A quadriplex PCR assay for rapid detection of diarrhoeacausing parasitic protozoa from spiked stool samples

Diarrhoea is a leading killer of children, accounting for 9% of all deaths among children under age 5 worldwide and 3% in Malaysia in 2015. A large proportion of diarrhoea illnesses among children in developing countries are ascribed to an unknown etiology because microscopic examination was the only available technique which has low detection limits. The proposed study aimed to evaluate a new quadriplex PCR assay to detect parasitic pathogens namely E. histolytica, G. lamblia and C. parvum which considered responsible for the majority of human infections. Three set of specific primer pairs were designed for detection of parasitic pathogens. Quadriplex PCR assay was optimized and an internal amplification control was incorporated to check for PCR inhibitors in samples. The PCR assay was evaluated using spiked stool samples. Specific primer pairs were successfully designed and simultaneously amplified the targeted genes. The analytical sensitivity of the quadriplex PCR at the DNA level was found to be 50 ng DNA. The analytical specificity was evaluated with 11 reference protozoal and bacterial strains and was found to be 100%. We concluded that the developed quadriplex PCR assay was rapid and gave results within 5 hours which is essential for the identification of parasitic pathogen and might be useful as an additional diagnostic tool whenever time is important in the diagnosis of parasite that cause diarrhoea.

Microsatellite instability and loss of heterozygosity in oral squamous cell carcinoma in Malaysian population

Loss of heterozygosity (LOH) and microsatellite instability (MSI) have been documented as important events in oral squamous cell carcinoma (OSCC). Five microsatellite markers D3S192, D3S966, D3S647, D3S1228 and D3S659 were selected on chromosome 3p because of high frequency of alterations reported in head and neck squamous cell carcinoma and the involvement of von Hippel Lindau (VHL) at 3p25-26 and the fragile histidine triad (FHIT) at 3p14.2 genes proven in many tumour types. A total of 50 archival tissue samples of OSCC and corresponding normal samples were analyzed for LOH and MSI status. The overall LOH for the markers selected on 3p was 56 out of 189 informative cases (29.6%). The most frequent LOH was identified for the marker D3S966 which was 18/42 (42.8%) of informative cases suggesting the presence of putative tumour suppressor genes (TSGs) in this loci. In this study, high frequency of microsatellite instability was found in D3S966 which was 28.6% of informative cases; this reveals the possibility of mutations of MMR genes in this region. Frequent microsatellite alterations (MA) were observed in 3 markers D3S966 (71.4%), D3S1228 (56.7%) and D3S192 (41.0%). There was no significant association between LOH with gender, tumour stages and differentiation grades. However, there was a significant association between tumour stage and differentiation grades with MSI status in OSCC in Malaysian population with p values of 0.002 and 0.035, respectively. There was also a significant association between MA and differentiation grades (p=0.041).