1.Prevalence and Distribution of Anti-Amoebic IgG Antibody among Orang Asli (Aborigines) in Peninsular Malaysia
Wong, W.K. ; Lim, B.H. ; Hamid Jan, J.M. ; Foo, P.C.
Tropical Biomedicine 2016;33(4):739-745
Entamoeba species are commonly detected in stool samples of Orang Asli due to
their substandard living conditions and poor hygiene. Among the Entamoeba spp., Entamoeba
histolytica is the only known primary pathogenic species. This study determined the prevalence
and distribution of anti-amoebic IgG antibody among Orang Asli in Peninsular Malaysia. The
results would reflect the prevalence of amoebiasis in the population. This study analysed a
total of 375 serum samples from archives of two Orang Asli projects conducted between 2011
and 2014. They were from six different states in Malaysia, namely Johor, Kedah, Kelantan,
Pahang, Perak, and Selangor. Anti-amoebic IgG antibody was detected using an enzymelinked
immunosorbent assay (ELISA) with crude soluble antigen produced from axenically
grown E. histolytica trophozoites. From the analysis, the overall seropositivity was
approximately 71% (266/375), while the seropositivity rates for each of the three Orang Asli
tribes i.e. Senoi, Negrito and Proto-Malay, were 66% (137/208), 92% (103/112), and 43% (17/
41) respectively. Orang Asli from Kedah [95% (52/55)] showed the highest seropositivity,
followed by Kelantan [79% (54/68)], Perak [73% (78/107)], Pahang [60% (57/95)], Selangor
[56% (14/25)], and Johor [48% (10/21)]. Orang Asli from rural [76% (192/254)] and peripheral
urban [65% (69/106)] areas showed significantly higher seropositivity (p=0.002) than those
from urban areas [36% (4/11)]. The high prevalences of anti-amoebic IgG antibody in these
Orang Asli populations comprised both active and past infections. This study provides current
insights of amoebiasis in selected Orang Asli settlements in Peninsular Malaysia. The high
seropositivity of anti-amoebic IgG antibody suggests that the settlements are endemic for
amoebiasis and there is a high risk of acquiring E. histolytica infection among the dwellers.
2.Development and validation of TaqMan real-time PCR for the detection of Burkholderia pseudomallei isolates from Malaysia
Mohd Ali, M.R ; Foo, P.C. ; Hassan, M. ; Maning, N. ; Hussin, A. ; Syed Ahmad Yunus, S.Z. ; Fauzi, M.H. ; Muhd Besar, A. ; Harun, A. ; Ismail, N. ; Chan, Y.Y.
Tropical Biomedicine 2019;36(2):379-389
Rapid detection of Burkholderia pseudomallei, the etiologic agent of melioidosis,
allows for timely initiation of appropriate treatment and better clinical outcomes. In the
current gold standard, the culture method is time consuming and suffers from low sensitivity.
Meanwhile, previously reported molecular assays are fast and sensitive, but their performance
on isolates from Malaysia, an endemic region of melioidosis is under reported. This study
designed oligonucleotides targeting orf2 of Type III secretion system (TTSS) genes cluster
for the detection of Malaysian B. pseudomallei isolates and evaluated the assay on 95 local
B. pseudomallei strains, 58 other microorganisms and 71 clinical specimens from patients.
The developed assay exclusively detected all tested B. pseudomallei isolates with a detection
limit of 20 fg per reaction (equivalent to ~2.5 copies). Subsequent testing on clinical samples
showed that the assay detected all confirmed specimens with the growth of B. pseudomallei
(n = 10/10). None of the negative specimens had a detectable signal of our TTSS-orf2 assay
(n = 0/61). In conclusion, the present study provides crucial preliminary data for a subsequent
study and should be considered as a potential alternative to current time-consuming culture
method for the detection of B. pseudomallei.