Potential Foodborne Pathogens Research Articles

Microbiological quality of irrigation water on highly diverse fresh produce smallholder farms: elucidating environmental routes of contamination.

To evaluate the microbiological safety, potential multidrug-resistant bacterial presence and genetic relatedness (DNA fingerprints) of Escherichia coli isolated from the water-soil-plant nexus on highly diverse fresh produce smallholder farms. Irrigation water (n=44), soil (n=85), and fresh produce (n=95) samples from six smallholder farms with different production systems were analysed for hygiene indicator bacterial counts and the presence of shigatoxigenic E. coli and Salmonella spp. using standard microbiological methods. Identities of isolates were confirmed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and the genetic relatedness of the E. coli isolates determined using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) analysis. Irrigation water E. coli levels ranged between 0 and 3.45 log MPN/100 ml-1 with five farms having acceptable levels according to the World Health Organization limit (3 log MPN/100 ml-1). Fresh produce samples on four farms (n=65) harboured E. coli at low levels (<1 log CFU/g-1) except for one sample from kale, spring onion, green pepper, onion, and two tomato samples, which exceeded international acceptable limits (100 CFU/g-1). Only one baby carrot fresh produce sample tested positive for Salmonella spp. Of the 224 samples, E. coli isolates were identified in 40% (n=90) of all water, soil, and fresh produce types after enrichment. Additionally, the DNA fingerprints of E. coli isolates from the water-soil-plant nexus of each respective farm clustered together at high similarity values (>90%), with all phenotypically characterized as multidrug-resistant. The clustering of E. coli isolated throughout the water-soil-plant nexus, implicated irrigation water in fresh produce contamination. Highlighting the importance of complying with irrigation water microbiological quality guidelines to limit the spread of potential foodborne pathogens throughout the fresh produce supply chain.

Street-vended grilled beef sausages as potential vehicles of bacterial and fungal pathogens: An exploratory survey in Ho, the capital city of the Volta Region of Ghana.

Grilled beef sausage is a popular street delicacy in many countries, and Ghana is no exception. This study assessed street-vended grilled beef sausages as a potential vehicle of microorganisms that present food safety risks to the general public in Ho City. Twenty grilled beef sausages were obtained from various vended locations within Ho municipality by convenient sampling and were analyzed by standard microbiological protocols for food safety followed by statistical analysis with a test of significant difference at p < .05. Total aerobic bacteria count of the potential foodborne pathogens ranged from 2.75 × 104 to 1.85 × 107 CFU/g. The microbial species identified included Staphylococcus aureus with a load from 6.15 × 102 to 1.67 × 105 CFU/g, Escherichia coli from 4.2 × 102 to 3.9 × 104 CFU/g, Bacillus cereus from 3.05 × 102 to 7.1 × 104 CFU/g, and Salmonella spp. from 2.8 × 102 to 5.5 × 104 CFU/g. Total fungal counts also ranged from 0.0 to 9.83 × 103 CFU/g, and the species identified included Aspergillus spp. and Rhizopus spp. all of which were within the acceptable limits of the International Commission for Microbiological Specification of Foods. However, for total viable bacteria, 75% of the samples were above the acceptable limits in the guidelines by the Ghana Standards Authority, indicating that the consumption of grilled beef sausages poses serious food safety and hygiene risks to consumers. Hygienic processing of the sausages under sanitary environments, proper handling and preservation procedures, and periodic follow-up visits to the vended areas should be employed to reduce the risk of occurrence of potential pathogens in the products.

Bacteriological quality and safety of bottle food and associated factors among bottle-fed babies attending pediatric outpatient clinics of Government Health Institutions in Arba Minch, southern Ethiopia

BackgroundMicrobial contamination of baby bottle food has been identified as a significant public health concern, especially in developing countries, but it remains overlooked. Therefore, this study aimed to determine microbiological hazards, compliance with hygiene practices, and critical control points of contamination in baby bottle food in Arba Minch, southern Ethiopia.ObjectiveTo evaluate the bacteriological quality and prevalence of foodborne pathogens in baby bottle food and to identify associated factors among bottle-fed babies attending three government health institutions in Arba Minch, southern Ethiopia.MethodsA cross-sectional study was conducted between February 24 and March 30, 2022. A total of 220 food samples, comprising four types prepared with different sources of materials, were collected from systematically selected bottle-fed babies attending health facilities. The data on sociodemographic characteristics, food hygiene, and handling practices were solicited by face-to-face interview using a semi-structured questionnaire. Food samples (10 mL) were quantitatively analyzed for total viable counts (TVC) and total coliform count (TCC) and qualitatively for the presence of common foodborne bacterial pathogens. Data were analyzed using SPSS; ANOVA and multiple linear regression analyses were done to identify factors influencing microbial counts.ResultsResults revealed that the means and standard deviations of TVC and TCC were 5.3 ± 2.3 log10 colony forming units (CFU)/mL and 4.1 ± 2.6 log10 CFU/mL, respectively. Of the various food samples analyzed, 57.3 and 60.5% had a TVC and TCC above the maximum acceptable limits, respectively. The result of the ANOVA showed that there was a significant difference in the mean score of TCV and TCC among the four types of food samples (p < 0.001). Enterobacteriaceae were found in the majority of positive food samples (79.13%), followed by Gram-positive cocci (20.8%). Salmonella spp., diarrheagenic Escherichia coli, and Staphylococcus aureus were the common foodborne pathogens detected in 8.6% of tested foods. The regression result revealed that the type of baby food, hand washing practices of mothers or caregivers, and sterilizing and disinfecting procedures of feeding bottles are independent determinants of bacterial contamination (p < 0.001).ConclusionThe high microbial load and the presence of potential foodborne bacterial pathogens in the bottle food samples analyzed indicate unsanitary practices and the potential risk of exposure to foodborne pathogens in bottle-fed babies. Thus, interventions such as educating parents about proper hygiene practices, sterilizing feeding bottles and limiting bottle feeding practices are critical to reducing the risk of foodborne to bottle-fed infants.

Optimization of a natural antimicrobial formulation against potential meat spoilage bacteria and food-borne pathogens: Mixture design methodology and predictive modeling.

This study is about the combined antimicrobial effect of essential oils (EOs), namely Mediterranean (MN) EO, German thyme (GT) EO, Cinnamon (CN) EO, Indian (IN) EO, Asian (AN) EO, and citrus extract (CE) against spoilage bacteria (Lactobacillus sakei, Lactobacillus curvatus, Leuconostoc mesenteroides, Carnobacterium divergens, Brochothrix thermosphacta, and Pseudomonas aeruginosa) and selected pathogenic bacteria (E. coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes). Firstly, each EO and CE were screened for antibacterial activity by microdilution assay, and the most efficient antimicrobial extracts were selected based on the lowest MIC values to perform the combination assays. Afterward, a simplex-centroid mixture design was used to develop optimal antimicrobial mixtures capable of protecting meat from spoilage and pathogenic bacteria. The optimization tool allowed us to postulate models and validate them statistically as well as to create a prediction profile of the experiment. Thus, the optimal mixtures named active formulation 1 (AF1) containing MN EO/GT EO/VC EO/CE with a ratio of 1:2:2:1 and active formulation 2 (AF2) containing IN EO/AN EO/CE/VC EO with a ratio of 2:2:1:2, were developed based on the demonstration of their synergistic effect against tested bacteria. The obtained formulations at organoleptically acceptable concentrations could be applied in the preservation of meat and meat products.

Microbiological quality, antibiotic resistant bacteria and relevant resistance genes in ready-to-eat Pacific oysters (Magallana gigas).

Oysters are a highly valued seafood but can endanger public health, if they are eaten raw or barely cooked. We evaluated the microbiological quality of Pacific oysters (Magallana gigas) by international standard methods in four groups (each with four to five animals) acquired from supermarkets and directly from a farm producer. Most of the groups presented satisfactory microbiological quality. In two groups of oysters, 'questionable' or 'unsatisfactory' quality was observed for the coagulase-positive Staphylococcus parameter. Culture-based methods did not detect Salmonella spp. or enteropathogenic Vibrio spp., but Vibrio alginolyticus, a potential foodborne pathogen, was identified by molecular analysis. Fifty strains, belonging to 19 species, were isolated in antibiotic-supplemented media, and their antibiotic susceptibility profile was evaluated. Genes coding for β-lactamases were searched by PCR in bacteria showing resistance phenotype. Decreased susceptibility or resistance to distinct antibiotics were observed for bacteria from depurated and non-depurated oysters. The blaTEM gene was identified in Escherichia fergusonii and Shigella dysenteriae strains, which showed multidrug-resistant phenotypes. The possibility that oysters might be a source of antibiotic-resistant bacteria/antibiotic resistance genes is of great concern and highlights the need for stricter controls and preventative measures to mitigate and counteract the dissemination of antibiotic resistance across the food chain.

Tolerance of foodborne Acinetobacter spp. to sanitizer agents.

The bacteria Acinetobacter spp. are extremely relevant in clinical settings. Recently, they have emerged as potential food-borne opportunistic pathogens. Their ability to form biofilms contributes to antibiotic resistance by generating an environment that facilitates the acquisition and transfer of resistance genes. Studies on the tolerance of Acinetobacter spp. from food sources to sanitizers used in the food industry and homes are necessary to help mitigate food contamination by these microorganisms. Isolates from ready-to-eat salads (n = 11) and raw goat milk (n = 4) were evaluated for their tolerance to sodium hypochlorite (NaClO), quaternary ammonium compound/biguanide (QAC/BG), and peracetic acid (PAA). The Food and Drug Administration (FDA) recommends that the concentration of these sanitizers in food-processing equipment and utensils and other food-contact articles should not exceed 200 parts per million (ppm). The minimum inhibitory (MIC) and bactericidal (MBC) concentrations of NaClO were above 312.5 ppm for all isolates tested and ≥ 2,500 ppm for four isolates from salads. Only three isolates from salads and four isolates from goat milk were inhibited by an MIC lower than 200 ppm of PAA. QAC/BG presented the lowest MIC and MCB values (9.37/6.25 ppm for all isolates tested), suggesting that it is the most effective agent against the isolates used in this study. Our results demonstrate that Acinetobacter spp. isolates from food can be tolerant to the recommended concentrations of NaClO and PAA, which highlights the health risks to consumers.

Exploring the Microbial Community and Functional Characteristics of the Livestock Feces Using the Whole Metagenome Shotgun Sequencing.

The foodborne illness is the important public health concerns, and the livestock feces are known to be one of the major reservoirs of foodborne pathogens. Also, it was reported that 45.5% of foodborne illness outbreaks have been associated with the animal products contaminated with the livestock feces. In addition, it has been known that the persistence of a pathogens depends on many potential virulent factors including the various virulent genes. Therefore, the first step to understanding the public health risk of livestock feces is to identify and describe microbial communities and potential virulent genes that contribute to bacterial pathogenicity. We used the whole metagenome shotgun sequencing to evaluate the prevalence of foodborne pathogens and to characterize the virulence associated genes in pig and chicken feces. Our data showed that the relative abundance of potential foodborne pathogens, such as Bacillus cereus was higher in chickens than pigs at the species level while the relative abundance of foodborne pathogens including Campylobacter coli was only detected in pigs. Also, the microbial functional characteristics of livestock feces revealed that the gene families related to "Biofilm formation and quorum sensing" were highly enriched in pigs than chicken. Moreover, the variety of gene families associated with "Resistance to antibiotics and toxic compounds" were detected in both animals. These results will help us to prepare the scientific action plans to improve awareness and understanding of the public health risks of livestock feces.

The Prevalence of Aliarcobacter Species in the Fecal Microbiota of Farm Animals and Potential Effective Agents for Their Treatment: A Review of the Past Decade.

There is an endless demand for livestock-originated food, so it is necessary to elucidate the hazard points for livestock breeding. Pathogens are one of the hazard points that threaten the biosecurity of farm-animal breeding and public health. As a potential foodborne pathogen, Aliarcobacter is a member of the intestinal microbiota of farm animals with and without diarrhea. Aliarcobacter spp. are capable of colonizing livestock intestines and are transmitted through the feces. Hence, they endanger slaughterhouses and milk products with fecal contamination. They also have other, rarer, vertical and horizontal transmission routes, including the offspring that abort in farm animals. Gastrointestinal symptoms and abort cases demonstrate potential financial losses to the industry. Viewed from this perspective, the global circulation of farm-animal products is a significant route for zoonotic agents, including Aliarcobacter. In the last decade, worldwide prevalence of Aliarcobacter in fecal samples has ranged from 0.8% in Italy to 100% in Turkey. Furthermore, antibiotic resistance is recognized as a new type of environmental pollutant and has become a hot topic in animal breeding and the food industry. Increasing antibiotic resistance has become a significant problem impacting productivity. The increase in antimicrobial resistance rates in Aliarcobacter is caused by the misuse of antimicrobial drugs in livestock animals, leading to the acquiring of resistance genes from other bacteria, as well as mutations in current resistance genes. The most resistant strains are A. butzleri, A. cryaerophilus, and A. skirrowii. This review analyzes recent findings from the past decade on the prevalence of Aliarcobacter in the intestinal microbiota and the current effective antibiotics against Aliarcobacter. The paper also highlights that A. cryaerophilus and A. skirrowii are found frequently in diarrheal feces, indicating that Aliarcobacter should be studied further in livestock diarrheal diseases. Moreover, Aliarcobacter-infected farm animals can be treated with only a limited number of antibiotics, such as enrofloxacin, doxycycline, oxytetracycline, and gentamicin.

In Vitro Bioactivities of Food Grade Extracts from Yarrow (Achillea millefolium L.) and Stinging Nettle (Urtica dioica L.) Leaves

Yarrow (Achillea millefolium L., AM) and nettle (Urtica dioica L., UD) are bioactive plants used commercially in functional food and supplement applications and traditionally to alleviate gastric disorders. In this work, the effects of food-grade optimized extracts of Finnish early-season AM and UD were tested on bacterial growth including potential beneficial and foodborne pathogens, as well as murine norovirus (MNV). The anti-inflammatory properties of the extracts were also tested in vitro by NF-κB reporter cells. The food-grade extraction was optimized with the response surface modelling in terms of total carotenoid, chlorophyll, and phenolic compounds contents and antioxidant capacities. The optimal food-grade extraction parameters were a 1-h extraction in 70% ethanol at 45 °C for AM, and at 49 °C for UD. There were no significant effects on the beneficial bacteria (Lacticaseibacillus and Bifidobacterium strains), and the extracts were more effective against gram-positive than gram-negative foodborne bacteria and potential pathogens. Listeria innocua was the most susceptible strain in the optimized extracts with a growth rate of 0.059 ± 0.004 for AM and 0.067 ± 0.006 for UD, p < 0.05 compared to control. The optimized extracts showed a logarithmic growth reduction of 0.67 compared to MNV. The hydroethanolic extracts were cytotoxic to both cell lines, whereas aqueous AM and UD extracts induced and reduced TLR4 signalling in a reporter cell line, respectively. The results provide novel food-grade extraction parameters and support the bioactive effects of AM and UD in functional food applications, but more research is needed to elucidate the precise biological activity in vivo for gastric health.

An Optimization of Oregano, Thyme, and Lemongrass Essential Oil Blend to Simultaneous Inactivation of Relevant Foodborne Pathogens by Simplex-Centroid Mixture Design.

(1) Background: This study aimed to use the simplex-centroid mixture design methodology coupled with a microdilution assay to predict optimal essential oil (EO) formulations against three potential foodborne pathogens simultaneously through the desirability (D) function. (2) Methods: Oregano (ORE; Origanum vulgare), thyme (THY; Thymus vulgaris), and lemongrass (LG; Cymbopogon citratus) and their blends were evaluated concerning minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for Salmonella enterica serotype Enteritidis, Escherichia coli and Staphylococcus aureus. (3) Results: THY combined with ORE or LG were the most promising EO formulations in inhibiting and killing each bacterium separately. Regarding the simultaneous effect, the optimal proportion for maximum inhibition was composed of 75% ORE, 15% THY, and 10% LG, while for maximum inactivation was 50% ORE, 40% THY, and 10% LG. (4) Conclusion: The multiresponse optimization allowed identifying an EO blend to simultaneously control three potential foodborne pathogens. This first report could be a helpful natural and green alternative for the industry to produce safer food products and mitigate public health risks.

Molecular Detection of Listeria Monocytogenes in Milk and Some Milk Products

Listeria monocytogenes is considered one of the major potential foodborne pathogens which often threaten human health and life. Our study assessed both existence and virulence of L. monocytogenes in raw milk and different milk byproducts in Damietta Governorate, Egypt. One hundred and fifty random samples of raw milk, Kariesh cheese, Domiati cheese, Roomi cheese, yogurt and cream (twenty-five samples for each) were gathered from small retails and various supermarkets at for isolation of L. monocytogenes as well as direct detection of the pathogen in the samples’ using PCR technique that targeting 16S rRNA. Also, the study aimed to investigate the presence of virulence genes; (hly A, inl A, inl B, prf A, plc A) in L. monocytogenes isolates. The PCR findings for direct detection of L. monocytogenes declared that 41 out 150 examined samples were positive to 16S rRNA meanwhile by culture methods L. monocytogenes was recovered from 36 out of 150 examined samples. With regard to detection of virulence genes in isolates, 100% of the isolates (36) harbor inl A gene while 35 isolate (97.2%) harbor hly A gene. It was found that 100% of the samples (41) that were positive to 16S rRNA were also found positive to hly A and inl A genes. plcA gene was not detected in all samples whether directly or in isolates. inlB was detected in 8 out of 41 (19.5%) positive samples directly detected while it was detected in 15 out of 36 (41.6%) of isolates. prfA gene was detected in 25 out of 41 (60.9%) positive samples while it was detected in 20 out of 36 (55.5%) of isolates. Our study revealed that the considerable high isolation of L. monocytogenes among examined raw milk and its byproducts constitutes a potential public health hazard. Usually, PCR is seen as important technique for precise diagnosis of microorganisms rather than the classical cultural methods.

Hygienic quality of raw and fermented cow milk in the local milk sector of the Liptako-Gourma area in Niger.

Background and Aim:Milk is a food of high nutritional value, which occupies an undeniable place in the human food ration, but is an ideal medium for microbial growth. This study aims to assess the hygienic quality of local raw and fermented milk from the Liptako-Gourma region in Niger.Materials and Methods:We performed physical and bacteriological analyses on 330 samples of bovine milk from local breeds, including 110 individual milk samples (per cow), 110 fermented milk samples, and 110 blended milk samples. The microbiological parameters were determined using standard methods.Results:The physical analysis revealed temperatures during sample collection for all milk types between 35.2°C and 37.8°C. The average pH of fermented milk varied between 3.16 and 4.92 and those of individual and blended raw milks between 5.42 and 6.98. The titratable acidity varied from 15° to 18.1°D for raw milk and between 59° and 122°D for fermented milk. The average density of individual and blended milks ranged between 1.028 and 1.035. Regionally, milk samples from Tillaberi had a significantly higher aerobic mesophilic germ (GAM) load (7.42 ± 0.53 × 107 Colony-forming unit/mL; p = 0.0025) compared to the Dosso and Niamey regions. The prevalence of Staphylococcus aureus, Escherichia coli, and Salmonella spp. were 86.36%, 12.73%, and 20.91%, respectively, in fermented milk. Phenotypic identification pointed toward three genera: E. coli (30.76% ± 0.25%), S. aureus (20.58% ± 0.14%), and Salmonella spp. (2.74 ± 0.04%).Conclusion:The present data suggest that milk samples collected from three regions in Liptako-Gourma had low quality; further, some of the bacteria identified (E. coli, S. aureus, and Salmonella spp.) could be potential foodborne pathogens.

Antibiofilm efficacy of novel biogenic silver nanoparticles from Terminalia catappa against food-borne Listeria monocytogenes ATCC 15,313 and mechanisms investigation in-vivo and in-vitro

Listeria monocytogenes(LM) is a potential foodborne pathogen, known to form biofilms, which ultimately leads to serious problems in the food industry. This study demonstrates a comprehensive approach for the synthesis of silver nanoparticles using the phytochemicals present in the leaf aqueous extractof Terminalia catappa for the inhibition of L. monocytogens biofilms. The phytochemical analysis by UV–vis spectrum of the extract revealed the presence of polyphenolic compounds such as ellagic acid, gallic acid, chebulinic acid, and chebulgic acid. The shape, structure and size of the synthesized AgNPs were determined as 23–100 nm using the scanning electron microscopic images, and particle size distribution curve analysis. Thein vitrostudies using the AgNPs against L. monocytogenesrevealed the inhibition of biofilm formation, reduction in the Virulence factors such as protease production at sub-inhibitory concentrations of AgNPs. In vivo experiments performed with the Caenorhabditis elegans model showed that AgNPs prolonged the lifespan of infected worms by about 90%. In addition, the non-hazardous nature and in vivo anti-adherence potential of AgNPs were also established with LM - C. elegans infection model.

Efficacy and safety of phage therapy against Salmonella enterica serovars Typhimurium and Enteritidis estimated by using a battery of in vitro tests and the Galleria mellonella animal model

In light of spreading antibiotic resistance among pathogenic bacteria, the development of novel approaches to combat such microorganisms is crucial. Salmonella enterica is pathogenic to humans, however, it can also infect poultry, being a potential foodborne pathogen when poultry-derived food is contaminated by this bacterium. Phage therapy is one of the alternative ways to treat Salmonella-infected animals while the establishment of this method and its introduction to a general practice requires detailed studies on safety and efficacy. Here, we present the results of such studies with two previously isolated and characterized bacteriophages, vB_SenM2 and vB_Sen-TO17, and four strains of S. enterica belonging to two serovars, Typhimurium and Enteritidis. We demonstrated effective reduction of bacterial cell number and cell culture density when using each phage alone, and in combination (as a cocktail). These phages were also effective in reducing bacterial biofilm. The efficacy of this in vitro phage therapy was compared to the action of known antibiotics, as was the efficiency of appearance of bacteria resistant to both these types of antibacterial agents. Safety of the use of bacteriophages was demonstrated using the LAL chromogenic test and the chicken fibroblast viability assay. Finally, the efficacy of phage therapy was assessed with the in vivo model of S. enterica-infected Galleria mellonella larvae, showing a significant improvement in the survival of the animals. In conclusion, we demonstrated high efficacy and acceptable safety profiles of phage therapy against S. enterica strains using vB_SenM-2 and vB_Sen-TO17 phages (both alone and in a cocktail). These results open a possibility for a trial with the use of poultry and these phages which might potentially allow to introduce of this method for practical use in poultry farming.

A Review on the Prevalence of Arcobacter in Aquatic Environments

Arcobacter is an emerging pathogen that is associated with human and animal diseases. Since its first introduction in 1991, 33 Arcobacter species have been identified. Studies have reported that with the presence of Arcobacter in environmental water bodies, animals, and humans, a possibility of its transmission via water and food makes it a potential waterborne and foodborne pathogen. Therefore, this review article focuses on the general characteristics of Arcobacter, including its pathogenicity, antimicrobial resistance, methods of detection by cultivation and molecular techniques, and its presence in water, fecal samples, and animal products worldwide. These detection methods include conventional culture methods, and rapid and accurate Arcobacter identification at the species level, using quantitative polymerase chain reaction (qPCR) and multiplex PCR. Arcobacter has been identified worldwide from feces of various hosts, such as humans, cattle, pigs, sheep, horses, dogs, poultry, and swine, and also from meat, dairy products, carcasses, buccal cavity, and cloacal swabs. Furthermore, Arcobacter has been detected in groundwater, river water, wastewater (influent and effluent), canals, treated drinking water, spring water, and seawater. Hence, we propose that understanding the prevalence of Arcobacter in environmental water and fecal-source samples and its infection of humans and animals will contribute to a better strategy to control and prevent the survival and growth of the bacteria.

Microbiological safety of spinach throughout commercial supply chains in Gauteng Province, South Africa and characterization of isolated multidrug-resistant Escherichia coli.

To investigate the microbiological quality, potential foodborne pathogen presence, and to phenotypically (antimicrobial resistance [AMR] profiles) and genotypically (DNA fingerprints and diarrhoeagenic genes) characterize Escherichia coli isolated throughout spinach production systems from farm-to-sale. Samples (n=288) were collected from two commercial supply chains using either river or borehole irrigation water. E. coli was enumerated throughout the chain where river water was directly used for overhead irrigation at levels between 0.00 and 3.22logcolony forming unit (CFU)g-1 . Following enrichment, isolation and matrix-assisted laser desorption ionization time-of-flight mass spectrometry identification, E. coli was isolated from 22.57% (n=65/288) of all samples. Salmonella spp. were isolated from 3% (n=9/288) of river and irrigation water samples on one farm, and no Listeria monocytogenes was detected throughout the study. Of the 80 characterized E. coli isolates, one harboured the stx2 virulence gene, while 43.75% (n=35) were multidrug resistant. Overall, 26.30% of the multidrug-resistant E. coli isolates were from production scenario one that used river irrigation water, and 17.50% from the second production scenario that used borehole irrigation water. A greater percentage of resistance phenotypes were from water E. coli isolates (52.50%), than isolates from spinach (37.50%). E. coli isolates from spinach and irrigation water clustered together at high similarity values (>90%) using enterobacterial repetitive intergenic consensus-polymerase chan reaction analysis. This study reported the presence of multidrug-resistant environmental E. coli throughout spinach production from farm, during processing and up to retail. Furthermore, the similarity of multi-drug resistant E. coli isolates suggests transfer from irrigation water to spinach in both scenarios, reiterating that irrigation water for vegetables consumed raw, should comply with standardized microbiological safety guidelines. Multidrug-resistant E. coli presence throughout spinach production emphasizes the necessity of increased surveillance of AMR in fresh produce and the production environment within a One Health paradigm to develop AMR mitigation strategies.

A milk-line sampling system to detect foodborne pathogens: A field case investigation from the United States and Argentina.

The objective of this short communication was to discuss two field case investigations to determine the usefulness of a milk‐line sampling device to detect bacteria either coming from a group of cows suffering from mastitis or from the milking line potentially contaminated with environmental bacteria. In Case 1, the in‐line sampling device was able to detect certain segments of the milk‐line contaminated with environmental bacteria, but not coming from the cows. In Case 2, 19 out of 25 pooled in‐line samples were in agreement with at least one of the individual sampled cows shedding either Staphylococcus or Streptococcus spp. or both, which accounted for 76% accordance between both methods. The in‐line system, although not perfect, provided a reliable method to detect individual cows shedding mastitis‐causing organisms. In conclusion, the milk‐line sampling device system was able to help identify foodborne pathogens. Regular monitoring of the microbial quality of milk through a milk‐line sampling device is recommended for groups of cows within the dairy herd to detect potential mastitis‐causing microorganisms. Furthermore, the sampling device was an effective tool to screen the efficacy of cleaning and disinfecting mechanisms of the milk lines to identify and control potential foodborne pathogens that are collected in the bulk tank.

Prevalence of Shigella spp and Methicillin-Resistant Staphylococcus aureus in Select Commercially Processed Meat Products

Aim: The aim of this study was to determine the prevalence of Shigella spp and methicillin resistant Staphylococcus aureus in some selected commercially processed ready-to-eat snail (Archachatina marginata) and edible worm (Rhynchophorus phoenicis).&#x0D; Study Design: Cross-sectional analysis.&#x0D; Place and Duration of Study: Samples were obtained from vendors along the Benin-Sapele express road, South-South Nigeria, over a two months period (November to December, 2019).&#x0D; Methodology: The enumeration of total heterotrophic counts, total Shigella counts and total Staphylococcus aureus counts were done using nutrient agar, Salmonella Shigella agar and mannitol salt agar respectively. All isolates were further identified by their cultural, morphological and biochemical characteristics. Methicillin resistant Staphylococcus aureus were identified using methicillin-oxacillin agar, while the antibiogramic profile of selected isolates and their multidrug resistant profile were done according to the CSLI guideline.&#x0D; Results: The mean heterotrophic bacterial counts (THCs) obtained in Rhynchophorus phoenicis ranged from 0.00 × 10³ ± 0.00 cfu/g to 500.00 × 10³ ± 0.00 cfu/g, while the mean THCs obtained in Archachatina marginata ranged from 13.3 × 10³ ± 1.15 cfu/g to 500 × 10³ ± 0.00 cfu/g. The total Staphylococcus aureus obtained in Rhynchophorus phoenicis was between 0.00 × 10³ ± 0.00 cfu/g to 294 × 10³ ± 4.7 cfu/g and the Shigella bacteria counts from 0.00 × 10³ ± 0.00 cfu/g to 258 × 10³ ± 14.64 cfu/g. The antibiogram of Staphylococcus aureus isolated from both Rhynchophorus phoenicis and Archachatina marginata, found the majority of isolates (96.67%) to be resistant to ceftazidime and cefuroxime, while 83.33% of the isolates were sensitive to ofloxacin. All Staphylococcus isolates were resistant to ceftriaxone, cloxacillin and amoxycillin clavulanate. The multidrug resistant index recorded was between 37.5 and 100. All Staphylococcus (9) isolates tested for methicillin resistance was observed to be positive.&#x0D; Conclusion: This study demonstrated that RTE vended meat products sold in along Benin City By-pass, contains Shigella and methicillin resistant Staphylococcus species, which are potential foodborne pathogens and efforts should be made at eliminating them from these vended meat products.

Bacterial Contamination of Some Domestic and Laboratory Refrigerators in Port Harcourt Metropolis

Background: A refrigerator is a potential source of pathogen contamination leading to food spoilage and food borne diseases. It forms an essential connection in broad chain of cross contamination which might possibly lead to the outbreaks of food borne diseases.&#x0D; Purpose: The aim of the study was to evaluate bacterial Contamination of Some Domestic and Laboratory Refrigerators in Port Harcourt Metropolis.&#x0D; Methodology: This study was done in Port Harcourt metropolis in Rivers state, Nigeria. Sterile swab sticks moistened with peptone water were used to swab the handles, bases, sides and shelves of domestic (90) and laboratory (60) refrigerators. One hundred and fifty (150) samples obtained in total were inoculated and identified using standard conventional methods of bacteria identification.&#x0D; Results: The results showed 100% bacterial contamination. With prevalence rates of Staphylococcus aureus(30.6%), Klebsiella pneumonia (5.3%), Vibro cholera (4.7%), Escherichia coli (4%), Salmonella typhi (3.3%), Pseudomonas aeruginosa (2%), Bacillus cereus (1.3%), Clostridium botulinium (1.3%), Shigellaspecies (1.3%), Listeria monocytogenes (1.3%), Proteus mirabilis (1.3%), Vibroparahaemolyticus (1.3%), Yersinia enterocolitica (1.3%) and Clostridium perfringens(0.7%). Chi square confirms that relationships exist between bacteria isolate with the batch sampled (chi square =139.239; df=54; p=0.00), Gram reaction (chi square =150.000; df=18; p=0.00) and the refrigerator type (chi square =35.325; df=18; p=0.00). However, no statistically significant association exists between isolates and positions on Refrigerator (chi square = 68.080; df=72; p=0.61).&#x0D; Conclusion: The outcome of this study confirms the presence of mesophilics and psychrotrophic bacteria in refrigerators, including potential foodborne pathogens which can cause serious health challenges. Hence, refrigerators are potential pathogen contamination sources. Therefore, proper hand hygiene, awareness and sensitization on maintenance of appropriate, good storage and refrigerator management is recommended for all.

Impact of heat treatment on microbiota of black soldier fly larvae reared on soybean curd residues

Entomophagy has emerged as an alternative and viable source of high-quality animal-derived proteins and fats for livestock production or as a human food supplement. The use of black soldier fly larvae (BSFL) as a dietary protein source for animals needs to be hygienically safe. The authors analysed the microbial community structure of the BSFL raised on different diets and investigated the effect of various heat treatments on the bacterial composition through 16S rRNA gene amplicon pyrosequencing. The results revealed that the diet of BSFL could alter the bacterial community structure. However, there are substantial differences in the abundance or diversity of individual bacterial populations. The bacterial community was dominated by four common phyla, including Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. Most of the samples show the presence of some potential foodborne pathogens such as Bacillus, Aeromonas, Campylobacter, Pseudomonas, Proteus, Klebsiella, Helicobacter, and Enterococcus. Furthermore, looking at the microbial community structure of BSFL, the post-harvest heat treatment showed a significant effect on human pathogens when compared to those in the control group without heat treatment. Enterococcus in BSFL raised on soybean curd residues (SCR) diet disappeared after heat treatments in all groups. Moreover, Staphylococcus in BSFL raised on artificial feed (AF) diet disappeared after heat treatment. The heat-treated samples of BSFL reared on SCR, and AF (Group OD22 samples dried in the oven for 22 minutes and at a temperature of 150 °C) had a better influence on the community structure as compared to all heat treatments. This study provides the baseline data on the microbial composition and potential pathogens of BSFL reared on different dietary sources and showed the effect of different heat treatments on the microbial community.