1.Sequence analysis of E/NS1 gene junction of Dengue Type-1 viruses isolated in Klang Valley 2010 to 2012
Nur Liyana, K., Fauziah, M.K., Zainah, S., Nor Aziyah R., and Thayan, R.
Tropical Biomedicine 2016;33(2):348-358
Dengue is a mosquito-borne viral disease caused by four serotypes of dengue
virus, affecting the human population for decades in many tropical and subtropical regions of
the world. In Malaysia, all four dengue serotypes co-circulates in a dengue season even
though any one of the serotypes can predominate. In this study, serum samples were collected
from dengue fever and severe dengue fever patients within Klang Valley from 2010-2012 to
determine the prevailing dengue serotypes. In addition, sequencing of the envelope/nonstructural
1 (E/NS1) gene junction of the virus isolated was performed to identify the presence
of any mutations that are suggestive of increased virulence in the virus. The results showed
that Dengue-1 (DEN-1) was the predominant circulating serotype. The E/NS1 gene sequences
of the isolates were analysed to trace the evolutionary knowledge of the strains. All sequences
of the isolates were compared with DEN-1 prototype Hawaii strain as the reference sequence.
The E/NS1 sequences of other dengue strains from neighbouring regions as well as other
parts of the world obtained from the GenBank database were also included in the phylogenetic
tree analysis. Analyses showed that there was 97% to 100% similarity among the ten isolates
at the nucleotide level. Similarly, the amino acid analogue also showed 98% to 100% homology.
However, all five non-severe dengue isolates showed variation at position 780, resulting in an
amino acid change from valine to alanine as compared to severe dengue isolates. A rooted
phylogenetic tree was performed using neighbour-joining method with DEN-2 and DEN-3 as
the outgroups. Results showed that all ten isolates were classified as genotype I. In addition,
the five isolates from severe dengue patients were found to be clustered together with
JN697057 and JN697058, Malaysian DEN-1 strains from the 2005 outbreak.
2.Drug resistance mutations among virological failure HIV-1 infected patients in Malaysia
Mohd Zain, R. ; Ibrahim, N. ; Ismail, S. ; Mat-Rahim, N.A. ; Suppiah, J. ; Thayan, R. ; , Z.
Tropical Biomedicine 2016;33(3):486-493
The determination of HIV drug resistance mutations (DRMs) towards antiretroviral
(ARV) drugs among HIV-1 treated patients with virological failure is crucial for further
management of the patient. This study aimed to assess the most common genomic mutation
and to analyse subtypes among the HIV-1 patients with viral load level > 1,000 copies/mL. A
total of 101 virological failure HIV-1 patients from four different regions of Peninsular Malaysia
with a viral load measurement facility were included in the study. Majority of patients (89.1%)
have at least 1 mutation associated with clinical resistance to either protease inhibitors
(PIs), nucleoside reverse transcriptase inhibitors (NRTIs) or nonnucleoside reverse
transcriptase inhibitors (NNRTIs). Major resistance mutations among the patients towards
NRTIs and NNRTIs were 70.3% and 18.8%, respectively. The most common mutation for
NRTIs was M184V while K103N mutation was detected in the majority of patients who were
treated with NNRTIs. The most commonly observed mutations for major PI and minor PI seen
among the study population were V82A/T and L10V, respectively. In HIV-1 subtype analysis,
CRF33_01B was the most predominant HIV-1 subtype in this study group. The vast detection
of DRMs in this study emphasized the importance of genotypic resistance test in the
management of HIV patients as DRMs can alter patient’s susceptibility towards ARV drugs.
Further study on larger number of samples is essential for the development of a database on
HIV-1 DRMs among patients that experience virological failure in Malaysia.
3.Anti-inflammatory effect of mushrooms in dengue-infected human monocytes
Ellan, K. ; Thayan, R. ; Phan, C.W ; Sabaratnam, V.
Tropical Biomedicine 2019;36(4):1087-1098
Pathogenesis of dengue fever has been associated with the activation of the
cytokine cascade that triggered inflammatory responses. The inflammatory reactions in
dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS) are the main cause of
haemorrhagic manifestations, coagulation disorders, vascular permeability, hypotension and
shock which could exacerbate the condition of the disease. In an earlier study, extracts
belonging to Lignosus rhinocerotis, Pleurotus giganteus, Hericium erinaceus,
Schizophyllum commune and Ganoderma lucidium mushrooms were screened for antidengue
virus activities. We found that hot aqueous extract (HAE) and aqueous soluble separated
from ethanol extract (ASE) exhibited their potential to reduce dengue viral load which were
observed in plaque reduction assay and real-time RT-PCR. In continuation of our previous
findings, this study was initiated to further investigate the other aspect; the anti-inflammatory
activities of HAE and ASE of L. rhinocerotis, P. giganteus, H. erinaceus, S. commune and G.
lucidium on human monocytes infected with dengue virus-2 (DENV-2) New guinea C strain.
Human monocytes infected with DENV-2 were treated with mushroom extracts for 48 hours.
The cytokine profile coincides with dengue infection, i.e. IFN-γ, TNF-α, IL-1β, IL-6, IL-8, and
IL-10 were measured by BD OptEIATM Elisa Kit. The expression of these cytokines was
significantly elevated in untreated infected cells two days after infection. However, after
treated with mushroom extracts prominent anti-inflammatory effect were detected towards
IFN-γ, IL-10, TNF-α, IL-6, and IL-1β. The most significant anti-inflammatory effects were
detected in HAE of G. lucidium, S. commune, P. giganteus and ASE of L. rhinocerotis and
the effects were comparable with dexamethasone, the reference inhibitor. These results
demonstrated that mushroom HAE or ASE could successfully have suppressed cytokine
production in dengue-infected monocytes and has a great potential to develop an antiinflammatory
agent from mushroom extract for the treatment of dengue infection.
4.HIV-2 Infection in Malaysia: Current situation and the use of in-house real-time reverse transcription PCR for HIV-2
Mohd Zain, R. ; Ismail, S. ; Ellan, E.K. ; Wan Mahmood, N.A.N. ; Md Kassim, F. ; Thayan, R.
Tropical Biomedicine 2018;35(3):769-774
HIV-2 surveillance has been carried out in Malaysia for more than 25 years ago.
Tests to discriminate HIV-1 and HIV-2 are available but the options of test are limited and the
need to develop a new in-house HIV-2 real-time reverse transcription PCR (RT-PCR) is crucial.
A study was done on 29 samples from hospitals in Malaysia which were found to be positive
screening for HIV-2 antibodies by the commercial Western Blot assay. These samples were
further tested by a Western Blot assay that detects specific antibodies to HIV-2. Detection of
HIV-2 genome was then performed by using a commercial kit. Fifteen samples were evaluated
by using in-house real-time RT-PCR for HIV-2. Ninety-three percent (27/29) of samples have
positive results for HIV-2 on HIV-2 Western Blot with only 2 samples showing indeterminate
results. All samples showed negative results for HIV-2 genomes by using a PCR commercial
kit and the 15 samples that were subjected to our in-house real-time RT-HIV-2 PCR were also
tested negative for HIV-2 RNA. Results of HIV-2 Western Blot did not reflect the actual
positivity as both HIV-1 and HIV-2 antibodies may cross-react with either viral proteins. None
of the samples was confirmed positive for HIV-2 by the commercial and in-house real-time RTPCR.
In-house real-time RT-HIV-2 PCR assay can be further used to confirm the presence of
HIV-2 genome. Up to the year 2015, Malaysia is still free from HIV-2 infection.
5.Phylogenomic analysis of SARS-CoV-2 from third wave clusters in Malaysia reveals dominant local lineage B.1.524 and persistent spike mutation A701V
Suppiah, J. ; Kamel, K.A. ; Mohd-Zawawi, Z. ; Afizan, M.A. ; Yahya, H. ; Md-Hanif, S.A. ; Thayan, R.
Tropical Biomedicine 2021;38(No.3):289-293
The emergence of a third wave of COVID-19 infection in Malaysia since September 2020 has led to imminent changes in public health prevention and control measures. As high as 96.2% of registered COVID-19 cases and 88.5% of confirmed deaths in Malaysia occurred during this third wave of infection. A phylogenomic study on 258 SARS-CoV-2 full genomes from February 2020-February 2021 has led to the discovery of a novel Malaysian lineage B.1.524. This lineage contains another spike mutation A701V that co-exists with the D614G spike mutation that was predominant in most of the third-wave clusters. The study provides vital genomic insights on the rapid spread of the SARS-CoV-2 variants in Malaysia in conjunction with the presence of a dominant SARS-CoV-2 lineage during the third wave of COVID-19 infection.
6.Environmental surface sampling of SARS-CoV-2 in selected hospitals in Malaysia
Rajendiran, S. ; Thahir, S.S.A. ; Veloo, Y. ; Suppiah, J. ; Pahrol, M.A. ; Shakor, A.S.A. ; Mohamad, N. ; Ramly, N. ; Shariff, H.M. ; Karim, R.A. ; Chidambaram, S.K. ; Senian, R. ; Ahmad, N. ; Thayan, R. ; Shaharudin, R.
Tropical Biomedicine 2021;38(No.3):462-468
COVID-19 has spread rapidly worldwide. The role of fomites in facilitating onward transmission is plausible. This study aimed to determine the presence of viable virus and its persistence on the surfaces of fomites in wards treating COVID-19 patients in Malaysia. This study was conducted in two stages. First, environmental sampling was performed on random days in the intensive care unit (ICU) and general wards. Then, in the second stage, samples were collected serially on alternate days for 7 days in two selected general wards. In Stage 1, a total of 104 samples were collected from the surfaces of highly touched and used areas by patients and healthcare workers. Only three samples were tested positive for SARS-COV-2. In Stage 2, three surface samples were detected positive, but no persistence of the virus was observed. However, none of the SARS-CoV-2 RNA was viable through tissue culture. Overall, the environmental contamination of SARS-CoV-2 was low in this hospital setting. Hospitals’ strict infection control and the compliance of patients with wearing masks may have played a role in these findings, suggesting adherence to those measures to reduce occupational exposure of COVID-19 in hospital settings.