Escherichia coli O157:H7 is a major food-borne pathogen that has resulted in numerous
outbreaks around the world. Widespread distribution of the organism in various ecological
niches impedes the control measures. This study aimed to detect and quantify E. coli O157:H7
in beef sold in wet markets and hypermarkets in Malaysia and to determine the risk of E. coli
O157:H7 infection linked to consumption of beef. The rfbO157 and flicH7 primers targeted on
somatic antigen (O157) and flagellar antigen (H7) respectively of E. coli O157:H7 was used for
the MPN-PCR method. A total of 99 beef samples were collected from local wet markets and
hypermarkets. The highest E. coli O157:H7 contamination rate was observed in beef samples
collected from wet markets (89.50%), whereas the contamination rate in hyper market A and B
were compratively low (35.35 and 20% respectively). However, the microbial load was highest
in the beef samples from hypermarket A (1100 MPN/g) while E. coli O157:H7 bacterial load
in beef samples from hypermarket B and wet market ranged from 3 to 93 MPN/g and 3 to 240
MPN/g, respectively. Using the Quantitative Microbial Risk Assessment (QMRA) approach
the risk was estimated incorporating the findings of the prevalence study and predictions
based on home storage, cooking and consumption patterns. Three different exposure pathways
were investigated to estimate the risk associated with contaminated beef and Monte Carlo
simulation was used to determine the level of uncertainty. The developed model predicated that
consumption of contaminated beef can be accountable for 1.83E+06 E. coli O157:H7 cases per
year in Malaysia. The reliability of the model, data gaps and further research needs, is discussed.
Through continuous improvement Quantitative Microbial Risk Assessment provides valuable
insight into controlling and prevention strategies.
Cross contamination is one of the most important contributing factors in foodborne illness
originating in household environments. The objective of this research was to determine the
transfer between naturally contaminated chicken liver and leg to cutting board, hand glove,
knife and cucumber, during slicing. The microorganism tested was Campylobacter jejuni and
the results showed that the pathogen transferred to all utensils, at different transfer rate, despite
the low level of the naturally contaminating pathogen. With unknown concentration bacteria in
the naturally contaminated samples, a proportion of the utensils were still contaminated with C.
jejuni and not surprisingly, when the sample were contaminated with higher concentrations of
the pathogen, a higher proportion of the utensils had detectable C. jejuni cells present, though
in many cases cross contamination seems to be a random event. Transfer of the naturally
contaminating C. jejuni from the chicken liver and leg to the utensils were
The safety level of microwaved foods remains at vague as this subject was less addressed
scientifically. A study was initiated to address the matter by investigating on the
survivability of Salmonella and Shiga-toxigenic Escherichia coli (STEC) O157 in
microwave heated ready-to-eat (RTE) foods using the Most Probable Number coupled
Polymerase Chain Reaction (MPN-PCR) technique. A total of 329 samples of various
ready-to-eat (RTE) convenience meals were collected around Wilayah Persekutuan Kuala
Lumpur and Selangor regions. Salmonella was positively identified in 66 samples (20.1%,
This goal of this study was to investigate the presence of Vibrio cholerae in street food,
namely satar and otak-otak, using Loop-Mediated Isothermal Amplification (LAMP),
multiplex Polymerase Chain Reaction (mPCR) and conventional plating on Thiosulphate
Citrate Bile-Salt Sucrose (TCBS) agar methods. A total of 78 satar and 35 otak-otak were
purchased from different districts of Terengganu (Besut, Setiu, Kuala Terengganu and
Kemaman). V. cholerae was found in satar with LAMP (10.3%), mPCR (10.3%) and
plating (0%). No V. cholerae was found in otak-otak using the three methods. This might
be due to V. cholerae able to survive in satar after grilling due to its thickness which may
contribute to undercooking. This study concluded that low presence of V. cholerae in satar
and otak-otak can be detected by molecular methods but not the conventional plating
method. LAMP assay is a useful tool for rapid detection of pathogens in food due to its
simplicity, highly sensitive and visual interpretation capability. Though the prevalence of
V. cholerae was low in the samples, proper handling of this food will help in reducing the
risk of acquiring infection from V. cholerae in contaminated samples.
Bacteriophages are ubiquitous in our world, mainly in the oceans, soil, the water and food
we consume. They can be used efficiently in modern biotechnology, as well as alternatives
to antibiotics for many antibiotic resistant bacterial strains. Phages can be used as vehicles
for vaccines both DNA and protein, for the detection of pathogenic bacterial strain, as biocontrol
agents in agriculture and food industry. This review outlines the properties as well
as the influence of different external physical and chemical factors like temperature and
acidity on phage persistence. A better understanding of the complex problem of phage
sensitivity to external factors may be useful for other researchers working with phages.
Furthermore, the applications of bacteriophages were described in this paper as well.
Foodborne illness is a global burden that impacts a country politically, economically and
socio-economically. The severity of the burden can be unmeasurable as foodborne illness
is often an underestimated problem. In order to enlighten the burden, appropriate food
safety control measures should be taken. This study aimed to optimize a multiplex
Polymerase Chain Reaction (mPCR) detection method to identify foodborne pathogens
simultaneously. Six foodborne pathogens namely, Salmonella spp., Escherichia coli O157,
Vibrio parahaemolyticus, Vibrio cholerae, Listeria monocytogenes and Campylobacter
spp., were targeted in the mPCR detection method. Each mPCR parameter was tested and
the outcome was analysed to obtain a successful mPCR protocol to detect the targeted
foodborne pathogens. The amplified PCR products showed that the optimized mPCR
protocol will be a potential rapid diagnostic tool in foodborne pathogen detection.
According to the World Health Organisation (WHO), globally 600 million people suffer
from food-borne diseases (FBD), and 420,000 people die as a result. The European Food
Safety Authority (EFSA) has stated that FBD are linked to the food industry, with the
most common means of transmission being due to poor food handling and hygiene by
food handlers working in the food industry. The aim of this research was to investigate the
effectiveness of mandatory food handler training programmes (FHTP) to prevent FBD in
Malaysia and Ireland. To do this, the FHTP existing in Malaysia and Ireland were
analysed, in addition to the legislation they fall under in each respective country.
Effectiveness was determined by investigating the level of food safety knowledge (FSK)
and food safety practices (FSP) of food handlers in Malaysia and Ireland. A systematic
literature review (SLR) and a narrative literature review (NLR) were conducted for this
research. The SLR was based on the PRISMA diagram, using the Confidence in the
Evidence from Reviews of Qualitative research (CERQual) approach to evaluate the
studies used for this research. A total of 8 Malaysian studies and 1 Irish study were used to
determine the level of FSK and FSP of food handlers in each respective country, to
examine the effectiveness of FHTP. The results of the studies used for this research have
depicted overall good FSP and FSK of food handlers in Malaysia and Ireland; yet trends
continue to show that food handlers are one of the biggest contributors to FBD,
demonstrating that FHTP are not effective in preventing FBD. The findings from this
research highlights that although these trainings can be an effective tool to prevent FBD, if
they are not executed correctly, food handlers will continue to contribute to FBD.
Food safety in Malaysia is not considered an issue yet. From the previous year (2005-
2015) records, the incidence rate of food poisoning had been fluctuating and despite that,
cases continue to occur especially among school students. As a developing nation, it is
high-time that Malaysia begins to emphasize on food safety to reduce the burden of
foodborne illness in the socio-economic development of the country, and at the same time,
gain benefits in terms of economic returns and trade through food safety enforcement.
Most importantly, public health is achieved through food safety implementation and
accentuation. The current standing point of the Malaysia’s food safety is discussed in this
review. In addition, the review will also discuss the role of academicians as intervention
contributions in tackling food safety issues. The review is hoped to provide valuable and
concentrated information and knowledge to readers in the light to drive Malaysia into
ensuring safer food for the public.
The continued and increasing development of antimicrobial resistant bacteria among the
foodborne pathogens had caused worldwide to be alarmed. Being the earliest to develop
antimicrobial resistance, Staphylococcus aureus is constantly monitored for any new
resistance development. The resistance development is often linked to wastewater and the
treatment plants where the pressure of antibiotic is the highest. Hence, this study
investigated on the prevalence of high antimicrobial resistant S. aureus in the wastewater
eluted from a poultry slaughterhouse. A total of thirty wastewater samples were collected
from a poultry slaughterhouse in Semenyih, Selangor. Most probable number (MPN)-
plating method was employed to enumerate the S. aureus count in the wastewater. The
results indicated that S. aureus was highly present whereby all samples (100%) were
positive and the concentration ranged between 11 – 2.1 x 104 MPN/ml. Isolated S. aureus
strains were screened for their antimicrobial susceptibility using the Kirby-Bauer Disk
Diffusion Test method to classify their antimicrobial resistance eleven antibiotics. The
MAR index measured was between 0.18 and 0.91, inferring that the strains are highly
antimicrobial resistance. All S. aureus strains were 100% resistant to ampicillin (25 µg)
and cefazolin (30 µg). 94.1% of the strains were resistant to penicillin (10 µg) which
phenotypically indicated these strains are Methicillin-resistant S. aureus (MRSA).
Notably, 17.6% of the strains developed resistance to vancomycin and was categorized as
Vancomycin-resistant S. aureus (VRSA). There is a need to take drastic preventive
measures to control the resistance development in S. aureus to conserve public health.
The revolution of agriculture through biotechnology have produced large-scale of genetically
modified crops which brought up a controversy on the safety usage of genetically modified
organisms (GMOs). It has been implemented globally that all GMO products and its derived
ingredients should have regulations on the usage and labelling. Thus, it is necessary to develop
methods that allow rapid screening of GMO products to comply with the regulations. This
study employed a reliable and flexible multiplex polymerase chain reaction (PCR) method for
the rapid detection of transgenic elements in genetically modified soy and maize along with
the soybean LECTIN gene and maize ZEIN gene respectively. The selected four common
transgenic elements were 35S promoter (35S); Agrobacterium tumefaciens nopaline synthase
terminator (NOS); 5-enolypyruvylshikimate-3-phosphate synthase (epsps) gene; and Cry1Ab
delta-endotoxin (cry1Ab) gene. Optimization of the multiplex PCR methods were carried out
by using 1% Roundup ReadyTM Soybean (RRS) as the certified reference material for soybean
that produced fourplex PCR method detecting 35S promoter, NOS terminator, epsps gene and
soybean LECTIN gene and by using 1% MON810 as the certified reference material for maize
that produced triplex PCR method detecting 35S promoter, cry1Ab gene and maize ZEIN gene
prior to screening of the GMO traits in various food products and animal feeds. 1/9 (11.1%) of
the animal feed contained maize and 1/15 (6.7%) of the soybean food products showed positive
results for the detection of GMO transgenic gene. None of the maize food products showed
positive results for GMO transgenic gene. In total, approximately 4% of the food products
and animal feed were positive as GMO. This indicated GMOs have not widely entered the
food chain. However, it is necessary to have an appropriate screening method due to GMOs’
unknown potential risk to humans and to animals. This rapid screening method will provide
leverage in terms of being economically wise, time saving and reliable.
To date, cholera has cycle the world seven times through the seven pandemic cycles that has
affected tens of millions of people. The objective of this study was to determine the presence
and density as well as the antibiotic resistance profile of Vibrio cholerae isolated from catfish
(Pangasius hypohthalamus). From the combination of the Most Probable Number-Polymerase
Chain Reaction-plating on TCBS agar methods, V. cholerae was detected in 32 samples and
V. cholerae O139 was detected in 7 samples, with a density ranging between
Irrespective of its health effects, street foods are very popular with the consumers. The main
purpose of this research was to study the biosafety of Escherichia coli in popiah, a Malaysian
street food sold at a roadside food stall and a restaurant in Sri Serdang, Selangor, Malaysia,
using the combination of the most probable number (MPN)-Polymerase Chain Reaction
(PCR) assay-plating on Eosin Methylene Blue (EMB) agar methods. Using these biomolecular
methods, E. coli was detected in 12/15 (80%) and 11/15 (73%) of the collected samples from
the roadside food stall and the restaurant respectively. The incidence of stx virulence-associated
genes was detected in 1/15 (7%) among the E. coli isolated from samples taken from the
roadside food stall while the E. coli isolated from the restaurant was 3/15 (20%). The density
of E. coli ranged from 1100 MPN/g and the density of E. coli positive with stx genes
was
The effect of 18 different chemicals, which included acidic compounds (sulfuric acid, chloridric acid, phosphoric acid, benzoic acid, citric acid, acetic acid), alkaline compounds (ammonia, sodium bicarbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide), salts (acetate ammonium, sodium bisulfite, sodium hydrosulfite, sodium chloride, sodium sulfate) and oxidising agents (hydrogen peroxide, sodium hypochlorite), on the reduction of aflatoxins B(1), B(2), G(1) and G(2) and ochratoxin A (OTA) was investigated in black and white pepper. OTA and aflatoxins were determined using HPLC after immunoaffinity column clean-up. Almost all of the applied chemicals showed a significant degree of reduction on mycotoxins (p < 0.05). The lowest and highest reduction of aflatoxin B(1), which is the most dangerous aflatoxin, was 20.5% ± 2.7% using benzoic acid and 54.5% ± 2.7% using sodium hydroxide. There was no significant difference between black and white peppers (p < 0.05).
The diversity of specific bacteria taxa, such as the actinomycetes, has not been reported from the Antarctic island of Barrientos. The diversity of actinomycetes was estimated with two different strategies that use PCR-denaturing gradient gel electrophoresis. First, a PCR was applied, using a group-specific primer that allows selective amplification of actinomycete sequences. Second, a nested-PCR approach was used that allows the estimation of the relative abundance of actinomycetes within the bacterial community. Molecular identification, which was based on 16S rDNA sequence analysis, revealed eight genera of actinomycetes, Actinobacterium, Actinomyces, an uncultured Actinomycete, Streptomyces, Leifsonia, Frankineae, Rhodococcus, and Mycobacterium. The uncultured Actinomyces sp and Rhodococcus sp appear to be the prominent genera of actinomycetes in Barrientos Island soil. PCR-denaturing gradient gel electrophoresis patterns were used to look for correlations between actinomycete abundance and environmental characteristics, such as type of rookery and vegetation. There was a significant positive correlation between type of rookery and abundance of actinomycetes; soil samples collected from active chinstrap penguin rookeries had the highest actinomycete abundance. Vegetation type, such as moss, which could provide a microhabitat for bacteria, did not correlate significantly with actinomycete abundance.
Pennywort (Centella asiatica) is a herbaceous vegetable commonly consumed raw as ‘ulam’ or salad. Consumption of raw leafy green vegetables is one of the pathogenic mechanisms that could cause foodborne outbreaks. The aim of the present work was therefore to investigate the effect of pulsed light (PL) treatment at fluences of 1.5, 4.2, 6.9, 9.6, and 12.3 J/cm² on the microbiological and physical quality of pennywort stored at 4 ± 1°C. Escherichia coli (E. coli) were inoculated onto the pennywort leaves before being exposed to PL and viewed using scanning electron microscopy (SEM). PL fluences of 6.9, 9.6, and 12.3 J/cm² significantly reduced the microbial count; however, the highest inactivation was obtained by using fluences of 9.6 and 12.3 J/cm². The color of pennywort was not significantly affected by PL treatment applied at lower fluences of 1.5, 4.2, and 6.9 J/cm²; however, at higher fluence, 9.6 and 12.3 J/cm², the color was affected. PL at 1.5, 4.2, 6.9, and 9.6 J/cm² was able to retain the texture appearance of the leaves. To conclude, PL at 6.9 J/cm² showed the best fluence to reduce total aerobic mesophilic count while retaining the physical properties of pennywort leaves and extend the shelf life to about four days. The inactivation of E. coli population was significantly higher at PL fluence of 6.9 J/cm². It was observed that PL caused the destruction to the surface of E. coli’s cell membrane. The reductions of samples inoculated with E. coli were better than those achieved in native microbiota. Furthermore, the present work also demonstrated that PL treatment was able to reduce the microbial count on pennywort leaves.
Vibrio cholerae still represents a significant threat to human health worldwide despite the advances in hygiene, consumer knowledge, food treatment and food processing. In Malaysia, statistics in year 2009 have shown that among the food and water borne diseases, food poisoning has the highest incidence rate of 36.17 per 100,000 populations and with a mortality rate of 0.01 per 100,000 populations. In this study, 22 seafood samples comprising of fish, squid, crustacean and mollusks purchased from wet market and supermarket were analyzed. The Most Probable Number (MPN) and real time PCR was used to enumerate the Vibrio cholerae in seafood sample. The results showed that MPN-real time PCR of the samples from wet market had a maximum of >1100 MPN/g compare to 93 MPN/g enumerated from the MPN plate. The MPN-real time PCR in the samples from supermarket indicated 290 MPN/g as compared to 240 MPN/g enumerated from the MPN plate. The standard curves showed that there was a good linear correlation between the Ct values. The minimum level of detection of Vibrio cholerae standard DNA at targeted gene was 3 x 10-5 ng/μl.
Salmonella has caused foodborne illnesses globally and it has been a rising threat on fresh produce. The objective of this study was to determine the prevalence and concentration of Salmonella spp., Salmonella Typhi and Salmonella Typhimurium in freshly prepared fruit juice sold at hawker stalls. Analysis was conducted by employing most probable number-polymerase chain reaction (MPN-PCR). A total of 50 freshly prepared fruit juices were examined and the prevalence of Salmonella spp., Salmonella Typhi and Salmonella Typhimurium in the fruit juices were 34%, 20% and 10%, respectively, with an estimated microbial load varying from 0 to 42 MPN/g. Of the five different fruits, carrot juice had the highest prevalence of Salmonella spp. (60%) and Salmonella Typhi (40%). However, Salmonella Typhimurium was detected in apple (30%), orange (10%) and starfruit juice (10%). Factors contributing to the presence of Salmonella were cross-contamination and poor sanitation practice. Besides, negligence on temperature and storage time also led to the growth of Salmonella. Proper monitoring and risk assessment are needed in order to establish control measures to ensure the quality and safety of fruit juices in Malaysia.
Vibrio parahaemolyticus is a gram negative bacterium and causes gastrointestinal illness in humans. In this study, twenty five out of fifty cockle samples from Padang, Indonesia produced purple colonies when they were grown on selective medium, CHROMagarTM Vibrio. Specific–PCR for toxR gene detection gave positive results in which a band with 368 base pairs size appeared on the gel for all the isolates that confirmed the presence of V. parahaemolyticus. In the virulence properties test, all the isolates showed negative results for tdh and trh genes detection. The results indicate that the isolates under this study do not contain virulence properties that correlate to the ability of infection and diseases, which means that they are nonpathogenic.
This study aimed to determine the biofilm formation ability by Salmonella Typhi on cucumber, mango and guava surface, as well as to determine the relationship between time contact and biofilm formation. Crystal violet assay was performed to quantify the biofilm formation based on the value of optical density at 570 nm of the destaining crystal violet at the specific interval time. The result showed that the attachment of the bacterial cells on the fresh produce surface increased with the contact time. The readings of OD570at time 12 h for cucumber, mango and guava surfaces were 0.824, 0.683 and 0.598, respectively, indicating that the biofilm formation by Salmonella Typhi on different fresh produce surface varied with time. Since the result showed that Salmonella Typhi formed biofilm on fresh produce surfaces, hygienic practice from farm to fork including handling, processing, distribution and storage of the fresh produce should be of concern.
Klebsiella pneumoniae (K. pneumoniae) is one of the most important members of Klebsiella genus in Enterobacteriacae family, which is responsible for pneumonia (the destructive lung inflammation disease). Vegetables are known as source of contamination with K. pneumonia. Raw vegetables are usually consumed in salads and other dishes. The aim of this study was to investigate the occurrence of K. pneumoniae in raw vegetables marketed in Malaysia. Two hundred commonly used salad vegetables (lettuces, parsley, cucumber, tomato and carrot) from hypermarkets and wet markets were investigated for presence of K. pneumoniae using Most Probable Number-Polymerase Chain Reaction (MPN-PCR). K. pneumoniae was found to be significantly more frequent (100%) and (82.5%) in lettuce and cucumbers, respectively. K. pneumoniae contamination was lowest in carrot samples (30%). All samples were contaminated with K. pneumoniae ranging from