1.A reproducible method for extraction of Plasmodium falciparum DNA by microwave irradiation and its potential for rapid molecular diagnosis
Narong Jaturas ; Thulasi Kumar ; Brandon Mong Guo Jie ; Subashini Onichandran ; Tian Chye Tan ; Veeranoot Nissapatorn
Tropical Biomedicine 2015;32(4):753-760
Malaria remains one of the most important communicable diseases. A rapid, simple
and accurate method is a crucial part of malaria diagnosis. The aim of this study was to reevaluate
the microwave irradiation method to extract DNA from Plasmodium falciparum
and compare with six other existing DNA extraction methods such as QIAamp DNA mini kit
(Qiagen), FTA elute card, phenol-chloroform, Chelex, Chelex without proteinase-K and Rapid
boiling. Two different P. falciparum isolates were used: (i) Laboratory strains with 0.3%
parasitemia and (ii) clinical isolate with 0.6% parasitemia. Each DNA extraction method was
validated for the presence of P. falciparum by a routine nested and real time PCR. In order to
evaluate the sensitivity of the DNA extraction by microwave, double serial dilution of P.
falciparum from in vitro culture at parasitemia that ranged from 0.0001 to 0.17% were used
to extract the DNA by microwave and the P. falciparum DNA was then detected by nested
and real-time PCR. The nested and real-time PCR were able to detect. P. falciparum DNA at
the parasitemia level as low as 0.0003% and 0.0001%, respectively. Our results can reproduce
the results from earlier studies and reveal microwave as a rapid and simple tool to extract P.
falciparum DNA and subsequent molecular diagnosis of malaria.
2.Molecular identification of blow flies recovered from human cadavers during crime scene investigations in Malaysia
Rajagopal Kavitha ; Wasi Ahmad Nazni ; Tian Chye Tan ; Han Lim Lee ; Mohd Noor Mat Isa ; Mohd Sofian Azirun
The Malaysian Journal of Pathology 2012;34(2):127-132
Forensic entomology applies knowledge about insects associated with decedent in crime scene
investigation. It is possible to calculate a minimum postmortem interval (PMI) by determining the age
and species of the oldest blow fly larvae feeding on decedent. This study was conducted in Malaysia
to identify maggot specimens collected during crime scene investigations. The usefulness of the
molecular and morphological approach in species identifications was evaluated in 10 morphologically
identifi ed blow fl y larvae sampled from 10 different crime scenes in Malaysia. The molecular
identifi cation method involved the sequencing of a total length of 2.2 kilo base pairs encompassing
the ‘barcode’ fragments of the mitochondrial cytochrome oxidase I (COI), cytochrome oxidase II
(COII) and t-RNA leucine genes. Phylogenetic analyses confi rmed the presence of Chrysomya megacephala, Chrysomya rufifacies and Chrysomya nigripes. In addition, one unidentified blow fly species was found based on phylogenetic tree analysis.
3.Molecular identification of blow flies recovered from human cadavers during crime scene investigations in Malaysia.
Kavitha, Rajagopal ; Nazni, Wasi Ahmad ; Tan, Tian Chye ; Lee, Han Lim ; Isa, Mohd Noor Mat ; Azirun, Mohd Sofian
The Malaysian Journal of Pathology 2012;34(2):127-32
Forensic entomology applies knowledge about insects associated with decedent in crime scene investigation. It is possible to calculate a minimum postmortem interval (PMI) by determining the age and species of the oldest blow fly larvae feeding on decedent. This study was conducted in Malaysia to identify maggot specimens collected during crime scene investigations. The usefulness of the molecular and morphological approach in species identifications was evaluated in 10 morphologically identified blow fly larvae sampled from 10 different crime scenes in Malaysia. The molecular identification method involved the sequencing of a total length of 2.2 kilo base pairs encompassing the 'barcode' fragments of the mitochondrial cytochrome oxidase I (COI), cytochrome oxidase II (COII) and t-RNA leucine genes. Phylogenetic analyses confirmed the presence of Chrysomya megacephala, Chrysomya rufifacies and Chrysomya nigripes. In addition, one unidentified blow fly species was found based on phylogenetic tree analysis.
4. Anti-encystment and amoebicidal activity of Lonicera japonica Thunb. and its major constituent chlorogenic acid in vitro
Tooba MAHBOOB ; Abdul-Majid AZLAN ; Tian-Chye TAN ; Veeranoot NISSAPATORN ; Chandramathi SAMUDI ; Shamala Devi SEKARAN ; Christophe WIART
Asian Pacific Journal of Tropical Medicine 2016;9(9):866-871
Objective To examine the acanthamoebicidal effects of ethyl acetate, aqueous and butanol fractions of dried flower buds of Lonicera japonica (L. japonica) Thunb. (Flos Lonicerae) in vitro. Methods Acanthamoeba triangularis isolates were obtained from environmental water samples and identified by PCR. They were exposed to ethyl acetate, water and butanol fractions of L. japonica Thunb. at concentrations ranging from 0.5 mg/mL to 1.5 mg/mL. The extracts were evaluated for growth inhibition at 24, 48 and 72 h, respectively. Chlorogenic acid at a concentration of 1 mg/mL was examined for inhibition of encystment. Results Ethyl acetate fraction at a concentration of 1.5 mg/mL evoked a significant reduction of trophozoite viability by 48.9% after 24 h, 49.2% after 48 h and 33.7% after 72 h chlorogenic acid, the major active constituent of L. japonica Thunb. at the concentration of 1 mg/mL reduced the cysts/trophozoite ratio by 100% after 24 h, 84.0% after 48 h and 72.3% after 72 h. This phenolic compound at concentration of 1 mg/mL concurrent with 0.6% hydrogen peroxide inhibited hydrogen peroxide-induced encystment by 92.8% at 72 h. Conclusions Results obtained from this study show that ethyl acetate fraction at 1.5 mg/mL is the most potent fraction of L. japonica Thunb. and its major constituent chlorogenic acid showed the remarkable inhibition of encystment at a concentration of 1 mg/mL.