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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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Piqueras J, Chassard C, Callon C, Rifa E, Theil S, Lebecque A, Delbès C. Lactic Starter Dose Shapes S. aureus and STEC O26:H11 Growth, and Bacterial Community Patterns in Raw Milk Uncooked Pressed Cheeses. Microorganisms 2021; 9:microorganisms9051081. [PMID: 34069983 PMCID: PMC8157849 DOI: 10.3390/microorganisms9051081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 01/04/2023] Open
Abstract
Adding massive amounts of lactic starters to raw milk to manage the sanitary risk in the cheese-making process could be detrimental to microbial diversity. Adjusting the amount of the lactic starter used could be a key to manage these adverse impacts. In uncooked pressed cheeses, we investigated the impacts of varying the doses of a lactic starter (the recommended one, 1×, a 0.1× lower and a 2× higher) on acidification, growth of Staphylococcus aureus SA15 and Shiga-toxin-producing Escherichia coli (STEC) O26:H11 F43368, as well as on the bacterial community patterns. We observed a delayed acidification and an increase in the levels of pathogens with the 0.1× dose. This dose was associated with increased richness and evenness of cheese bacterial community and higher relative abundance of potential opportunistic bacteria or desirable species involved in cheese production. No effect of the increased lactic starter dose was observed. Given that sanitary criteria were paramount to our study, the increase in the pathogen levels observed at the 0.1× dose justified proscribing such a reduction in the tested cheese-making process. Despite this, the effects of adjusting the lactic starter dose on the balance of microbial populations of potential interest for cheese production deserve an in-depth evaluation.
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Affiliation(s)
- Justine Piqueras
- UMR 0545 Fromage, Université Clermont Auvergne, INRAE, VetAgro Sup, 20 Côte de Reyne, F-15000 Aurillac, France; (J.P.); (C.C.); (C.C.); (S.T.); (A.L.)
| | - Christophe Chassard
- UMR 0545 Fromage, Université Clermont Auvergne, INRAE, VetAgro Sup, 20 Côte de Reyne, F-15000 Aurillac, France; (J.P.); (C.C.); (C.C.); (S.T.); (A.L.)
| | - Cécile Callon
- UMR 0545 Fromage, Université Clermont Auvergne, INRAE, VetAgro Sup, 20 Côte de Reyne, F-15000 Aurillac, France; (J.P.); (C.C.); (C.C.); (S.T.); (A.L.)
| | - Etienne Rifa
- UMR INSA/INRA 792, Toulouse Biotechnology Institute, INSA/CNRS 5504, 135 Avenue de Rangueil, F-31077 Toulouse, France;
| | - Sébastien Theil
- UMR 0545 Fromage, Université Clermont Auvergne, INRAE, VetAgro Sup, 20 Côte de Reyne, F-15000 Aurillac, France; (J.P.); (C.C.); (C.C.); (S.T.); (A.L.)
| | - Annick Lebecque
- UMR 0545 Fromage, Université Clermont Auvergne, INRAE, VetAgro Sup, 20 Côte de Reyne, F-15000 Aurillac, France; (J.P.); (C.C.); (C.C.); (S.T.); (A.L.)
| | - Céline Delbès
- UMR 0545 Fromage, Université Clermont Auvergne, INRAE, VetAgro Sup, 20 Côte de Reyne, F-15000 Aurillac, France; (J.P.); (C.C.); (C.C.); (S.T.); (A.L.)
- Correspondence: ; Tel.: +33-471-456-419
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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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Delpech P, Rifa E, Ball G, Nidelet S, Dubois E, Gagne G, Montel MC, Delbès C, Bornes S. New Insights into the Anti-pathogenic Potential of Lactococcus garvieae against Staphylococcus aureus Based on RNA Sequencing Profiling. Front Microbiol 2017; 8:359. [PMID: 28337182 PMCID: PMC5340753 DOI: 10.3389/fmicb.2017.00359] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/21/2017] [Indexed: 11/13/2022] Open
Abstract
The bio-preservation potential of Lactococcus garvieae lies in its capacity to inhibit the growth of staphylococci, especially Staphylococcus aureus, in dairy products and in vitro. In vitro, inhibition is modulated by the level of aeration, owing to hydrogen peroxide (H2O2) production by L. garvieae under aeration. The S. aureus response to this inhibition has already been studied. However, the molecular mechanisms of L. garvieae underlying the antagonism against S. aureus have never been explored. This study provides evidence of the presence of another extracellular inhibition effector in vitro. This effector was neither a protein, nor a lipid, nor a polysaccharide, nor related to an L-threonine deficiency. To better understand the H2O2-related inhibition mechanism at the transcriptome level and to identify other mechanisms potentially involved, we used RNA sequencing to determine the transcriptome response of L. garvieae to different aeration levels and to the presence or absence of S. aureus. The L. garvieae transcriptome differed radically between different aeration levels mainly in biological processes related to fundamental functions and nutritional adaptation. The transcriptomic response of L. garvieae to aeration level differed according to the presence or absence of S. aureus. The higher concentration of H2O2 with high aeration was not associated with a higher expression of L. garvieae H2O2-synthesis genes (pox, sodA, and spxA1) but rather with a repression of L. garvieae H2O2-degradation genes (trxB1, ahpC, ahpF, and gpx). We showed that L. garvieae displayed an original, previously undiscovered, H2O2 production regulation mechanism among bacteria. In addition to the key factor H2O2, the involvement of another extracellular effector in the antagonism against S. aureus was shown. Future studies should explore the relation between H2O2-metabolism, H2O2-producing LAB and the pathogen they inhibit. The nature of the other extracellular effector should also be determined.
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Affiliation(s)
- Pierre Delpech
- Université Clermont Auvergne, INRA, UMRF Aurillac, France
| | - Etienne Rifa
- Université Clermont Auvergne, INRA, UMRF Aurillac, France
| | - Graham Ball
- John van Geest Cancer Research Centre, School of Science and Technology, Nottingham Trent University Nottingham, UK
| | - Sabine Nidelet
- Montpellier GenomiX, Institut de Génomique Fonctionnelle Montpellier, France
| | - Emeric Dubois
- Montpellier GenomiX, Institut de Génomique Fonctionnelle Montpellier, France
| | | | | | - Céline Delbès
- Université Clermont Auvergne, INRA, UMRF Aurillac, France
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5
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Escherichia coli O26:H11 growth in co-culture with an antagonistic strain of Hafnia alvei according to pH and temperature. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.10.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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6
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Duquenne M, Derzelle S, Fleurot I, Aigle M, Darrigo C, Hennekinne JA, Mutel I, Bouix M, Deperrois-Lafarge V, Delacroix-Buchet A. Milk maturation temperature and time are key technological parameters to limit staphylococcal enterotoxin production during uncooked semi-hard cheese manufacture. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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7
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Staphylococcus aureus transcriptomic response to inhibition by H2O2-producing Lactococcus garvieae. Food Microbiol 2015; 51:163-70. [PMID: 26187841 DOI: 10.1016/j.fm.2015.05.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 05/26/2015] [Accepted: 05/28/2015] [Indexed: 12/19/2022]
Abstract
Growth of the foodborne pathogen Staphylococcus aureus can be inhibited in milk and in cheese by the hydrogen peroxide-producing Lactococcus garvieae N201 dairy strain. Transcriptomic responses of two S. aureus strains, the S. aureus SA15 dairy strain and the MW2 human pathogenic strain, to this growth inhibition were investigated in Brain-Heart Infusion broth under a high or a low aeration level. We demonstrated that S. aureus MW2 had a higher resistance to L. garvieae inhibition under the high aeration level: this correlated to a higher survival under hydrogen peroxide exposure. Conversely, the two strains were similarly inhibited under the low aeration level. Expression of S. aureus genes involved in response to H2O2 or other stresses as well as in cell division was generally repressed by L. garvieae. However, differential expressions between the two S. aureus strains were observed, especially under the high aeration level. Additionally, expression of virulence-related genes (enterotoxins, regulatory genes) was modulated by L. garvieae depending on the aeration level and on the S. aureus strain. This study led to new insights into potential molecular mechanisms of S. aureus inhibition by Lactic Acid Bacteria via H2O2 production.
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Saraoui T, Fall PA, Leroi F, Antignac JP, Chéreau S, Pilet MF. Inhibition mechanism of Listeria monocytogenes by a bioprotective bacteria Lactococcus piscium CNCM I-4031. Food Microbiol 2015; 53:70-8. [PMID: 26611171 DOI: 10.1016/j.fm.2015.01.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/31/2014] [Accepted: 01/09/2015] [Indexed: 11/27/2022]
Abstract
Listeria monocytogenes is a pathogenic Gram positive bacterium and the etiologic agent of listeriosis, a severe food-borne disease. Lactococcus piscium CNCM I-4031 has the capacity to prevent the growth of L. monocytogenes in contaminated peeled and cooked shrimp. To investigate the inhibititory mechanism, a chemically defined medium (MSMA) based on shrimp composition and reproducing the inhibition observed in shrimp was developed. In co-culture at 26 °C, L. monocytogenes was reduced by 3-4 log CFU g(-1) after 24 h. We have demonstrated that the inhibition was not due to secretion of extracellular antimicrobial compounds as bacteriocins, organic acids and hydrogen peroxide. Global metabolomic fingerprints of these strains in pure culture were assessed by liquid chromatography coupled with high resolution mass spectrometry. Consumption of glucose, amino-acids, vitamins, nitrogen bases, iron and magnesium was measured and competition for some molecules could be hypothesized. However, after 24 h of co-culture, when inhibition of L. monocytogenes occurred, supplementation of the medium with these compounds did not restore its growth. The inhibition was observed in co-culture but not in diffusion chamber when species were separated by a filter membrane. Taken together, these data indicate that the inhibition mechanism of L. monocytogenes by L. piscium is cell-to-cell contact-dependent.
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Affiliation(s)
- Taous Saraoui
- Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EM(3)B), Ifremer, Rue de l'Ile d'Yeu, 44311 Nantes Cedex 03, France; LUNAM Université, Oniris, UMR 1014 Secalim, Site de la Chantrerie, Nantes, F-44307, France; INRA, Nantes, F-44307, France
| | - Papa Abdoulaye Fall
- Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EM(3)B), Ifremer, Rue de l'Ile d'Yeu, 44311 Nantes Cedex 03, France; LUNAM Université, Oniris, UMR 1014 Secalim, Site de la Chantrerie, Nantes, F-44307, France; INRA, Nantes, F-44307, France
| | - Françoise Leroi
- Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EM(3)B), Ifremer, Rue de l'Ile d'Yeu, 44311 Nantes Cedex 03, France
| | - Jean-Philippe Antignac
- LUNAM Université, Oniris, USC INRA 1329, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France
| | - Sylvain Chéreau
- LUNAM Université, Oniris, USC INRA 1329, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France
| | - Marie France Pilet
- LUNAM Université, Oniris, UMR 1014 Secalim, Site de la Chantrerie, Nantes, F-44307, France; INRA, Nantes, F-44307, France.
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Mohammadi K, Hanifian S. Growth and enterotoxin production of
Staphylococcus aureus
in Iranian ultra‐filtered white cheese. INT J DAIRY TECHNOL 2014. [DOI: 10.1111/1471-0307.12158] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Khosrow Mohammadi
- Department of Food Hygiene and Aquatics College of Veterinary MedicineTabriz BranchIslamic Azad UniversityTabriz Iran
- Biotechnology Research Center College of Agriculture Tabriz Branch Islamic Azad University Tabriz Iran
| | - Shahram Hanifian
- Biotechnology Research Center College of Agriculture Tabriz Branch Islamic Azad University Tabriz Iran
- Department of Food Science and Technology College of Agriculture Tabriz Branch Islamic Azad University Tabriz Iran
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Kadiroğlu P, Korel F, Ceylan C. Quantification of Staphylococcus aureus in white cheese by the improved DNA extraction strategy combined with TaqMan and LNA probe-based qPCR. J Microbiol Methods 2014; 105:92-7. [PMID: 25016130 DOI: 10.1016/j.mimet.2014.06.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/30/2014] [Accepted: 06/30/2014] [Indexed: 10/25/2022]
Abstract
Four different bacterial DNA extraction strategies and two different qPCR probe chemistries were studied for detection of Stapylococcus aureus from white cheeses. Method employing trypsin treatment followed by a commercial kit application and TaqMan probe-based qPCR was the most sensitive one detecting higher counts than standards in naturally contaminated samples.
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Affiliation(s)
- Pınar Kadiroğlu
- Department of Food Engineering, İzmir Institute of Technology, Urla, İzmir, Turkey.
| | - Figen Korel
- Department of Food Engineering, İzmir Institute of Technology, Urla, İzmir, Turkey.
| | - Cagatay Ceylan
- Department of Food Engineering, İzmir Institute of Technology, Urla, İzmir, Turkey.
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11
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The effect of undissociated lactic acid on Staphylococcus aureus growth and enterotoxin A production. Int J Food Microbiol 2013; 162:159-66. [DOI: 10.1016/j.ijfoodmicro.2013.01.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 12/20/2012] [Accepted: 01/07/2013] [Indexed: 11/23/2022]
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12
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Phage inactivation of Staphylococcus aureus in fresh and hard-type cheeses. Int J Food Microbiol 2012; 158:23-7. [PMID: 22795798 DOI: 10.1016/j.ijfoodmicro.2012.06.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 06/15/2012] [Accepted: 06/21/2012] [Indexed: 11/23/2022]
Abstract
Bacteriophages are regarded as natural antibacterial agents in food since they are able to specifically infect and lyse food-borne pathogenic bacteria without disturbing the indigenous microbiota. Two Staphylococcus aureus obligately lytic bacteriophages (vB_SauS-phi-IPLA35 and vB_SauS-phi-SauS-IPLA88), previously isolated from the dairy environment, were evaluated for their potential as biocontrol agents against this pathogenic microorganism in both fresh and hard-type cheeses. Pasteurized milk was contaminated with S. aureus Sa9 (about 10(6) CFU/mL) and a cocktail of the two lytic phages (about 10(6) PFU/mL) was also added. For control purposes, cheeses were manufactured without addition of phages. In both types of cheeses, the presence of phages resulted in a notorious decrease of S. aureus viable counts during curdling. In test fresh cheeses, a reduction of 3.83 log CFU/g of S. aureus occurred in 3h compared with control cheese, and viable counts were under the detection limits after 6h. The staphylococcal strain was undetected in both test and control cheeses at the end of the curdling process (24 h) and, of note, no re-growth occurred during cold storage. In hard cheeses, the presence of phages resulted in a continuous reduction of staphylococcal counts. In curd, viable counts of S. aureus were reduced by 4.64 log CFU/g compared with the control cheeses. At the end of ripening, 1.24 log CFU/g of the staphylococcal strain was still detected in test cheeses whereas 6.73log CFU/g was present in control cheeses. Starter strains were not affected by the presence of phages in the cheese making processes and cheeses maintained their expected physico-chemical properties.
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14
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Didienne R, Defargues C, Callon C, Meylheuc T, Hulin S, Montel MC. Characteristics of microbial biofilm on wooden vats ('gerles') in PDO Salers cheese. Int J Food Microbiol 2012; 156:91-101. [PMID: 22483401 DOI: 10.1016/j.ijfoodmicro.2012.03.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 03/06/2012] [Accepted: 03/07/2012] [Indexed: 11/20/2022]
Abstract
The purpose of this study was to characterize microbial biofilms from 'gerles' (wooden vats for making PDO Salers cheese) and identify their role in milk inoculation and in preventing pathogen development. Gerles from ten farms producing PDO Salers cheese were subjected to microbial analysis during at least 4 periods spread over two years. They were distinguished by their levels of Lactobacillus (between 4.50 and 6.01 log CFU/cm(2)), Gram negative bacteria (between 1.45 and 4.56 log CFU/cm(2)), yeasts (between 2.91 and 5.57 log CFU/cm(2)), and moulds (between 1.72 and 4.52 log CFU/cm(2)). They were then classed into 4 groups according their microbial characteristics. These 4 groups were characterized by different milk inoculations (with either sour whey or starter culture, daily or not), and different washing procedures (with water or whey from cheese making). The farm gerles were not contaminated by Salmonella, Listeria monocytogenes or Staphylococcus aureus. Only one slight, punctual contamination was found on one gerle among the ten studied. Even when the milk was deliberately contaminated with L. monocytogenes and S. aureus in the 40 L experimental gerles, these pathogens were found neither on the gerle surfaces nor in the cheeses. Using 40 L experimental gerles it was shown that the microbial biofilms on the gerle surfaces formed in less than one week and then remained stable. They were mainly composed of a great diversity of lactic acid bacteria (Leuconostoc pseudomesenteroides, Lactococcus lactis, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus hilgardii,…), Gram positive catalase positive bacteria (Curtobacterium flaccumfaciens, Curtobacterium oceanosedimentum Citrococcus spp., Brachybacterium rhamnosum, Kocuria rhizophila, Arthrobacter spp.…) and yeast (Kluyveromyces lactis, Kluyveromyces marxianus). In less than 1 min, even in a 500 L farm gerle, the gerle's microbial biofilm can inoculate pasteurized milk with micro-organisms at levels superior to those in raw milk.
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Affiliation(s)
- Robert Didienne
- INRA, UR 545, Fromagères, 20 côte de Reyne, F-15000 Aurillac, France
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15
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Tammar wallaby mammary cathelicidins are differentially expressed during lactation and exhibit antimicrobial and cell proliferative activity. Comp Biochem Physiol A Mol Integr Physiol 2011; 160:431-9. [PMID: 21824524 DOI: 10.1016/j.cbpa.2011.07.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 07/21/2011] [Accepted: 07/21/2011] [Indexed: 12/25/2022]
Abstract
Cathelicidins secreted in milk may be central to autocrine feedback in the mammary gland for optimal development in addition to conferring innate immunity to both the mammary gland and the neonate. This study exploits the unique reproductive strategy of the tammar wallaby (Macropus eugenii) model to analyse differential splicing of cathelicidin genes and to evaluate the bactericidal activity and effect of the protein on mammary epithelial cell proliferation. Two linear peptides, Con73 and Con218, derived from the heterogeneous carboxyl end of cathelicidin transcripts, MaeuCath1 and MaeuCath7 respectively, were evaluated for antimicrobial activity. Both Con73 and Con218 significantly inhibited the growth of Staphylococcus aureus, Pseudomonas aureginosa, Enterococcus faecalis and Salmonella enterica. In addition both MaeuCath1 and MaeuCath7 stimulated proliferation of primary tammar wallaby mammary epithelial cells (WallMEC). Lactation-phase specific alternate spliced transcripts were determined for MaeuCath1 showing utilisation of both antimicrobial and proliferative functions are required by the mammary gland and the suckled young. The study has shown for the first time that temporal regulation of milk cathelicidins may be crucial in antimicrobial protection of the mammary gland and suckled young and mammary cell proliferation.
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Delbes-Paus C, Dorchies G, Chaabna Z, Callon C, Montel MC. Contribution of hydrogen peroxide to the inhibition of Staphylococcus aureus by Lactococcus garvieae in interaction with raw milk microbial community. Food Microbiol 2010; 27:924-32. [PMID: 20688234 DOI: 10.1016/j.fm.2010.05.031] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 05/26/2010] [Accepted: 05/27/2010] [Indexed: 11/28/2022]
Abstract
The response of Staphylococcus aureus growth inhibition by Lactococcus garvieae to catalase and milk lactoperoxidase, and its efficiency in raw milk cheese were evaluated. S. aureus and L. garvieae were co-cultivated in broth buffered at pH 6.8, and in raw, pasteurized and microfiltered milk, in presence and absence of catalase. Although H2O2 production by L. garvieae was detected only in agitated broth, the inhibition of S. aureus by L. garvieae was reduced by catalase both in static and shaking cultures by 2.7 log, pasteurized milk (approximately 0.7 log), microfiltered milk (approximately 0.6 log) and raw milk (approximately 0.2 log). The growth of S. aureus alone in microfiltered milk was delayed compared with that in pasteurized milk and inhibition of S. aureus by L. garvieae was stronger in microfiltered milk. The inhibition of coagulase-positive staphylococci (CPS) by L. garvieae in raw milk cheese was similar to that in raw milk (approximately 0.8 log), but weaker than that in pasteurized and microfiltered milks. L. garvieae also had an early antagonistic effect on the growth of several other microbial groups, which lastingly affected populations levels and balance during cheese ripening.
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Affiliation(s)
- Céline Delbes-Paus
- Unité de Recherches Fromagères UR545, INRA, 20 Côte de Reyne, F-15000 Aurillac, France.
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Medveďová A, Valík Ľ, Liptáková D, Hudecová A. Growth dynamic of ewes’ lump cheese microflora. POTRAVINARSTVO 2010. [DOI: 10.5219/52] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The preparation of ewes’ lump cheese has been known in Slovakia for a long time. It is made from raw or pasteurized ewes’ milk, especially due to the activity of lactic acid bacteria. The encouragement of the acidification process by the starters is profitable to use with the respect to the quality of the product. In our study we focused on the growth analysis of Staphylococcus aureus and Escherichia coli in ewes’ cheeses prepared in laboratory conditions with or without addition of starter culture from raw or heat treated milk. According to our experimental data, the addition of the lactic acid bacteria culture and the following pH decrease on the levels lower than 5.0 for 1 to 2 days were able to inhibit the growth of S. aureus and E. coli on concentrations lower than 104 CFU/g required by European Union legislation. The growth data found in this work may provide the information for food technologists and microbiologists to get the studied organisms under the control.
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Chhour KL, Hinds LA, Jacques NA, Deane EM. An observational study of the microbiome of the maternal pouch and saliva of the tammar wallaby, Macropus eugenii, and of the gastrointestinal tract of the pouch young. MICROBIOLOGY-SGM 2009; 156:798-808. [PMID: 19833775 DOI: 10.1099/mic.0.031997-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Marsupial mammals, born in an extremely atricial state with no functional immune system, offer a unique opportunity to investigate both the developing microbiome and its relationship to that of the mother and the potential influence of this microbiome upon the development of the immune system. In this study we used a well-established marsupial model animal, Macropus eugenii, the tammar wallaby, to document the microbiome of three related sites: the maternal pouch and saliva, and the gastrointestinal tract (GIT) of the young animal. We used molecular-based methods, targeting the 16S rDNA gene to determine the bacterial diversity at these study sites. In the maternal pouch, 41 unique phylotypes, predominantly belonging to the phylum Actinobacteria, were detected, while in the saliva, 48 unique phylotypes were found that predominantly belonged to the phylum Proteobacteria. The GIT of the pouch young had a complex microbiome of 53 unique phylotypes, even though the pouch young were still permanently attached to the teat and had only been exposed to the external environment for a few minutes immediately after birth while making their way from the birth canal to the maternal pouch. Of these 53 phylotypes, only nine were detected at maternal sites. Overall, the majority of bacteria isolated were novel species (<97 % identity to known 16S rDNA sequences), and each study site (i.e. maternal pouch and saliva, and the GIT of the pouch young) possessed its own unique microbiome.
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Affiliation(s)
- Kim-Ly Chhour
- Department of Biological Sciences, Division of Environmental and Life Sciences, Macquarie University, NSW 2109, Australia
| | - Lyn A Hinds
- CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia
| | - Nicholas A Jacques
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, NSW 2145, Australia
| | - Elizabeth M Deane
- The Chancelry, The Australian National University, Canberra, ACT 0200, Australia
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