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Emiliano JVDS, Fusieger A, Camargo AC, Rodrigues FFDC, Nero LA, Perrone ÍT, Carvalho AFD. Staphylococcus aureus in Dairy Industry: Enterotoxin Production, Biofilm Formation, and Use of Lactic Acid Bacteria for Its Biocontrol. Foodborne Pathog Dis 2024. [PMID: 39021233 DOI: 10.1089/fpd.2023.0170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024] Open
Abstract
Staphylococcus aureus is a well-known pathogen capable of producing enterotoxins during bacterial growth in contaminated food, and the ingestion of such preformed toxins is one of the major causes of food poisoning around the world. Nowadays 33 staphylococcal enterotoxins (SEs) and SE-like toxins have been described, but nearly 95% of confirmed foodborne outbreaks are attributed to classical enterotoxins SEA, SEB, SEC, SED, and SEE. The natural habitat of S. aureus includes the skin and mucous membranes of both humans and animals, allowing the contamination of milk, its derivatives, and the processing facilities. S. aureus is well known for the ability to form biofilms in food processing environments, which contributes to its persistence and cross-contamination in food. The biocontrol of S. aureus in foods by lactic acid bacteria (LAB) and their bacteriocins has been studied for many years. Recently, LAB and their metabolites have also been explored for controlling S. aureus biofilms. LAB are used in fermented foods since in ancient times and nowadays characterized strains (or their purified bacteriocin) can be intentionally added to prolong food shelf-life and to control the growth of potentially pathogenic bacteria. Regarding the use of these microorganism and their metabolites (such as organic acids and bacteriocins) to prevent biofilm development or for biofilm removal, it is possible to conclude that a complex network behind the antagonistic activity remains poorly understood at the molecular level. The use of approaches that allow the characterization of these interactions is necessary to enhance our understanding of the mechanisms that govern the inhibitory activity of LAB against S. aureus biofilms in food processing environments.
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Affiliation(s)
- Jean Victor Dos Santos Emiliano
- InovaLeite - Laboratório de Pesquisa em Leites e Derivados, Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Andressa Fusieger
- InovaLeite - Laboratório de Pesquisa em Leites e Derivados, Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Anderson Carlos Camargo
- InovaLeite - Laboratório de Pesquisa em Leites e Derivados, Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Viçosa, Brazil
- InsPOA - Laboratório de Inspeção de Produtos de Origem Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Fabíola Faria da Cruz Rodrigues
- InovaLeite - Laboratório de Pesquisa em Leites e Derivados, Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Luís Augusto Nero
- InsPOA - Laboratório de Inspeção de Produtos de Origem Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Ítalo Tuler Perrone
- Faculdade de Farmácia, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Antônio Fernandes de Carvalho
- InovaLeite - Laboratório de Pesquisa em Leites e Derivados, Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Viçosa, Brazil
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Yolmeh M, Khomeiri M, Ghaemi E, Şilbir MS. Acute toxicity and anti-enterotoxigenic activity of pigment extracted from Micrococcus roseus. Braz J Microbiol 2024; 55:1753-1758. [PMID: 38532186 PMCID: PMC11153400 DOI: 10.1007/s42770-024-01316-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 03/21/2024] [Indexed: 03/28/2024] Open
Abstract
Microbial pigments are considered as one of the main sources of natural types, and the attention to them is increasing in the food and pharmaceutical industries. This study aimed to investigate the effects of pigments extracted from Micrococcus roseus (PEM) on the gene expression of a and b staphylococcal enterotoxins (sea and seb) and their acute toxicity. Real-time PCR was used to study the anti-enterotoxigenic activity of PEM against Staphylococcus aureus at sub-inhibitory concentrations. In addition, the acute toxicity of PEM was evaluated on albino mice through alkaline phosphatase (ALP), aspartate aminotransferas (AST), and alanine aminotransferase (ALT) of liver and its histopathological changes. Based on the results, the expression of sea and seb was decreased in the presence of PEM at sub-inhibitory concentrations. The 2-∆∆CT was measured 0.02 and 0.01 for the expression of sea and seb of S. aureus grown in the MHB containing 16 mg/ml PEM. The results showed that the expression of seb is more sensitive to PEM compared to the expression of sea. After treatment of mice with PEM for two weeks, the condition of mice was normal, and the results of liver enzymatic activities and histopathological changes showed insignificant difference compared to the control sample.
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Affiliation(s)
- Mahmoud Yolmeh
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Rua Monteiro Lobato, 80, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP: 13083-862, Brazil.
| | - Morteza Khomeiri
- Department of Food Science and Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Ezzatollah Ghaemi
- Infectious Research Centre and Microbiology Department, Golestan University of Medical Sciences and Health Services, Gorgan, Iran
| | - Mehmet Selim Şilbir
- Department of Food Engineering, Faculty of Engineering, Iğdır University, Iğdır, Turkey
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Wang H, Kim R, Wang Y, Furtado KL, Sims CE, Tamayo R, Allbritton NL. In vitro co-culture of Clostridium scindens with primary human colonic epithelium protects the epithelium against Staphylococcus aureus. Front Bioeng Biotechnol 2024; 12:1382389. [PMID: 38681959 PMCID: PMC11045926 DOI: 10.3389/fbioe.2024.1382389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/28/2024] [Indexed: 05/01/2024] Open
Abstract
A complex and dynamic network of interactions exists between human gastrointestinal epithelium and intestinal microbiota. Therefore, comprehending intestinal microbe-epithelial cell interactions is critical for the understanding and treatment of intestinal diseases. Primary human colonic epithelial cells derived from a healthy human donor were co-cultured with Clostridium scindens (C. scindens), a probiotic obligate anaerobe; Staphylococcus aureus (S. aureus), a facultative anaerobe and intestinal pathogen; or both bacterial species in tandem. The co-culture hanging basket platform used for these experiments possessed walls of controlled oxygen (O2) permeability to support the formation of an O2 gradient across the intestinal epithelium using cellular O2 consumption, resulting in an anaerobic luminal and aerobic basal compartment. Both the colonic epithelial cells and C. scindens remained viable over 48 h during co-culture. In contrast, co-culture with S. aureus elicited significant damage to colonic epithelial cells within 24 h. To explore the influence of the intestinal pathogen on the epithelium in the presence of the probiotic bacteria, colonic epithelial cells were inoculated sequentially with the two bacterial species. Under these conditions, C. scindens was capable of repressing the production of S. aureus enterotoxin. Surprisingly, although C. scindens converted cholic acid to secondary bile acids in the luminal medium, the growth of S. aureus was not significantly inhibited. Nevertheless, this combination of probiotic and pathogenic bacteria was found to benefit the survival of the colonic epithelial cells compared with co-culture of the epithelial cells with S. aureus alone. This platform thus provides an easy-to-use and low-cost tool to study the interaction between intestinal bacteria and colonic cells in vitro to better understand the interplay of intestinal microbiota with human colonic epithelium.
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Affiliation(s)
- Hao Wang
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Raehyun Kim
- Department of Bioengineering, University of Washington, Seattle, WA, United States
- Department of Biological and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| | - Yuli Wang
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Kathleen L. Furtado
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, United States
| | - Christopher E. Sims
- Department of Bioengineering, University of Washington, Seattle, WA, United States
- Department of Medicine/Division of Rheumatology, University of Washington, Seattle, WA, United States
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, United States
| | - Nancy L. Allbritton
- Department of Bioengineering, University of Washington, Seattle, WA, United States
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Gao M, Abdallah MF, Song M, Xu Y, Sun D, Lu P, Wang J. Novel Endophytic Pseudescherichia sp. GSE25 Strain Significantly Controls Fusarium graminearum and Reduces Deoxynivalenol in Wheat. Toxins (Basel) 2023; 15:702. [PMID: 38133206 PMCID: PMC10747052 DOI: 10.3390/toxins15120702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/09/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023] Open
Abstract
Fusarium heading blight (FHB) is a devastating disease in wheat, primarily caused by field invasion of Fusarium graminearum. Due to the scarcity of resistant wheat varieties, the agricultural sector resorts to chemical fungicides to control FHB incidence. On the other hand, biocontrol represents a promising, eco-friendly approach aligned with sustainable and green agriculture concepts. In the present study, a bacterial endophyte, Pseudescherichia sp. (GSE25), was isolated from wheat seeds and identified through complete genome sequencing and phylogenetic analysis. In vitro testing of this endophytic strain demonstrated strong antifungal activity against F. graminearum PH-1 by inhibiting spore germination, suppressing germ tube growth, and causing cell membrane damage. Under field conditions, the strain GSE25 significantly reduced the FHB incidence and the associated deoxynivalenol mycotoxin accumulation by over 60% and 80%, respectively. These findings highlight the potential of the isolated bacterial endophyte Pseudescherichia sp. GSE25 strain as a biocontrol agent in protecting wheat from FHB-caused F. graminearum. This is the first report showing a biocontrol effect of Pseudescherichia sp. a strain against phytopathogens.
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Affiliation(s)
- Meiling Gao
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China;
- State Key Laboratory of Crop Stress Resistance and High-Efficiency Production, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (M.S.)
| | - Mohamed F. Abdallah
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium;
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Assiut University, Assiut 71515, Egypt
| | - Minggui Song
- State Key Laboratory of Crop Stress Resistance and High-Efficiency Production, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (M.S.)
| | - Yiqian Xu
- State Key Laboratory of Crop Stress Resistance and High-Efficiency Production, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (M.S.)
| | - Daiyuan Sun
- State Key Laboratory of Crop Stress Resistance and High-Efficiency Production, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (M.S.)
| | - Ping Lu
- The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, China
| | - Jianhua Wang
- Institute for Agri-Food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
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Cai H, Pei S, Zhang Y, Liu R, Lu S, Li B, Dong J, Wang Q, Zhu X, Ji H. Construction of a dynamic model to predict the growth of Staphylococcus aureus and the formation of enterotoxins during Kazak cheese maturation. Food Microbiol 2023; 112:104234. [PMID: 36906305 DOI: 10.1016/j.fm.2023.104234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/03/2023] [Accepted: 02/03/2023] [Indexed: 02/07/2023]
Abstract
Staphylococcus aureus is a common pathogen found in cheese whose Staphylococcal enterotoxins (SE) are the main pathogenic factors that cause food poisoning. The objective of this study was to construct two models to evaluate the safety of Kazak cheese products in terms of composition, changes in S. aureus inoculation amount, Aw, fermentation temperature during processing, and growth of S. aureus in the fermentation stage. A total of 66 experiments comprised of five levels of inoculation amount (2.7-4 log CFU/g), five levels of Aw (0.878-0.961), and six levels of fermentation temperature (32-44 °C) were performed to confirm the growth of S. aureus and the presence of SE limit conditions. Two artificial neural networks (ANN) successfully described the relationship between the assayed conditions and the growth kinetic parameters (maximum growth rates and lag times) of the strain. The good fitting accuracy (R2 values were 0.918 and 0.976, respectively) showed that the ANN was appropriate. Experimental results showed fermentation temperature had the greatest influence on the maximum growth rate and lag time, followed by the Aw and inoculation amount. Furthermore, a probability model was built to predict the production of SE by logistic regression and neural network under the assayed conditions, which proved to be concordant in 80.8-83.8% of the cases with the observed probabilities. The maximum total number of colonies predicted by the growth model in all combinations detected with SE exceeded 5 log CFU/g. Within the range of variables, the minimum Aw for predicting SE production was 0.938, and the minimum inoculation amount for predicting SE production was 3.22 log CFU/g. Additionally, as competition between S. aureus and lactic acid bacteria (LAB) occurs in the fermentation stage, higher fermentation temperatures are conducive to the growth of LAB, which can reduce the risk of S. aureus producing SE. This study can help manufacturers to make decisions on the most appropriate production parameters for Kazak cheese products and to prevent S. aureus growth and SE production.
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Affiliation(s)
- Huixue Cai
- School of Food Science and Technology, Shihezi University, 832003, China
| | - Sijie Pei
- College of Food Science and Technology, Northwest University, Xi'an, 710069, China
| | - Yan Zhang
- School of Food Science and Technology, Shihezi University, 832003, China; Zhoukou Vocational College of Arts and Science, Zhoukou, Henan, 466000, China
| | - Rongrong Liu
- School of Food Science and Technology, Shihezi University, 832003, China
| | - Shiling Lu
- School of Food Science and Technology, Shihezi University, 832003, China
| | - Baokun Li
- School of Food Science and Technology, Shihezi University, 832003, China
| | - Juan Dong
- School of Food Science and Technology, Shihezi University, 832003, China
| | - Qingling Wang
- School of Food Science and Technology, Shihezi University, 832003, China
| | - Xinrong Zhu
- School of Food Science and Technology, Shihezi University, 832003, China
| | - Hua Ji
- School of Food Science and Technology, Shihezi University, 832003, China.
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Moula Ali AM, Sant'Ana AS, Bavisetty SCB. Sustainable preservation of cheese: Advanced technologies, physicochemical properties and sensory attributes. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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7
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Borges F, Briandet R, Callon C, Champomier-Vergès MC, Christieans S, Chuzeville S, Denis C, Desmasures N, Desmonts MH, Feurer C, Leroi F, Leroy S, Mounier J, Passerini D, Pilet MF, Schlusselhuber M, Stahl V, Strub C, Talon R, Zagorec M. Contribution of omics to biopreservation: Toward food microbiome engineering. Front Microbiol 2022; 13:951182. [PMID: 35983334 PMCID: PMC9379315 DOI: 10.3389/fmicb.2022.951182] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/14/2022] [Indexed: 01/12/2023] Open
Abstract
Biopreservation is a sustainable approach to improve food safety and maintain or extend food shelf life by using beneficial microorganisms or their metabolites. Over the past 20 years, omics techniques have revolutionised food microbiology including biopreservation. A range of methods including genomics, transcriptomics, proteomics, metabolomics and meta-omics derivatives have highlighted the potential of biopreservation to improve the microbial safety of various foods. This review shows how these approaches have contributed to the selection of biopreservation agents, to a better understanding of the mechanisms of action and of their efficiency and impact within the food ecosystem. It also presents the potential of combining omics with complementary approaches to take into account better the complexity of food microbiomes at multiple scales, from the cell to the community levels, and their spatial, physicochemical and microbiological heterogeneity. The latest advances in biopreservation through omics have emphasised the importance of considering food as a complex and dynamic microbiome that requires integrated engineering strategies to increase the rate of innovation production in order to meet the safety, environmental and economic challenges of the agri-food sector.
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Affiliation(s)
- Frédéric Borges
- Université de Lorraine, LIBio, Nancy, France
- *Correspondence: Frédéric Borges,
| | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Cécile Callon
- Université Clermont Auvergne, INRAE, VetAgro Sup, UMR 545 Fromage, Aurillac, France
| | | | | | - Sarah Chuzeville
- ACTALIA, Pôle d’Expertise Analytique, Unité Microbiologie Laitière, La Roche sur Foron, France
| | | | | | | | - Carole Feurer
- IFIP, Institut de la Filière Porcine, Le Rheu, France
| | | | - Sabine Leroy
- Université Clermont Auvergne, INRAE, MEDIS, Clermont-Ferrand, France
| | - Jérôme Mounier
- Univ Brest, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Plouzané, France
| | | | | | | | | | - Caroline Strub
- Qualisud, Univ Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de La Réunion, Montpellier, France
| | - Régine Talon
- Université Clermont Auvergne, INRAE, MEDIS, Clermont-Ferrand, France
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Carneiro Aguiar RA, Ferreira FA, Dias RS, Nero LA, Miotto M, Verruck S, De Marco I, De Dea Lindner J. Graduate Student Literature Review: Enterotoxigenic potential and antimicrobial resistance of staphylococci from Brazilian artisanal raw milk cheeses. J Dairy Sci 2022; 105:5685-5699. [DOI: 10.3168/jds.2021-21634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 03/22/2022] [Indexed: 11/19/2022]
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9
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Green strategies to control redox potential in the fermented food industry. Food Res Int 2022; 156:111154. [DOI: 10.1016/j.foodres.2022.111154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 03/12/2022] [Accepted: 03/15/2022] [Indexed: 11/18/2022]
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Possas A, Bonilla-Luque OM, Valero A. From Cheese-Making to Consumption: Exploring the Microbial Safety of Cheeses through Predictive Microbiology Models. Foods 2021; 10:foods10020355. [PMID: 33562291 PMCID: PMC7915996 DOI: 10.3390/foods10020355] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/01/2021] [Accepted: 02/03/2021] [Indexed: 12/12/2022] Open
Abstract
Cheeses are traditional products widely consumed throughout the world that have been frequently implicated in foodborne outbreaks. Predictive microbiology models are relevant tools to estimate microbial behavior in these products. The objective of this study was to conduct a review on the available modeling approaches developed in cheeses, and to identify the main microbial targets of concern and the factors affecting microbial behavior in these products. Listeria monocytogenes has been identified as the main hazard evaluated in modelling studies. The pH, aw, lactic acid concentration and temperature have been the main factors contemplated as independent variables in models. Other aspects such as the use of raw or pasteurized milk, starter cultures, and factors inherent to the contaminating pathogen have also been evaluated. In general, depending on the production process, storage conditions, and physicochemical characteristics, microorganisms can grow or die-off in cheeses. The classical two-step modeling has been the most common approach performed to develop predictive models. Other modeling approaches, including microbial interaction, growth boundary, response surface methodology, and neural networks, have also been performed. Validated models have been integrated into user-friendly software tools to be used to obtain estimates of microbial behavior in a quick and easy manner. Future studies should investigate the fate of other target bacterial pathogens, such as spore-forming bacteria, and the dynamic character of the production process of cheeses, among other aspects. The information compiled in this study helps to deepen the knowledge on the predictive microbiology field in the context of cheese production and storage.
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Abstract
This study was conducted to assess, for the first time, the survival of the pathogenic bacteria Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus during the ripening of protected designation of origin (PDO) Pecorino Romano cheese. A total of twenty-four cheese-making trials (twelve from raw milk and twelve from thermized milk) were performed under the protocol specified by PDO requirements. Sheep cheese milk was first inoculated before processing with approximately 106 colony-forming unit (CFU) mL−1 of each considered pathogen and the experiment was repeated six times for each selected pathogen. Cheese composition and pathogens count were then evaluated in inoculated raw milk, thermized milk, and cheese after 1, 90, and 150 days of ripening. pH, moisture, water activity, and salt content of cheese were within the range of the commercial PDO Pecorino Romano cheese. All the cheeses made from raw and thermized milk were microbiologically safe after 90 days and 1 day from their production, respectively. In conclusion, when Pecorino Romano cheese is produced under PDO specifications, from raw or thermized milk, a combination of factors including the speed and extent of curd acidification in the first phase of the production, together with an intense salting and a long ripening time, preclude the possibility of growth and survival of L. monocytogenes, Salmonella spp., and E. coli O157:H7. Only S. aureus can be still detectable at such low levels that it does not pose a risk to consumers.
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Prevalence of an Intestinal ST40 Enterococcus faecalis over Other E. faecalis Strains in the Gut Environment of Mice Fed Different High Fat Diets. Int J Mol Sci 2020; 21:ijms21124330. [PMID: 32570702 PMCID: PMC7352901 DOI: 10.3390/ijms21124330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
E. faecalis is a commensal bacterium with specific strains involved in opportunistic and nosocomial infections. Therefore, it is important to know how the strains of this species are selected in the gut. In this study, fifteen E. faecalis strains, isolated over twelve weeks from the faeces of mice fed standard chow or one of three high fat diets enriched with extra virgin olive oil, refined olive oil or butter were subjected to a genetic “Multilocus Sequence Typing” study that revealed the presence of mainly two genotypes, ST9 and ST40, the latter one prevailing at the end of the research. A V3–V5 sequence comparison of the predominant ST40 strain (12B3-5) in a metagenomic study showed that this sequence was the only E. faecalis present in the mouse cohort after twelve weeks. The strain was subjected to a comparative proteomic study with a ST9 strain by 2D electrophoresis and mass spectrometry. After comparing the results with a E. faecalis database, unshared entries were compared and 12B3-5 showed higher antimicrobial production as well as greater protection from environmental factors such as xenobiotics, oxidative stress and metabolite accumulation, which could be the reason for its ability to outcompete other possible rivals in an intestinal niche.
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Al-Nabulsi AA, Osaili TM, AbuNaser RA, Olaimat AN, Ayyash M, Al-Holy MA, Kadora KM, Holley RA. Factors affecting the viability of Staphylococcus aureus and production of enterotoxin during processing and storage of white-brined cheese. J Dairy Sci 2020; 103:6869-6881. [PMID: 32505390 DOI: 10.3168/jds.2020-18158] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 04/01/2020] [Indexed: 12/24/2022]
Abstract
Staphylococcus aureus is a major foodborne pathogen that causes severe disease in humans. It is commonly found in milk and dairy products, particularly in fresh brined cheese. Our aim was to investigate the behavior of Staph. aureus and enterotoxin production during the storage of white-brined cheese prepared with or without a starter culture and stored in a 10 or 15% NaCl brine at 10°C and 25°C for 28 d. NaCl concentration, water activity, pH, and number of Staph. aureus and lactic acid bacteria were determined in cheese and brine. Only 1 of 4 Staph. aureus strains (ATCC 439) was positive for enterotoxin production, and its production was detected in unsalted UHT milk, but not in salted milk or in any of the cheese treatments held at 37°C for 1, 3, or 7 d. Staphylococcus aureus grew in the cheese stored in both brines at 10°C and 25°C, regardless of the presence of a starter culture, although the latter significantly reduced Staph. aureus growth in cheese or its brine at 10°C. Staphylococcus aureus numbers were increased by 2.26 and 0.47 log10 cfu/g in cheese stored in 10 and 15% NaCl brine, respectively, in the presence of starter culture, and by 2.78 and 2.96 log10 cfu/g, respectively, in the absence of starter culture at 10°C. Nonetheless, the pathogen grew, but at a lower number in the brines. The salt concentration of cheese stored in 10% brine remained at approximately 5% during storage; however, in 15% brine, the salt concentration increased to almost 8% (wt/wt) by 28 d. The addition of a starter culture, high salt concentration, low temperature, and pH (∼5.2) had inhibitory effects on the growth of Staph. aureus. Moreover, lactic acid bacterial numbers increased considerably in cheese and brine by d 28. The use of starter cultures, salt (15%), and low storage temperature (10°C) reduced the growth of Staph. aureus, and salt may have prevented enterotoxin production in white-brined cheese.
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Affiliation(s)
- Anas A Al-Nabulsi
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, Irbid 22110, Jordan.
| | - Tareq M Osaili
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, Irbid 22110, Jordan; Department of Clinical Nutrition and Dietetics, University of Sharjah, Sharjah, PO Box 27272, United Arab Emirates
| | - Roa A AbuNaser
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Amin N Olaimat
- Department of Clinical Nutrition and Dietetics, Faculty of Allied Health Sciences, Hashemite University, Zarqa 13115, Jordan
| | - Mutamed Ayyash
- Department of Food, Nutrition, and Health, College of Food and Agriculture, United Arab Emirates University, Al-Ain 15551, United Arab Emirates.
| | - Murad A Al-Holy
- Department of Clinical Nutrition and Dietetics, Faculty of Allied Health Sciences, Hashemite University, Zarqa 13115, Jordan
| | - Khaled M Kadora
- Department of Food Laboratories, Jordan Food and Drug Administration, Amman 11181, Jordan
| | - Richard A Holley
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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