Vibrio parahaemolyticus is a foodborne bacterial pathogen that may cause gastroenteritis in humans through the consumption of seafood contaminated with this microorganism. The emergence of antimicrobial and multidrug-resistant bacteria is another serious public health threat worldwide. In this study, the prevalence and antibiotic susceptibility test of V. parahaemolyticus in blood clams, shrimps, surf clams, and squids were determined. The overall prevalence of V. parahaemolyticus in seafood was 85.71% (120/140), consisting of 91.43% (32/35) in blood clam, 88.57% (31/35) in shrimps, 82.86% (29/35) in surf clams, and 80% (28/35) in squids. The majority of V. parahaemolyticus isolates from the seafood samples were found to be susceptible to most antibiotics except ampicillin, cefazolin, and penicillin. The MAR indices of V. parahaemolyticus isolates ranged from 0.04 to 0.71 and about 90.83% of isolates were found resistant to more than one antibiotic. The high prevalence of V. parahaemolyticus in seafood and multidrug-resistant isolates detected in this study could pose a potential risk to human health and hence appropriate control methods should be in place to minimize the potential contamination and prevent the emergence of antibiotic resistance.
Kitchen mishandling practices contribute to a large number of foodborne illnesses. In this study, the transfer and cross-contamination potential of Vibrio parahaemolyticus from bloody clams to ready-to-eat food (lettuce) was assessed. Three scenarios were investigated: 1) direct cross-contamination, the transfer of V. parahaemolyticus from bloody clams to non-food contact surfaces (hands and kitchen utensils) to lettuce (via slicing), was evaluated; 2) perfunctory decontamination, the efficacy of two superficial cleaning treatments: a) rinsing in a pail of water, and b) wiping with a kitchen towel, were determined; and 3) secondary cross-contamination, the microbial transfer from cleaning residuals (wash water or stained kitchen towel) to lettuce was assessed. The mean of percent transfer rates through direct contact was 3.6%, and an average of 3.5% of total V. parahaemolyticus was recovered from sliced lettuce. The attempted treatments reduced the transferred population by 99.0% (rinsing) and 94.5% (wiping), and the relative amount of V. parahaemolyticus on sliced lettuce was reduced to 0.008%. V. parahaemolyticus exposure via secondary cross-contamination was marginal. The relative amount of V. parahaemolyticus recovered from washed lettuce was 0.07%, and the transfers from stained kitchen towel to lettuce were insubstantial. Our study highlights that V. parahaemolyticus was readily spread in the kitchen, potentially through sharing of non-food contact surfaces. Results from this study can be used to better understand and potentially raising the awareness of proper handling practices to avert the spread of foodborne pathogens.
Silver nanoparticles (AgNPs) used in this study were synthesized using pu-erh tea leaves extract with particle size of 4.06 nm. The antibacterial activity of green synthesized AgNPs against a diverse range of Gram-negative foodborne pathogens was determined using disk diffusion method, resazurin microtitre-plate assay (minimum inhibitory concentration, MIC), and minimum bactericidal concentration test (MBC). The MIC and MBC of AgNPs against Escherichia coli, Klebsiella pneumoniae, Salmonella Typhimurium, and Salmonella Enteritidis were 7.8, 3.9, 3.9, 3.9 and 7.8, 3.9, 7.8, 3.9 μg/mL, respectively. Time-kill curves were used to evaluate the concentration between MIC and bactericidal activity of AgNPs at concentrations ranging from 0×MIC to 8×MIC. The killing activity of AgNPs was fast acting against all the Gram-negative bacteria tested; the reduction in the number of CFU mL-1 was >3 Log10 units (99.9%) in 1-2 h. This study indicates that AgNPs exhibit a strong antimicrobial activity and thus might be developed as a new type of antimicrobial agents for the treatment of bacterial infection including multidrug resistant bacterial infection.
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.
Campylobacter is globally recognized as a major cause of foodborne infection in humans, whilst the development of antimicrobial resistance and the possibility of repelling therapy increase the threat to public health. Poultry is the most frequent source of Campylobacter infection in humans, and southeast Asia is a global leader in poultry production, consumption, and exports. Though three of the world's top 20 most populated countries are located in southeast Asia, the true burden of Campylobacter infection in the region has not been fully elucidated. Based on published data, Campylobacter has been reported in humans, animals, and food commodities in the region. To our knowledge, this study is the first to review the status of human Campylobacter infection in southeast Asia and to discuss future perspectives. Gaining insight into the true burden of the infection and prevalence levels of Campylobacter spp. in the southeast Asian region is essential to ensuring global and regional food safety through facilitating improvements in surveillance systems, food safety regulations, and mitigation strategies.
Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from <3 to >10(5) MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >10(5) MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk assessment model to estimate health risks associated with the consumption of short mackerels contaminated with pathogenic V. parahaemolyticus.
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
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.
Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces (n = 100), beef (n = 120) from wet markets and beef (n = 120) from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cattle fecal samples, 14.2% in raw beef from wet market and 7.5% in raw beef from the hypermarket. The multiplex-polymerase chain reaction (PCR) identified 55% of the strains as C. jejuni, 26% as C. coli, and 19% as other Campylobacter spp. A high percentage of Campylobacter spp. were resistant to tetracycline (76.9%) and ampicillin (69.2%), whilst low resistance was exhibited to chloramphenicol (7.6%). The MAR Index of Campylobacter isolates from this study ranged from 0.09 to 0.73. The present study indicates the potential public health risk associated with the beef food system, hence stringent surveillance, regulatory measures, and appropriate interventions are required to minimize Campylobacter contamination and prudent antibiotic usage that can ensure consumer safety.
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
Given the remarkable increase of public interest in organic food products, it is indeed critical to evaluate the microbiological risk associated with consumption of fresh organic produce. Organic farming practices including the use of animal manures may increase the risk of microbiological contamination as manure can act as a vehicle for transmission of foodborne pathogens. This study aimed to determine and compare the microbiological status between organic and conventional fresh produce at the retail level in Malaysia. A total of 152 organic and conventional vegetables were purchased at retail markets in Malaysia. Samples were analyzed for mesophilic aerobic bacteria, yeasts and molds, and total coliforms using conventional microbiological methods. Combination methods of most probable number-multiplex polymerase chain reaction (MPN-mPCR) were used to detect and quantify foodborne pathogens, including Escherichia coli O157:H7, Shiga toxin-producing E. coli (STEC), Listeria monocytogenes, Salmonella Typhimurium, and Salmonella Enteritidis. Results indicated that most types of organic and conventional vegetables possessed similar microbial count (P > 0.05) of mesophilic aerobic bacteria, yeasts and molds, and total coliforms. E. coli O157:H7 and S. Typhimurium were not detected in any sample analyzed in this study. Among the 152 samples tested, only the conventional lettuce and organic carrot were tested positive for STEC and S. Enteritidis, respectively. L. monocytogenes were more frequently detected in both organic (9.1%) and conventional vegetables (2.7%) as compared to E. coli O157:H7, S. Typhimurium, and S. Enteritidis. Overall, no trend was shown that either organically or conventionally grown vegetables have posed greater microbiological risks. These findings indicated that one particular type of farming practices would not affect the microbiological profiles of fresh produce. Therefore, regardless of farming methods, all vegetables should be subjected to appropriate post-harvest handling practices from farm to fork to ensure the quality and safety of the fresh produce.
Salmonellosis is one of the major food-borne diseases in many countries. This study was carried out to determine the occurrence of Salmonella spp., Salmonella Enteritidis, and Salmonella Typhimurium in raw chicken meat from wet markets and hypermarkets in Selangor, as well as to determine the antibiotic susceptibility profile of S. Enteritidis and S. Typhimurium. The most probable number (MPN) in combination with multiplex polymerase chain reaction (mPCR) method was used to quantify the Salmonella spp., S. Enteritidis, and S. Typhimurium in the samples. The occurrence of Salmonella spp., S. Enteritidis, and S. Typhimurium in 120 chicken meat samples were 20.80%, 6.70%, and 2.50%, respectively with estimated quantity varying from <3 to 15 MPN/g. The antibiogram testing revealed differential multi-drug resistance among S. Enteritidis and S. Typhimurium isolates. All the isolates were resistance to erythromycin, penicillin, and vancomycin whereas sensitivity was recorded for Amoxicillin/Clavulanic acid, Gentamicin, Tetracycline, and Trimethoprim. Our findings demonstrated that the retail chicken meat could be a source of multiple antimicrobial-resistance Salmonella and may constitute a public health concern in Malaysia.
Vibrio parahaemolyticus is a main foodborne disease in seafood and generally seafood is
easily deteriorates in quality of color and flavor. In this study, clove (Syzygium aromaticum)
extract shows potent antibacterial activity against growth of antibiotics resistant Vibrio
parahaemolyticus on seafood samples (cockles and shrimps). Vibrio parahaemolyticus was
artificial contaminates on the samples with 106 CFU/ml. The samples were treated with different
concentration of cloves extract with 10 mg/ml which are 0.5%, 5% and 10% concentration
from methanol food grade extraction in 0 hr, 5 min, 10 min, 15 min, 30 min, 60 min and
120 min. Tab water and deionized water were selected as a negative control. As a result, the
amount of 10 % cloves managed to mitigates the number of V. parahaemolyticus on seafood
samples in 5 minutes and 15 min on both samples. Therefore, our results signify the fact that
cloves can be apply as natural sanitizer which could meet consumer demands for safe and
traditionally consumed either raw without any undesirable effect when applied in the seafood
system industries.
This study aimed to investigate the susceptibility pattern of Staphylococcus aureus isolated from
human and environmental surfaces in a research laboratory. A total of 320 samples from nostril
(n=80), hand (n=80), door knob (n=80) and table surface (n=80) were collected for 16 weeks,
before and after work. A total number of 256 samples were found positive for Staphylococcus
aureus. Out of 80 randomly selected isolates, 50 (62.5%) isolates were resistant to methicillin
(MRSA). Hence, the precautionary measures should be taken on self and environmental
hygiene as MRSA may be transferred from humans and environmental surfaces.
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.
During 2009 to 2010, a total of 408 blood samples collected from malaria patients in Ranong (149) and Yala (259) Provinces, Thailand were investigated for Plasmodium spp using microscopic examination. There are no statistical differences in the prevalence of P. falciparum and P. vivax in samples collected from Ranong and Yala (46% vs 52%, and 54% vs 45%, respectively). Single nucleotide polymorphism of codon 86 in pfmdr1 (encoding P. falciparum multidrug resistance protein 1) was investigated among 75 samples of P. falciparum and 2 samples of P. knowlesi. A pfmdr1 N86Y mutation was detected in 1 out of 29 samples and 45 out of 46 samples obtained from Ranong and Yala Provinces, respectively. It is interesting that pfmdr1 was detected in two P. knowlesi DNA samples obtained previously from Ranong Province which was 99% homologous to pfmdr1 obtained from falciparum parasites in the same area but the mutation was not observed. The difference in multidrug resistance protein in Plasmodium obtained from those two border areas of Thailand will be of use in monitoring drug resistance in these border regions of the country.
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.
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.