Microbiological food safety: a dilemma of developing societies

Durable Surface Modification of Low-Density Polyethylene/Nano-Silica Composite Films with Bacterial Antifouling and Liquid-Repelling Properties for Food Hygiene and Safety

The growing prevalence of antimicrobial resistance in bacterial strains has increased the demand for preventing biological deterioration on the surfaces of films used in applications involving food contact materials (FCMs). Herein, we prepared superhydrophobic film surfaces using a casting process that involved the combination of low-density polyethylene (LDPE) with solutions containing surface energy-reducing silica (SRS). The bacterial antifouling properties of the modified film surfaces were evaluated using Escherichia coli O157:H7 and Staphylococcus epidermidis via the dip-inoculation technique. The reduction in bacterial populations on the LDPE film embedded with SRS was confirmed to be more than 2 log-units, which equates to over 99%, when compared to the bare LDPE film. Additionally, the modified film demonstrated liquid-repelling properties against food-related contaminants, such as blood, beverages, and sauces. Moreover, the modified film demonstrated enhanced durability and robustness compared to one of the prevalent industry methods, dip-coating. We anticipate that the developed LDPE/nano-silica composite film represents a promising advancement in the multidisciplinary aspects of food hygiene and safety within the food industry, particularly concerning FCMs.

Comparison of SARIMA model, Holt-winters model and ETS model in predicting the incidence of foodborne disease

BACKGROUND

According to the World Health Organization, foodborne disease is a significant public health issue. We will choose the best model to predict foodborne disease by comparison, to provide evidence for government policies to prevent foodborne illness.

METHODS

The foodborne disease monthly incidence data from June 2017 to April 2022 were obtained from the Chongqing Nan'an District Center for Disease Prevention and Control. Data from June 2017 to June 2021 were used to train the model, and the last 10 months of incidence were used for prediction and validation The incidence was fitted using the seasonal autoregressive integrated moving average (SARIMA) model, Holt-Winters model and Exponential Smoothing (ETS) model. Besides, we used MSE, MAE, RMSE to determine which model fits better.

RESULTS

During June 2017 to April 2022, the incidence of foodborne disease showed seasonal changes, the months with the highest incidence are June to November. The optimal model of SARIMA is SARIMA (1,0,0) (1,1,0)12. The MSE, MAE, RMSE of the Holt-Winters model are 8.78, 2.33 and 2.96 respectively, which less than those of the SARIMA and ETS model, and its prediction curve is closer to the true value. The optimal model has good predictive performance.

CONCLUSION

Based on the results, Holt-Winters model produces better prediction accuracy of the model.

Synthetic and natural antimicrobials as a control against food borne pathogens: A review

Food borne pathogens are one of the most common yet concerning cause of illnesses around the globe. These microbes invade the body via food items, through numerous mediums of contamination and it is impossible to completely eradicate these organisms from food. Extensive research has been made regarding their treatment. Unfortunately, the only available treatment currently is by antibiotics. Recent exponential increase in antibiotic resistance and the side effect of synthetic compounds have established a need for alternate therapies that could be utilized either on their own or along with antibiotics to provide protection against food-borne diseases. The aim of this review is to provide information regarding some common food borne diseases, their current and possible natural treatment. It will include details regarding some common foodborne pathogens, the disease they cause, prevalence, manifestations and treatment of the respective disease. Some natural modes of potential treatment will be summarized, which including phytochemicals, derived from plants either as crude extracts or as purified form and Bacteriocins as microbial based treatment, obtained from various types of bacteria. The paper will describe their mechanism of action, classification, susceptible organisms, some antimicrobial compounds and producing organisms, application in food systems and as potential treatment. Along with that, synthetic treatment i.e., antibiotics will be discussed including the first-line treatment of some common food borne infections, prevalence and mechanism of resistance against antibiotics in the pathogens.

Iron/iron oxide-based magneto-electrochemical sensors/biosensors for ensuring food safety: recent progress and challenges in environmental protection

Foodborne diseases have arisen due to the globalization of industry and the increase in urban population, which has led to increased demand for food and has ultimately endangered the quality of food. Foodborne diseases have caused some of the most common public health problems and led to significant social and economic issues worldwide. Food quality and safety are affected by microbial contaminants, growth-promoting feed additives (β-agonists and antibiotics), food allergens, and toxins in different stages from harvesting to storage and marketing of products. Electrochemical biosensors, due to their reduced size and portability, low cost, and low consumption of reagents and samples, can quickly provide valuable quantitative and qualitative information about food contamination. In this regard, using nanomaterials can increase the sensitivity of the assessment. Magnetic nanoparticle (MNP)-based biosensors, especially, are receiving significant attention due to their low-cost production, physicochemical stability, biocompatibility, and eco-friendly catalytic characteristics, along with magnetic, biological, chemical and electronic sensing features. Here, we provide a review on the application of iron-based magnetic nanoparticles in the electrochemical sensing of food contamination. The types of nanomaterials used in order to improve the methods and increase the sensitivity of the methods have been discussed. Then, we stated the advantages and limitations of each method and tried to state the research gaps for each platform/method. Finally, the role of microfluidic and smartphone-based methods in the rapid detection of food contamination is stated. Then, various techniques like label-free and labelled regimes for the sensitive monitoring of food contamination were surveyed. Next, the critical role of antibody, aptamer, peptide, enzyme, DNA, cells and so on for the construction of specific bioreceptors for individual and simultaneous recognition by electrochemical methods for food contamination were discussed. Finally, integration of novel technologies such as microfluidic and smartphones for the identification of food contaminations were investigated. It is important to point out that, in the last part of each sub-section, attained results of different reports for each strategy were compared and advantages/limitations were mentioned.

Review on Sensor Array-Based Analytical Technologies for Quality Control of Food and Beverages

Food quality control is an important area to address, as it directly impacts the health of the whole population. To evaluate the food authenticity and quality, the organoleptic feature of the food aroma is very important, such that the composition of volatile organic compounds (VOC) is unique in each aroma, providing a basis to predict the food quality. Different types of analytical approaches have been used to assess the VOC biomarkers and other parameters in the food. The conventional approaches are based on targeted analyses using chromatography and spectroscopies coupled with chemometrics, which are highly sensitive, selective, and accurate to predict food authenticity, ageing, and geographical origin. However, these methods require passive sampling, are expensive, time-consuming, and lack real-time measurements. Alternately, gas sensor-based devices, such as the electronic nose (e-nose), bring a potential solution for the existing limitations of conventional methods, offering a real-time and cheaper point-of-care analysis of food quality assessment. Currently, research advancement in this field involves mainly metal oxide semiconductor-based chemiresistive gas sensors, which are highly sensitive, partially selective, have a short response time, and utilize diverse pattern recognition methods for the classification and identification of biomarkers. Further research interests are emerging in the use of organic nanomaterials in e-noses, which are cheaper and operable at room temperature.

A Systematic Review and Meta-analysis of Antibiotic Resistance of Foodborne Pathogenic Bacteria in West Africa Between 2010 and 2020

OBJECTIVE

In the past, studies on antimicrobial resistance were carried out on pathogens in the clinical areas. However, since then, this phenomenon has become a general case both in the environment and in the food sector. This systematic review aimed to review the various scientific publications on the resistance of bacteria to antibiotics in foods in West Africa.

METHODS

An extensive literature search was carried out through an electronic database including PubMed, Google Scholar, Research Gate, and African Journals Online (AJOL). Articles published from fifteen countries of the Economic Community of West African States (ECOWAS) between 2010 and 2020 on antibiotic resistance of foodborne pathogens were included in the study. The titles and abstracts of the retrieved articles and then the full texts of the selected articles were reviewed.

RESULTS

Out of the 565 articles found in our initial research, 149 publications (26.55%) were considered suitable for inclusion in this review. Globally, 2018, 2019, and 2020 had more included papers (n = 21 to 25) than the other years. Of the 149 publications analyzed, four types of food commodities were identified as products of high consumption based on the number of publications in the field such as poultry (39/149), read-to-eat food (22/149), meat, and animal products (20/149). Most studies have shown that E. coli has the highest prevalence followed by Salmonella and Staphylococcus. Only 33 (22.14%) of the 149 publications were based on further molecular characterization of the isolates. Publications analyzed showed that the most prevalent detected genes were tet(A), tet(B), tet(C), tet(K) blaTEM, catA1, catA2, cmlA, blaCTXM and qnrA, qnrB, qnrS, parC, and qepA4.

CONCLUSION

From these results, antibiotic use in the food areas must be strongly regulated, especially in developing countries, particularly in Africa. This highlights the need to implement suitable and appropriate control strategies to reduce complications and prevent the dissemination of resistant bacteria isolates in foods. One health antimicrobial resistance surveillance system in the region must be a great concern.

Duplex detection of foodborne pathogens using a SERS optofluidic sensor coupled with immunoassay

Herein, we developed a surface-enhanced Raman spectroscopy (SERS) optofluidic sensor coupled with immunoprobes to simultaneously separate and detect the foodborne pathogens, Escherichia coli O157:H7, and Salmonella in lettuce and packed salad. The method consists of three steps of (i) enrichment to enhance detection sensitivity, (ii) selective separation and labelling of target bacteria by their specific antibody-bearing SERS-nanotags and (iii) detection of tagged bacterial cells using SERS within a hydrodynamic flow-focusing SERS optofluidic device, where even low counts of bacterial cells were detectable in the very thin-film-like sample stream. SERS-nanotags consisted of different Raman reporter molecules, representing each species, i.e., the detection of Raman reporter confirms the presence of the target pathogen. The anti-E. coli antibody used in this study functions against all strains of E. coli O157:H7 and the anti-Salmonella antibody used in this work acts on a wide range of Salmonella enterica strains. Bacterial counts of 1000, 100, and 10 CFU/ 200 g sample were successfully detected after only 15 min enrichment. Our method showed a very low detection limit value of 10 CFU/ 200 g sample for the bacterial mixture in both lettuce and packed salad, proving the efficiency and high sensitivity of our method to detect multiple pathogens in the food samples. The total analysis time, including sample preparation for simultaneous detection of multiple bacteria, was estimated to be 2 h, which is much less than the time required in conventional methods. Hence, our proposed protocol is considered a promising rapid and efficient approach for pathogen screening of food samples.

Descriptive study of foodborne disease using disease monitoring data in Zhejiang Province, China, 2016-2020

Background

This study aimed to identify the epidemiology, seasonality, aetiology and clinical characteristics of sporadic foodborne diseases in Zhejiang province during 2016–2020.

Methods

Descriptive statistical methods were used to analyze the data from surveillance network established by the Zhejiang Provincial Center for Disease Control and Prevention. There were 31 designated hospitals in all 11 cities which were selected using probability proportionate to size sampling method.

Results

During the study period, the surveillance system received 75,124 cases with 4826 (6.42%) hospitalizations from 31 hospitals. The most common cause was Norovirus, 6120 cases (42.56%), followed by Salmonella, 3351 cases (23.30%). A significant seasonal trend was observed for the V. parahaemolyticus, with the highest rates over the summer period, peaking in August, 1171 cases (38.75%), a similar trend was also observed with Salmonella and Diarrheagenic E. coli. Norovirus infections showed the highest rate in November (904, 14.77%) and March (660,10.78%), the lowest in August, 215 cases (3.51%). Patients between 19 ~ 40 years were more likely to infected by Norovirus, V. parahaemolyticus and Diarrheagenic E. coli, patients below 1 year were the highest among patients with Salmonella infection, 881 cases (26.3%). The Norovirus, V. parahaemolyticus and Diarrheagenic E. coli infection with the highest positive detection rates among the workers were observed. The largest number cases of food categories were from aquatic product infection. The private home was the most common exposure setting.

Conclusion

Our study highlighted the necessity for conducting an active, comprehensive surveillance for pathogens in all age groups, to monitor the changing dynamics in the epidemiology and aetiology of foodborne diseases to guide policies that would reduce related illnesses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14226-1.

Assessment of food safety knowledge, attitude, practices of food handlers and microbial contamination in foods at the canteens of a University in Pakistan

Developing nations are striving to assure food safety that rely mainly upon handling procedures. The current study focused upon the understanding level and practices of food handlers working at various canteens of University of the Punjab, Quid-i-Azam campus, Lahore. Different canteens were selected where 300 different food handlers were judged for their approach towards food safety through a closed ended questionnaire. Samples of different food products were also taken randomly for their microbiological safety evaluation. The whole data was analyzed using chi-square to assess the proportion of correct and incorrect responses among various parameters. The non-significant variation was observed among the knowledge, attitude and practices scores of university and its hostels’ canteens food handlers. Overall, 60% of the responses were correct from the university and hostel canteens food handlers. Similarly, 50-60% of the responses regarding attitude and practices were correct from the university and hostel canteen food handlers. With many technical flaws, these food handlers showed moderate level of knowledge. Not only apprentices but the supervisors too, lacked the basic knowledge of temperature as major factor creating potential food safety threats. Lack of knowledge about personal hygiene and workplace sanitation were few contributing factors towards heedless behavior. Incidence of Salmonella and Staphylococcus aureus contamination in food samples was found 29% and 57%, respectively, while 35% food samples were found contaminated with E. coli. It further exposed the negligence, emphasizing proper training of employees as part and parcel of food safety procedures. It was concluded that more training programs along with periodic validation of food manufacturing standards are required to ensure food safety. Furthermore, strict surveillance and implementation of GMPs by the administrative authorities are needed to safeguard the consumers’ health.

Biofilms as a microbial hazard in the food industry: A scoping review

Biofilms pose a serious public health hazard with a significant economic impact on the food industry. The present scoping review is designed to analyze the literature published during 2001-2020 on biofilm formation of microbes, their detection methods, and association with antimicrobial resistance (if any). The peer-reviewed articles retrieved from 04 electronic databases were assessed using PRISMA-ScR guidelines. From the 978 preliminary search results, a total of 88 publications were included in the study. On analysis, the commonly isolated pathogens were Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., Escherichia coli, Bacillus spp., Vibrio spp., Campylobacter jejuni and Clostridium perfringens. The biofilm-forming ability of microbes was found to be influenced by various factors such as attachment surfaces, temperature, presence of other species, nutrient availability etc. A total of 18 studies characterized the biofilm-forming genes, particularly for S. aureus, Salmonella spp., and E. coli. In most studies, polystyrene plate and/or stainless-steel coupons were used for biofilm formation, and the detection was carried out by crystal violet assays and/or by plate counting method. The strain-specific significant differences in biofilm formation were observed in many studies, and few studies carried out analysis of multi-species biofilms. The association between biofilm formation and antimicrobial resistance wasn't clearly defined. Further, viable but non-culturable (VBNC) form of the foodborne pathogens is posing an unseen (by conventional cultivation techniques) but potent threat food safety. The present review recommends the need for carrying out systematic surveys and risk analysis of biofilms in food chain to highlight the evidence-based public health concerns, especially in regions where microbiological food hazards are quite prevalent.

The impact of incorporating Lactobacillus acidophilus bacteriocin with inulin and FOS on yogurt quality

The current study aimed to figure out the effect of using a combination of 2% inulin, and 2% Fructo-oligosaccharides (FOS) with Lactobacillus acidophilus and their bacteriocin on some yogurt properties such as coagulation time, extending the shelf life of set yogurt and its microbiological quality, also the acceptance by consumers. The results indicated that coagulation time increased by 22.75% in yogurts prepared with Lactobacillus acidophilus and their bacteriocins compared to the control, and titratable acidity increased gradually in all treatments during storage. Hence control acidity (%) increased from 0.84 ± 0.02^A at zero time to 1.23 ± 0.03^A after 14 days of cold storage, while treatment (T4) was 0.72 ± 0.01^C at zero time and reached 1.20 ± 0.5^A after 39 days at the same conditions. The sensory properties showed the superiority of inulin, FOS, and Lactobacillus acidophilus bacteriocin groups. Lactobacillus bulgaricus, Streptococcus thermophiles, and Lactobacillus acidophilus count increased in the treatments compared to the control group, with an extended shelf life to 39 days of storage in the medicines containing lactobacillus acidophilus bacteriocin. Coliforms, Moulds, and yeasts did not detect in the treatments comprising 2% inulin, 2% FOS, and lactobacillus acidophilus bacteriocin for 39 days of refrigerated storage. This study proved that 2% inulin, 2% FOS, and Lactobacillus acidophilus bacteriocin fortification extended the shelf life by more than 5 weeks.

Assessment of Foodborne Disease Hazards in Beverages Consumed in Nigeria: A Systematic Literature Review

Risk assessment is a formal process of identifying hazards and assessing the risk associated with them (risk is a combination of the severity of illness and the probability of occurrence). This review highlights foodborne disease hazards reported in beverages consumed in Nigeria for the period between 2000 and 2020. Based on a preregistered protocol and search syntax, studies were retrieved from the PubMed, Google Scholar, and ScienceDirect databases. Rayyan QCRI software was used to screen the articles. Data were then extracted from the included full-text articles, into a standardized excel workbook. A total of 18,762 articles were identified, from which 126 were included in the final analyses. The common beverages studied were sachet water (14.9%), borehole/well water (13.9%), cereal-based beverages (12.1%), raw/fresh milk (8.3%) and nono/nunu, which is a fermented milk-cereal beverage (7.2%). Sufficient data were available to undertake pooled prevalence estimates for some hazards within select beverages and revealed contamination rates for Staphylococcus spp. in raw/fresh milk, 12.3% (95% CI 6.3–20.0); Salmonella spp. in borehole/well water, 19.8% (95% CI 13.1–27.4); Klebsiella spp. in sachet water, 40.0% (95% CI 12.4–71.7); Staphylococcus spp. in nono/nunu, 32.6% (95% CI 14.7–53.8), and Escherichia spp. in nono/nunu, 30.7% (95% CI 21.9–40.2). Heterogeneity was present in the aggregate summary estimates. This review has highlighted the presence of several hazards of high importance to public health in commonly consumed beverages in Nigeria. The data presented here provide an entry point for future quantitative risk assessments both to determine the level of exposure of the community to these hazards and also for the identification of the most effective mitigation strategies to reduce these risks and improve health outcomes in Nigeria.

Prevalence and epidemiological distribution of selected foodborne pathogens in human and different environmental samples in Ethiopia: a systematic review and meta-analysis

Bacterial Foodborne Pathogens (FBP) are the commonest cause of foodborne illness or foodborne diseases (FBD) worldwide. They contaminate food at any stages in the entire food chain, from farm to dining-table. Among these, the Diarrheagenic Escherichia coli (DEC), Non typhoidal Salmonella (NTS), Shigella spp. and Campylobacter spp. are responsible for a large proportion of illnesses, deaths; and, particularly, as causes of acute diarrheal diseases. Though existing studies indicate the problem may be severe in developing countries like Ethiopia, the evidence is commonly based on fragmented data from individual studies. A review of published and unpublished manuscripts was conducted to obtain information on major FBP and identify the gaps in tracking their source attributions at the human, animal and environmental interface. A total of 1753 articles were initially retrieved after restricting the study period to between January 2000 and July 2020. After the second screening, only 51 articles on the humans and 43 on the environmental sample based studies were included in this review. In the absence of subgroups, overall as well as human stool and environmental sample based pooled prevalence estimate of FBP were analyzed. Since, substantial heterogeneity is expected, we also performed a subgroup analyses for principal study variables to estimate pooled prevalence of FBP at different epidemiological settings in both sample sources. The overall random pooled prevalence estimate of FBP (Salmonella, pathogenic Escherichia coli (E. coli), Shigella and Campylobacter spp.) was 8%; 95% CI: 6.5-8.7, with statistically higher (P <  0.01) estimates in environmental samples (11%) than in human stool (6%). The subgroup analysis depicted that Salmonella and pathogenic E. coli contributed to 5.7% (95% CI: 4.7-6.8) and 11.6% (95% CI: 8.8-15.1) respectively, of the overall pooled prevalence estimates of FBD in Ethiopia. The result of meta-regression showed, administrative regional state, geographic area of the study, source of sample and categorized sample size all significantly contributed to the heterogeneity of Salmonella and pathogenic E. coli estimates. Besides, the multivariate meta- regression indicated the actual study year between 2011 and 2015 was significantly associated with the environmental sample-based prevalence estimates of these FBP. This systematic review and meta-analysis depicted FBP are important in Ethiopia though majority of the studies were conducted separately either in human, animal or environmental samples employing routine culture based diagnostic method. Thus, further FBD study at the human, animal and environmental interface employing advanced diagnostic methods is needed to investigate source attributions of FBD in one health approach.

Microbial Food Safety in China: Past, Present, and Future

Food safety is a major public health issue worldwide, especially in heavily populated countries such as China. As in other countries, the predominant food safety issues in China are foodborne diseases caused by microbial pathogens. Hence, this review provides a systematic overview on microbial food safety in the past, present, and future in China. Management of microbial food safety in China is generally divided into three stages: Stage I before 2000, Stage II from 2000 to 2009, and Stage III from 2010 to present. At Stage I, China's main food concern gradually shifted from food security to food safety. At Stage II, foodborne pathogen surveillance was initiated and gradually became a focus of microbial food safety marked by the establishment of national food contamination monitoring system in 2000 and the promulgation of China Food Safety Law in 2009, although chemical food safety was considered a priority issue during this stage. At Stage III, microbial food safety was recognized as a high priority supported by many national food safety policies such as the launch of a national foodborne disease molecular tracing network in 2013 and the revision of China Food Safety Law in 2015. Advancement in food safety education and research support by central and local governments has also made significant contributions to tackling and solving microbial food safety problems. Management in the future should be focused on active involvement of food industries in mitigating microbial risks by introducing ISO 22000, regulatory enforcement to oversee compliances to standards and rules, and application of molecular tools for fast detection and source tracking to support decision-making. Future research efforts may include, but are not limited to, exploitation of interaction mechanisms among pathogenic bacteria, food and gut microbiota, smart traceability of microbial hazards, and development of novel antimicrobial strategies.

Multicolor Coding Up-Conversion Nanoplatform for Rapid Screening of Multiple Foodborne Pathogens

Technologies for rapid screening of multiple foodborne pathogens have been urgently needed because of the complex food matrix and high outbreaks of foodborne diseases. In this study, multicolor coding up-conversion nanoparticles (UCNPs) were synthesized and applied for rapid and simultaneous detection of five kinds of foodborne pathogens. The multicolor coding UCNPs were obtained through doping different concentrations of a sensitizer (Yb³⁺) on the shell of the synthesized NaYF₄:Yb³⁺, Tm³⁺ (20%/2%)@NaYF₄:Yb³⁺, and Er³⁺ (x %/2%) core/shell nanocrystals. All the UCNPs could emit red and green luminescence simultaneously once excited with near-infrared wavelength (980 nm), and the ratio of red and green (R/G ratio) emission light intensity of each kind of UCNPs varied depending on the Yb³⁺ doping concentration. In addition, the magnetic nanoparticles (MNPs) modified with the monoclonal antibodies (mAbs) against the target bacteria were used to capture and separate the bacteria, resulting in obtaining the MNP-bacterium complexes. Different UCNPs with multicolor coding acted as signal probes were also modified with the mAbs to react with the MNP-bacterium complexes to form the MNP-bacterium-UCNP sandwich complexes. After the sandwich complexes were excited with a wavelength of 980 nm, the obtained R/G ratios and the green photoluminescence intensity (PL intensity) could be used to distinguish and quantitatively detect foodborne pathogens, respectively. This proposed nanoplatform could detect five foodborne pathogens simultaneously within 2 h with good sensitivity and specificity, showing great potential for multiplex detection of other targets in the fields of medical diagnosis and food security.

Nanobioengineered Sensing Technologies Based on Cellulose Matrices for Detection of Small Molecules, Macromolecules, and Cells

Recent advancement has been accomplished in the field of biosensors through the modification of cellulose as a nano-engineered matrix material. To date, various techniques have been reported to develop cellulose-based matrices for fabricating different types of biosensors. Trends of involving cellulosic materials in paper-based multiplexing devices and microfluidic analytical technologies have increased because of their disposable, portable, biodegradable properties and cost-effectiveness. Cellulose also has potential in the development of cytosensors because of its various unique properties including biocompatibility. Such cellulose-based sensing devices are also being commercialized for various biomedical diagnostics in recent years and have also been considered as a method of choice in clinical laboratories and personalized diagnosis. In this paper, we have discussed the engineering aspects of cellulose-based sensors that have been reported where such matrices have been used to develop various analytical modules for the detection of small molecules, metal ions, macromolecules, and cells present in a diverse range of samples. Additionally, the developed cellulose-based biosensors and related analytical devices have been comprehensively described in tables with details of the sensing molecule, readout system, sensor configuration, response time, real sample, and their analytical performances.

Characterization of Bacillus Species from Market Foods in Beijing, China

Foodborne diseases have been witnessing a constant rising trend worldwide, mainly caused by pathogenic microorganisms, such as Bacillus spp., posing a direct threat to public health. The purpose of this study was to evaluate the biological risk of foodborne and probiotic Bacillus spp. in Beijing markets. A total of 55 Bacillus isolates, including 29 B. cereus, 9 B. licheniformis and 7 B. subtilis, mostly found in dairy products (32.7%), were recovered from 106 samples and identified by matrix-assisted laser desorption/ionization mass spectrometry and polymerase chain reaction methods. The susceptibility towards 16 antibiotics was determined using a broth microdilution method. Bacillus showed a high level of resistance to florfenicol (100%), lincomycin (100%), tiamulin (78.2%) and ampicillin (67.3%), while they were all susceptible or intermediate to vancomycin and rifampin. Additionally, we obtained the whole genome of 19 Bacillus strains using high-throughput sequencing, and the rates of resistance genes van, fosB, erm and tet were 57.9%, 57.9%, 21.1% and 26.3%, respectively. Moreover, 100%, 9.1%, 45.5% and 100% of these isolates carried virulence genes nhe, hbl, cytK and entFM, respectively. Lastly, 60% Bacillus strains were positive in hemolysis tests, and 3 B. licheniformis strains displayed an inhibitory activity on the growth of S. aureus ATCC 29213 using agar overlay technique. Our study outlines the characteristics of foodborne Bacillus spp. and provides information for the monitoring of food safety.

MOL-PCR and xMAP Technology: A Multiplex System for Fast Detection of Food- and Waterborne Viruses

Viruses are common causes of food- and waterborne diseases worldwide. Conventional identification of these agents is based on cultivation, antigen detection, electron microscopy, or real-time PCR. Because recent technological advancements in detection methods are focused on fast and robust analysis, a rapid multiplexing technology, which can detect a broad spectrum of pathogenic viruses connected to food or water contamination, was utilized. A new semiquantitative magnetic bead-based multiplex system has been designed for simultaneous detection of several targets in one reaction. The system includes adenoviruses 40/41 (AdV), rotavirus A (RVA), norovirus (NoV), hepatitis E virus (HEV), hepatitis A virus (HAV), and a target for external control of the system. To evaluate the detection system, interlaboratory ring tests were performed in four independent laboratories. Analytical specificity of the tool was tested on a cohort of pathogenic agents and biological samples with quantitative PCR as a reference method. Limit of detection (analytical sensitivity) of 5 × 10⁰ (AdV, HEV, and RVA) and 5 × 10¹ (HAV and NoV) genome equivalents per reaction was reached. This robust, senstivie, and rapid multiplexing technology may be used to routinely monitor and manage viruses in food and water to prevent food and waterborne diseases.

Contamination of ready-to-eat street food in Pakistan with Salmonella spp.: Implications for consumers and food safety

OBJECTIVES

Ready-to-eat (RTE) food sold in Quetta, Pakistan was assessed for microbial contamination.

METHODS

Equal numbers of samples were collected from four categories of RTE food - burgers, shawarma, pizza and sandwiches - from January 2018 to December 2018. Microbial contamination of individual food samples was assessed by quantifying the total aerobic count obtained from plating samples on bacterial growth medium. Salmonella spp. serovars were identified using polymerase chain reaction.

RESULTS

Approximately 38% (121/320) of RTE food samples were not fit for human consumption. The most contaminated type of RTE food was shawarma (49%). Microbial contamination of food samples was higher in summer compared with the other seasons. Approximately 40% (49/121) of food samples that were not fit for human consumption were contamined with Salmonella spp. Salmonella enteritidis (69%) and Salmonella typhimurium (31%) were the only serovars among the samples testing positive for Salmonella spp. Of the 49 samples with high microbial counts, S. enteritidis was present in 34 samples and S. typhimurium was present in 15 samples. The antibiotic sensitivity results demonstrated that both S. enteritidis and S. typhimurium were resistant to amoxicillin. In addition, S. enteritidis was resistant to chloramphenicol and erythromycin, and S. typhimurium presented high resistance to erythromycin. Both S. typhimurium and S. enteritidis were highly sensitive to kanamycin.

CONCLUSION

RTE food sold by street vendors in Quetta was found to be contaminated with Salmonella spp. and poses a great health risk to consumers. As such, consumption should be avoided, and the health authorities should take stringent action to ensure the quality of street food in order to reduce the healthcare burden.

Prevalence of Salmonella enterica Isolated from Food Contact and Nonfood Contact Surfaces in Cambodian Informal Markets

ABSTRACT

The lack of hygiene and sanitation practices and insufficient infrastructure in Cambodian informal markets may increase the risk of food contamination, specifically raw vegetables, which in turn may increase the chances of contracting a foodborne disease. The aims of this study in informal markets in Cambodia were (i) to quantify the prevalence of Salmonella enterica based upon differences in season of the year (rainy versus dry), surface types (food contact surfaces versus nonfood contact surfaces), and location of vendors within the market (inside versus outside) and (ii) to characterize S. enterica serotype prevalence. A total of 310 samples were screened for S. enterica prevalence following the U.S. Department of Agriculture guidelines, and results were confirmed by PCR assay. Whole genome sequencing was used to determine the serotype for each isolate in silico using SeqSero 1.0 on draft genomes. A total of 78 samples were confirmed positive for S. enterica. During the dry season, S. enterica was more prevalent on food contact surfaces than on nonfood contact surfaces (estimated probability of detection [confidence interval]: 0.41 [0.25, 0.59] and 0.17 [0.08, 0.32], respectively; P = 0.002), but no differences were apparent in the rainy season. No differences in S. enterica prevalence were found based on location within the market (P = 0.61). Sixteen S. enterica serotypes were detected across multiple surfaces. The most common S. enterica serotypes were Rissen (18 isolates), Hvittingfoss (11), Corvallis (10), Krefeld (8), Weltevreden (6), and Altona (6). Accurate data on the prevalence of S. enterica in informal markets are crucial for the development of effective surveillance and implementation of suitable intervention strategies at the domestic level, thus preventing foodborne illness.

HIGHLIGHTS

Characterisation of Bacteriocins Produced by Lactobacillus spp. Isolated from the Traditional Pakistani Yoghurt and Their Antimicrobial Activity against Common Foodborne Pathogens

Lactic acid bacteria (LAB) are widely known for their probiotic activities for centuries. These bacteria synthesise some secretory proteinaceous toxins, bacteriocins, which help destroy similar or interrelated bacterial strains. This study was aimed at characterising bacteriocins extracted from Lactobacillus spp. found in yoghurt and assessing their bactericidal effect on foodborne bacteria. Twelve isolated Lactobacillus spp. were examined to produce bacteriocins by the organic solvent extraction method. Bacteriocins produced by two of these strains, Lactobacillus helveticus (BLh) and Lactobacillus plantarum (BLp), showed the most significant antimicrobial activity, especially against Staphylococcus aureus and Acinetobacter baumannii. Analysis of SDS-PAGE showed that L. plantarum and L. helveticus bacteriocins have a molecular weight of ~10 kDa and ~15 kDa, respectively. L. plantarum (BLp) bacteriocin was heat stable while L. helveticus (BLh) bacteriocin was heat labile. Both bacteriocins have shown activity at acidic pH. Exposure to a UV light enhances the activity of the BLh; however, it had negligible effects on the BLp. Different proteolytic enzymes confirmed the proteinaceous nature of both the bacteriocins. From this study, it was concluded that bacteriocin extracts from L. helveticus (BLh) can be considered a preferable candidate against foodborne pathogens as compared to L. plantarum (BLp). These partially purified bacteriocins should be further processed to attain purified product that could be useful for food spoilage and preservation purposes.

Preharvest Transmission Routes of Fresh Produce Associated Bacterial Pathogens with Outbreak Potentials: A Review

Disease outbreaks caused by the ingestion of contaminated vegetables and fruits pose a significant problem to human health. The sources of contamination of these food products at the preharvest level of agricultural production, most importantly, agricultural soil and irrigation water, serve as potential reservoirs of some clinically significant foodborne pathogenic bacteria. These clinically important bacteria include: Klebsiella spp., Salmonella spp., Citrobacter spp., Shigella spp., Enterobacter spp., Listeria monocytogenes and pathogenic E. coli (and E. coli O157:H7) all of which have the potential to cause disease outbreaks. Most of these pathogens acquire antimicrobial resistance (AR) determinants due to AR selective pressure within the agroecosystem and become resistant against most available treatment options, further aggravating risks to human and environmental health, and food safety. This review critically outlines the following issues with regards to fresh produce; the global burden of fresh produce-related foodborne diseases, contamination between the continuum of farm to table, preharvest transmission routes, AR profiles, and possible interventions to minimize the preharvest contamination of fresh produce. This review reveals that the primary production niches of the agro-ecosystem play a significant role in the transmission of fresh produce associated pathogens as well as their resistant variants, thus detrimental to food safety and public health.

A one health perspective on dairy production and dairy food safety

As the global population approaches 9.7 billion inhabitants by the year 2050, humanity faces enormous challenges to feed, house, and provide basic living requirements for the growing population while preserving the health of wildlife and the ecosystem. Dairy source foods play an important part in providing nutrient and energy dense sources of calories and establishing Bifidobacterium as a keystone species in the gut for positive health outcomes in infants and children. In developed countries, dairy products have a high food safety record when pasteurized and properly processed. However, when milk is consumed unpasteurized, as often occurs in developing countries where regulation and oversight of the dairy industry is lacking, dairy can serve as a vector for zoonotic transmission of disease and can contain adulterants such as antibiotic residues. Here we provide an overview for the importance of dairy source foods for nutrition and with a One Health perspective and discuss the historical events that have resulted in a high standard of dairy food safety in the United States. This review article covers the Origins of One Health, the role of milk in transmission of disease, management practices and regulations to ensure safe dairy products reach consumers, current challenges facing the dairy industry and impacts on public health, and how these standards can be employed in low and middle income countries to improve public health, nutrition and economic benefits to farmers.

A Meta-Analysis of Major Foodborne Pathogens in Chinese Food Commodities Between 2006 and 2016

Prevalence of pathogenic bacteria in food commodities in China have been reported in numerous publications over time. However, the results are scattered and varied. To calculate a robust point estimate with a higher statistical power, we applied meta-analytic approach for investigating the prevalence of common foodborne pathogens in major food items in China. Data, on prevalence of bacteria in various food commodities were extracted and analyzed from 361 (132 English and 229 Chinese) publications. Prevalence of eight most frequently reported pathogens on six broad food categories was used for pooled and subgroup meta-analysis by DerSimonian-Laird method in random-effects model. The estimated overall prevalence of pathogens in the foods was 8.5% (95% CI 8.2-8.7). The highest prevalence, irrespective of the pathogen type, was in the aquatic produce at 12.8% (12.0-13.5), while the least was in the vegetables at 3.0% (2.6-3.4). Among the pathogens, the most prevalent was Vibrio at 21.3% (19.6-23.1), whereas the least was pathogenic Escherichia coli at 4.3% (3.3-5.2). The major food pathogens in Chinese foods in decreasing order of prevalence were Vibrio parahaemolyticus, Campylobacter, Bacillus cereus, Staphylococcus aureus, Salmonella, Enterobacter, Listeria monocytogenes, and pathogenic E. coli. Presence of these organisms in foods equates the risk of microbiological food safety in China with other developed countries rather than the developing countries. This justifies the need of novel perspectives for formulating policies on microbiological food safety and risk mitigation.

A novel perspective on MOL-PCR optimization and MAGPIX analysis of in-house multiplex foodborne pathogens detection assay

Multiplex oligonucleotide ligation-PCR (MOL-PCR) is a rapid method for simultaneous detection of multiple molecular markers within a single reaction. MOL-PCR is increasingly employed in microbial detection assays, where its ability to facilitate identification and further characterization via simple analysis is of great benefit and significantly simplifies routine diagnostics. When adapted to microsphere suspension arrays on a MAGPIX reader, MOL-PCR has the potential to outperform standard nucleic acid-based diagnostic assays. This study represents the guideline towards in-house MOL-PCR assay optimization using the example of foodborne pathogens (bacteria and parasites) with an emphasis on the appropriate choice of crucial parameters. The optimized protocol focused on specific sequence detection utilizes the fluorescent reporter BODIPY-TMRX and self-coupled magnetic microspheres and allows for a smooth and brisk workflow which should serve as a guide for the development of MOL-PCR assays intended for pathogen detection.

Emerging Point-of-care Technologies for Food Safety Analysis

Food safety issues have recently attracted public concern. The deleterious effects of compromised food safety on health have rendered food safety analysis an approach of paramount importance. While conventional techniques such as high-performance liquid chromatography and mass spectrometry have traditionally been utilized for the detection of food contaminants, they are relatively expensive, time-consuming and labor intensive, impeding their use for point-of-care (POC) applications. In addition, accessibility of these tests is limited in developing countries where food-related illnesses are prevalent. There is, therefore, an urgent need to develop simple and robust diagnostic POC devices. POC devices, including paper- and chip-based devices, are typically rapid, cost-effective and user-friendly, offering a tremendous potential for rapid food safety analysis at POC settings. Herein, we discuss the most recent advances in the development of emerging POC devices for food safety analysis. We first provide an overview of common food safety issues and the existing techniques for detecting food contaminants such as foodborne pathogens, chemicals, allergens, and toxins. The importance of rapid food safety analysis along with the beneficial use of miniaturized POC devices are subsequently reviewed. Finally, the existing challenges and future perspectives of developing the miniaturized POC devices for food safety monitoring are briefly discussed.

Mapping evidence on charitable food assistance system's compliance with safety and general hygiene requirements in Africa and the rest of the world: a systematic scoping review protocol

BACKGROUND

The charitable food assistance system has an influential role in the larger effort to curtail the problem of food insecurity globally. They often play a crucial role in meeting the food security needs of the poor, particularly resource-limited settings where food security is a challenge. The aim of our study is to compare evidence on the safety and general hygiene of charitable food assistance system in Africa and the rest of the world.

METHODS

This study will be conducted through a systematic scoping review. We will search for literature from the following electronic databases: African Index Medicus, PubMed, Google Scholar, EBSCOhost (MEDLINE with full text, Academic Search Complete, MEDLINE) and open access for unpublished theses and dissertations. Articles will also be searched through the 'Cited by' search as well as citations included in the reference lists of included articles. Websites, such as the World Health Organization (WHO) and the Departments of Health websites, will be searched for policies and guidelines for food charity practice. Studies will be identified by searching literature published in any language between 1967 and 2018. Then, following title screening, eligible studies will be exported to EndNote library where duplicates will be removed before the parallel screening of abstracts and full articles by two independent reviewers. Screening will be guided by the study eligibility criteria. Data from the included studies will be extracted, and the emerging themes will be analysed. The relationship of the emerging themes to the research question will be critically examined. The quality of the included studies will be determined by the use of Mixed Method Appraisal Tool (MMAT)-version 2011. The search results will be presented through the use of the adapted PRISMA-P chart.

DISCUSSION

We hope to find relevant studies that highlight evidence of charitable organisations' food safety and general hygiene practices, in order to effectively compare their performance to those of formal and informal food establishments. Findings of this study will be disseminated electronically, in print and through peer presentation, conferences and congresses on synergies between efforts to reduce food loss and waste and those practices of public health concern.

Distribution of virulence factors, determinants of antibiotic resistance and molecular fingerprinting of Salmonella species isolated from cattle and beef samples: suggestive evidence of animal-to-meat contamination

In this study, three hundred presumptive Salmonella strains isolated from cattle faeces and raw beef samples were subjected to both preliminary and confirmatory tests specific for Salmonella. PCR assays revealed that 100%, 20% and 26.7% of the isolates were positive for 16S rRNA, fliC and fljB gene fragments, respectively. Large proportions (62.4 to 94.3%) of these isolates were multiple antibiotic resistant (MAR) strains that were resistant to three or more antibiotics belonging to different classes. MAR phenotypes Ab1, Ab2, Ab3, Ab7, Ab8, Ab9, Ab26 and Ab27 were dominant among the isolates. Cluster analysis of antibiotic inhibition zone diameter data revealed two major clusters (clusters 1 and 2), and each cluster contained two sub-clusters (1A, 1B, 2A and 2B). PCR data revealed that 27.1% and 30.7% of the isolates possessed the spvC and invA virulent genes, respectively. There was a significant correlation between the possession of MAR phenotypes and virulent gene determinants. Analysis of restriction fragment length polymorphism (RFLP) of 16S rRNA gene fragments using EcoRI and HaeIII showed that large proportions of isolates from beef and cattle faeces produced similar genetic fingerprints. From these results, it is suggested that Salmonella species in cattle are transmitted to beef and, therefore, the consumption of undercooked beef could pose severe health complications on consumers. These findings provide baseline data that could be of great epidemiological importance and, thus, the need to utilise more sensitive typing tools in determining the genetic relatedness of isolates from different sources.

Photodynamic inactivation as an emergent strategy against foodborne pathogenic bacteria in planktonic and sessile states

Foodborne microbial diseases are still considered a growing public health problem worldwide despite the global continuous efforts to ensure food safety. The traditional chemical and thermal-based procedures applied for microbial growth control in the food industry can change the food matrix and lead to antimicrobial resistance. Moreover, currently applied disinfectants have limited efficiency against biofilms. Therefore, antimicrobial photodynamic therapy (aPDT) has become a novel alternative for controlling foodborne pathogenic bacteria in both planktonic and sessile states. The use of aPDT in the food sector is attractive as it is less likely to cause antimicrobial resistance and it does not promote undesirable nutritional and sensory changes in the food matrix. In this review, aspects on the antimicrobial photodynamic technology applied against foodborne pathogenic bacteria and studied in recent years are presented. The application of photodynamic inactivation as an antibiofilm strategy is also reviewed.

Evaluation of the efficacy of nisin-loaded chitosan nanoparticles against foodborne pathogens in orange juice

The current study aimed to fabricate nisin-loaded chitosan (N-CS) nanoparticles through ionic interactions between positive amino groups of chitosan and negatively charged tripolyphosphate ions in the presence of nisin and to evaluate their efficacy against foodborne pathogens in orange juice. The synthesized nanoparticles were sphere-shaped and homogenous with an average size of 64.34 ± 2.1 and 147.93 ± 2.9 for chitosan and N-CS nanoparticles, respectively. The encapsulation efficiency of nisin into nanoparticles was 67.32 ± 0.63%. Both chitosan and N-CS nanoparticles showed greater stability, as indicated by a higher zeta potential value of + 49.3 and + 33.4 mV, respectively. The in vitro antibacterial activities of chitosan and N-CS nanoparticles were investigated against the Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes and the Gram-negative bacteria Escherichia coli O157:H7 and Salmonella Typhimurium. N-CS nanoparticles showed higher activity compared with chitosan nanoparticles. The highest reduction of microorganisms was recorded for S. aureus of 3.82 log CFU/ml and L. monocytogenes of 3.61 log CFU/ml. The antimicrobial activity of N-CS nanoparticles in orange juice for 48 h revealed higher activity compared with the control against all the tested strains. The highest microbial reduction was recorded for N-CS nanoparticles against S. aureus with a 3.84 log CFU/ml reduction. L. monocytogenes and E. coli 0157:H7 were reduced by 3.54 and 3.44 log CFU/ml, respectively. The results showed high potential for the N-CS nanoparticles to be used as potent antibacterial agents in food and other related areas.

Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Workers in the Food Industry

Staphylococcus aureus is part of the common flora on the skin and mucous membranes of mammals and approximately 20–30% of humans are persistently colonized, mainly by mostly susceptible human-adapted isolates. In contrast, colonization with methicillin-resistant S. aureus is rare (approximately 1%), predominantly transient and associated with prior contact to the health care system. Additionally, in recent years livestock-associated S. aureus clones contributed to colonization in humans, especially in those working in close contact to farm animals. A considerable percentage of colonizing S. aureus isolates is equipped with enterotoxin genes. Humans carrying enterotoxigenic isolates represent a contamination source when handling food, thus generating a continuous risk of S. aureus food intoxication. Molecular characterization of isolates colonizing humans and obtained from food, respectively, enables the tracing of food-related outbreaks back to the source of food intoxication. We will summarize current knowledge about the S. aureus population colonizing humans, including those in close contact to animals and food, respectively. Additionally, we will review data on the molecular characterization of S. aureus isolates related to staphylococcal foodborne disease and the elucidation of staphylococcal foodborne outbreaks. Staphylococcal food poisoning is a common foodborne disease, mediated by the ingestion of enterotoxins produced by enterotoxigenic strains of S. aureus. For several outbreaks of foodborne S. aureus disease, colonized personnel could be identified as the source of food contamination. However, because of the widespread occurrence of enterotoxigenic strains as human colonizers and the often transient nature of colonization, the source of contamination cannot always be identified unambiguously. Therefore, compliance with hygiene measures is the most important requirement to prevent food contamination by both human colonization and environmental S. aureus reservoirs.

Caco-2 Invasion by Cronobacter sakazakii and Salmonella enterica Exposed to Drying and Heat Treatments in Dried State in Milk Powder

Due to the ability of foodborne pathogens to survive in low moisture food, the decontamination of milk powder is an important issue in food protection. The safety of food products is, however, not always insured and the different steps in the processing of food involve physiological and metabolic changes in bacteria. Among these changes, virulence properties may also be affected. In this study, the effect of drying and successive thermal treatments on the invasion capacity of Salmonella Typhimurium, Salmonella Senftenberg, and Cronobacter sakazakii was assessed. Bacteria were dried on milk powder at three different water activity levels (0.25, 0.58, and 0.80) and heated at two different temperatures (90°C and 100°C) for 30 and 120 s. After recovery, stressed bacterial populations were placed in contact with Caco-2 cells to estimate their invasion capacity. Our results show that drying increases the invasion capacity of foodborne pathogens, but that heat treatment in the dried state did not exert a selective pressure on bacterial cells depending on their invasion capacity after drying. Taken together, our findings add to the sum of knowledge on food safety in dried food products and provide insight into the effects of food processing.

Ensuring food safety using aptamer based assays: Electroanalytical approach

Aptamers, are being increasingly employed as favorable receptors for constructing highly sensitive biosensors, for their remarkable affinities towards certain targets including a wide scope of biological or chemical substances, and their superiority over other biologic receptors. The selectivity and affinity of the aptamers have been integrated with the wise design of the assay, applying suitable modifications, such as nanomaterials on the electrode surface, employing oligonucleotide-specific amplification strategies or, their combinations. After successful performance of the electrochemical aptasensors for biomedical applications, the food sector with its direct implication for human health, which demands rapid and sensitive and economic analytical solutions for determination of health threatening contaminants in all stages of production process, is the next field of research for developing efficient electrochemical aptasensors. The aim of this review is to categorize and introduce food hazards and summarize the recent electrochemical aptasensors that have been developed to address these contaminants.

Development of a gold nanoparticle-based universal oligonucleotide microarray for multiplex and low-cost detection of foodborne pathogens

Bacterial foodborne diseases remain major threats to food safety and public health, especially in developing countries. In this study a novel assay, combining gold nanoparticle (GNP)-based multiplex oligonucleotide ligation-PCR and universal oligonucleotide microarray technology, was developed for inexpensive, specific, sensitive, and multiplex detection of eight common foodborne pathogens, including Shigella spp., Campylobacter jejuni, Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, and Vibrio parahaemolyticus. The target fragments of the eight pathogens were enriched by multiplex PCR and subjected to multiplex ligase detection reaction. Ligation products were enriched and labeled with GNPs by universal asymmetric PCR, using excess GNP-conjugated primers. The labeled single-stranded amplicons containing complementary tag sequences were captured by the corresponding tag sequences immobilized on microarrays, followed by silver staining for signal enhancement. Black images of microarray spots were visualized by naked eyes or scanned on a simple flatbed scanner, and quantified. The results indicated that this assay could unambiguously discriminate all eight pathogens in single and multiple infections, with detection sensitivity of 3.3-85CFU/mL for pure cultures. Microarray results of ninety-five artificially contaminated and retail food samples were consistent with traditional culture, biochemical and real-time PCR findings. Therefore, the novel assay has the potential to be used for routine detection due to rapidity, low cost, and high specificity and sensitivity.

Prevalence of foodborne pathogens in food from selected African countries - A meta-analysis

Food safety information in the African region is insufficient and fragmented due to lack of surveillance, documentation and reporting, thereby resulting in inefficient utilization of resources, duplication of activities, and lack of synergy among the countries of the region. This paper reviews the prevalence of foodborne pathogens in seven African countries (Benin, Botswana, Ghana, Kenya, Nigeria, Sudan and Uganda) from papers in regional or international journals published between January 2000 and December 2015. One hundred and sixteen publications that dealt with food microbiology were reviewed for general analysis, while 66 papers on contamination of pathogenic bacteria were used for meta-analysis of prevalence. The food items were split into two categories: raw foods and ready-to-eat (RTE) foods (including street food and beverages) for meta-analysis. Majority of the reviewed studies (67.2%, 78/116) dealt with food of animal origin: 38.8% for meat and eggs, 17.2% for dairy products and 11.2% for aquatic products. Only 8.6% examined foods of plant origin (fruits and vegetables). The remaining 24.1% was the composite RTE food and beverages. Enterobacteriaceae, Escherichia coli, Salmonella, Staphylococcus aureus and Listeria monocytogenes were the most frequently reported organisms in those studies. Although the data were highly heterogeneous, a striking feature is high prevalence of the major pathogens in RTE foods, almost as high as in raw foods. E. coli averaged at 37.6% in raw foods and 31.6% in RTE foods. The corresponding prevalence for Salmonella was 19.9% vs 21.7%; S. aureus, 27.8% vs 25.1% and L. monocytogenes, 19.5% vs 6.7%. The average prevalence of foodborne pathogens in these countries was 34.2% (29.0-39.3%). Differences in food types as well as non-uniform protocols for sampling and identification might have contributed to high heterogeneity (I² >97%) although some high prevalence data could be factual with extensive varieties of raw and RTE foods. Need for improved hygienic practices in handling of raw or RTE foods are suggested. Implementation of surveillance programs that use uniform laboratory protocols across the region could give homogeneous results.

Malnutrition in South Asia-A Critical Reappraisal

Malnutrition continues to be a major public health challenge especially in South Asian developing countries. The aim of the present review is to spotlight the magnitude of the prevalence of malnutrition and its dynamics in South Asian region and to suggest potential approaches for the prevention and control of this issue of public health significance. An extensive review of literature, covering malnutrition and its determinants, health and economic consequences and pragmatic preventive strategies was performed on computer based bibliographic databases (PubMed, Google Scholar, Scopus, Medline and Sciencedirect.com ) to retrieve abstracts and full texts for India, Pakistan, Bangladesh, Sri Lanka and Nepal. All relevant titles and abstracts were examined and evaluated for malnutrition and its prevalence in South Asia. The results revealed malnutrition to be a major public health problem and a potential cause of high disease burden and mortality in South Asia. Compelling evidence suggests malnutrition to be the leading cause of stunting, wasting and underweight with drastic economic consequences among vulnerable populations. Reduced cognitive performance and low productivity have also been associated with micronutrients malnutrition. Suboptimal breastfeeding, inadequate food supply, micronutrient deficiencies, low household income, poor health care system, increased healthcare costs, illiteracy, unhygienic and substandard living, inappropriate child's care and the caregiver, food insecurity and on top of that vicious cycle of poverty, have been recognized as principal indicators for growing malnutrition prevalence in South Asia. Global organizations, local governments, program managers, NGOs, academia, industry in particular and the society at large need to take up the challenge to completely confiscate malnutrition from the region for economic prosperity and a healthier future.

Foodborne pathogens and their toxins

Foodborne pathogens, mostly bacteria and fungi, but also some viruses, prions and protozoa, contaminate food during production and processing, but also during storage and transport before consuming. During their growth these microorganisms can secrete different components, including toxins, into the extracellular environment. Other harmful substances can be also liberated and can contaminate food after disintegration of food pathogens. Some bacterial and fungal toxins can be resistant to inactivation, and can survive harsh treatment during food processing. Many of these molecules are involved in cellular processes and can indicate different mechanisms of pathogenesis of foodborne organisms. More knowledge about food contaminants can also help understand their inactivation. In the present review the use of proteomics, peptidomics and metabolomics, in addition to other foodomic methods for the detection of foodborne pathogenic fungi and bacteria, is overviewed. Furthermore, it is discussed how these techniques can be used for discovering biomarkers for pathogenicity of foodborne pathogens, determining the mechanisms by which they act, and studying their resistance upon inactivation in food of animal and plant origin.

BIOLOGICAL SIGNIFICANCE

Comprehensive and comparative view into the genome and proteome of foodborne pathogens of bacterial or fungal origin and foodomic, mostly proteomic, peptidomic and metabolomic investigation of their toxin production and their mechanism of action is necessary in order to get further information about their virulence, pathogenicity and survival under stress conditions. Furthermore, these data pave the way for identification of biomarkers to trace sources of contamination with food-borne microorganisms and their endo- and exotoxins in order to ensure food safety and prevent the outbreak of food-borne diseases. Therefore, detection of pathogens and their toxins during production, transport and before consume of food produce, as well as protection against food spoilage is a task of great social, economic and public health importance.