1.Entamoeba infections and associated risk factors among migrant workers in Peninsular Malaysia
Sahimin, N. ; Yunus, M.H. ; Douadi, B. ; Yvonne Lim, A.L. ; Noordin, R. ; Behnke, J.M. ; Mohd Zain, S.N.
Tropical Biomedicine 2019;36(4):1014-1026
The influx of low skilled migrant workers to Malaysia from low socio-economic
countries where gastrointestinal parasitic infections are prevalent has raised concerns about
transmission to the local population. Three methods for detection (serology, microscopy and
molecular techniques) were utilized to identify Entamoeba infections amongst the targeted
cohort and determine risk factors associated with infection. Serological screening of 484
migrant workers from five working sectors in Peninsular Malaysia using IgG4 ELISA based on
the rPPDK antigen showed an overall seroprevalence of 7.4% (n = 36; CL95 = 5.3–10.1%) with
only one factor statistically associated with seropositivity of anti-amoebic antibodies, i.e.
years of residence in Malaysia (χ2
1 = 4.007, p = 0.045). Microscopic examination of 388 faecal
samples for protozoan cysts and trophozoites showed a slightly higher prevalence (11.6%;
n=45; CL95: 8.4–14.8%). Meanwhile, amplification of the 16S rDNA gene detected two species
i.e. Entamoeba dispar (23/388; 5.9%; CL95: 3.6–8.3%) and E. histolytica (11/388; 2.8%; CL95:
1.2–4.5%) and mixed infections with both parasites in only three samples (3/388; 0.8%; CL95:
0.2–2.2%). Entamoeba dispar infection was significantly associated with those employed in
food and domestic services (χ2
4 = 12.879, p = 0.012). However, none of the factors affected
the prevalence of E. histolytica infection. Despite the low prevalence of E. histolytica in
faecal samples of the study cohort, the presence of this pathogenic parasite still poses
potential public health risks and calls for tighter control strategies based on better availability
of chemotherapeutic treatment and accessibility to appropriate health education.
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.