To explore new approaches of phage-based bio-process of specifically pathogenic Escherichia coli bacteria in food products within a short period. One hundred and forty highly lytic designed coliphages were used. Escherichia coli naturally contaminated and Enterohemorrhagic Escherichia coli experimentally inoculated samples of lettuce, cabbage, meat, and egg were used. In addition, experimentally produced biofilms of E. coli were tested. A phage concentration of 10(3) PFU/ml was used for food products immersion, and for spraying of food products, 10(5) PFU/ml of a phage cocktail was used by applying a 20-s optimal dipping time in a phage cocktail. Food samples were cut into pieces and were either sprayed with or held in a bag immersed in lambda buffer containing a cocktail of 140 phages. Phage bio-processing was successful in eliminating completely E. coli in all processed samples after 48 h storage at 4°C. Partial elimination of E. coli was observed in earlier storage periods (7 and 18 h) at 24° and 37°C. Moreover, E. coli biofilms were reduced >3 log cycles upon using the current phage bio-processing. The use of a phage cocktail of 140 highly lytic designed phages proved highly effective in suppressing E. coli contaminating food products. Proper decontamination/prevention methods of pathogenic E. coli achieved in this study can replace the current chemically less effective decontamination methods.
Innovative technologies for the pasteurization of food products have increased due to the global demand for higher-quality food products. In this regard, the current article aimed to provide an overview regarding the latest research on US application in the decontamination of fungi in food products and highlight the parameters influencing the effectiveness of this method. Therefore, the related article with inactivation of fungi and mycotoxins by ultrasound among last four years (2018-2021) by using terms such as 'mycotoxin,' 'inactivation,' 'ultrasound,' 'decontamination' among some international databases such as PubMed, Web of Science, Embase and Google Scholar" was retrieved. Ultrasound (US) is considered a non-thermal decontamination method for food products. In US, the release of energy due to the acoustic phenomenon destroys microorganisms. This technology is advantageous as it is inexpensive, eco-friendly, and does not negatively affect food products' food structure and organoleptic properties. The influence of the US on food structure and organoleptic properties dramatically depends on the intensity and energy density applied In addition, it can preserve higher levels of ascorbic acid, lycopene, and chlorophyll in sonicated food products. The treatment conditions, including frequency, intensity, duration, temperature, and processing pressure, influence the effectiveness of decontamination. However, US displays synergistic or antagonistic effects on bacteria, yeasts, molds, and mycotoxins when combined with other types of decontamination methods such as chemical and thermal approaches. Thus, further research is needed to clarify these effects. Overall, the application of US methods in the food industry for decreasing the microbial content of food products during processing has been applied. However, the use of US with other techniques needs to be studied further.
Edible bird nests (EBNs) are consumed worldwide for various health benefits. EBNs are nests built from the saliva of swiftlets of Aerodramus species. The global market for EBNs is on the rise, especially from Hong Kong and mainland China. In the past, EBNs were harvested mainly from natural caves; however in the recent years, there has been a rapid growth of swiftlet farming. Little is known about the actual composition of EBNs except for protein, carbohydrate, ash and lipid contents, amino acids, vitamins and macro/ micronutrients. Besides the biochemical components of EBNs, are there any other structures that are associated with EBNs? This paper reports on the structural analysis of raw unprocessed farm and processed commercial EBNs. The raw EBNs were purchased from swiftlet farms in five locations in Peninsula Malaysia: Kuala Sanglang (Perlis; 6° 16' 0"N, 100° 12' 0"E), Pantai Remis (Perak; 4º 27' 0" N, 100º 38' 0" E), Kluang (Johor; 02º 012 303N 103º 192 583E), Kajang (Selangor; 2º 59' 0"N, 101º 47' 0"E) and Kota Bharu (Kelantan; 6º 8' 0"N, 102º 15' 0"E). The commercial nests were purchased from five different Chinese traditional medicinal shops (Companies A-E). A portion of each EBN was randomly broken into small fragments, attached to carbon tape and coated with gold and palladium particles for examination and photography under a scanning electron microscope. Structural analysis revealed the presence of mites, fungi, bacteria and feather strands on both the raw and commercial nests. Mite eggshells and faecal pellets, and body parts of other arthropods were seen only in the raw nests. The commercial nests had a variety of unidentified structures and substances coated on the nests' surfaces that were not found on the raw nests. The presence of these contaminants may jeopardise the quality of EBNs and pose health risks to consumers. Further identification of the mites and their allergens, fungi and bacteria are on-going and will be reported separately.
Caborca is one of the most productive asparagus-growing regions in the state of Sonora in northwest Mexico, an area where some fresh fruits and vegetables are sold at unregulated open-air street markets. This is a cross-sectional study in which fifty bundles of asparagus for exportation, 50 bundles of sub-standard asparagus, and 50 bundles of asparagus from open-air markets were selected randomly and then subjected to Faust, Kinyoun and ELISA testing to detect intestinal parasites. Pearson's chi-square (χ2) and Student-NewmanKeuls tests were used to estimate differences among the sampling site groups (P < 0.05). The pathogens Cryptosporidium spp. (29%) G. intestinalis (5%) and Cyclospora spp. (3%) were found in the asparagus sold in the region. The prevalence of Cryptosporidium spp. was higher in both the sub-standard asparagus and the product sampled from the open-air markets than in the samples for exportation (P < 0.05). This is the first study to demonstrate contamination by intestinal parasites in asparagus sold in different markets in northwest Mexico.
The microbiological quality of thirty ready-to-eat (RTE) keropok lekor (a sausage shape Malaysian fish product) was evaluated in comparison to microbiological guidelines for ready to eat foods. The two E. coli isolates were subjected to DNA sequencing, identified and tested for their resistance towards fifteen different antibiotics. The survival and growth of the isolated E. coli strains inoculated in keropok lekor at atmospheric air and vacuum packaging were also evaluated. Results revealed that four samples (13.33%) contained Enterobacteriaceae counts that exceeded the recommended allowable counts of 4.0 log10 CFU/g. Unsatisfactory level of coliforms (< 1.7 log10 CFU/g) was also observed in ten of the samples; two of which contained E. coli (2.1 ± 0.17 and 3.7 ± 0.02 log10 CFU/g), suggesting of poor hygiene and sanitation practices. While the 'Possible E10' E. coli strain was observably resistant towards Nalidixic acid (30µg) alone, B10 E. coli isolate was worryingly resistant towards Ampicillin (10µg), Ceftazidime (30µg), Ciprofloxacin (5µg), Ceftriaxone (30µg), Nalidixic acid (30µg) and Tetracycline (30µg). This study also revealed that the growth and survival of the 'Possible E10' and B10 E. coli strains were not significantly affected by vacuum packaging when stored at both 4°C and 28°C. Therefore, intervention programmes to alert and educate smallmedium enterprisers (SMEs) of keropok lekor producers on food safety as well as potential health risks that can be associated due to inappropriate handling procedures of such product, merits consideration.
Paragonimiasis is an infection caused by Paragonimus, a lung fluke and is acquired by eating raw or undercooked crustaceans containing the infective metacercariae. Herein, we report a case of paragonimiasis in a Malaysian man who presented with incidental findings from chest radiographs. Examination of his biopsied lung tissue and sputum specimen revealed Paragonimus sp. eggs, whereas stool examination showed the presence of Giardia cysts. Patient was succesfully treated with praziquantel and metronidazole respectively.
Raw or undercooked fish dishes are the major sources of human infection of fishborne trematodes (FBT) and the situation of metacercarial infection in fish greatly affect the prevalence in humans, especially those fish that are commonly used for raw consumption. To investigate the situation of infection with metacercaria of FBT in fish often used to prepare raw fish dishes by local people to assess the risk of infection to humans in Ninh Binh province, Vietnam. 345 fish belonging to five species of freshwater and one species of brackish water fish were collected from fishermen or small-scale fish dealers in Kim Son and Yen Khanh districts, Ninh Binh province between May 2017 and May 2018. Metacercaria of FBT was discovered by pepsin and hydrochloric acid digestion techniques and identified by the morphological and molecular analysis. Among examined fish, 44.06% infected with FBT metacercaria and the highest prevalence was in Cyprinus carpio (86.54%), Ctenopharyngodon idellus (78.43%) and Hypophthalmichthys molitrix (66.67%) while Konosirus punctatus - the brackish water fish - were free from infection. Three species of FBT were found; namely Haplorchis pumilio (accounting for 99.84% of collected metacercariae), Haplorchis taichui and Clonorchis sinensis. The average density was 1.06 metacercariae per gram of freshwater fish and the highest number was of C. idellus (6.38 cysts/gram) followed by Cirrhinus molitorella and C. carpio. Results of the study show the high prevalence of infection of FBT metacercariae among freshwater fish often used to prepare raw fish dishes in Ninh Binh province. These findings suggest the need for greater awareness of the risk from raw fish dishes among public health authorities and people.
Domestic mites have been recognized as the most common allergen responsible for respiratory allergy. Herein, we report a case of anaphylaxis due to ingestion of dust mitecontaminated food. A 14-year-old boy presented to the Emergency Department with chest discomfort, wheezing, eyelid angioedema, and urticarial rash twice in a month after eating meals, including tempura fried squids and onion fritters (containing wheat flour, eggs, squid, and onion). Anaphylaxis had been diagnosed and successfully treated. The investigations showed that the patient was sensitive to house dust mites. Positive skin prick-to-prick test response to incriminated flour and negative tests to wheat allergen extract and uncontaminated flour were demonstrated. The microscopic analysis of causative cooking flour identified the presence of Dermatophagoides farinae. During the oral food challenge test, the patient was able to eat tempura-fried squids and onion fritters, made with uncontaminated flour, without any adverse reaction. Hence, oral ingestion of dust mite-contaminated food was the culprit of this severe allergic reaction.
Mycotoxins are naturally occurring food toxins worldwide that can cause serious health effects. The measurement of mycotoxin biomarkers in biological fluids is needed to assess individuals' exposure. The aim of this study was to investigate the incidence of mycotoxins in the Qatari population. Serum samples from 412 adults and urinary samples from 559 adults were analyzed for the presence of mycotoxin biomarkers. Multimycotoxin approaches have been applied, using liquid chromatography mass spectrometry methods. Samples were further analyzed for the oxidative stress markers and compared with regard to the incidence of mycotoxins. The presence of mycotoxins was identified in 37% of serum samples and in less than 20% of urine samples. It was found that 88% of positive of the samples were positive for only one mycotoxin, while 12% of positive samples had two or more mycotoxins. Trichothecenes and zearalenone metabolites were most commonly detected mycotoxins, followed by aflatoxins, roquefortine C and mycophenolic acid. The presence of mycotoxins was found to positively correlate with oxidative stress markers. The obtained results illustrate the importance of mycotoxin biomonitoring studies in humans and the need to elucidate the underlying mechanisms of mycotoxin-induced toxicity.
Mycotoxins are the secondary toxic metabolites produced naturally by fungi. Analysis of mycotoxins is essential to minimize the consumption of contaminated food and feed. In this present work, an ultrasensitive electrochemical immunosensor for the detection of aflatoxin B₁ (AFB₁) was successfully developed based on an indirect competitive enzyme-linked immunosorbent assay (ELISA). Various parameters of ELISA, including antigen⁻antibody concentration, blocking agents, incubation time, temperature and pH of reagents, were first optimized in a 96-well microtiter plate to study the antigen⁻antibody interaction and optimize the optimum parameters of the assay. The optimized assay was transferred onto the multi-walled carbon nanotubes/chitosan/screen-printed carbon electrode (MWCNTs/CS/SPCE) by covalent attachment with the aid of 1-Ethyl-3-(3-dimetylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Competition occurred between aflatoxin B₁-bovine serum albumin (AFB₁⁻BSA) and free AFB₁ (in peanut sample and standard) for the binding site of a fixed amount of anti-AFB₁ antibody. Differential pulse voltammetry (DPV) analysis was used for the detection based on the reduction peak of TMB(ox). The developed immunosensor showed a linear range of 0.0001 to 10 ng/mL with detection limit of 0.3 pg/mL. AFB₁ analysis in spiked peanut samples resulted in recoveries between 80% and 127%. The precision of the developed immunosensor was evaluated by RSD values (n = 5) as 4.78% and 2.71% for reproducibility and repeatability, respectively.
A study was conducted to screen the occurrence and level of aflatoxin M1 (AFM1) in urine samples of 206 urban and rural residents in Terengganu, Malaysia. The level of AFM1 was quantified by competitive enzyme-linked immune-absorbent assay (ELISA). Of the 206 samples, 84 were positive for AFM1 (40.8%) in a range of 0.07-5.53 ng/ml (mean = 0.589 ng/ml). Residents of Terengganu are moderately exposed to AFM1. Age, ethnicity, marital status and employment status were associated with urinary level of AFM1. Subjects aged 30 years and above, non-Malays, married, and those unemployed had significantly higher levels of urinary AFM1 (p
Fourier transform infrared spectroscopy (FTIR) combined with multivariate calibration of partial least square (PLS) was developed and optimized for the analysis of Nigella seed oil (NSO) in binary and ternary mixtures with corn oil (CO) and soybean oil (SO). Based on PLS modeling performed, quantitative analysis of NSO in binary mixtures with CO carried out using the second derivative FTIR spectra at combined frequencies of 2977-3028, 1666-1739, and 740-1446 cm(-1) revealed the highest value of coefficient of determination (R (2), 0.9984) and the lowest value of root mean square error of calibration (RMSEC, 1.34% v/v). NSO in binary mixtures with SO is successfully determined at the combined frequencies of 2985-3024 and 752-1755 cm(-1) using the first derivative FTIR spectra with R (2) and RMSEC values of 0.9970 and 0.47% v/v, respectively. Meanwhile, the second derivative FTIR spectra at the combined frequencies of 2977-3028 cm(-1), 1666-1739 cm(-1), and 740-1446 cm(-1) were selected for quantitative analysis of NSO in ternary mixture with CO and SO with R (2) and RMSEC values of 0.9993 and 0.86% v/v, respectively. The results showed that FTIR spectrophotometry is an accurate technique for the quantitative analysis of NSO in binary and ternary mixtures with CO and SO.
Three ELISA test kits, the Randox ELISA beta-agonist test kit, Euro-Diagnostica test kit, and Ridascreen beta-agonist test kit, were evaluated for screening of meat and liver for beta-agonist residues in fortified and field-incurred samples. It was found that the Randox beta-agonist test kit was more suitable as a screening tool due to its accuracy, ease of use, and lower cost. The tests were able to detect beta-agonist residues at the minimum level of detection, as claimed by the suppliers. The performance of the method as assessed through recovery rates of beta-agonists in fortified samples was satisfactory with a low coefficient of variation (1-3%). Repeatability, as measured through the coefficient of correlation was also satisfactory. For field-incurred positive samples, the test kit showed a sensitivity of 100% and a low rate of false positives for goat and cow tissues. However, a high rate of apparent false positives was obtained for tissues of swine.
Enterotoxin production by strains of Staphylococcus aureus isolated from human, food and animal sources was investigated. Of the 130 isolates studied, 27 (20.8%) were found to be enterotoxigenic. The most common enterotoxin detected from human sources was enterotoxin C whereas enterotoxin B occurred more frequently in staphylococcal strains of food origin. The 2 enterotoxigenic strains, from animals isolated from a dog and a goat, produced enterotoxins A and C, respectively. Enterotoxin E was not detected alone from any of the enterotoxigenic strains studied, but occurred together with other enterotoxins. The need to detect enterotoxin in staphylococcal strains and in suspected foods for the confirmation of staphylococcal food poisoning is discussed.
A study on the kinetics of accumulation and depuration of Zn, Cu, Pb and Cd by the oysters (Crassostrea iredalei and Crassostrea belcheri) cultured at two locations in the Merbok Estuary, Malaysia was conducted. A first-order kinetic model was employed to fit the experimental data in order to estimate the rate constants for uptake and elimination processes and to predict the bioconcentration factors (BCF). Among the four metals studied, only the Zn accumulation process could not be modelled using first-order kinetics. The elimination rate constants estimated from depuration data for C. iredalei are found to be much greater than those from accumulation data. The results suggest that the values of kinetic parameters and BCFs derived under conditions of both aqueous and dietary exposure are probably more site- than species-specific.
No report was found on the occurrence of microplastics in processed seafood products that are manufactured for direct human consumption. This study investigates the potential presence of micro- and mesoplastics in 20 brands of canned sardines and sprats originating from 13 countries over 4 continents followed by their chemical composition determination using micro-Raman spectroscopy. The particles were further inspected for their inorganic composition through energy-dispersive X-ray spectroscopy (EDX). Plastic particles were absent in 16 brands while between 1 and 3 plastic particles per brand were found in the other 4 brands. The most abundant plastic polymers were polypropylene (PP) and polyethylene terephthalate (PET). The presence of micro- and mesoplastics in the canned sardines and sprats might be due to the translocation of these particles into the edible tissues, improper gutting, or the result of contamination from the canneries. The low prevalence of micro- and mesoplastics sized >149μm, and the absence of potentially hazardous inorganic elements on them, might indicate the limited health risks associated with their presence in canned sardines and sprats. Due to the possible increase in micro- and mesoplastic loads in seafood products over time, the findings of this study suggest their quantification to be included as one of the components of food safety management systems.
This paper examines the trend and possible contributing factors for the occurrence of the food borne diseases outbreaks in Malaysia. These diseases mainly are cholera, typhoid fever, hepatitis A, dysentery and food poisoning. The outbreaks still occur sporadically in certain high risk areas throughout the country. The incidence rate of all the other three major food borne diseases steadily declined from the year 1988 to 1997 except for food poisoning and cholera. Statistic of food poisoning from the year 1996 to 1997 showed that 66.5% of the outbreak occurred in schools whereas only 0.4% originated from the contaminated food sold at various public food outlets. The school age group is always more affected than the general population. Amongst the contributing factors identified are related to unhygienic food handling practices followed by inadequate safe water supply and poor environmental sanitation. A multisectoral approach between Ministry of Health and other government agencies or private agents needs to be undertaken in the management of the food borne diseases in order to curb the incidences of food borne diseases in Malaysia.