As the society begin to realize the importance of combating antimicrobial resistance, going
back to silver might be the solution. Silver has been known for its potential antimicrobial
activity since ancient times and, the development of nanoparticles has increased its potential
into becoming an antimicrobial agent that can be applied in broad-spectrum. Antimicrobial
resistance has spread into an irrepressible manner which requires drastic action plan as a number
of pathogenic bacteria began to acquire resistance genes. Methicillin Resistant Staphylococcus
aureus (MRSA) is one of the earliest reported resistant clones which is the center of this study.
This study focused on the dissemination and evolution of MRSA on its resistance towards
antibiotics. Disc Diffusion Test was employed to create the antibiograms of MRSA isolates. All
isolates showed resistance towards amoxicillin, ampicillin, cefazolin, oxacillin and penicillin.
In contrast, all isolates were susceptible towards erythromycin. The findings also discovered
isolates that were vancomycin-resistant (66.7%) and vancomycin-intermediate (33.3%). As the
efficacy of antibiotic treatment is at a question, we also investigated on the antimicrobial activity
of colloidal silver in the hope as an alternative treatment. Shiga Toxin producing Escherichia
coli (STEC) and MRSA (ATCC 33591) was tested using modified Quantitative suspension
test for the evaluation of bactericidal activity for chemical disinfectants and antiseptics based
on BS EN 1276:2009. The outcome of this study indicated that the colloidal silver is working
effectively against STEC and MRSA (ATCC 33591), showing killing percentages well above
99.0% at 4 minutes and 8 minutes of contact. Vancomycin-resistant S. aureus (VRSA) and
Vancomycin-intermediate S. aureus (VISA) were also tested and the results indicated that
VISA had higher killing percentages at 4 minutes (99.83%) and 8 minutes (99.85%) compared
to VRSA at 4 minutes (96.72%) and 8 minutes (98.35%). This opens a solution to the rising
problem of antimicrobial resistance.
Vibrio parahaemolyticus is well known to be abundantly distributed in marine, coastal and
estuarine environments. Since 1951, V. parahaemolyticus had been the source of numerous
outbreaks related to contaminated or mishandled seafood. However, V. parahaemolyticus
had been detected on other types of food. This issue has prompted this study to investigate
on the prevalence of V. parahaemolyticus in various food samples and determine the risk
associated with it. The results of the MPN-plating technique of the study indicated that V.
parahaemolyticus was detected in seafood (33.3%, 95% Confidence Interval [CI] 31.9 – 34.8 ,
94 – 290 MPN/g) and vegetables (10.0%, 95% CI 9.7 – 10.3 , 9.2 – 23 MPN/g) while negative
V. parahaemolyticus was detected in fruits (0.0%, 95% CI 0 – 1,
Antibiotic susceptibility and genetic diversity of E. coli isolated from cultured catfish and their surrounding environment were determined. The levels of resistance of the E. coli isolates towards six different antibiotics tested differed considerably. Though the isolates displayed resistance towards some of the antibiotics tested, none of the isolates showed resistant towards norfloxacin, sulphametoxazole/trimethoprim and chloramphenicol. RAPD-PCR analysis using single primer and primers combination clustered the E. coli isolates into 3 and 5 groups, respectively. The results of this study suggest that the E. coli isolates from the catfish and their surrounding environment derived from a mixture of sensitive and resistant strains with diverse genetic contents. The use of the RAPD analysis is sufficiently discriminatory for the typing of the E. coli isolates.
The aim of this work was to investigate the antioxidant and antimicrobial of Phyllanthus amarus, Phyllanthus niruri and Phyllanthus urinaria. P. niruri was found to possess the highest antioxidant activity, the activity decreased in the order P. niruri > P. amarus > P. urinaria for water extract. However, the activity decreased in the order P. niruri > P. urinaria > P. amarus for methanol extract. The result correlation between the antioxidant activity and total phenolic content revealed a positive correlation of 0.954 < r 2 < 1.000 for both water and methanol extract. Methanol extract showed higher total phenolic content and antioxidant activity as compared with water extract. Lowest Minimum Inhibitory Concentration (MIC) value for water extract against the selected microorganism was >2.5 mg/mL meanwhile, for methanol extract was 2.5 mg/mL and >0.625 mg/mL were the value for water and methanol extract. Methanol extract showed better inhibition potential than water extract
Vibrio parahaemolyticus is a halophilic Gram-negative bacterium that is considered among
gastrointestinal pathogens. Thirty isolates were tested for their susceptibility using 14 different
antibiotics. One V. parahaemolyticus isolate was resistant to 10 antibiotics (cefotaxime,
ceftazidime, tetracycline, amikacin, ciprofloxacin, levofloxacin, ofloxacin, ampicillin,
amoxicillin-calv-acid, and cefepime). The V. parahaemolyticus isolates were resistant to
ampicillin (90%), amoxicillin–clavulanic acid (63.3%), cefotaxime (60%), ceftazidime (46.7%),
cefepime (50%), tetracycline (36.6%), and amikacin (26.7%). However, the isolates were highly
susceptible to imipenem (100%), and piperacillin and gentamicin (96.7%). Approximately
55% of the isolates showed a multiple antibiotic resistance (MAR) index of >0.2, thereby
indicating the high risk of sources where these isolates originated. The occurrence of MAR
asserted the importance of determining drug susceptibility and monitoring the antimicrobial
resistance profile to improve and ensure food safety and public health.
Hepatitis A virus infection occurs globally and is causing a public health concern, primarily in developing countries due to its persistent circulation in the environment. The improved sanitary condition and increase in awareness of personal hygiene have led to the marked reduction of HAV prevalence in industrialized countries during childhood and to a shift of the infection towards adulthood. HAV is an environmentally stable, positive single stranded RNA virus that is primarily transmitted by the fecal-oral route, person to person contact or ingestion of contaminated food and drink. One of the main causes leading to HAV infection is epidemiologically linked to the consumption of raw or undercooked shellfish particularly oysters and clams. Due to their filter-feeding style, these shellfishes readily concentrate viruses from the surrounding water containing municipal sewage, and as a consequence pose a health threat to consumers. Therefore, development of detection techniques possessing the requisite sensitivity and specificity for the practical routine monitoring purposes is of great importance necessary for the protection of shellfish-consuming public. Nucleic acid based method such as reverse transcription PCR has emerged as the popular method of choice in view of its rapidity, accuracy and
sensitivity in contrary of the time-consuming conventional cell culture and hybridization techniques. However, detection of hepatitis A virus is firstly hampered by the non-cytophatic effect of wild type HAV strain, secondly, the low concentration of viral genome present in the environmental sample which requires effective isolation and concentration of virions and lastly the labor-extensive purification and thorough removal of the abundance of the PCR inhibitors which will unfavorably reduce the efficiency of PCR detection.
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.
Ninety one leaf samples of Josapine pineapple cultivar (Kelantan, n=8; Pahang, n=20; Perak, n=11; Sabah, n=15; Johor, n=37) showing symptoms of heart rot disease were collected to determine the incidence of Erwinia chrysanthemi. Sixteen strains of E. chrysanthemi were isolated from 13 leaf samples from Pahang (n=4), Sabah (n=2) and Johor (n=7). All of the E. chrysanthemi strains displayed resistance to bacitracin with two strains showing resistance to sulfamethoxazole. None of the E. chrysanthemi strains were resistant toward ampicillin, carbenicillin, cephalothin, ceftriaxone, cefuroxime, gentamicin, kanamycin, nalidixic acid, penicillin G, streptomycin and tetracycline. All of the E. chrysanthemi strains were plasmidless. The dendrogram generated from the ERIC-PCR fingerprinting showed that the E. chrysanthemi strains formed 4 clusters and 7 single isolates at 80% similarity level. The restriction fragment length polymorphism (RFLP) analysis for 16 strains of E. chrysanthemi with HinfI and HaeIII endonuclease, 2 and 4 restriction profiles were obtained, respectively. The combinations of the four techniques were able to differentiate the 16 E. chrysanthemi strains into 14 genome types, suggesting a wide diversity of strains examined. ERICPCR fingerprinting method is found to be more discriminating and useful for the determination of the E. chrysanthemi strains relatedness.
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.
Vibrio parahaemolyticus is one of the most widely recognized pathogenic Vibrio species due to numerous outbreaks and its’ wide occurrence in marine environment. In this study, 32 isolates of V. parahaemolyticus isolated from cockles were tested for sensitivity to 16 antibiotics and the presence of plasmids. All the isolates were multi-resistance, defined as resistant to atleast three different antibiotics with multiple antibiotic resistance indexes ranging from 0.31 to 0.69, indicating the isolates originate from high risk sources of contamination where antibiotics are often used. In the plasmid profiling test, only 15 isolates (47%) harbored plasmid DNA, which ranged in size from 2.7 to 56.2 kb, separating the isolates into 14 plasmid profiles. Hence, food contaminated with antibiotic resistant V. parahaemolyticus could be a major threat to public health due to the distinct possibility that they can be a significant reservoir of genes encoding antibiotic resistance determinants that can be transferred intra or interspecies. As in many developing countries, raw food hygiene and antimicrobial resistance epidemiology is still in the infancy stage in the locality of the study and thus our data provide a current baseline profile of antimicrobial resistance and plasmid of V. parahaemolyticusfrom cockles in Padang, Indonesia.
Biochemical analysis was carried out for pH profiles, freshness in terms of K-values, amino acids profiles, total volatile bases (TVB), total volatile acids (TVA) and biogenic amines for fresh and preserved Macrobrachium rosenbergii. Results showed that pH profiles of Macrobrachium rosenbergii explain the inability of this parameter to be used to evaluate the quality of Macrobrachium rosenbergii. Thus changes in pH profiles of Macrobrachium rosenbergii should be combined with indicators such as total volatile acids and total volatile bases. Total volatile acids of the shrimps increased steadily in small amounts throughout the storage period. A rapid increase in TVB at 100C was detected due to the increase in total aerobic bacteria at elevated temperatures. The microbial activities caused the decrease in the amino acids arginine, lysine and histidine which correlated well with the increase in the corresponding biogenic amines such as putrescine, cadaverine and histamine respectively. Preservatives used in this study controlled the production of these biogenic amines without significantly altering the pH of preserved shrimp.
A study to determine the antibiotic sensitivity pattern and genotyping using RAPD-PCR was performed on 50 C. jejuni isolated from sushi retailed in different supermarkets. With less than half of the isolates susceptible to the antibiotics tested, resistant to two or more antibiotics were observed in most of the isolates. The banding patterns obtained from RAPD-PCR revealed that no predominant clone exists and the bacterial population is rather diverse. Hence, the resistance of the C. jejuni to different classes of antibiotic as well as their diverse genotypes suggests that these C. jejuni isolates were generated from different sources in the contaminated supermarkets where sushi were retailed. Our data showed that C. jejuni can be an important reservoir for resistance genes and that study with comprehensive collections of samples are urgently required to establish better measures to reduce or eliminate the risk from antibiotic resistant and pathogenic bacteria originating from minimally processed ready-to-eat food.
Salmonella has been reported to be presence both in raw and processed foods worldwide. In this study, the prevalence, quantification and antibiotic susceptibility of Salmonella isolated from raw vegetables or locally known as ulam such as asiatic pennywort (Centella asiatica (L) Urb), water dropwort (Oenanthe javanica (Blume) DC), long bean (Vigna sinensis EndL), and winged bean (Psophocarpus tetragonolobus (L) DC) obtained from retail markets in Selangor, Malaysia were carried out. From 96 samples tested, the overall prevalence of Salmonella spp. was 97.9%, Salmonella Enteritidis was 54.2% and Salmonella Typhimurium was 82.3% respectively. Samples were contaminated with Salmonella ranging from < 3 to 2400 MPN/g. Salmonella Enteritidis and Salmonella Typhimurium isolates obtained from the raw vegetables (ulam) were found to exhibit high resistance against ampicillin (100%), erythromycin (100%), amoxicillin/clavunic acid (81.3%), cephalothin (75%), streptomycin (50%) and ciprofloxacin (50%). All Salmonella isolates showed multi drug resistant (MDR) profile with each isolate being resistant to 3 or more antibiotics. The multiple antibiotic resistance (MAR) index of Salmonella isolates ranged from 0.27 to 0.55 for Salmonella Enteritidis and 0.27 to 0.82 for Salmonella Typhimurium. The presence of Salmonella on raw vegetables (ulam) and high antibiotic resistance isolates indicated that raw vegetables could be contaminated and thus imposes possible health risk to local consumers.
Klebsiella pneumoniae is a foodborne pathogen associated with pneumoniae. Multiresistance to antibiotics of K. pneumoniae is a significant public health treat. Recently, the use of natural products such as herbs to inhibit the growth of pathogens is increasing. Java turmeric (Curcuma xanthorrhiza Roxb.) has been reported to possess antibacterial activity against foodborne pathogens. Unfortunately, the antibacterial activity of java turmeric extract against the resistance to multiantibiotics of K. pneumoniae has not been investigated. In this study, the antibacterial activity of Java turmeric extract was tested against 24 isolates of resistant K. pneumoniae that was isolated from several vegetables; lettuce, cucumber, tomato and carrot, using the methods recommended by the Clinical and Laboratory Standard Institute (CSLI), including disc diffusion method, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and killing time at concentration 0× MIC, ½× MIC, 1× MIC, 2× MIC and 4× MIC with predetermined time of 0, 0.25 , 0.5, 1, 2 and 4 h. The results showed that Java turmeric extract is susceptible to all resistant K. pneumoniae with inhibition zones ranging from 8.67 ± 0.58 to 10.00 ± 0.00 mm. The MIC and MBC values for the K. pneumoniae isolates against all bacterial isolates was 1.25 and 2.5 mg/ml, respectively. The killing time curve shows the reduction of resistant K. pneumoniae cells is fast acting; > 3 log10 within less than 15 min at 4× MIC (5.0 mg/ml). Finally, the isolates were completely killed at 4× MIC for 15 min. In conclusion, the Java turmeric extracts can be developed as natural antimicrobial agent to inhibit the growth of K. pneumoniae in food system.
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 (
Listeria monocytogenes (L. monocytogenes) is an important foodborne pathogen which can cause foodborne listeriosis with high mortality rates especially in susceptible population groups such as pregnant women, elderly and immunocompromised individuals. The biosafety level of L. monocytogenes in chicken offal has becomes a great concern as chicken offal is a cheap source of protein and it is often served as side dishes in South East Asian countries. In Malaysia, the consumption of chicken offal has almost doubled from 5 g per capita per day in the early 1980s to 9 g per capita per day in 2009. In this study, risk assessment was conducted to estimate the risk of acquiring listeriosis from consumption of chicken offal in Malaysia. A microbial survey on the prevalence and concentration of L. monocytogenes in chicken offal were carried out in Selangor, Malaysia over a one-year period (November 2010 to October 2011). It was assumed that there were no seasonal changes in the prevalence and consumption pattern all year round. Assuming that 5.6 million people in Selangor, Malaysia consume a single serving (125 g) of chicken offal per week, it is estimated that in a year there could be 0.61 cases and 1.98 × 10-4 cases of listeriosis per 100,000 population of pregnant woman and immunocompromised individual, respectively. However, the potential for getting listeriosis among the healthy population was very low, only 1.39 × 10-8 cases per 100,000 population. This study demonstrated risk assessment model not only used as a tool to estimate the risk of acquiring illness but it can influence public health surveillance and providing data in setting appropriate level of protection.
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.
Foodborne pathogens have become a constant threat to the consumer and food industry.
Reduce efficacy of antibiotics with emergence of resistant bacteria has limited the opportunities
for controlling pathogenic bacteria in food commodities and treating foodborne infections.
Bacteriophages can be a promising alternative for alleviate the risk of transmitting pathogenic
bacteria via food commodities. Therefore, this research was conducted to find distribution of
bacteriophages in diverse niches in order to identify suitable sources for isolating bacteriophages
to use controlling foodborne pathogens. Firstly bacterial strains were screened for lysogenic and
selected suitable host bacterial strains were used for isolating and determining bacteriophage titer
in fresh raw food and environmental samples. Eighteen different lytic bacteriophages effective
against Campylobacter, S. aureus, L. monocytogenes and E. coli were isolated from this study.
Bacteriophages titer was determined within range of 102
to 1010 PFU/mL and bacteriophages
were most frequently isolated from chicken (60%) samples. The isolated bacteriophages could
be potential candidates for controlling foodborne diseases.
Street food is popular in Asia due to its availability, low price and good taste. The safety of
street food has been always questionable due to its poor handling which probably leads to
microbial contamination. The objective of this study was to determine the surviving quantities
of V. parahaemolyticus under various conditions in street-vended food, namely satar and otakotak
after anticipated cross-contamination to support policy and regulatory documents. The
satar and otak-otak were prepared from minced and unminced fish flesh, respectively, together
with other ingredients. Each satar and otak-otak were prepared with 0, 0.5, 1.5 and 3% of
sodium chloride (NaCl), respectively. V. parahaemolyticus inoculum at approximately 8.66 log
CFU/ml were inoculated into the samples and incubated for up to 6 h. Samples were taken at 0,
1, 3 and 6 h for enumeration of V. parahaemolyticus using spread plate method on Thiosulphate
Citrate Bile Salts Sucrose (TCBS) agar. For control samples, V. parahaemolyticus was not
immediately inactivated in distilled water even though significant better survivability was
observed in Phosphate Buffer Saline (PBS). The numbers of V. parahaemolyticus was found
to decrease by varying amounts based on the salt content and duration of holding. However,
significant amounts survived to indicate potential risk.
Ultra high temperature (UHT) treated milk products and formula milk are known to be
frequently contaminated with Bacillus cereus. Presence of B. cereus in these milk products is
of particular concern considering the majority of consumers are infants and children. Possible
sources of contamination are contaminated raw milk, cross-contamination during processing,
under-processing and mishandling of milk products. This study was conducted to detect the
presence of B. cereus in both formula milk (n=12) and UHT milk (n=20) sold in selected retail
markets. The approach consisted of enumerating by MPN/g followed by PCR assay aimed
at detecting gyrB gene in B. cereus, that encode for the subunit B protein of DNA gyrase
(topoisomerase type II). Contamination level of B. cereus in both types of samples examined
ranged from < 3 to > 1100 MPN/g. The contamination level of B. cereus was found to be
highest in full cream UHT milk (> 1100 MPN/g) and formula milk (> 1100 MPN/g). The PCR
analysis showed that 41.7% (5/12) formula milk and 30% (6/20) UHT milk samples were
detected with B. cereus, respectively. This is the first report of such study demonstrating the
presence of B. cereus in formula milk from Malaysia. Therefore, constant surveillance of these
milk products would reduce the potential risk of B. cereus-linked outbreaks.