1.Light microscopy and molecular identification of Sarcocystis spp. in meat producing animals in Selangor, Malaysia
Tropical Biomedicine 2015;32(3):444-452
One thousand and forty-five tissue samples of skeletal muscles, tongue, heart,
diaphragm and esophagus were collected from 209 animals (43 sheep, 89 goats and 77 cattle)
from an abattoir in Selangor between February and October, 2013. Each sample was divided
into three pieces with each piece measuring 2-3 mm3. Each piece was then squeezed between
two glass slides and examined microscopically at x 10 magnification for the presence of
sarcocystosis. Three positive samples from each animal species were then fixed in 10%
formalin for histological processing. Seven positive samples collected from each animal
species were preserved at -80°C or 90% ethanol for gene expression studies. Microsarcocysts
were detected in 114 (54.5%) animals by light microscopy (LM). The infection rates in sheep,
goat and cattle were 86, 61.8 and 28.6% respectively. The highest rate of infection was in the
skeletal muscles of sheep (64.9%) and goats (63.6%) and in the heart of cattle (63.6%). The
cysts were spindle to oval in shape and two stages were recognized, the peripheral metrocytes
and centrally located banana-shaped bradyzoites. 18S rRNA gene expression studies confirmed
the isolates from the sheep as S. ovicanis, goats as S. capracanis and cattle as S. bovicanis.
This, to the best of our knowledge, is the first molecular identification of an isolate of S.
ovicanis and S. capracanis in Malaysia. Further studies with electron microscopy (EM) are
required in the future to compare the features of different types of Sarcocysts spp.
2.Zika virus antibody-positivity among symptomatic/asymptomatic pregnant women in the Aseer region displays pre-exposure to dengue viruses
Harish, C.C. ; Ayed, A.A. ; Alhanshani, A.A. ; Youssef, A.A. ; Esther, P. ; Riyad, A.A.M. ; Abdullah, M.A. ; Anandalakshmi, S. ; Ashish, K. ; Ahmed, M.A.H.
Tropical Biomedicine 2023;40(No.3):337-343
Antibody cross-reactivity among flaviviruses is a major limitation in understanding the prevalence
without vector control measures. In this study, we investigated the presence of Zika virus (ZIKV)-specific
antibodies and the significance of their cross-reactivity with other flaviviruses, which could affect the
serological specificity in both symptomatic and asymptomatic pregnant women. Among the results
obtained from 217 serum samples tested for ZIKV-specific IgM and IgG, no specific predictions regarding
seropositivity or exposure due to extensive cross-reactivity with dengue virus (DENV) serology could be
made. Clear-cut positivity was observed in 1.8% (n = 4) and 1.0% (n = 2) for ZIKV IgM and IgG, respectively.
The same samples assessed for DENV showed 1.3% (n = 3) seropositivity each for IgM and IgG levels.
None of the samples were positive for ZIKV and DENV IgM or IgG. However, one sample (0.4%) tested
positive for ZIKV and DENV IgM. No significant correlation was observed between DENV IgM and IgG
when comparing the overlapped serotiters. On the other hand, the ZIKV IgG-positive sample showed
higher serotiters for DENV IgG, indicating cross-reactivity with ZIKV but without statistical significance.
Therefore, screening for the incidence of ZIKV becomes particularly challenging in a population where
the presence or pre-exposure to DENV is observed. Our observations further suggest that unless
flavivirus prevalence is properly addressed, determining the prevalence of ZIKV antibodies, which may
be confounded with other uninvestigated flaviviruses, will be complicated.