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Isothermal amplification is a technique that can amplify target DNA sequences at a single incubation temperature. Loop-mediated isothermal amplification (LAMP) is an extension of the isothermal DNA amplification technique that combines rapidity, simplicity, high specificity and sensitivity. Due to its overwhelming characteristics, LAMP has been explored for its feasibility in detecting various subjects, and recently in meat-based food products for DNA-based meat species authentication. It has been developed to target various meat species such as porcine, chicken, horse, and ostrich with sensitivity as low as 0.1 pg/μL. Further improvement with the use of magnetic beads, electrochemiluminescence and special dye such as calcein and crystal violet had increased the sensitivity of the LAMP assay. Other important characteristics were specific target gene primers as well as a shorter incubation time, warranting a good prospect for rapid testing authentication. [ABSTRACT FROM AUTHOR]

Escherichia coli and Escherichia coli O157 were identified from "selom" (Oenanthe stolonifera), "pegaga" (Centella asiatica), beef, chicken, lamb, buffalo, "ulam Raja" (Cosmos caudatus) and "tenggek burung" (Euodia redlevi). The bacteria were recovered using chromagenic agar. Isolated Escherichia coli and Escherichia coli 0157 were further characterized by plasmid profiling and enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The virulence genes of the isolates (VT1, VT2, LT, ST, eaeA, inV) that produces pathogenic Escherichia coli and 16S rRNA gene were screened by a multiplex PCR assay. The plasmid profiling analysis showed that out of 176 isolates, only 103 isolates contained plasmids. ERIC-PCR analysis generated amplified products in the range of ~150 bp to > 1000 bp categorizing isolates into a total of 52 different profiles. Multiplex PCR showed that 20 (32.3%) of the isolates carried eaeA gene, 6 (9.7%) isolates possessed inV genes, only 1 (1.6%) have VT2 genes and 1 (1.6%) as well carried VT1 genes, 2 (3.2%) of the isolates harboured LT genes, and only 1 (1.6%) isolate possessed ST genes. There were no correlation between plasmid, ERIC-PCR and virulence genes profiles. [ABSTRACT FROM AUTHOR]

Presence of Norovirus in food can cause viral gasteroenteritis. Recently, lots of reports relating to Norovirus in food have been published. Special attention must be paid to the raw foods as they are not subjected to further heat treatment. In this study, pegaga, kesum, tauge and ulam raja (popular salad vegetables in Malaysia) were investigated for Norovirus. A total of 32 samples from each type of salad vegetables were purchased from local market and analyzed using One-step RTPCR (Reverse Transcriptase-Polymerase Chain Reaction) for both genogroups namely Norovirus Genogroup I and Genogroup II. Results showed that tauge had the highest contamination with Norovirus Genogroup I (15.6%) comparing to pegaga (9.4%), kesum (12.5%) and ulam raja (0%). Samples were free from Norovirus Genogroup II. The study showed that raw vegetables are high-risk foods and can be contaminated with Norovirus. [ABSTRACT FROM AUTHOR]

Mid-exponential phase Saccharomyces rouxii YSa40 cells subsequently stressed at low aw/pH in the 0.64 aw/pH 3.5 glycerol/CPB system became injured. Such injury was detected by the loss of ability of the stressed population to form colonies on secondary-stress plating medium (glycerol/BM agar at 0.94 aw/pH 3.5 (lactic acid)) while colony forming ability on secondary non-stress plating medium (sugars/BM agar at 0.94 aw/pH 3.5 (lactic) was unaffected. The injury was shown to be due to sensitivity to glycerol/lactic acid. Results of the present study will be useful for achieving complete decontamination of 'Intermediate Moisture Foods' against xerotolerant molds and yeast. [ABSTRACT FROM AUTHOR]

A total of 49 isolates of V. parahaemolyticus and 8 isolates of V. cholerae isolated from freshwater fish of patin (Pangasius hypopthalmus) and red tilapia (Oreochromis sp.) were purchased from different retail level in Selangor, Malaysia. All of the isolates showed a multiple resistances towards all 15 antibiotics tested. Some of the isolates show a high resistance to different antibiotics including bacitracin, vancomycin, tetracycline, furazididone, cephalothin and erythromycin. However, both species was susceptible towards imipenem. Overall antibiotics resistance patterns of all isolates were resistant from 2 to 14 resistance patterns with multiple antibiotic resistance (MAR) index ranging from 0.13 to 0.93 respectively. As the results obtained in the dendrogram produced from both species had indicates that these antibiotics were intensively used whether in the aquaculture farm through feeds during culture or at the hatchery production of seed. Thus, this study will provides an essential information of the MAR index and also the clustering analysis in order to determine the biosafety of Vibrio spp. in freshwater aquaculture fish sold at different retail level in Malaysia. [ABSTRACT FROM AUTHOR]

A total of sixty V. parahaemolyticus strains isolated from local cockles (Anadara granosa) were investigated by their antibiotic resistance patterns and plasmid profiles. The isolates showed multiple resistances towards most of the antibiotics tested. All strains of V. parahaemolyticus isolated harbored 1-3 plasmids, with sizes ranging from 2.7 to 54 kb. All V. parahaemolyticus strains showed high multiple antibiotics in frequencies of 0.58 - 0.94 indicating that the strains were derived from high-risk sources. In addition, no particular plasmid profile was predictive of a particular pattern of antibiotic susceptibility. These findings are essential because of the suggested involvement of seafood especially shellfish and environment in transmission of this pathogen to human. Thus, indicating that seafood may be a source of food- acquired antibiotic resistant bacteria to consumer. [ABSTRACT FROM AUTHOR]

In this study, Listeria spp. were isolated from naturally contaminated samples of beef burger, minced beef and sliced cheese using PALCAM and CHROMagar™. Samples were enriched with FDA-BAM method and plated on PALCAM and CHROMagar™ Listeria before confirmation using PCR on hlyA and LLO toxin genes specific to L. monocytogenes. Identification of isolates showed a total of 45 isolates of Listeria spp. and two L. monocytogenes. All the 47 isolates were then subjected to RAPD analysis using two oligomers (OPA14 and OPA15) and fingerprint clustering was able to cluster the L. monocytogenes from Listeria spp. based on isolation from agar types as well as L. monocytogenes from Listeria spp. Studies showed that OPA14 and OPA15 are useful for rapid discrimination of Listeria spp. and L. monocytogenes. The differences observed on the isolation of Listeria spp. from PALCAM and CHROMagar™ Listeria that may have an impact on epidemiological studies. [ABSTRACT FROM AUTHOR]

Little is known on the biosafety level of Vibrio spp. in freshwater fish in Malaysia. The purpose of this study was to investigate the prevalence and concentration of Vibrio spp. and V. parahaemolyticus in freshwater fish using the Most Probable Number-Polymerase Chain Reaction (MPN-PCR) method. The study was conducted on 150 samples from two types of freshwater fish commonly sold at hypermarkets, i.e. Pangasius hypophthalmus (catfish) and Oreochromis sp. (red tilapia). Sampling was done on the flesh, intestinal tract and gills of each fish. The prevalence of Vibrio spp. and V. parahaemolyticus was found to be 98.67% and 24% respectively with higher percentages detected in samples from the gills followed by the intestinal tract and flesh. Vibrio spp. was detected in almost all red tilapia and catfish samples. V. parahaemolyticus was detected in 25% of the catfish samples compared to 22.6% of red tilapia fish. The density of Vibrio spp. and V. parahaemolyticus in the samples ranged from 0 to 1.1x107 MPN/g. Although the maximum value was 1.1x107 MPN/g, most samples had microbial loads ranging from 0 to >104 MPN/g. The outcome on the biosafety assessment of Vibrio spp. and V. parahaemolyticus in freshwater fish indicates another potential source of food safety issues to consumers. [ABSTRACT FROM AUTHOR]

Several Norovirus cases due to consumption of green onions have been reported during recent years but reports on red onions are not found. Onions are one of the major tastes in Malaysian food which are sometimes consuming raw especially the green onion. Viral contamination in onions can occur due to planting condition and not properly prepared food. This situation can pose the human health risk. A method was developed to detect the Norovirus that might present on different type of onions. In this study, 60 samples were collected from local market. Elution by Tryptose Phosphate Glycine broth and concentration steps using negatively charge filter were applied to enhance the detection of virus in food due to low copies of virus on food surface. The viral RNA was extracted using Qiagen Rneasy Mini kit before further detection using One-step RT-PCR. The total incidence of Norovirus in green onion and red onion was 13.33% (4/30) and 3.33 % (1/30) respectively. This is the first report of the detection of Norovirus in red and green onions in Malaysia. Based on the results, it is concluded that this method is reliable to detect Norovirus on onions and vegetables surface and hence can be applied in the laboratories for routine or food borne outbreak investigation. [ABSTRACT FROM AUTHOR]

Salmonellosis continues to be a major public health problem worldwide. It also contributes to negative economic impacts due to the cost of surveillance investigation, treatment and prevention of illness. As such, research on Salmonella has gained great interest and concern from scientists. The purpose of this review is to discuss the classification and nomenclature, characteristic, clinical manifestation, epidemiology, transmission vehicles, antibiotic resistance and quorum sensing of Salmonella. [ABSTRACT FROM AUTHOR]

Genetically modified organisms (GMO) are increased remarkably from year to year and the estimated global area cultivated with genetically modified (GM) crops reached 125 million hectares in year 2008. However, insect resistance maize based on Bacillus thuringienses (Bt) is of the most cultivated GM crop in worldwide. Bacillus thuringiensis (Bt) is an aerobic, gram-positive bacterium that synthesize one or more Cry protein that are toxic to various types crop and forestry insects pests. To date, several cry genes have been introduced into GM plant to combat with various type of insect. Worldwide commercialization of GM crops has raised the customers' concern about the Biosafety issues, and thus, many countries have implemented the labeling legislations for GM food and their derivatives. In this study, we introduced the quantitative analysis method based on the recombinant plasmid DNA as calibrators that can be used to determine the percentage of GMO content in various types of food and feed samples. Therefore, we have reported 7.5% (6/80) of the samples were contained StarLink maize and 1.25% (1/80) samples were contained Bt176 maize. Additionally, the percentage of GM content in each positive sample were further determined with the developed quantitative method. The percentage of the StarLink corns that present in the positive samples were varies from 0.09% to 2.53% and Bt176 corn that present in the positive sample was 16.90%. The present study demonstrated that the recombinant plasmid DNA that used in quantitative real-time method as good alternative quantitative analysis of GM content. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine vegetarian burger patties manufactured by two producers in Malaysia for the presence of Listeria monocytogenes. Brand A was produced by an established food manufacturer while Brand B was produced by a small-scaled food producer. A total of 108 samples of vegetarian burger patties produced by both manufacturers were sampled from retail market and were analyzed by combined MPN-PCR and MPN plating method. Of all the samples tested, ten (9.3%) were found to be contaminated with L. monocytogenes. The L. monocytogenes contamination level in vegetarian burger patties manufactured by producer A (20.9% of the samples were contaminated with 3-1100 MPN/g of L. monocytogenes) was significantly higher (P<0.05) than vegetarian burger patties manufactured by producer B (1.5% of the samples harbored 9.2 MPN/g of L. monocytogenes). Based on the detection and isolation rate obtained with MPN-PCR and MPN-plating, the recovery rate of the L. monocytogenes was estimated to be only 40.0% by MPN-plating approach. [ABSTRACT FROM AUTHOR]

Adhesion of microorganism to food contact surface can become a source of microbial contamination. Enhanced resistances to environmental stresses are exhibited by biofilm producers. In this study, biofilm formation by Salmonella Typhi and Salmonella Typhimurium on plastic cutting board was accessed before the evaluation of the transfer of these two pathogens from plastic cutting board to dragon fruit. By using crystal violet assay, it was found that the adhesion on plastic cutting board by these two pathogens was the greatest at time 12 h. Results showed that Salmonella adhesion is strain-dependent and varied with time. The mean transfer rate from contaminated plastic cutting board to dragon fruit was examined to be 0.79 and 0.72 for Salmonella Typhi and Salmonella Typhimurium, respectively. This indicated that there is a risk of cross-contamination which should be concerned. [ABSTRACT FROM AUTHOR]