Presence Of Foodborne Pathogens Research Articles

Monitoring foodborne pathogens of food served at an institutional cafeteria

The provision of food by cafeterias is an opportunity to promote health through a balanced diet and safe food, offering the prospect of sustainably developing the well-being a community and the local economy. This study assessed the hygiene conditions of an institutional cafeteria. The presence of foodborne pathogens and indicators of general hygiene in 143 food and environmental samples were analyzed using the TEMPO and VIDAS food safety testing machines. All food samples tested negative for Salmonella sp., and Staphylococcus aureus counts were below the GCC Standardization Organization (GSO) limit. Escherichia coli was detected at level above the set limit in six food samples. Sixteen food samples showed aerobic bacterial counts above the set limit. Total coliforms and Enterobacteriaceae were each detected above the set limits in eight food samples. Yeasts and molds were detected above the set limit in 14 food samples. Coliform bacteria, S. aureus, and mold were detected on the hands and white coats of cafeteria workers and on work surfaces, machines, and cutting boards. The hygiene conditions of the cafeteria are not suitable for food preparation, and to improve hygienic conditions in cafeterias, regular inspection of food and food preparation facilities is strongly recommended.

Effect of Different Temperatures on the Microbiological Status of Donkey Milk

Summary Donkey milk is usually sold for human consumption directly at farms and agricultural households and it is used in the raw state because of its well-known medicinal properties. Sometimes, however, such milk has poor microbiological status due to inappropriate conditions during hand milking and storage. The aim of this paper was to examine the microbiological status of donkey milk exposed to different temperature treatments (refrigerated at 4 ℃ for 3 h, frozen at −18 ℃ for 1 day, and pasteurized at 80 ℃ for 10 minutes). The number of molds and yeasts, total viable count, Enterobacteriaceae, Escherichia coli, coagulase-positive Staphylococcus, and the presence of foodborne pathogens, including Salmonella spp., Listeria monocytogenes, and Campylobacter spp. were evaluated to estimate the microbiological status of donkey milk. As expected, freezing and pasteurization reduced the number of tested microorganisms, and no examined foodborne pathogens were detected. The total viable count was reduced by 0.64 log CFU/mL by freezing and by 2.23 log CFU/mL by pasteurization. The total molds and yeasts and total Enterobacteriaceae count were significantly reduced by pasteurization. In conclusion, frozen and pasteurized donkey milk is safer than raw milk. In order to be able to recommend the best temperature treatment before consumption, the effects of freezing and pasteurization on the quality and antibacterial properties of donkey milk have to be further investigated.

Aureimonas altamirensis: First Isolation from a Chicken Slaughterhouse in Italy Followed by Genotype and Phenotype Evaluations

The presence of foodborne pathogens in meat is linked to several contamination sources, and the slaughterhouse environment represents a relevant reservoir of contamination. Aureimonas altamirensis is a Gram-negative bacteria associated with different isolation sources, including human clinical cases. This study aims to identify and characterize an A. altamirensis isolate from chicken guts collected in an Italian slaughterhouse. The study approach includes whole-genome analysis jointly with phenotypical tests. Whole-genome sequencing (WGS) confirms the initial MALDI-TOF MS identification, finding putative virulence and biofilm-related genes. Moreover, the gene class evaluation reveals that the numerically largest gene category in the A. altamirensis genome is related to amino acid metabolism and transport. The analyses performed on a human gut mucus-producing cell line (HT29-MTX-E12) demonstrated the ability of A. altamirensis to colonize the host cell layer. Moreover, the antibiotic resistance test showed a high resistance of A. altamirensis to gentamicin (MIC 0.5 mg/L). The detection of a potential pathogenic and antibiotic-resistant A. altamirensis strain isolated from a slaughterhouse underlines the necessity of active surveillance studies focused on this species and the need for further studies about A. altamirensis in foods.

Factors Associated with Foodborne Pathogens among Food Handlers: A Case Study of Thika, Kiambu County, Kenya

Increasing risks of infections with foodborne pathogens may occur as a result of poor food handling practices. The present cross-sectional study employed a mixed-methods approach to determine the factors associated with foodborne pathogens among food handlers working in the food establishments in Thika, Kiambu County, Kenya. Random sampling was used to enroll respondents in the survey. A single stool specimen was collected from each study participant. Laboratory analysis of the specimen was done to test the selected foodborne pathogens. Overall, 44 out of the 285 food handlers who took part in the study had at least one food-transmitted pathogen, putting the prevalence of foodborne infections among the food handlers at 15.4% (95% confidence interval (CI) 11.7%–20.1%). The findings from multivariate logistic regression indicated the following protective factors for foodborne pathogens among the studied food handlers: being female (adjusted odds ratio (AOR) 0.098 (95% CI 0.0304–0.315, p < 0.001 )); having a valid medical examination certificate (AOR 0.141 (95% CI 0.141–1. 0.439, p = 0.001 )); not boiling or treating water before serving the water to customers was a risk factor for having infections with foodborne pathogens (AOR 3.043 (95% CI 1.2225–7.577, p = 0.017 )). The presence of foodborne pathogens among the food handlers in the study area potentially highlights the need to address the spread and transmission of foodborne infections in the study area. There is a need to institute appropriate control measures, including regular screening of food handlers for foodborne illnesses in addition to training them on safe food handling practices, hand hygiene practices, and regular monitoring of the food handling practices.

Double bipolar electrode electrochemiluminescence color switch for food-borne pathogens detection

Color-switch electrochemiluminescence (ECL) sensing platform based on a dual-bipolar electrode (D-BPE) is reported in this work. The D-BPE was composed of a cathode filled with buffer and two anodes filled with [Ru(bpy)3]2+-TPrA and luminol-H2O2 solutions, respectively. Both anodes were modified with capture DNA and served as ECL reporting platforms. After introducing ferrocene-labeled aptamer (Fc-aptamer) on both anodes, the ECL emission signal of the [Ru(bpy)3]2+ was difficult to be observed (anode 1), while luminol emitted a strong and visible ECL signal (anode 2). Ferrocene (Fc) did not only prevent the oxidation of [Ru(bpy)3]2+ due to its lower oxidation potential, its oxidation product Fc+ also quenched the [Ru(bpy)3]2+ ECL through efficient energy transfer. For luminol, Fc+ catalyzes the accelerated formation of the excited-state of the luminol anion radical, which leads to the enhancement of the luminol ECL. In the presence of food-borne pathogens, the aptamer was assembled with them, leading to the leaving of Fc from the surface of the D-BPE anodes. The ECL intensity of [Ru(bpy)3]2+ was enlarged, meanwhile, the blue emission signal of luminol became weakened. By self-calibrating the ratio of the two signals, 1–106 CFU mL−1 food-borne pathogenic bacteria can be sensitively detected with a detection limit of 1 CFU mL−1. Ingeniously, the color-switch biosensor can be used to detect S. aureus, E. coli and S. typhimurium by assembling the corresponding aptamers onto the D-BPE anodes.

Conditional Forest Models Built Using Metagenomic Data Accurately Predicted Salmonella Contamination in Northeastern Streams.

The use of water contaminated with Salmonella for produce production contributes to foodborne disease burden. To reduce human health risks, there is a need for novel, targeted approaches for assessing the pathogen status of agricultural water. We investigated the utility of water microbiome data for predicting Salmonella contamination of streams used to source water for produce production. Grab samples were collected from 60 New York streams in 2018 and tested for Salmonella. Separately, DNA was extracted from the samples and used for Illumina shotgun metagenomic sequencing. Reads were trimmed and used to assign taxonomy with Kraken2. Conditional forest (CF), regularized random forest (RRF), and support vector machine (SVM) models were implemented to predict Salmonella contamination. Model performance was assessed using 10-fold cross-validation repeated 10 times to quantify area under the curve (AUC) and Kappa score. CF models outperformed the other two algorithms based on AUC (0.86, CF; 0.81, RRF; 0.65, SVM) and Kappa score (0.53, CF; 0.41, RRF; 0.12, SVM). The taxa that were most informative for accurately predicting Salmonella contamination based on CF were compared to taxa identified by ALDEx2 as being differentially abundant between Salmonella-positive and -negative samples. CF and differential abundance tests both identified Aeromonas salmonicida (variable importance [VI] = 0.012) and Aeromonas sp. strain CA23 (VI = 0.025) as the two most informative taxa for predicting Salmonella contamination. Our findings suggest that microbiome-based models may provide an alternative to or complement existing water monitoring strategies. Similarly, the informative taxa identified in this study warrant further investigation as potential indicators of Salmonella contamination of agricultural water. IMPORTANCE Understanding the associations between surface water microbiome composition and the presence of foodborne pathogens, such as Salmonella, can facilitate the identification of novel indicators of Salmonella contamination. This study assessed the utility of microbiome data and three machine learning algorithms for predicting Salmonella contamination of Northeastern streams. The research reported here both expanded the knowledge on the microbiome composition of surface waters and identified putative novel indicators (i.e., Aeromonas species) for Salmonella in Northeastern streams. These putative indicators warrant further research to assess whether they are consistent indicators of Salmonella contamination across regions, waterways, and years not represented in the data set used in this study. Validated indicators identified using microbiome data may be used as targets in the development of rapid (e.g., PCR-based) detection assays for the assessment of microbial safety of agricultural surface waters.

Microbiological quality and safety of vacuum-packaged white-tailed deer meat stored at 4 °C

Vacuum packaging is widely used for extending the shelf life of commercial fresh meat products. It also ensures product hygiene during distribution and storage. However, very little information exists concerning the effects of vacuum packaging on the shelf life of deer meat. One of our aims was to evaluate how storage under vacuum at 4 °C affects the microbial quality and safety of white-tailed deer (Odocoileus virginianus) meat cuts. This was assessed in a longitudinal study based on sensory analyses and measurements of (1) mesophilic aerobic bacteria (MAB), (2) lactic acid bacteria (LAB), (3) enterobacteria (EB), (4) and Escherichia coli (EC) counts, and the presence of foodborne pathogens (Campylobacter, Salmonella, stx-harbouring E. coli (STEC), Yersinia and Listeria). Microbiomes were additionally investigated by 16S rRNA gene amplicon sequencing at the time of spoilage. In total, 50 vacuum-packaged meat cuts from the carcasses of 10 wild white-tailed deer harvested in southern Finland in December 2018 were analysed. A significant (p < 0.001) drop in the odour and appearance scores and a significant increase in MAB (p < 0.001) and LAB (p = 0.001) counts of the vacuum-packaged meat cuts were observed after 3 weeks of storage at 4 °C. A very strong correlation (rs = 0.9444, p < 0.001) between the MAB and LAB counts were found during the 5-week sampling period. Clear spoilage changes, manifested as sour off-odours (odour scores ≤2) and pale colour, were detected in the meat cuts spoilt after 3-week storage. High (≥8 log10 cfu/g) MAB and LAB counts were also detected. According to the 16S rRNA gene amplicon analyses, Lactobacillus was the dominant bacterial genus in these samples, demonstrating that LAB can cause rapid spoilage of vacuum-packaged deer meat cuts stored at 4 °C. The rest of the samples were spoilt after four or five weeks of storage, and a vast number of bacterial genera were identified in them. Listeria and STEC were detected by PCR in 50 % and 18 % of the meat cut samples, respectively, which may indicate a public health problem. Our results demonstrate that it is very challenging to ensure the quality and safety of vacuum-packaged deer meat stored at 4 °C, and freezing is therefore recommended to prolong the shelf life.

Microbiological Quality and Presence of Foodborne Pathogens in Raw and Extruded Canine Diets and Canine Fecal Samples.

Pet food can be a source of microbiological hazards that might affect companion animals and owners. Even though owners usually rely on conventional pet diets, such as extruded diets, new feeding practices, such as raw meat-based diets (RMBDs), have grown. RMBDs' benefits are still scientifically uncertain, while its risks have been documented. The use of canine RMBDs might increase the exposure to zoonotic pathogens, such as Salmonella spp., Listeria monocytogenes, Campylobacter spp., among others. Identifying pathogen prevalence in canine food and pets is required to contribute to public health measures. The aims of this study were: (1) to compare the microbiological quality of RMBDs and extruded diets (2) to identify and compare the prevalence of Salmonella spp., Campylobacter jejuni, and L. monocytogenes from raw and extruded canine diets and canine fecal samples, and (3) to characterize pet owners according to the diet chosen to be used on their pets, their motivations for using RMBDs, and their knowledge about benefits and risks related to this feeding practice. Conventional and molecular microbiological methods were used to identify pathogen presence from food and fecal samples, while pulsed-field gel electrophoresis (PFGE) was performed to evaluate the clonal relationship between isolates. Aerobic plate counts for RMBDs were higher than those detected for extruded diets. Salmonella spp. and L. monocytogenes were isolated from 35.7% (15/42) RMBDs, while Salmonella spp., C. jejuni, and L. monocytogenes from 33.3% (11/33) fecal samples from RMBD-fed dogs. From the RMBD samples positive to Salmonella spp., chicken was the main meat ingredient composing the diets. PFGE analysis confirmed a genetic association between Salmonella spp. isolates from fecal and raw food samples from the same household. We did not detect pathogens from extruded food samples or feces from extruded-fed dogs. Using a survey, we identified dog owners' unawareness and/or underestimation of risks related to RMBDs. We demonstrated that canine raw pet food might be a source of zoonotic foodborne pathogens that represent a health risk for both humans and pets. While clinical findings caused by the mentioned pathogens vary among pets, the zoonotic potential implies a significant concern.

Data on antibiograms and resistance genes of Enterobacterales isolated from ready-to-eat street food of Ambato, Ecuador.

Foodborne pathogens represent a significant cause of negative impacts on human health and the economy worldwide. Unfortunately, information about epidemiological insights in Latin American countries is scarce. The consumption of ready-to-eat street food in Ecuador is extensive, and information about the presence of foodborne pathogens, their virulence factors, and antimicrobial resistance is negligible. This data includes the occurrence, phenotypic antibiotic resistance profiles, and antibiotic resistance genes of Enterobacterales isolated from ready-to-eat street food in Ambato, central Ecuador during 2020 and 2021. The most common genera detected were Escherichia coli, Klebsiella spp., and Cronobacter spp. Agar disk diffusion assays were performed to determine their phenotypic resistance. The presence of antibiotic resistance genes conferring resistance against colistin, β-Lactams, aminoglycosides, tetracyclines, sulfonamides, fluoroquinolones, and amphenicols was detected via polymerase chain reaction (PCR) amplification.

Determination of Phylloplane Associated Bacteria of Lettuce from a Small-Scale Aquaponic System via 16S rRNA Gene Amplicon Sequence Analysis

Fresh vegetables harbour diverse bacterial populations on their surfaces which are important for plant health and growth. Information on epiphytic bacteria is limited to only a few types of vegetables and it is unknown how the lettuce epiphytic bacterial community structure may respond when a probiotic product is added to an aquaponic system. In this study, we evaluated lettuce growth and analysed epiphytic bacterial communities of lettuce based on metabarcoding analysis of the V3-V4 region of the 16S rRNA gene obtained from paired-end Illumina MiSeq reads. The addition of Bacillus probiotics resulted in a significant increase of nitrate and phosphate in the deep-water culture solution, as well as increased vegetative growth of lettuce. Metabarcoding analysis revealed that the most abundant phyla on lettuce leaf surfaces were Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. The in-depth bacterial composition analysis indicated that genera Chryseobacterium, Bacillus, Pantoea, Pseudoduganella, Flavobacterium, Paludibacter, and Cloacibacterium were dominant in leaf samples obtained from Bacillus-treated systems. Analysis of lettuce epiphytic bacterial communities of the fresh lettuce leaf surfaces also indicated the presence of food-borne pathogens belonging to the Shigella and Aeromonas genera, which were less abundant in the probiotic treated systems. This study provides the first characterization of the epiphytic bacterial community structure and how it can be modulated by the addition of a probiotic mixture to the nutrient solution of aquaponic systems.

Bacterial load determination of poultry feed with seasonality effect in Karachi, Pakistan.

Background: The escalating rate of food-borne diseases via poultry feeds necessitates the characterization of the pathogens to reduce the health risk factor for humans and animals. The poultry feed microbial analysis help to control food-borne illness. In addition, the knowledge about seasonal effects on microbial growth helps the manufacturers to take precautionary measures in alarming months to maintain the standard quality of poultry feed.&#x0D; Methodology: This study was designed to identify and enumerate bacteria and their seasonal variation. Total feed samples (n=204) were evaluated through traditional culture techniques, microscopic inspection, and biochemical properties. However, bacterial load was determined by using the total viable count.&#x0D; Results: As a result, five genera, including Salmonella enterica (39.05%), Escherichia coli (22.48%), Bacillus subtilis (18.34%), Staphylococcus aureus (11.24%), and Streptococcus sp (8.87%), were isolated. The proportion of occurrence of the bacterial load was lowest in December-February (64.4%) and highest in June-August (96.2%). Whereas in September-November was (87.6%) and March-May (77.5%). On the whole, the total percentage of positive samples was 82.8%. Statistical analysis revealed that (9.9×10-8 cfu/g) was the highest viable bacterial count recorded from June to August. The presence of food-borne pathogens, especially S.enterica and E.coli, is bothersome. Moreover, June to August is considered the most troubling month due to the elevated level of contamination.&#x0D; Conclusion: To evade microbial contamination, the microbiological security rules must be followed throughout the process of formulation and storage period, especially in sensitive hot and humid months of June to August. Also, standard inspection should be taken to control the dissemination of food-borne illness.

The prevalence of Escherichia coli O157:H7 and Salmonella in frozen and fresh goat meat The demand for goat meat is on the rise in the U.S. A common concern in the production and harvest of animals for human consumption is the presence of foodborne pathog

The demand for goat meat is on the rise in the U.S. A common concern in the production and harvest of animals for human consumption is the presence of foodborne pathogens, Escherichia coli O157:H7 and Salmonella. As an “under-researched food vehicle”, there are minimal strategies for the control and prevention of foodborne pathogens with goat meat. Freezing can be an effective way of preventing microbial growth in meat, but it does not eradicate bacteria. Five samples of fresh and frozen goat meat, respectively, were collected and utilized in prevalence determination and microbial quality comparison. Using selective and differential media, 25 grams from each sample were tested for both E. coli O157:H7 and Salmonella. Three of five frozen samples contained E. coli O157:H7 suspects (p = 0.08377); whereas no E. coli O157:H7 suspects were detected with the fresh samples. Two fresh samples and one frozen sample were indicative of the presence of Salmonella. Frozen samples were more heavily contaminated than fresh samples, but overall, there was a low prevalence of these bacteria in the two meat types. These findings could be further substantiated with the inclusion of larger sample size and more confirmative tests.&#x0D;

Microbiological survey and occurrence of bacterial foodborne pathogens in raw and ready-to-eat green leafy vegetables marketed in Tehran, Iran.

Fresh leafy (FL) and ready-to-eat (RTE) vegetables are recognized as an important source of foodborne disease outbreaks worldwide. Currently, there are no data available for the prevalnce of bacterial foodborne pathogens (FBPs) in raw vegetables consumed in Iran. Here, we evalated the presence of common bacterial FBPs among 366 samples of raw vegetables including 274 FL and 92 RTE collected from 21 districts of Tehran. The presence of FBPs were screened using conventional microbiological culture methods and real-time PCR assays. Overall, a higher rate of bacterial contamination was detected in FL compared to RTE samples using both detection methods. The results obtained by microbiological methods showed that Staphylococcus aureus (134/366, 36.6%), followed by Escherichia coli (85/366, 23.2%) and Clostridium perfringens (66/366, 18%) were detetcted as the most prevalent pathogens in this study. Vibrio cholerae was not detected in any of the samples either by microbiological methods or by the real-time PCR assays. There was a noticeable reduction in the proportion of Campylobacter positive samples using conventional microbiological methods (3.5%) compared to the real-time PCR assay (20.7%). The proportion of FL and RTE positive samples obtained by conventional microbiological methods was significantly different (P<0.05) for C. perfringens, Campylobacter spp. and S. aureus. The proportion of positive samples in FL and RTE vegetables obtained by the real-time PCR assays was significantly different (P<0.05) for C. perfringens, S. aureus, Helicobacter pylori and STEC/EHEC, the last one was found more frequently in RTE than in FL samples. Our findings indicated a contamination of FL and RTE vegetables in Iran with a range of well-known and emerging FBPs. Positivity and the distribution of bacterial species from the current data indicated different contamination sources, and overall a lack of effective decontamination steps during the production chain. Moreover, further information about the quality of the water, the hygiene measures implemented during the processing, storage and marketing are required to better identify the critical points and define the proper measures.

Two Food Waste By-Products Selectively Stimulate Beneficial Resident Citrus Host-Associated Microbes in a Zero-Runoff Indoor Plant Production System

The global production of food waste is a far-reaching problem with sizable financial, ethical, social, and environmental costs. Over 66 million tons of food waste is produced annually in the United States alone. This waste can be converted into valuable digestate by-products that promote a circular economy within agri-food systems. The present work investigated the use of two liquid digestates of microaerobic fermentation from mixed food waste and beer mash, respectively, as biostimulants for non-bearing citrus plants (nursery stock) grown in a zero-runoff greenhouse system with recirculating irrigation. The digestates' impact on the structure and diversity of the microbiota was determined on the irrigation water, soil, leaves, roots, and rhizosphere of citrus plants. A combination of culture-dependent (selective media) and culture-independent approaches (Next-Generation Sequencing) was used to assess the composition of the microbial communities and to single out the presence of foodborne pathogens. Our results suggest that the use of digestates is safe (i.e., no human or plant pathogens were present in the digestates or enriched in the plant production system following amendments). Digestates application to the irrigation water reduced the bacterial diversity within 24–48 h and selectively and significantly stimulated beneficial resident host-associated microorganisms (Pseudomonas putida) by two to three orders of magnitude. Carbon dynamics were analyzed in the nutrient solutions by measuring dissolved organic carbon and characterizing carbon species through gas chromatography-electron ionization-mass spectrometry. Our results indicate that dissolved organic carbon in the recirculating irrigation water spikes after each digestate amendment and it is quickly metabolized by bacteria, plateauing 24 h after application. Soil carbon, nitrogen, and nutrient dynamics were also analyzed, and results suggest that digestates increased the concentration of some plant nutrients in soils without causing a surge of potentially toxic elements. This study represents a proof-of-concept for the safe re-use of organic wastes, from farming and consumers, in agriculture. Implementing this type of integrated plant production system could reduce the environmental impact of food waste and benefit the public by improving soil health, reducing agricultural footprint, and increasing crop fitness by deploying a method based on a circular economy and sustainable food production approaches.

Microbiological quality and safety of raw milk from direct sale in northern Germany

The microbiological status of raw milk sold from vending stations at farm level in northern Germany was determined in relation to hygiene quality parameters and the presence of foodborne pathogens. For this, one hundred and ten samples were examined. The total viable count (TVC) was higher than 5 log cfu mL−1 in 36.4% of the milk samples. Counts of Pseudomonas spp., Enterobacteriaceae, yeasts and moulds were detected at mean values of 3.9 ± 1.3 log cfu mL−1, 2.7 ± 1.2 log cfu mL−1, 3.1 ± 0.9 log cfu mL−1 and 1.5 ± 0.8 log cfu mL−1, respectively. Overall, only 43% of the raw milk samples were of satisfactory quality from a microbiological point of view. Campylobacter jejuni and Arcobacter butzleri were determined in the enrichment broth of three raw milk samples. A long-term monitoring of three farms revealed that individual differences in farm management practice influenced raw milk quality.

Presence of Foodborne Pathogens in Seafood and Risk Ranking for Pathogens.

This study aims at examining the contamination of coliform bacteria, Escherichia coli, Listeria monocytogenes, Vibrio vulnificus, and Vibrio cholerae, which carry extremely serious risks to the consumer health, in 700 seafood belonging to 4 different (raw sea fish, raw mussels, raw shrimp, and raw squid) categories. The total number of samples was determined as 700. When the obtained results were viewed in total, they were found to be 48.14%, 18.71%, 8.57%, and 3.42% for coliform bacteria, E. coli, L. monocytogenes, and V. vulnificus, respectively. V. cholerae, one of the factors studied, was not found. Conventional microbiological cultivation methods were used in the analysis stage as well as the real-time PCR method. This study aims at making a risk ranking modeling for consumer health based on product category and pathogens by interpreting the results of the analysis with statistical methods. According to the statistical analysis, significantly binary correlations were determined among some parameters that stimulate one another for reproducing. In the light of the obtained results of the study, it has been concluded that the studies of the most detailed examinations of the microbiological risks associated with seafood, forms of microbial pollution and microorganisms that cause deterioration in seafood and threaten consumer health and the path that their epidemiologies follow, are of primary importance to both protecting consumer health and obtaining safe and quality seafood.

Assessment of microbial communities on freshly killed wild boar meat by MALDI-TOF MS and 16S rRNA amplicon sequencing

Wild boars (Sus scrofa) are the most widely distributed large mammals and recent increase in consumption of wild boar meat urges the need of microbiological quality criteria. The aim of the study was to characterize the initial bacterial contamination on freshly-killed wild boar meat using a culture-dependent approach with ISO-methods combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry identification and 16S rRNA amplicon sequencing. Moreover, the presence of foodborne pathogens was examined using Real-Time-PCR and confirmed by classical isolation. Analysing 22 unrelated wild boar meat samples showed a higher bacterial contamination level compared to pork, with Salmonella present in almost one third of the samples. A great variability of the microbial contamination between the samples was recorded, as well as complementary results between culturing and 16S rRNA amplicon sequencing as frequently isolated genera were not always detected, and vice versa. Furthermore, the foodborne pathogen Salmonella was never detected with 16S rRNA amplicon sequencing, demonstrating the necessity for a cautious approach in the implementation of new analysis techniques in food safety. The present work determines that attention should be paid to the trade of non-inspected meat directly to retail or consumers.

Health Risk Assessment of Heavy Metals and Microbial Quality of Local Tomato (&amp;lt;i&amp;gt;Solanum lycopersicum&amp;lt;/i&amp;gt;) of Ouagadougou, Burkina Faso

Tomato fruit enormously consumed in Burkina Faso is a source of health risk due to its quality. The plant of tomato cultivated in most the industrially polluted area as Ouagadougou, accumulates significant quantities of heavy metals and microorganisms and could be dangerous for consumption. The present study was conducted to investigate heavy metal and microbial contamination in soils wastewater and vegetables (tomato fruit) and to evaluate the possible health risks associated with the consumption of vegetables. Total concentrations of As, Cd, Cr, Cu, Hg, Ni, Se and Zn were determined using atomic absorption spectrophotometry. Transfer factor (TF), daily intake of metals (DIM) and health risk index (HRI) were also calculated. Microbial quality was analyzed for the presence of foodborne pathogens. The pH involved from 6.50 ± 0.1 to 9.40 ± 0.12 respectively for Boulmiougou and Kossodo. The mean metal concentrations indicated that soils were strongly polluted followed by wastewater and vegetable. The range of the mean values (in mg · kg-1) exhibited by As, Cd, Cr, Cu, Hg, Ni, Se and Zn in tomato fruit was 17.80 ± 0.32, 2.71 ± 0.02, 11.57 ± 0.2, 203.41 ± 1.20, 15.13 ± 0.30, 53.18 ± 0.20, 38.56 ± 0.10, 109.13 ± 0.25 concerning samples of Boulmiougou and 3.47 ± 0.15, 2.78 ± 0.01, 22.11 ± 0.1, 242.85 ± 2.10, 14.86 ± 0.10, 132.19 ± 1.50, 33.23 ± 0.15, 146.43 ± 1.12 for Kossodo. Microbial count was below to acceptable limits for vegetable, but underlined the presence of spoiler and foodborne pathogens. However, the daily intake of metals (DIM) and the health risk index (HRI) values were found to be under to the prescribed maximum tolerable.

Prevalence of Foodborne Pathogens on Cheeses Made from Farmstead Milk Processing Plants in Korea

To solve the problem of raw milk surplus, the Korean government encouraged the farmstead milk processing industry. However, the hygiene of farmstead dairy products has not been evaluated. Therefore, the microbiological analysis of farmstead cheeses was performed in this study. Farmstead cheeses (Berg, Colby, Cottage, Gouda, Mozzarella, String, Tilsiter, and Quark) were purchased from 16 dairy farms. In qualitative analysis, the presence of foodborne pathogens (Bacillus cereus, Escherichia coli, Clostridium perfringens, Salmonella, Staphylococcus aureus, Listeria monocytogenes, and Campylobacter spp.) were examined. Also, total aerobic bacteria, Pseudomonas spp., coliform, and E. coli, and yeast/mold were enumerated. Seventeen samples (37.8%) of 45 farmstead cheeses were contaminated with B. cereus and the highest detection rate was observed in String cheese. Two samples (4.4%) were E. coli positive and seven samples (15.6%) were S. aureus positive. Four other foodborne pathogens were not detected in all farmstead cheeses. Also, the mean levels of total aerobic bacteria, coliform, E. coli, and yeast/mold were 4.3 Log CFU/g, 1.4 Log CFU/g, 1.1 Log CFU/g, and 3.8 Log CFU/g, respectively. These results indicate that the food safety of farmstead cheese is extremely poor and, thus, the hygiene management of farmstead cheese should be improved to provide safe farmstead cheese to consumers.

Incorporation of Heavy Water for Rapid Detection of Salmonella typhimurium by Raman Microspectroscopy

The presence of foodborne pathogens is one of the leading causes of food safety incidents; hence, early monitoring of the status of microbial contamination is a permanent concern. Here, a rapid and sensitive method for detection of Salmonella typhimurium was firstly developed by combining heavy water (D2O) labeling and Raman microspectroscopy to measure bacterial metabolic activity. It was based on the characteristics of Raman signals of carbon–deuterium (C–D) vibration as cells incorporate deuterium in place of hydrogen (H) during biosynthetic activity, and the live and dead Salmonella typhimurium cells could be distinguished by their metabolic activity within 1 h. The CD / (CD + CH)% of D2O-incorporated Salmonella typhimurium in logarithmic growth phase was linearly related to the log of the initial concentration, and Salmonella typhimurium with the initial concentration of 102–106 colony-forming unit (CFU)/mL could be quantified within 4–8 h. Furthermore, desirable recovery ranging from 95.41 to 106.6% was obtained to assess the practicality and stability of this method for rapid detection of Salmonella typhimurium in milk, indicating promising application for the detection of bacterial contamination in food.