Which domestic refrigerator temperatures in Europe? - Focus on shelf-life studies regarding Listeria monocytogenes (Lm) in ready-to-eat (RTE) foods.

Listeria monocytogenes (Lm) is a pathogenic bacteria able to grow at refrigerated temperatures, widely distributed in the environment. This bacteria is susceptible to contaminate various food products of which refrigerated ready-to-eat foods (RTEF) may pose a risk for public health. In Europe, food business operators (FBOs) shall ensure that foodstuffs comply with the relevant microbiological criteria set out in the Regulation (EC) N°2073/2005. Food safety criteria for Lm are defined in RTEF throughout their shelf-life. FBOs should implement studies to demonstrate that the concentration of Lm does not exceed 100 CFU/g at the end of the shelf-life, taking into account foreseeable conditions of distributions, storage and use, including the use by consumers. However, this last part of the cold chain for food products is the most difficult to capture and control. For this purpose, the European Union Reference Laboratory for Lm (EURL Lm) launched an inquiry to its National Reference Laboratory network and reviewed the scientific literature from 2002 to 2020. The outcomes were integrated in the technical guidance document of the EURL Lm to assess shelf-life of RTEF which resulted in the recommendation to use 10 °C as the reference temperature to simulate the reasonably foreseen storage conditions in domestic refrigerators.

Antibiotic resistance patterns of Staphylococcus aureus and Enterobacteriaceae isolated from street foods in selected towns of Ethiopia.

BACKGROUND: Street foods are any foods or drinks prepared or sold by street vendors in an open space. The purpose of this study was to determine the Bacteriological safety and antibiotic resistance patterns of Staphylococcus aureus and Enterobacteriaceae isolated from street foods. METHOD: A laboratory-based cross-sectional study was used from December 2022 to February 2023 on street foods of Addis Ababa, Hawassa, Dire Dawa, and Jimma towns of Ethiopia. 525 street foods and 175 water samples were taken from 175 street food vending stalls. Proportional allocation to the total town population and stratified sampling techniques were used to select vending stalls. Samples were analyzed for the presence of bacteria following the standard microbiological methods used for the isolation, enumeration, and identification of bacteria. Pour plate technique was used to transfer the suspension to MacConkey agar, Mannitol Salt Agar, and Salmonella Shigella Agar. The antibiotic susceptibility test was performed using the Kirby-Bauer disk diffusion method. SPSS software was used to analyze the data. RESULT: Out of 525 food samples, 279 (53%) were contaminated by bacteria. From 175 water samples, 95 (54.3%) were contaminated with Escherichia coli. From both samples in total, eleven bacterial species were isolated. Staphylococcus aureus was the most frequently isolated species. Shigella, Klebsiella, and Salmonella group A have statistically significant with the type of food. Erythromycin (54%), Streptomycin (17%), and Amoxicillin (14%) were the most resistant antibiotics. Least resistance was observed to Ciprofloxacin (5%). CONCLUSION: Street foods of the selected towns were highly contaminated with various antibiotic-resistant organisms. Hence, the relevant authorities ought to ensure the proper handling of street food by enforcing safety measures. Additionally, they should initiate a widespread awareness campaign promoting the prudent use of antibiotics among both street food vendors and the broader population.

Quantum dots (QDs) attached magnetic beads (MBs) for on-chip efficient capture and detection of bacteria in ready-to-eat (RTE) foods.

In this study, we established a versatile and simple magnetic-assisted microfluidic method for fast bacterial detection. Quantum dots (QDs) were loaded onto magnetic beads (MBs) to construct performance enhanced on-chip capture of bacteria. Escherichia coli (E. coli), as a model bacterium was studied. CdSe QDs were deposited onto the surface of Fe3O4 MBs through layer-by-layer self-assembly to enhance the loading of antibodies (Abs). MBs functionalized with anti-E. coli antibody molecules in a micropillar-based microfluidic chip were utilized to capture E. coli, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used for characterization of captured bacteria. This method was found capable of specifically isolating E. coli within the range of 1.0 to 1.0 × 109 CFU/mL, having a detection limit (LOD) of 10 CFU/mL. The average similarity score among mass spectra for the bacterial capture obtained in independent experiments is calculated as 0.97 ± 0.01 (n = 3), which shows this work's excellent reproducibility for bacterial capture. Bacterial growth on ready-to-eat (RTE) foods during its time of storage was successfully monitored. The present protocol has promising potential for microbial control and pathogen detection in the food industry.

Ethiopian Street Foods: Working Conditions and Governance Perspectives. A Qualitative Study.

Introduction: Street foods are foods and beverages as either ready for direct consumption or minimally processed, prepared, and/or sold by vendors and handlers. The objective of this study was to explore the condition and governance of street foods in Ethiopia. Method: A qualitative exploratory study was employed from December 2022 to January 2023 in Addis Ababa, Hawassa, Dire Dawa, and Jimma, cities of Ethiopia. Twelve respondents comprised key informants from selected governmental sectors were interviewed. The purposive sampling method was used to recruit study participants. The number of participants interviewed was determined by the information saturation criterion, and data were collected at the interviewee's offices. Data were collected by using key informant interview technique and audio recorded. An interview guide was used to facilitate interviews and thematic analysis was employed. The Overall data management process was conducted using Atlas-ti V 8 software. Result: The result revealed there were 4 thematic areas these were street food vendors and vending process, policy content and implementation, integration and coordination of sectors, and the way forward. The street food vendors prepared their food in an insanitary manner, absence of common working places for the vendors, lack of due emphasis for the street food vendors in the national food and nutrition policy, lack of formalization and legalization of street food vendors, poor coordination among sectors and institutions work on street food governance, and weakness on the implementation of rules and regulations in controlling street food vendors were the prominent gaps that were identified in the policy. Conclusion: Though Ethiopia has a national food and nutrition policy, the policy doesn't adequately address the street food vending sector. Besides, it is not well communicated to the implementers resulting in poor policy implementation. Quantifying socio-economic benefits of street food vending activities in Ethiopia needs further investigation.

Prevalence, Antibiotic Resistance, and Molecular Typing of Staphylococcus aureus Isolated from Ready-to-Eat Foods in Guangdong, South China.

The increasing global popularity of ready-to-eat (RTE) foods for their convenience simultaneously brings along a risk, as these products can be contaminated with various microorganisms, including potentially harmful pathogens. We aimed to investigate the food contamination of Staphylococcus aureus (S. aureus) in RTE foods in Guangdong, South China. All S. aureus isolates were subjected to characterization through antimicrobial susceptibility tests, multilocus sequence typing (MLST), and PCR analysis for detecting mec and blaZ genes. A total of 824 RTE food samples were collected from 2017 to 2022, of which 73 (8.9%) were found to be contaminated with S. aureus. Contamination levels were mostly in the range of 0.3-1.0 most probable number (MPN)/g, with 10 samples exceeding 110 MPN/g. Of the 73 S. aureus isolates, 10 were identified as methicillin-resistant S. aureus (MRSA). In MRSA, resistance was most frequently observed to penicillin (100%, 10/10), followed by erythromycin (80.0%, 8/10) and tetracycline (70%, 7/10). And in methicillin-sensitive S. aureus (MSSA), resistance was most frequently observed to penicillin (98.4%, 62/63), followed by tetracycline (30.2%, 19/63) and erythromycin (23.8%, 15/63). Overall, 98.6% (72/73) of the isolates demonstrated resistance to at least one antimicrobial agent, whereas 31.5% (23/73) were resistant to three or more antimicrobials. Fifty-seven S. aureus isolates harbored the penicillin-resistant gene blaZ, and 10 isolates carried the mec gene. In addition, 30.1% of the isolates harbored genes for classical staphylococcal enterotoxins (SEs), with seb being the most frequently detected SE gene. MLST revealed that the 73 isolates belonged to 14 different sequence types (STs), the most prevalent of which was ST7. In MRSA, the most common prevalent clone is ST6, and in MSSA, ST7 was the most common isolates. The prevalent multidrug resistance indicates that the resistance situation of foodborne S. aureus in Guangdong is severe, posing a potential threat to consumer safety and health.

Kinetic and proteomic studies in milk show distinct patterns among major Listeria monocytogenes clones.

Listeria monocytogenes, a contaminant of raw milk, includes hypervirulent clonal complexes (CC) like CC1, CC4, and CC6, highly overrepresented in dairy products when compared to other food types. Whether their higher prevalence in dairy products is the consequence of a growth advantage in this food remains unknown. We examined growth kinetics of five L. monocytogenes isolates (CC1, CC4, CC6, CC9, and CC121) at 37 and 4 °C in ultra-high temperature (UHT) milk and raw milk. At 4 °C, hypovirulent CC9 and CC121 isolates exhibit better growth parameters in UHT milk compared to the hypervirulent CC1, CC4, and CC6 isolates. CC9 isolate in raw milk at 4 °C exhibited the fastest growth and the highest final concentrations. In contrast, hypervirulent isolates (CC1, CC4, and CC6) displayed better growth rates in UHT milk at 37 °C, the mammalian host temperature. Proteomic analysis of representative hyper- (CC1) and hypovirulent (CC9) isolates showed that they respond to milk cues differently with CC-specific traits. Proteins related to metabolism (such as LysA or different phosphotransferase systems), and stress response were upregulated in both isolates during growth in UHT milk. Our results show that there is a Listeria CC-specific and a Listeria CC-common response to the milk environment. These findings shed light on the overrepresentation of hypervirulent L. monocytogenes isolates in dairy products, suggesting that CC1 and CC4 overrepresentation in dairy products made of raw milk may arise from contamination during or after milking at the farm and discard an advantage of hypervirulent isolates in milk products when stored at refrigeration temperatures.

Consumer attitudes and perceptions towards chilled ready-to-eat foods: a multi-national study.

Understanding consumers' behavior and their handling of high-risk foods at home is essential for reducing the number of foodborne illnesses. This study shows the results of a cross-national analysis of consumers' perception from nine countries, and the identification of customers' clusters and its characteristics in order to understand customers' behavior, and to build safe chilled ready-to-eat (RTE) foods prevention strategies. The cluster analysis resulted in two clusters: (1) "Precautious consumers" characterized by the orientation towards pre-packed RTE foods, with consumers mainly coming from Bosnia and Herzegovina, India, Poland, Portugal, Spain, and Turkey. Their attitudes and self-reported practices may be categorized as less risky in terms of food-borne illnesses connected with the consumption of RTE foods; (2) "Unconcerned consumers" preferred cutting and slicing RTE foods freshly at the point of purchase, usually sold at the delicatessen department in a supermarket or at open markets. Those consumers mostly came from Croatia, Serbia and Slovenia and their attitudes and self-reported practices were riskier. These results allow a better understating of what characterizes consumers of RTE foods in different countries.

Survival of Salmonella enterica and Listeria monocytogenes in date palm paste and syrup at different storage temperatures.

This study aimed to investigate the behavior of Salmonella enterica and Listeria monocytogenes in processed date paste and syrup at different temperatures. Commercial products were inoculated with approximately 6 log CFU/mL of S. enterica or L. monocytogenes and stored at 4, 10, and 24°C for 90 days. S. enterica was able to survive in date products until the end of storage at 4°C. At this temperature, numbers decreased by 2.1 log CFU/g in date paste and by 3.4 log CFU/g in date syrup; however, at 10°C, cells were reduced >4.2 log CFU/g and were undetectable by direct plating in date paste or by enrichment (complete elimination) in syrup. Further, at 24°C, complete elimination of S. enterica was achieved in date paste and syrup by 30 and 7 days, respectively. L. monocytogenes numbers decreased by 1.4, 4.4, and >4.6 log CFU/g in date paste stored at 4, 10, and 24°C for 90 days, respectively. In date syrup, numbers of L. monocytogenes decreased to undetectable levels by 50, 14, and 4 days at 4, 10, and 24°C, respectively, by direct plating and complete elimination was observed at 10 and 24°C by 50 and 30 days of storage, respectively. The initial pH values of date paste and syrup were 4.7 and 4.8, respectively, and remained stable until the end of storage except for L. monocytogenes-inoculated syrup. PRACTICAL APPLICATION: Salmonella enterica and Listeria monocytogenes can easily survive in date paste and syrup particularly at refrigerator temperature, which explains the necessity of preventing the contamination of date products with foodborne pathogens.

Microbiological quality and antimicrobial resistance of Bacteria species recovered from ready-to-eat food, water samples, and palm swabs of food vendors in Accra, Ghana.

This study sought to investigate microbial quality and antimicrobial resistance of bacteria species from Ready-to-Eat (RTE) food, water, and vendor palm swab samples. Between 2019 and 2020, RTE food, water and vendor palm swab samples were collected from food vending sites in Accra, Ghana. Samples were cultured and confirmed using the Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF). Antimicrobial susceptibility testing (AST) was conducted using disk diffusion method. Beta-lactamase and Diarrheagenic Escherichia coli (DEC) genes were determined using Polymerase Chain Reaction (PCR). Total plate count (TPC) and Total coliform count (TCC) were performed on food and water samples. In total, 179 RTE food, 72 water and 10 vendor palm swab samples were collected. Enterobacter spp. (16.8 %), Citrobacter spp. (10.1 %), Enterococcus faecalis (7.8 %), Pseudomonas spp. (6.7 %) and Klebsiella pneumoniae (4.0 %) occurred in food. Isolates from water and palm were Klebsiella pneumoniae (20.8 %), Aeromonas spp. (16.7 %) and Enterobacter cloacae (11.1 %). Resistance to Amoxicillin-clavulanate, Tetracycline, Azithromycin, Sulfamethoxazole-trimethoprim, and Nitrofurantoin were common among Enterobacterales. High mean TPC and TCC showed in some RTE food and different water types used in vending depicting their unsafe condition for consumption and usage. The blaSHV and blaTEM genes were present in some Enterobacterales from food and water. The lt gene was identified in two food samples. AMR organisms associated with nosocomial infections in the samples investigated, calls for continuous surveillance in the food industry in Ghana. Also, the unsafe outcome of RTE food and water depicts the need for the enforcement of Ghana's food safety laws.

Role of dehydration technologies in processing for advanced ready-to-eat foods: A comprehensive review.

Advanced ready-to-eat foods, which can be consumed directly or only need simple processed before consumption, refer to the products that processing with cutting-edge food science and technology and have better quality attribute. Cold chain and chemical addition are commonly used options to ensure microbial safety of high moisture advanced ready-to-eat foods. However, this requires freezing/thawing processing at high cost or has undesirable residue. Dehydration treatment has the potential to compensate those shortcomings. This article reviewed the positive effects of dehydration on advanced ready-to-eat foods, current application status of dehydration technologies, novel dehydration related technologies and the pathogenic bacteria control of products. It is observed that dehydration treatment is receiving increasing attention for ready-to-eat foods including space foods, 3 D-printed personalized foods and formula foods for special medical purposes. Recently developed drying technologies such as pulsed spouted microwave freeze-drying and infrared freeze-drying have attracted much interest due to their excellent drying characteristics. Finally, intelligent drying, dehydration-nano-hybridization and dehydration-induced multi-dimensional modification technology are some of the emerging R and D areas in this field.

Associação entre o consumo de alimentos ultraprocessados e a composição corporal de adolescentes / Association between ultraprocessed food consumption and body composition of adolescents / Asociación entre el consume de alimentos ultraprocesados y la composición corporal de los adolescentes

O processo de transição nutricional vem elevando o consumo de alimentos ultraprocessados na população. Esses alimentos apresentam alta densidade energética e baixas propriedades nutricionais, afetando o estado nutricional e a composição corporal, inclusive dos adolescentes. Este trabalho visa avaliar a associação entre o consumo de alimentos ultraprocessados e a composição corporal de adolescentes. Este é um estudo transversal, realizado com adolescentes matriculados em uma instituição filantrópica de ensino. Foram coletados dados sociodemográficos, antropométricos e de consumo de alimentos ultraprocessados. Foi realizada uma análise de associação entre o consumo regular de alimentos ultraprocessados e o excesso de peso, por meio do teste qui-quadrado de Pearson, com nível de significância de 5%. Para as análises estatísticas, foi utilizado o programa IBM SPSS versão 22.0. Cerca de um terço da amostra apresentava excesso de peso (índice de massa corporal: 27,2%; pregas cutâneas: 33,9%; bioimpedância: 29,6%). O consumo regular de alimentos ultraprocessados esteve presente em 64,2% da amostra e foi associado ao excesso de peso avaliado pela bioimpedância (p = 0,016) e pelas pregas cutâneas (p = 0,008). Os indivíduos que apresentaram maior prevalência de excesso de peso não consumiam regularmente alimentos ultraprocessados. Destaca-se a necessidade de realização de outros estudos, principalmente longitudinais, para avaliar e compreender a associação entre o consumo de alimentos ultraprocessados e a composição corporal dos adolescentes.

The nutritional transition has been increasing the consumption of ultraprocessed foods in the population. These foods have high energy and low nutritional properties, affecting the nutritional status and body composition, including of adolescents. This study aims to evaluate the association between ultraprocessed food consumption and body composition in adolescents. This is a cross sectional study carried out with adolescents enrolled in a philanthropic education institution. Sociodemographic, anthropometric, and ultraprocessed food consumption data were collected. An analysis of association between regular ultraprocessed food consumption and overweight was performed using Pearson's Chi-square test, with a significance level of 5%. The program IBM SPSS version 22.0 was used for statistical analyzes. About one-third of the sample was overweight (body mass index: 27.2%; skin folds: 33.9%; bioimpedance: 29.6%). Regular ultraprocessed food consumption was found in 64.2% of the sample and was associated with overweight assessed by bioimpedance (p = 0.016) and skin folds (p = 0.008). The individuals who had higher prevalence of overweight did not consume ultraprocessed food regularly. Carrying out other studies, especially longitudinal studies, to evaluate and understand how the association between ultraprocessed food intake and body composition occurs in adolescents is necessary.

El proceso de transición nutricional ha incrementado el consumo de alimentos ultraprocesados en la población. Estos alimentos tienen alta densidad energética y bajas propriedades nutricionales, afectando el estado nutricional y la composición corporal, incluso de los adolescentes. Este trabajo pretende evaluar la asociación entre el consumo de alimentos ultraprocesados y la composición corporal de adolescentes. Este es un estudio transversal realizado con adolescentes matriculados en una institución educativa filantrópica. Se recogieron datos sociodemográficos, antropométricos y de consumo de alimentos ultraprocesados. El análisis de la asociación entre el consumo regular de los ultraprocesados y el exceso de peso se realizó mediante la prueba de chi-cuadrado de Pearson, con nivel de significancia del 5%. Para el análisis estadístico se utilizó el programa IBM SPSS, versión 22.0. Casi un tercio de la muestra tenía exceso de peso (índice de masa corporal: 27,2%; pliegues cutáneos: 33,9%; bioimpedancia: 29,6%). El consumo habitual de alimentos ultraprocesados estuvo presente en el 64,2% de la muestra y se asoció con el exceso de peso evaluado por bioimpedancia (p=0,016) y pliegues cutáneos (p=0,008). Las personas que tenían una mayor prevalencia de exceso de peso no consumían regularmente alimentos ultraprocesados. Se necesitan más estudios, principalmente longitudinales, para evaluar y comprender la asociación entre el consumo de los ultraprocesados y la composición corporal en adolescentes.

Isolation, identification, and antibiogram studies of Escherichia coli from ready-to-eat foods in Mymensingh, Bangladesh.

Background and Aim: Ready-to-eat (RTE) foods are widely used at home, restaurants, and during festivals in Bangladesh. So it is very important to investigate possible microbial contamination in RTE foods. Therefore, this study aimed to determine the total coliform count (TCC), isolate, identify, and characterize the Escherichia coli in RTE foods. The antimicrobial sensitivity of E. coli obtained from RTE foods was also performed using 12 commonly used antibiotics. Materials and Methods: A total of 100 RTE food samples were collected aseptically and comprised of ten samples each: Burger, pizza, sandwich, chicken roll, chicken meat loaf, chicken fry, salad vegetable, ice-cream, yogurt, and milkshake sold in Mymensingh City. Samples were inoculated onto Eosin methylene blue agar and incubated at 37°C for 24 h. Isolation and identification of bacteria were performed based on cultural, staining, and biochemical properties, followed by a polymerase chain reaction. Results: The TCC in Chicken meat loaf, burger, pizza, sandwich, salad vegetable ice-cream, and yogurt samples were 3.57 ± 0.96, 3.69 ± 0.08, 3.50 ± 0.60, 2.60 ± 0.20, 4.09 ± 0.29, 4.44 ± 0.25, and 3.14 ± 0.30 mean log colony-forming units ± standard deviation/mL, respectively. The study found a higher prevalence of E. coli in RTE salad vegetable products than in RTE meat and milk products. Forty percent of the mixed vegetable salad samples showed positive results for E. coli. Whereas E. coli prevalence in RTE meat and milk products was 20% and 16.7%, respectively. All the 21 isolates were subjected to antibiotic susceptibility test against 12 different antibiotics. It was observed that 46.1% were susceptible, 16.6% were intermediate, 46.1% were resistant, and 47.6% were multidrug-resistant (MDR) among seven different antibiotic classes. E. coli isolates were resistant to cephalexin, ceftazidime, oxytetracycline, and ampicillin and sensitive to gentamycin, followed by kanamycin, ceftriaxone, colistin, and enrofloxacin. Conclusion: The study revealed that RTE foods are a serious issue from a public health point of view. To achieve a safer level of E. coli in RTE foods sold for human consumption, public food outlets must improve hygienic and good production procedures. Moreover, MDR E. coli in these foods pose serious public health threats.

Genomic Insights of Enterococcus faecium UC7251, a Multi-Drug Resistant Strain From Ready-to-Eat Food, Highlight the Risk of Antimicrobial Resistance in the Food Chain.

The presence of multi-drug resistant (MDR) bacteria in ready-to-eat foods comprises a threat for public health due to their ability to acquire and transfer antibiotic-resistant determinants that could settle in the microbiome of the human digestive tract. In this study, Enterococcus faecium UC7251 isolated from a fermented dry sausage was characterized phenotypically and genotypically to hold resistance to multiple antibiotics including aminoglycosides, macrolides, ß-lactams, and tetracyclines. We further investigated this strain following a hybrid sequencing and assembly approach (short and long reads) and determined the presence of various mobile genetic elements (MGEs) responsible of horizontal gene transfer (HGT). On the chromosome of UC7251, we found one integrative and conjugative element (ICE) and a conjugative transposon Tn916-carrying tetracycline resistance. UC7251 carries two plasmids: one small plasmid harboring a rolling circle replication and one MDR megaplasmid. The latter was identified as mobilizable and containing a putative integrative and conjugative element-like region, prophage sequences, insertion sequences, heavy-metal resistance genes, and several antimicrobial resistance (AMR) genes, confirming the phenotypic resistance characteristics. The transmissibility potential of AMR markers was observed through mating experiments, where Tn916-carried tetracycline resistance was transferred at intra- and inter-species levels. This work highlights the significance of constant monitoring of products of animal origin, especially RTE foodstuffs, to stimulate the development of novel strategies in the race for constraining the spread of antibiotic resistance.

Bacteriological Quality and Public Health Risk of Ready-to-Eat Foods in Developing Countries: Systematic Review and Meta Analysis.

Background: Ready-to-eat foods are foods that are consumed at the point of sale or later, without any further processing or treatment. Foodborne diseases are on the rise worldwide, involving a wide range of diseases caused by pathogenic bacteria, and are becoming a public health problem. Therefore, this study sought to identify and determine the bacteriological quality and public health risks in ready-to-eat foods in developing countries. Methods: The studies published from 2012 to 2020 were identified through systematic searches of various electronic databases such as Google Scholar, PubMed and MEDLINE, MedNar, EMBASE, CINAHL, Scopus, and Science Direct. The articles were searched using a Boolean logic operator ("AND," "OR," "NOT") combination with Medical Subject Headings (MeSH) terms and keywords. All identified keywords and an index term were checked in all included databases. In addition, a quality assessment is performed to determine the relevance of the article, and then the data are extracted and analyzed. Results: The current study found that the pooled prevalence of Staphylococcus aureus, Enterobacter species, Klebsiella, Escherichia coli, Salmonella, Bacillus cereus, Pseudomonas species, and Shigella in ready-to-eat foods was 30.24% (95% CI: 18.8, 44.65), 11.3% (95% CI: 6.6, 18.7), 9.1% (95% CI: 7.0, 11.8), 23.8% (95% CI: 17.5, 31.5), 17.4% (95% CI: 11.6, 25.31)], 26.8% (95% CI: 13.7, 45.9), 6.1% (95% CI: 2.8, 12.6), 34.4% (95% CI: 18.1-55.4), respectively. Conclusions: Most of the reviewed articles reported on various pathogenic bacterial species that are potentially harmful to human health, such as Staphylococcus aureus, Salmonella, Shigella, and Escherichia coli in ready-to-eat food above the maximum allowable limit. Therefore, relevant national and international organizations must take corrective measures to prevent foodborne diseases and protect human health.

Listeria monocytogenes survives better at lower storage temperatures in regular and low-salt soft and cured cheeses.

The behaviour of Listeria monocytogenes was investigated in soft pasteurized milk cheese elaborated with different salt concentrations (1.17 and 0.30% w/w) and in cured raw sheep milk cheese over storage up to 189 days at different isothermal conditions. Commercial 25-g cheese samples were inoculated with a 4-strain cocktail of L. monocytogenes (serovars 4b, 1/2a, 1/2b and 1/2c) at approximately 104 CFU/g. The inoculated samples were stored at 4 and 22 °C and withdrawn at proper intervals for L. monocytogenes enumeration. The prevalence of the different serovar strains of L. monocytogenes was characterized on soft cheese samples over storage at 4 °C using multiplex PCR. Salt reduction did not affect the survival of L. monocytogenes in soft cheeses and a maximum of 1-log reduction was observed in both regular and low-salt cheeses after 189 days of storage at 4 °C. The pathogen showed greater survival capacity in both soft and cured cheeses during storage at 4 °C compared to the storage at 22 °C, where more than 2.5 log reductions were computed. The fate of L. monocytogenes was described through a Weibull model fitted to survival data. The time required for a first tenfold reduction of the L. monocytogenes population (δ) at 4 °C is around 150 days in soft and 72 days in cured cheeses. At 22 °C, the estimated δ values are at least 60% lower in both cheese types. Among the four L. monocytogenes serovars present in the inoculated cocktail, the serovar 4b strain was the most sensitive to refrigerated storage, while the prevalence of serovar 1/2c strain increased over time in soft cheeses. Overall, the data obtained in this study help to deepen knowledge into factors affecting L. monocytogenes behaviour on cheeses and evidenced the variability between serovars in terms of survival capacity, which may be considered when performing microbial risk assessments.

Fecal indicator bacteria along multiple environmental exposure pathways (water, food, and soil) and intestinal parasites among children in the rural northwest Ethiopia.

BACKGROUND: Children in low-resource settings are exposed to multiple risk factors for enteropathogens. However, the probability of exposures may be different across exposure pathways. Accordingly, this study was conducted to assess environmental exposures of children to intestinal parasites in the east Dembiya district of Ethiopia. METHODS: A cross-sectional study was conducted for 372 households with children aged 24-59 months. The potential for external exposure of children to intestinal parasites was assessed by determining the presence of fecal indicator organism (Escherichia coli (E. coli)) in drinking water at point of use, ready-to-eat foods, and courtyard soil from children's outdoor play areas. For internal exposure assessment, ova of parasites in stool samples was detected using wet mount and Kato-Katz techniques to estimate exposure to intestinal parasites. The external and internal exposure assessments were also complemented using questionnaire and spot-check observations to assess behaviors that result in high risk of exposure. Individual and community-level predictors of intestinal parasites were identified using a multilevel logistic regression model. Statistically significant variables were identified on the basis of adjusted odds ratio (AOR) with 95% confidence interval (CI) and p-value < 0.05. RESULTS: Ova of one or more intestinal parasites was detected among 178 (47.8%) (95% CI 42.8, 52.6%) of the children. The most common intestinal parasites were A. lumbricoides (20.7%) and S. mansoni (19.1%). Furthermore, E. coli was detected in 69.1% of drinking water samples at point of use, 67.5% of ready-to-eat food samples, and 83.1% of courtyard soil samples from children's outdoor play areas. Exposure of children to intestinal parasites among children in the studied region was associated with poor hand hygiene of mothers (AOR 1.98, 95% CI (1.07, 3.66), poor hand hygiene of children (AOR 3.20, 95% CI (1.77, 5.77), mouthing of soil contaminated materials (AOR 2.31, 95% CI (1.26, 4.24), open defecation practices (AOR 2.22, 95% CI (1.20, 4.10), limited access to water (AOR 2.38, 95% CI (1.13, 5.01), water contamination (AOR 2.51, 95% CI (1.31, 4.80), food contamination (AOR 3.21, 95% CI (1.69, 6.09), and soil contamination (AOR 2.56, 95% CI (1.34, 4.90). CONCLUSION: An extensive E. coli contamination of water, foods, and courtyard soil was found in the studied region and the potential sources of contamination were open defecation practices, unhygienic disposal of wastes, poor animal husbandry and keeping practices, and poor water and food safety measures at household level. Moreover, fecal contamination of water, foods, and soil linked to exposure of children to intestinal parasites in the studied region. Thus, it is critical to implement individual-level interventions (such as latrine utilization, hand hygiene promotion, food safety, home-based water treatment, and containment of domestic animals), plus community-level interventions (such as protecting water sources from contamination, source-based water treatment, and community-driven sanitation).

Informal ready-to-eat food vending: a social practice perspective on urban food provisioning in Nigeria.

The way people access food in Nigeria is of central relevance for food security, health and sustainability. One key trend is the shift from household-based to primarily out-of-home food consumption as an increasing majority of the urban poor derive their daily nutrient intake from street foods. However, few studies have yet explored the role of the ready-to-eat food vending sector in urban food systems and the diets of the urban poor. This paper investigates the interrelations between these practices and the diversity of food groups provisioned among the urban poor in developing city contexts. A social practice approach is employed to explore differentiation among informal-ready-to-eat food vending practices in the city of Ibadan, Nigeria, in terms of their daily activities, competences and resources. Applied methods include GIS mapping, food log diaries, in-depth interviews and participant observation to map and classify informal-ready-to-eat food vending practices according to the nature of food provisioned and explore the everyday performances of different informal-ready-to-eat food vending practice initiatives and their relation to dietary diversity. The results reveal three key categories among these practices: traditional, processed and unprocessed-with varying levels of diversity in the food groups on offer. Traditional food vendors offer more diversified food compared to processed food vendors and unprocessed food vendors. The results reveal that material infrastructure, cooking bargaining and purchasing skills and nutritional knowledge are key to the diversity of food groups provisioned. The paper concludes by considering the wider relevance of these findings for urban food science and policy.

Quantitative microbial risk assessment associated with ready-to-eat salads following the application of farmyard manure and slurry or anaerobic digestate to arable lands.

Farmyard manure and slurry (FYM&S) and anaerobic digestate are potentially valuable soil conditioners providing important nutrients for plant development and growth. However, these organic fertilisers may pose a microbial health risk to humans. A quantitative microbial risk assessment (QMRA) model was developed to investigate the potential human exposure to pathogens following the application of FYM&S and digestate to agricultural land. The farm-to-fork probabilistic model investigated the fate of microbial indicators (total coliforms and enterococci) and foodborne pathogens in the soil with potential contamination of ready-to-eat salads (RTEs) at the point of human consumption. The processes examined included pathogen inactivation during mesophilic anaerobic digestion (M-AD), post-AD pasteurisation, storage, dilution while spreading, decay in soil, post-harvest washing processes, and finally, the potential growth of the pathogen during refrigeration/storage at the retail level in the Irish context. The QMRA highlighted a very low annual probability of risk (Pannual) due to Clostridium perfringens, norovirus, and Salmonella Newport across all scenarios. Mycobacterium avium may result in a very high mean Pannual for the application of raw FYM&S, while Cryptosporidium parvum and pathogenic E. coli showed high Pannual, and Listeria monocytogenes displayed moderate Pannual for raw FYM&S application. The use of AD reduces this risk; however, pasteurisation reduces the Pannual to an even greater extent posing a very low risk. An overall sensitivity analysis revealed that mesophilic-AD's inactivation effect is the most sensitive parameter of the QMRA, followed by storage and the decay on the field (all negatively correlated to risk estimate). The information generated from this model can help to inform guidelines for policymakers on the maximum permissible indicator or pathogen contamination levels in the digestate. The QMRA can also provide the AD industry with a safety assessment of pathogenic organisms resulting from the digestion of FYM&S.

Prevalence, Enterotoxigenic Potential and Antimicrobial Resistance of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Algerian Ready to Eat Foods.

Staphylococcus aureus causes a foodborne intoxication due to the production of enterotoxins and shows antimicrobial resistance, as in the case of methicillin-resistant strains (MRSA). Herein, we analyzed 207 ready-to-eat foods collected in Algeria, reporting a S. aureus prevalence of 23.2% (48/207) and respective loads of coagulase positive staphylococci (CPS) ranging from 1.00 ± 0.5 to 5.11 ± 0.24 Log CFU/g. The 48 S. aureus isolates were widely characterized by staphylococcal enterotoxin gene (SEg)-typing and 16S-23S rDNA intergenic spacer region (ISR)-PCR, as well as by detecting tst and mecA genes, genetic determinants of toxic shock syndrome toxin-1 and methicillin resistance, respectively. We found that the S. aureus isolates belonged to seven different SEg-types harboring the following combinations of genes: (1) selW, selX; (2) egc (seG, seI, seM, seN, seO), selW, selX; (3) seA, seH, seK, seQ, selW, selX; (4) seB, selW, selX; (5) seD, selJ, seR, selW, selX; (6) seH, selW, selX, selY; and (7) seA, egc, selW, selX, while among these, 2.1% and 4.2% were tst- and mecA- (staphylococcal chromosomal cassette mec-type IV) positive, respectively. Selected strains belonging to the 12 detected ISR-types were resistant towards antimicrobials including benzylpenicillin, ofloxacin, erythromycin, lincomycin, tetracyclin, kanamycin, oxacillin, and cefoxitin; 8.3% (1/12) were confirmed as MRSA and 16.7% (2/12) were multidrug resistant. The present study shows the heterogeneity of the S. aureus population in Algerian ready-to-eat foods as for their toxigenic potential and antimicrobial resistance, shedding the light on the quality and safety related to the consume of ready-to-eat foods in Algeria.

Physicochemical Parameters Affecting Norovirus Adhesion to Ready-To-Eat Foods.

The adhesion of noroviruses to strawberry, turkey slices, ham, and cheddar cheese was studied using murine norovirus 1 (MNV-1) as a surrogate for human norovirus (NoV). Based on plaque assay, the recovery and adhesion of MNV-1 depended on the food type (turkey versus strawberry), pH of the initial suspension buffer (pH 4 versus pH 7), and food fat composition (C8 versus C18). Recovery of infectious particles from turkey was 68% compared to 9.4% from strawberry. On turkey, adhesion of MNV-1 was lower at pH 7 (pH of fecal matter), and virus particles adhered to this pH were recovered more easily (33,875 PFU) than at pH 4 (pH of vomitus). The presence of fat and the composition of fatty acids seemed to increase MNV-1 recovery and adherent viral particles recovered but did not affect adhesion (68% on fat-free turkey and regular turkey). Adherent MNV-1 particles recovered from stainless steel coated with saturated fatty acid (C8, C14, C18) increased significantly with chain length (P < 0.05), but adhesion did not seem to change. Using liquid droplet contact angle to measure surface energy, it was deduced that hydrophobic interactions contribute considerably to the adhesion of MNV-1 to stainless steel, polyvinyl chloride, and high-density polyethylene. IMPORTANCE Ready-to-eat (RTE) foods are major vehicles of transmission of foodborne viral pathogens, including NoV. The high incidence of gastroenteritis caused by viruses is due largely to their persistence in the environment and adhesion to different kinds of surfaces in the food industry, including the foods themselves. Compared with bacteria, adhesion of viruses to surfaces is poorly understood. Better knowledge of the physicochemical parameters involved in the adhesion of NoV to ready-to-eat foods is essential to devising effective strategies for reducing the persistence and, thus, the transmission of this virus.