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.
A good temperature management, such as precooling and cold storage, can delay deterioration of fresh produce. In this study, different forced-air precooling times were applied on Musa AAA Berangan to investigate the influence of forced-air precooling time on the changes of quality attributes and consumer acceptance. The banana was subjected to forced-air precooling treatment (5 ± 1°C) for 0, 14, 50, and 120 min and then stored in a cold room (13 ± 1°C) for 2 weeks. Then, all the fruits were transferred to a ripening room (25 ± 2°C) and initiated to ripen with ethylene gas. Quality attributes analyses and sensory evaluations were conducted when the fruits reached maturity index 5. Quality parameters, such as soluble solids concentration, titratable acidity, pulp firmness, and peel colour, showed no significant differences when fruits were precooled at different times. Blackening of peel as a result of chilling injury occurred in fruits treated with forced-air precooling for 50 and 120 min. This blackening significantly influenced consumer acceptance, although it did not affect the pulp colour and taste.
This cross sectional study aimed to explored the pattern of socio-demographic distribution, to assess the level of KAP of food safety; and the relationship with the level of premise cleanliness in the food courts at Putrajaya. Distribution of food handlers socio-demographic profile was Malaysian (62.0%), male (70.4%), working experienced in food industry (82.0%) and attended food handler training (85.0%). The mean age was 28.7 years and 85.4% having income not less than RM 1,500 monthly. 78.5% of the food handlers at educational level were found as primary/secondary school. 15.0% of the respondents had not attended the food sanitation training. The findings reveal that food handlers’ KAP were high with a mean percentage score more than 79.0%.The majority of the food courts in Putrajaya had consistently moderate level of cleanliness (63.5%) with the mean of 83.03%. Only 27.4% of the food courts were in the level of clean situation (>89% of premise cleanliness score) and 9.1% were not in the clean condition (
The aims of this communication were to study characterization of serogroups among Salmonella isolates and the relationship of antimicrobial resistance to serogroups. Multiple antimicrobial resistance (MAR) was performed on 189 Salmonella enterica isolates associated with 38 different serovars that were recovered from poultry and four types of indigenous vegetables.
Listeria monocytogenes is a gram positive, facultative intracellular pathogen with the capacity to cause
food poisoning outbreaks as well as severe illness in vulnerable human population groups. It can cause a rare but serious disease called listeriosis with high fatality rates (20–30%) compared with other foodborne microbial pathogens. Although Listeria monocytogenes is infective to all human population groups, it is more likely to cause severe problems among pregnant women, immunocompromised individuals, the elderly and neonates. There are a variety of phenotyphic and genotyphic methods for the detection of Listeria monocytogenes in foods. Recent technological advances have increased the ability of scientists to detect Listeria monocytogenes. The purpose of this review is to discuss molecular characteristics of the Listeria monocytogenes pathogen, standard detection methods of this pathogen in foods based on culture methods, confirmation of species and subtyping based on phenotypic and genotyphic methods.
Successful DNA amplification is vital for the detection of specific DNA targets in feeds, and this in return depends on the ability of DNA extraction methods to produce good quality DNA. In this study, seven methods were compared for DNA extraction from feeds using quantitative polymerase chain reaction (PCR) of single copy maize (Zea mays) endogenous hmg (high mobility group) gene. Relative levels of hmg were used to evaluate the DNA quality. Spectrophotometer determination of DNA was also carried out to assess DNA yield and DNA purity, while electrophoretic analysis of genomic DNA extracts was carried out to investigate DNA integrity. The findings illustrate that the DNA extraction methods have a significant effect on DNA quality. Statistically, the Epicentre method extracted the highest DNA yield while the Wizard method had the lowest DNA yield with high DNA purity and integrity. However, the Wizard method recovered the most amplifiable DNA per reaction, indicating that template quality and integrity had greater influence over hmg amplification than DNA yield.
Food labeling in accordance with Novel Food Regulation has been enforced in the European Community since 1997 with a series of updated legislations namely, EC/258/97, EC/1139/98, EC/49/2000, EC/50/2000 and EC/1829/2003. Guidelines and labeling regulations for the use of GMOs materials in food and feed products has also been introduced in Malaysia and Vietnam. Therefore, the demand for the establishment and development of a robust and rapid operation procedure for GMO detection has increased recently in both countries. The procedure of GMO detection emphasizes not only on detection tests but also on confirmation assays. This study employed PCR technology for detection and direct DNA sequencing for confirmation procedures respectively. The results demonstrated for the first time the presence of GM plants with glyphosate-resistant trait led by the control of P35S promoter and NOS terminator in either Malaysian or Vietnamese feed with high frequency (20 positive samples out of 24 analyzed samples). The P35S promoter, EPSPS gene and NOS terminator sequences obtained showed some mutations on single-stranded and double-stranded targeted sequences caused by single nucleotide insertion or single nucleotide changes. These results reinforce the need for development of detection procedures to comply with food/feed labeling system.
The ability to detect the presence of transgenes in crop-derived foods depends on the quantity and quality of DNA obtained from a product to be analyzed. The efficiency of DNA extraction protocols differs due to the nature of each food product. In this paper, we described two main DNA extraction protocols and their modifications that have been applied and evaluated for DNA extraction from raw and processed food as well as animal feed. The yield and quality for five categories of food and feed samples namely, raw soybean, raw maize, animal feed, smooth tofu and soymilk are discussed. The statistical interaction analyses showed that the cetyltrimethyl ammonium bromide (CTAB) method was proven to be the best method to extract DNA from raw soybean, maize and animal feed samples which not only obtained high DNA yield of 32.7, 28.4 and 33.4 ng DNA/mg sample respectively, but also produced high quality DNA with the absorbance A260/A280 ratio of 1.9, 1.9 and 2.0, respectively. These DNA were suitable for PCR amplification which produced a 164 bp DNA fragment of the lectin gene from soybean, and a 277 bp DNA fragment of the zein gene from maize. In the processed food category, the Wizard isolation method was found to be the best for the extraction of DNA from smooth tofu and soymilk with the yield of 13.2 and 3.4 ng DNA/mg sample, and the quality of the DNA at the absorbance A260/A280 ratio ranged from 1.9 to 1.7. These DNA were successfully amplified using primers specific to the lectin gene of soybean.
Appropriate and safe antibacterial agents able to decontaminate meat surfaces have long been big concern of meat industry. In an attempt to manage beef carcass contamination, spray wash treatments utilizing three concentrations (1, 1.5 and 2%) of acetic, lactic, propionic and formic acids were performed to evaluate their efficacy in reducing numbers of Escherichia coli O157:H7 and Staphylococcus aureus on meat tissues. The procured beef pieces of freshly slaughtered animals were decontaminated with hot water and then inoculated with E. coli O157:H7 and S. aureus individually which then were spray washed with organic acids separately. The total plate count of the treated samples showed that the populations of bacteria decreased after being exposed to organic acids. Spray wash of formic acid resulted in the highest reduction of both bacterial species on meat surface. Significantly, higher log reductions were obtained for S. aureus than E. coli O157:H7. It was concluded that organic acids are highly effective in decontaminating meat surfaces and organic acids are shown to be safe, simple, efficient, and cheap modality of meat decontamination which can be highly recommended for industrial scales.
The antibacterial activity of solvent-extracted oil of noni (Morinda citrifolia L.), spinach (Spinacia oleracea L.), lady’s finger (Abelmoschus esculentus (L.) Moench), bitter gourd (Momordica charantia Linn.), and mustard (Brassica nigra L.) seed oils, and coconut (Cocos nucifera L.) oil, palm (Elaeis guineensis L.) mesocarp in hydrolyzed and unhydrolyzed form were determined in order to explore their potential usage as antibacterial agent. The hydrolysis process that was catalyzed by immobilized lipase of Rhizomucor miehei (RMIM) showed highest hydrolytic activity with 1.0 ml of added water volume except bitter gourd seed oil and palm mesocarp oil which has maximum hydrolytic activity with added water volume of 5 ml and 2.5 ml respectively. Before hydrolysis, all oil samples did not show inhibition ring zones (IRZ) on any of the tested bacteria strains (Salmonella typhimurium, Listeria monocytogenes and Escherichia coli O157:H7). Hydrolyzed lady’s finger and bitter gourd seed oil showed IRZ on all tested bacteria strains; hydrolyzed mustard seed oil on S. typhimurium and L. monocytogenes; hydrolyzed spinach seed oil and coconut oil on L. monocytogenes; hydrolyzed noni seed oil and palm mesocarp oil did not exhibit IRZ on any of the tested bacteria strains. Most of the hydrolyzed oil exhibit an inhibition activity that was different from their respective dominant fatty acids except noni seed oil and palm mesocarp oil.
E. coli O157:H7 is associated with life threatening diseases such as hemorrhagic colitis (HC), hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Raw milk is considered a high risk food as it is highly nutritious and serves as an ideal medium for bacterial growth. The aim of this study was to investigate the prevalence of E. coli O157:H7 in raw cow, goat and buffalo milk samples. MPN-PCR method targeting the major virulence rfbE gene and fliCH7gene of E. coli O157:H7 was used. Total of 177 raw milk samples were collected from local dairy farms in the state of Selangor, Malaysia. The highest prevalence of E. coli O157:H7 was found in raw cow milk (18.75%). E. coli O157:H7 was detected in 7.32% and 3.57% of raw goat and buffalo milk, respectively. The estimated quantity of E. coli O157:H7 in raw cow, goat and buffalo milk ranged from
Three strains of verotoxin-producing Escherichia coli isolated from patients with haemorrhagic colitis harboured plasmids ranging in size from 2.7 kb to 91.2 kb. Those plasmids ranging from 2.7 kb to 6.8 kb hybridized to Shiga-like toxin I and Shiga-like toxin II gene probes.
Thirty-six strains of Escherichia coli isolated from animals in Bario, a remote area in Sarawak, Malaysia, were examined for presence of plasmid DNA and their susceptibility to nine antimicrobial agents. Of the total 36 isolates, five bovine and six canine isolates were found to contain plasmid DNA ranging in sizes from 2.6 to 70 kilobases. All were susceptible to chloramphenicol, erythromycin, gentamicin, nalidixic acid and neomycin but resistance to ampicillin (47%), erythromycin (19%), streptomycin (25%) and tetracycline (11%) was observed. Resistance was associated with carriage of a 47 kb (SC98), 70 kb, (SC133) and 56 and 4.6 kb (SC119) plasmids which were transmissible to the Escherichia coli K12 recipient. It is concluded that animals form a potential reservoir of R plasmids carrying E. coli in the study area.
The aim of this study was to assess the most probable number-polymerase chain reaction (MPNPCR) technique for detection of Listeria monocytogenes in salad vegetables in comparison with reference EN ISO 11290-2 and Food Drug Administration Bacteriological Analytical Manual method using artificial and naturally contaminated samples. Based on recovery of L. monocytogenes from artificially contaminated samples, MPN-PCR showed a moderate correlation (R=0.67) between spiking concentration and microbial levels which was better than the FDA-BAM method (R=0.642) and ISO 11290-2:1998 method (R=0.655). With naturally contaminated samples, it was found that L. monocytogenes was detected in 25% of the vegetable samples using MPN-PCR; 15% of the samples by the FDA-BAM method and 8% of samples using ISO 11290-2:1998 method. Overall, MPN-PCR was found to be a rapid and reliable method that could facilitate the enumeration of L. monocytogenes in vegetables.
Listeria monocytogenes (L. monocytogenes) is a serious food-borne pathogen for immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments. The biofilm transfers contamination to food products and impose risk to public health. Transfers contamination to food products, and impose risk hazard to public health. The aim of this study was to investigate biofilm producing ability of L. monocytogenes isolates. Microtitre assay was used to measure the amount of biofilm production by ten L. monocytogenes isolates from minced chicken / meat, sausages and burgers. Results showed that all 10 L. monocytogenes isolates were able to form biofilm after 24 h at 20˚C on polystyrene surface (the common surface in food industries). Some strains were capable of forming biofilm more than the others. All strains showed a slight raise in the quantities of attached cells over 48 and 72 h. L. monocytogenes strains isolated from minced chicken, minced meat and burgers were better biofilm-producers comparing to the strains isolated from sausages.
Thirty-five veterinary isolates of Salmonella enteritidis were characterized by their susceptibility to 10 antimicrobial agents and by their plasmid profiles on agarose gel electrophoresis. All were susceptible to carbenicillin, chloramphenicol and nalidixic acid but 89% were resistant to tetracycline. When examined, 91% of the isolates harboured plasmids, with sizes ranging from 9.8 to 60 MDa. However, it was only possible to associate the presence of plasmids with tetracycline resistance; plasmids occurring in 90% of the tetracycline-resistant isolates. In conjugation experiments, with Escherichia coli K12 Nal(r) as recipient, the tetracycline resistance in three selected S. enteritidis isolates was observed to transfer at frequencies of 3.0×10(-3) to 1.0×10(-2)/donor cell. The concomitant transfer of a 56-MDa or 60-MDa plasmid in these three S. enteritidis isolates was also detected.
Molecular typing methods have been widely applied for many purposes. In this study, such methods were adopted as DNA fingerprinting tools to determine the origin and divergence of virulent Vibrio parahaemolyticus strains found in local seafood. Although not all strain carry virulent tdh and trh gene, increasing prevalence demands an effective fingerprinting scheme which can constantly monitor and trace the sources of such emerging food pathogens. By using ERIC-, RAPD-, and BOX-PCR methods, 33 Vibrio parahaemolyticus isolates from local Malaysia bloody clam (Anadara granosa) and Lala (Orbicularia orbiculata) with confirmed presence of tdh and trh gene were characterised, followed by determination of clonal relatedness among virulent strains using cluster analysis and discriminatory index. This study also involved application of Immunomagnetic Separation (IMS) Method which significantly improved the specificity of strain isolation. Cluster analysis using Unweighted Pair Group Mathematical Averaging (UPGMA) and Dice Coefficient shown clustering according to isolation food source, IMS level and haemolysin gene possessed. Nevertheless, different DNA fingerprinting methods generated different clustering at different similarity cut-off percentage, regardless as individual or as composite dendrograms. ERIC- and RAPD-PCR composite fingerprinting relatively shown the highest discriminatory index at following similarity cutoff percentage: 0.68 at 50%; 0.83 at 65%; and 0.93 at 75%. Discriminatory power increased with similarity cut-off percentage. However, result also suggested that BOX-PCR might be an effective fingerprinting tool, as it generated three clusters with no single-colony isolate at 70% similarity cut-off. This study not only achieved its objective to determine clonal relatedness among virulent strains from local seafood via characterisation, but also speculated the best possible combination of molecular typing methods to effectively do so.
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%,
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.
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.