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.
Establishing a microbial diagnosis for patients with community-acquired pneumonia (CAP) is still challenging and is often achieved in only 30-50% of cases. Polymerase chain reaction (PCR) has been shown to be more sensitive than conventional microbiological methods and it could help to increase the microbial yield for CAP patients. This study was designed to develop, optimize and evaluate multiplex real-time PCR as a method for rapid differential detection of five bacterial causes of CAP namely Streptococcus pneumoniae, Burkholderia pseudomallei and atypical bacterial pathogens, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila. Duplex and triplex real-time PCR assays were developed using five sets of primers and probes that were designed based on an appropriate specific gene for each of the above CAP pathogens. The performance of primers for each organism was tested using SYBR Green melt curve analysis following monoplex realtime PCR amplification. Monoplex real-time PCR assays were also used to optimize each primers-probe set before combining them in multiplex assays. Two multiplex real-time PCR assays were then optimized; duplex assay for the differential detection of S. pneumoniae and B. pseudomallei, and triplex assay for the atypical bacterial pathogens. Both duplex and triplex real-time PCR assays were tested for specificity by using DNA extracted from 26 related microorganisms and sensitivity by running serial dilutions of positive control DNAs. The developed multiplex real-time PCR assays shall be used later for directly identifying CAP causative agents in clinical samples.
Diarrheal diseases cause illness and death among children younger than 10 years in developing countries. Conventional testing for the detection of hemorrhagic bacteria takes 2 to 5 days to yield complete information on the organism and its antibiotic sensitivity pattern. Hence, in the present study, we developed a molecular-based diagnostic assay that identifies common hemorrhagic bacteria in stool samples. A set of specific primers were designed for the detection of Salmonella spp., Shigella spp., enterohemorrhagic Escherichia coli (EHEC), and Campylobacter spp., suitable for use in a one-tube PCR assay. The assay in the present study simultaneously detected five genes, namely, ompC for the Salmonella genus, virA for the Shigella genus, eaeA for EHEC, 16S rRNA for the Campylobacter genus, and hemA for an internal control. Specific primer pairs were successfully designed and simultaneously amplified the targeted genes. Validation with 20 Gram-negative and 17 Gram-positive strains yielded 100% specificity. The limit of detection of the multiplex PCR assay was 1 × 10(3) CFU at the bacterial cell level and 100 pg at the genomic DNA level. Further evaluation of the multiplex PCR with 223 bacterium-spiked stool specimens revealed 100% sensitivity and specificity. We conclude that the developed multiplex PCR assay was rapid, giving results within 4 h, which is essential for the identification of hemorrhagic bacteria, and it might be useful as an additional diagnostic tool whenever time is important in the diagnosis of hemorrhagic bacteria that cause diarrhea. In addition, the presence of an internal control in the multiplex PCR assay is important for excluding false-negative cases.