DNA of putative
T. semidecandra transformants was verified by PCR amplification with specific primers.

Matched MeSH terms: DNA; DNA Primers
Fulltext A simple protocol to isolate DNA from Malaysian stork blood collected on FTA® cards

YEE, ELSIE Y. S., ZAINAL ZAHARI, AHMAD ISMAIL, YAP, C.K., TAN, S. G.

Buletin Persatuan Genetik Malaysia, 2009;14(1):20-22.
MyJurnal

The blood of the Painted Storks (Mycteria leucocephala) and the Milky Storks (M. cinerea) from Malaysia were collected
invasively from the breeding site. The blood was dropped on to FTA® cards and stored at room temperature. DNA was isolated from
the FTA® cards through a modification of the Wizard DNA Purification kit (Promega) procedure and PCR was performed with 11 pairs
of microsatellite primers of the American Wood Stork (M. americana). The collection of a drop of blood onto the card is superior to the
usual practice of collecting about five ml of blood into a vacuum tube as it causes fewer traumas to these sensitive birds. Moreover, this
collection procedure can be adopted for use in various wild animal species which are usually found in the remote areas of Malaysia as
the sample collection cards can be transported back to the laboratory at room temperature. Our procedure allows the typing of several
molecular genetic markers from just a drop of blood collected in the field and stored at room temperature alleviating the need for storage
in expensive deep freezers or liquid nitrogen tanks.

Matched MeSH terms: DNA; DNA Primers
Fulltext Meat molecular detection: sensitivity of Polymerase Chain Reaction-Restriction Fragment Length Polymorphism in species differentiation of meat from animal origin

Ong, S.B., Zuraini, M.I., Jurin, W.G., Cheah Y.K., Tunung, R., Chai, L.C., et al.

International Food Research Journal, 2007;14(1):51-59.
MyJurnal

Three restriction enzymes were used in Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) using the mitochondrial cytochrome b region to establish a differential diagnosis which detect and discriminate between three meat species: pork, cow and chicken. DNA was extracted from samples containing meat of a single animal such as raw pork (Sus scrofa domesticus), chicken (Gallus gallus) and cow (Bos taurus) as well as mixed samples of two species of animals in different ratios. The amplified 359 base pairs (bp) portion of the mitochondrial cyt b gene from pure or mixed samples in different ratios was cut using three different restriction enzymes resulting in species specific restriction fragment length polymorphism (RFLP). This technique proved to be extremely reliable in detecting the presence of low levels of target DNA obtained from a 0.25 mg component in a particular mixed meat sample. This revealed the cyt b region as highly conserved and consequently a good molecular marker for diagnostic studies. Thus, this technique can be applied to food authentication for the identification of different species of animals in food products.

Matched MeSH terms: DNA; DNA Restriction Enzymes
Identification of the species origin of commercially available processed food products by mitochondrial DNA analysis

Chandrika, M., Maimunah, M., Zainon, M.N., Son, R.

International Food Research Journal, 2010;17(4):867-876.
MyJurnal

Legislation concerning the safety assessment and labelling of foodstuffs has been implemented in many countries. Consequential to a number of cases of food adulteration reported globally, a fast and reliable detection method for the food traceability is required in ensuring effective implementation of food legislation in a country. In this study, PCR-RFLP technique based on cyt b gene has been tested for its suitability for these purposes. This method combines the use of a pair of universal primer that amplifies a 359 bp fragment on the cyt b gene from meat muscle DNA and restriction enzyme analysis. Analysis of experimental beef frankfurter, minced beef, pork frankfurter and pork cocktail samples demonstrated the suitability of the assay for the detection of the beef (Bos taurus) and pork (Sus scrofa), but not applicable for some processed food, particularly detection of mackerel (Rasterelliger brachysoma), sardine (Saedinella Fimbriata) and tuna (Thunnus tonggol) origin in canned food. Commercial frauds through species mislabelling or misdescribed were not detected. The assay is demonstrated applicable for routine analysis of meat traceability of foodstuffs and legislation purposes, if sufficient availability of detectable mtDNA in the foodstuffs is ensured.

Matched MeSH terms: DNA, Mitochondrial; DNA Primers
Fulltext Molecular characterization and antimicrobial resistance profiling of Salmonella enterica subsp. enterica isolated from ‘Selom’ (Oenanthe stolonifera)

Learn-Han, L., Yoke-Kqueen, C., Shiran, M.S., Sabrina, S., Noor Zaleha, A.S., Sim, J.H., et al.

International Food Research Journal, 2009;16(2):191-202.
MyJurnal

Fifty-nine isolates of Salmonella enterica subsp. enterica (S. enterica) isolated from indigenous vegetables, ‘selom’ (Oenanthe stolonifera) associated with 13 different serovars were obtained from Chemistry Department of Malaysia. The isolates encompass the common serovar, Salmonella enterica subsp. enterica serovar Weltevreden (S. Weltevreden) (39%) and Salmonella enterica subsp. enterica serovar Agona (S. Agona) (8.5%). Frequencies of the other 11 Salmonella serovars were ranged from 1.7% to 5.1%. All isolates were characterized by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR), random amplified polymorphic DNA (RAPD), plasmid profiling and antimicrobial susceptibility testing. The results demonstrated ERIC-PCR, RAPD and composite analysis of both are suitable typing methods for S. enterica by demonstrating good discriminative ability and can be utilize as a rapid approach of comparing S. enterica isolates for epidemiological investigation. From this study, ERIC-PCR is exhibited lower discriminatory power when compare with RAPD. On the other hand, plasmid profiles yielded 32 profiles with molecular size ranging from 1129 bp to 17911 bp. Thirteen antimicrobial agents were included in this study and all isolates showed 100% (59/59) resistant to erythromycin and showed Multiple Antimicrobial Resistance (MAR) indexes ranging from 0.08 to 0.68. Dendrogram generated from antimicrobial resistance profiling exhibited poor discriminatory capability at serovar level. Although poultry still remain as the common reservoir for multidrug resistant (MDR) Salmonella. The isolation of 13 Salmonella serovars from selom that showed high MDR in this study is alarming. These results supported the notion that indigenous vegetable (selom) are gaining more antimicrobial resistance and could be potential health hazards.

Matched MeSH terms: DNA; Random Amplified Polymorphic DNA Technique
Fulltext Betulinic acid was more cytotoxic towards the human breast cancer cell line MDA-MB-231 than the human promyelocytic leukaemia cell line HL-60

Latifah Saiful Yazan, Faujan Ahmad, Ooi, Choong Li, Raha Abdul Rahim, Hisyam Abdul Hamid, Lee, Pei Sze

Malaysian Journal of Pharmaceutical Science, 2009;7(1):23-37.
MyJurnal

Betulinic acid (BA) is a pentacyclic triterpene found in several botanical sources that has been shown to cause apoptosis in a number of cell lines. This study was undertaken to determine the in vitro cytotoxic properties of BA towards the human mammary carcinoma cell line MDA-MB-231 and the human promyelocytic leukaemia cell line HL-60 and the mode of the induced cell death. The cytotoxicity and mode of cell death of BA were determined using the MTT assay and DNA fragmentation analysis, respectively. In our study, the compound was found to be cytotoxic to MDA-MB-231 and HL-60 cells with IC50 values of 58 μg/mL and 134 μg/mL, respectively. Cells treated with high concentrations of BA exhibited features characteristic of apoptosis such as blebbing, shrinking and a number of small cytoplasm body masses when viewed under an inverted light microscope after 24h. The incidence of apoptosis in MDA-MB-231 was further confirmed by the DNA fragmentation analysis, with the formation of DNA fragments of oligonucleosomal size (180-200 base pairs), giving a ladder-like pattern on agarose gel electrophoresis. BA was more cytotoxic towards MDA-MB-231 than HL-60 cells, and induced apoptosis in MDA-MB-231 cells.

Matched MeSH terms: DNA; DNA Fragmentation
Unexpected diversity of sandflies (Diptera: Psychodidae) in tourist caves in Northern Thailand

Sukantamala J, Sing KW, Jaturas N, Polseela R, Wilson JJ

Mitochondrial DNA A DNA Mapp Seq Anal, 2017 11;28(6):949-955.
PMID: 27759464 DOI: 10.1080/24701394.2016.1214728

Certain species of Phlebotomine sandflies (Diptera: Psychodidae) are vectors of the protozoa which causes leishmaniasis. Sandflies are found breeding in enclosed places like caves. Thailand is a popular tourist destination, including for ecotourism activities like caving, which increases the risk of contact between tourists and sandflies. Surveillance of sandflies is important for monitoring this risk but identification of species based on morphology is challenged by phenotypic plasticity and cryptic diversity. DNA barcodes have been used for the identification of sandflies in Thailand. We collected sandflies using CDC light trap from four tourist caves in Northern Thailand. Female sandflies were provisionally sorted into 13 morphospecies and 19 unidentified specimens. DNA was extracted from the thorax and legs of sandflies and the DNA barcode region of cytochrome c oxidase I mtDNA amplified and sequenced. The specimens were sorted into 22 molecular operational taxonomic units (MOTU) based on the 145 DNA barcodes, which is significantly more than the morphospecies. Several of the taxa thought to be present in multiple caves, based on morphospecies sorting, split into cave-specific MOTU which likely represent cryptic species. Several MOTU reported in an earlier study from Wihan Cave, Thailand, were also found in these caves. This supports the use of DNA barcodes to investigate species diversity of sandflies and their useful role in surveillance of sandflies in Thailand.

Matched MeSH terms: Sequence Analysis, DNA; DNA Barcoding, Taxonomic
Combined Overlap Extension PCR Method for Improved Site Directed Mutagenesis

Hussain H, Chong NF

Biomed Res Int, 2016;2016:8041532.
PMID: 27995143

The combined overlap extension PCR (COE-PCR) method developed in this work combines the strengths of the overlap extension PCR (OE-PCR) method with the speed and ease of the asymmetrical overlap extension (AOE-PCR) method. This combined method allows up to 6 base pairs to be mutated at a time and requires a total of 40-45 PCR cycles. A total of eight mutagenesis experiments were successfully carried out, with each experiment mutating between two to six base pairs. Up to four adjacent codons were changed in a single experiment. This method is especially useful for codon optimization, where doublet or triplet rare codons can be changed using a single mutagenic primer set, in a single experiment.

Matched MeSH terms: DNA/genetics*

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