Vibrio parahaemolyticus is prevalent in tropical marine environment in all seasons and can cause seafood-borne gastroenteritis. A total of 251 suspected isolates were tested including 60 from frozen shrimp, 50 from cultured live shrimp, 67 from sediments of culture ponds and 74 from water were subjected to polymerase chain reaction (PCR) targeting the toxR gene for confirmation as V. parahaemolyticus. Of the 128 toxR positive isolates, 15% of the isolates from culture environment (from live shrimp, sediments and water) and 7% of frozen shrimp samples were positive for the tdh and trh genes. Since urease production could be a marker of trh but not tdh in V. parahaemolyticus, a total of 189 of the 251 suspected V. parahaemolyticus isolates were tested for urease production and 41% of the isolates were found to be positive for urease production. However not all urease positive strains of V. parahaemolyticus were positive for either tdh or trh genes. Detection of virulent strains in shrimp culture environment in Malaysia suggests a probable risk for health of people consuming raw shrimp.
This study aimed to determine the amount of the fish (Oreachromi sp, Clarias sp. and Pangasius sutchii) consumption in Malaysia; the quantity of heavy metal residues (arsenic, cadmium, mercury and plumbum) in the fish and the level of the risk exposure. About 1440 respondents from six main production districts were randomly interviewed and the body weight of the respondents was also measured. A total of 240 ready to eat fish from food premises were also stratified randomly sampled where each sample was weighted to determine the average weight of one serving unit sold at food premises. The heavy metal residues were analyzed using Inductively Coupled Plasma–Optical Emission Spectrometer (ICP-OES) Optima 4300 DV (German). The level of heavy metals risk exposure was calculated as the percentage value of ’Provisional Tolerable Weekly Intakes’ (PTWI) and recalculated using computer programme @Risk 4.5 Excel (Palisade, USA). The result showed that 60.3% of the respondents consumed the fish. The level of heavy metal risk exposures were calculated as very low i.e. 0.14% (As), 0.31% (Cd), 0.09% (Hg) and 0.78% (Pb).
This study was conducted on selected local herbs such as ulam raja (Cosmos caudatus), kesum (Polygonum minus), selom (Oenanthe javanica), pegaga (Centella asiatica) and curry leaves (Murraya koenigii) to investigate their antioxidative activities. The water extracts of the herbs were analysed for total phenolic content, reducing antioxidant power, ferric thiocyanate (FTC) and the thiobarbituric acid (TBA) test was also accried out. Polygonum minus showed the highest total phenolic content and reducing power among the herbs. Increasing the concentration of the extracts resulted in increased Fe3+ reducing antioxidant power for all the herbs. FTC and TBA tests on the extracts during seven days of storage showed that all the herbs extracts had the ability to reduce oxidation compared to the control (P < 0.05). From the FTC analysis, Murraya koenigii leaves was best in reducing the oxidation rate (67.67%) compared to the other herbs studied. Analysis of TBA showed that Centella asiatica extract had the highest antioxidant effect. However, both TBA and FTC analysis for these two herbs showed no significant difference (P >0.05) from Polygonum minus and butylated hydroxyanisole (BHT) a synthetic antioxidant. Correlation analysis showed positive correlations between amount of total phenolic content and reducing power (r = 0.75) and antioxidative activities (r = 0.58) in linoleic acid emulsion system. This shows that antioxidative activities of these Malaysian herbal plants especially Polygonum minus may be a potential source of natural antioxidants with similar characteristics to the synthetic antioxidant, BHT.
This study was conducted to investigate the sensitivity and detection of porcine DNA in raw materials, ingredients and finished bakery products by polymerase chain reaction (PCR) - southern hybridization on chip analysis. A total of 20 samples (n=20* 3) with three replicates for each samples were obtained from a bakery factory located in Bangi, Selangor from January to December 2012. The sensitivity level of PCR-southern hybridization on chip was 0.001 ng. The species-specific oligonucleotide primers used in PCR-southern hybridization were targeted on the mitochondria DNA (mtDNA) of cytochrome b (cyt b) gene sequence, namely cty b biotin-labeled oligonucleotide primers. The amplicon from PCR amplification was 276 bp in size. None of the raw materials, ingredients and finished bakery product samples was positive towards porcine DNA, except for the positive control. The results in the present study demonstrated that the PCR- southern-hybridization technique on the gene chip (OliproTM Porcine gene chip) is a sensitive tool for monitoring the porcine component in highly processed ingredients and finished bakery products.
Forty three (n=43) genomic DNA of Escherichia coli (11 isolates from eggs and 32 isolates from imported beef meats) were characterized by shiga toxin 1 (stx1), enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and random amplified polymorphic DNA-PCR (RAPD-PCR) analyses. In the shiga toxin 1 (stx1) gene detection with primer stx 1F (5’-TTCTTCGGTATCCTATTCCC-3’) and stx 1R (5’- CTGTCACAGTAACAACCGT-3’), 9 E. coli of beef meats isolates were positive toward sxt1 gene. The results of the ERIC-PCR and RAPD-PCR were analyzed using GelCompar II software. ERIC-PCR with primer ERIC1 (5’-CACTTAGGGGTCCTCGAATGTA -3’) and ERIC2 (5’-AAGTAAGTGACTGGGGTGAGCG-3’) discriminated the E. coli into 6 clusters and 10 single isolates at 80% similarity. RAPD-PCR with primer Gen8 and Gen9, produced 10 clusters and 15 single isolates and 12 clusters and 14 single isolates of 80%, respectively. These results demonstrated that both ERIC-PCR and RAPD-PCR are useful and suitable tools for molecular typing of those isolates examined.
The study was conducted to detect the porcine DNA in pharmaceutical products in local market using polymerase chain reaction (PCR) and southern-hybridization on the biochip. A total of 113 (n=113) of hard (82 samples) and soft gel (31 samples) capsules from pharmaceutical products were purchased and tested for the presence of porcine DNA for Halal authentication. All capsules were gelatin-based purchased from local over the counter (OTC) markets. Of all samples tested, 37.2% (42/113) contained porcine DNA. While, none porcine DNA band was detected for 62.8% (71/113) of capsules tested. All samples which were positive toward porcine DNA were imported pharmaceutical products with none Halal logo. Results in the presence study demonstrated that the PCR techniques and southern-hybridization on the biochip is suitable tool for monitoring the Haram component in highly processed product of soft and hard capsule.