1.Prevalence and risk factors of Toxoplasma infection – an update in Malaysian pregnant women
Chemoh, W. ; Nur Farhana, M.N. ; Noor Azmi, M.A. ; Si Lay, K. ; Sawangjaroen, N. ; Tan, T.C. ; Chandramathi, S.R ; Nissapatorn, V.
Tropical Biomedicine 2019;36(3):694-702
Toxoplasma gondii is a protozoan parasite that is capable of causing a zoonotic
disease, known as toxoplasmosis. Vertical transmission of T. gondii from the mother to the
fetus, during pregnancy may cause severe complications to the developing fetus. This current
study aimed to determine the seroprevalence and investigate the associated risk factors of
Toxoplasma infection in pregnant women (n=219) visiting the antenatal clinic at UMMC.
While the elevated level of anti-Toxoplasma IgG and IgM antibodies indicates the presence
of infection, it fails to differentiate between a past and a recent infection. Thus, the study
also demonstrates the usefulness of IgG avidity in validating the timing of infection. The
serum samples were tested for the presence of anti-Toxoplasma IgG and IgM antibodies by
ELISA test, and the seropositive samples for both anti-Toxoplasma IgG and IgM antibodies
were further evaluated by IgG avidity. The results showed that the overall prevalence of T.
gondii seropositivity was 34.7%. Of these, 30.6% (67/219) were positive for anti-Toxoplasma
IgG antibody only, 2.3% (5/219) were positive for anti-Toxoplasma IgM only, and the remaining
1.8% (4/219) was positive for both anti-Toxoplasma IgG and IgM antibodies. All of the pregnant
women who were positive for both anti-Toxoplasma IgG and IgM antibody were found to
have past infection when evaluated by IgG avidity. In this study, Malay ethnicity and the
number of existing previous children were significantly associated with T. gondii seropositivity
(p<0.05). Based on these findings, information and education on the transmission and
prevention of congenital toxoplasmosis are very crucial as a public health effort towards a
healthier society.
2.Synthesis, characterization, anti-mycobacterial activity and in silico study of new 2,5-disubstituted-1,3,4-oxadiazole derivatives
Azmi, M.N. ; Hasmaruddin, N.S. ; Mat Ali, N.A. ; Osman, H. ; Mohamad, S. ; Parumasivam, T. ; Hassan, M.Z. ; Abd Ghani, M.S. ; Awang, K.
Tropical Biomedicine 2022;39(No.3):467-475
A series of new 2,5-disubstituted-1,3,4-oxadiazole derivatives (5a-j and 6a-j) have been designed and
synthesized in four-steps. Sixteen compounds among the twenty compounds are reported for the first
time. The compounds were characterized and confirmed by the FTIR, 1D- and 2D-NMR and HRMS
analyses, and were tested against Mycobacterium smegmatis and Mycobacterium tuberculosis H37Ra.
Compound 5d was the most active against M. smegmatis with MIC value of 25 µM, and exhibited
cidal activity with MBC of 68 µM, respectively. The time-kill assay showed the good killing rate at 77%
with the combination of isoniazid (INH). In addition, checkboard assay confirmed the interaction of
compound 5d was categorised as additive. Docking simulation has been performed to position 5d into
the pantothenate synthetase active site with binding free energy value –8.6 kcal mol-1. It also occupied
the same active site as that of standard native ligand with similar interactions, which clearly indicate
their potential as pantothenate synthetase inhibitor.