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Bagel A, Bouvier-Crozier M, Canizares M, Hamadou B, Courcol L, Lopez C, Michel V, Douellou T, Sergentet D. Surface proteins of Shiga toxin-producing Escherichia coli mediate association with milk fat globules in raw milk. Front Microbiol 2023; 14:1156374. [PMID: 37426002 PMCID: PMC10328742 DOI: 10.3389/fmicb.2023.1156374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/29/2023] [Indexed: 07/11/2023] Open
Abstract
Introduction By adhering to host cells and colonizing tissues, bacterial pathogens can successfully establish infection. Adhesion is considered the first step of the infection process and bacterial adhesion to anti-adhesive compounds is now seen as a promising strategy to prevent infectious diseases. Among the natural sources of anti-adhesive molecules, the membrane of milk fat globules (MFGs) is of interest because of its compositional diversity of proteins and glycoconjugates. However, few studies have focused on the bacterial molecules involved in MFG- mediated inhibition of bacterial adhesion to enterocytes. Methods We used three pathogenic Shiga toxin-producing Escherichia coli (STEC) strains (O26:H11 str. 21765, O157:H7 str. EDL933, and O103:H3 str. PMK5) as models to evaluate whether STEC surface proteins are involved in the affinity of STEC for MFG membrane proteins (MFGMPs). The affinity of STEC for MFGMPs was assessed both indirectly by a natural raw milk creaming test and directly by an adhesion test. Mass spectrometry was used to identify enriched STEC proteins within the protein fraction of MFGMs. Bacterial mutants were constructed and their affinity to MFGs were measured to confirm the role of the identified proteins. Results We found that free STEC surface proteins inhibit the concentration of the pathogen in the MFG-enriched cream in a strain-dependent manner. Moreover, the OmpA and FliC proteins were identified within the protein fraction of MFGMs. Our results suggest that FliC protein participates in STEC adhesion to MFGMPs but other STEC molecules may also participate. Discussion For the first time, this study highlighted, the involvement of STEC surface proteins in the affinity for MFGs. The mechanism of STEC-MFG association is still not fully understood but our results confirm the existence of receptor/ligand type interactions between the bacteria and MFGs. Further studies are needed to identify and specify the molecules involved in this interaction. These studies should consider the likely involvement of several factors, including adhesion molecules, and the diversity of each STEC strain.
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Affiliation(s)
- Arthur Bagel
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR 5557 Ecologie Microbienne Lyon, CNRS, Université de Lyon, VetAgro Sup, INRAE, Marcy-l’Etoile, France
| | - Marion Bouvier-Crozier
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR 5557 Ecologie Microbienne Lyon, CNRS, Université de Lyon, VetAgro Sup, INRAE, Marcy-l’Etoile, France
- Laboratoire d’Etudes des Microorganismes Alimentaires Pathogènes—French National Reference Laboratory for Escherichia coli Including Shiga Toxin-Producing E. coli (NRL-STEC), Université de Lyon, VetAgro Sup—Campus Vétérinaire, Marcy-l’Etoile, France
| | - Mélissa Canizares
- Laboratoire d’Etudes des Microorganismes Alimentaires Pathogènes—French National Reference Laboratory for Escherichia coli Including Shiga Toxin-Producing E. coli (NRL-STEC), Université de Lyon, VetAgro Sup—Campus Vétérinaire, Marcy-l’Etoile, France
| | - Badis Hamadou
- Laboratoire d’Etudes des Microorganismes Alimentaires Pathogènes—French National Reference Laboratory for Escherichia coli Including Shiga Toxin-Producing E. coli (NRL-STEC), Université de Lyon, VetAgro Sup—Campus Vétérinaire, Marcy-l’Etoile, France
| | - Louise Courcol
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR 5557 Ecologie Microbienne Lyon, CNRS, Université de Lyon, VetAgro Sup, INRAE, Marcy-l’Etoile, France
| | | | | | - Thomas Douellou
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR 5557 Ecologie Microbienne Lyon, CNRS, Université de Lyon, VetAgro Sup, INRAE, Marcy-l’Etoile, France
| | - Delphine Sergentet
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR 5557 Ecologie Microbienne Lyon, CNRS, Université de Lyon, VetAgro Sup, INRAE, Marcy-l’Etoile, France
- Laboratoire d’Etudes des Microorganismes Alimentaires Pathogènes—French National Reference Laboratory for Escherichia coli Including Shiga Toxin-Producing E. coli (NRL-STEC), Université de Lyon, VetAgro Sup—Campus Vétérinaire, Marcy-l’Etoile, France
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Brisson L, Caron A, Mazuy-Cruchadet C, Gilot-Fromont E, Lécu A, Mathieu B, Petit T, Sergentet D. COMPARING ANTIBIOTIC RESISTANCE IN FREE-RANGING VS. CAPTIVE AFRICAN WILD HERBIVORES. J Wildl Dis 2023:492376. [PMID: 37074787 DOI: 10.7589/jwd-d-21-00153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 07/22/2022] [Indexed: 04/20/2023]
Abstract
Antimicrobial resistance (AMR) is a critical challenge of the 21st century for public and animal health. The role of host biodiversity and the environment in the evolution and transmission of resistant bacteria between populations and species, and specifically at the wildlife-livestock-human interface, needs to be further investigated. We evaluated the AMR of commensal Escherichia coli in three mammalian herbivore species-impala (Aepyceros melampus), greater kudu (Tragelaphus strepsiceros), and plains zebra (Equus quagga)-targeting populations living under two conditions: captivity (French zoos) and free ranging (natural and private parks in Zimbabwe). From 137 fecal samples from these three host species, 328 E. coli isolates were isolated. We measured the AMR of each isolate against eight antibiotics, and we assessed the presence of AMR genes and mobile genetic element class 1 integrons (int1). Isolates obtained from captive hosts had a higher probability of being resistant than those obtained from free-ranging hosts (odds ratio, 293.8; confidence interval, 10-94,000). This statistically higher proportion of AMR bacteria in zoos than in natural parks was especially observed for bacteria resistant to amoxicillin. The percentage of int1 detection was higher when isolates were obtained from captive hosts, particularly captive impalas. Ninety percent of bacterial isolates with genes involved in antibiotic resistance also had the int1 gene. The sul1, sul2, blaTEM, and stra genes were found in 14, 19, 0, and 31%, respectively, of E. coli with respective antibiotic resistance. Finally, plains zebra carried AMR significantly more often than the other species.
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Affiliation(s)
- Lucie Brisson
- Vetagro-Sup, 1 avenue Bourgelat 69 280 Marcy l'Etoile, France
| | - Alexandre Caron
- ASTRE, Université Montpellier, CIRAD, INRA, 34398 Montpellier, France
- Faculdae de Veterinaria, Universidade Eduardo Mondlane, Maputo 01009, Mozambique
| | | | | | - Alexis Lécu
- Paris Zoo, Avenue Daumesnil, 75012 Paris, France
| | - Bourgarel Mathieu
- ASTRE, Université Montpellier, CIRAD, INRA, 34398 Montpellier, France
- CIRAD, UMR ASTRE, RP-PCP, Harare, Zimbabwe
| | - Thierry Petit
- La Palmyre Zoo, 6 Avenue de Royan, 17570 Les Mathes, France
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Bagel A, Lopez C, David-Briand E, Michel V, Douëllou T, Sergentet D. Serotype-dependent adhesion of Shiga toxin-producing Escherichia coli to bovine milk fat globule membrane proteins. Front Microbiol 2022; 13:1010665. [PMID: 36504830 PMCID: PMC9731836 DOI: 10.3389/fmicb.2022.1010665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) are food-borne pathogens that can cause severe symptoms for humans. Raw milk products are often incriminated as vehicule for human STEC infection. However, raw milk naturally contains molecules, such as the milk fat globule membrane and associated proteins, that could inhibit pathogen adhesion by acting as mimetic ligands. This study aimed to: (i) evaluate the capability of STEC cells to adhere to bovine milk fat globule membrane proteins (MFGMPs), (ii) highlight STEC surface proteins associated with adhesion and (iii) evaluate the variation between different STEC serotypes. We evaluated the physicochemical interactions between STEC and milk fat globules (MFGs) by analyzing hydrophobic properties and measuring the ζ-potential. We used a plate adhesion assay to assess adhesion between MFGMPs and 15 Escherichia coli strains belonging to three key serotypes (O157:H7, O26:H11, and O103:H2). A relative quantitative proteomic approach was conducted by mass spectrometry to identify STEC surface proteins that may be involved in STEC-MFG adhesion. The majority of E. coli strains showed a hydrophilic profile. The ζ-potential values were between -3.7 and - 2.9 mV for the strains and between -12.2 ± 0.14 mV for MFGs. Our results suggest that non-specific interactions are not strongly involved in STEC-MFG association and that molecular bonds could form between STEC and MFGs. Plate adhesion assays showed a weak adhesion of O157:H7 E. coli strains to MFGMPs. In contrast, O26:H11 and O103:H2 serotypes attached more to MFGMPs. Relative quantitative proteomic analysis showed that the O26:H11 str. 21,765 differentially expressed five outer membrane-associated proteins or lipoproteins compared with the O157:H7 str. EDL933. This analysis also found strain-specific differentially expressed proteins, including four O26:H11 str. 21,765-specific proteins/lipoproteins and eight O103:H2 str. PMK5-specific proteins. For the first time, we demonstrated STEC adhesion to MFGMPs and discovered a serotype effect. Several outer membrane proteins-OmpC and homologous proteins, intimin, Type 1 Fimbriae, and AIDA-I-that may be involved in STEC-MFG adhesion were highlighted. More research on STEC's ability to adhere to MFGMs in diverse biological environments, such as raw milk cheeses and the human gastrointestinal tract, is needed to confirm the anti-adhesion properties of the STEC-MFG complex.
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Affiliation(s)
- Arthur Bagel
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR5557 Ecologie Microbienne Lyon, National Center of Scientific Research (CNRS), Université de Lyon, Marcy-l’Etoile, France
| | | | | | | | - Thomas Douëllou
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR5557 Ecologie Microbienne Lyon, National Center of Scientific Research (CNRS), Université de Lyon, Marcy-l’Etoile, France
| | - Delphine Sergentet
- Bacterial Opportunistic Pathogens and Environment Research Group, UMR5557 Ecologie Microbienne Lyon, National Center of Scientific Research (CNRS), Université de Lyon, Marcy-l’Etoile, France,Laboratoire d’Etudes des Microorganismes Alimentaires Pathogènes, VetAgro Sup—Campus Vétérinaire, French National Reference Laboratory for Escherichia coli Including Shiga Toxin-Producing E. coli (NRL-STEC), Université de Lyon, Marcy-l‘Etoile, France,*Correspondence: Delphine Sergentet,
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Bagel A, Delignette-Muller ML, Lopez C, Michel V, Sergentet D, Douellou T. Strain- and serotype-dependent affinity of Shiga toxin-producing Escherichia coli for bovine milk fat globules. J Dairy Sci 2022; 105:8688-8704. [PMID: 36175225 DOI: 10.3168/jds.2022-21840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 07/01/2022] [Indexed: 11/19/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) are widely detected in raw milk products intended for human consumption. Although STEC are a worldwide public health problem, the pathogenicity of STEC in cheese remains unclear. In fact, bacterial association with compounds in raw milk cheeses could reduce their pathogenicity. A previous study showed the association of 2 STEC strains with raw milk cream in a natural creaming assay. Different concentrations of each strain were required to saturate the cream. In this study, we hypothesized that all STEC strains could be associated with milk fat globules (MFG) in raw milk and that the bacterial load required for saturation of the cream is serotype dependent. We evaluated the affinity of STEC strains belonging to the O157:H7, O26:H11, and O103:H2 serotypes for bovine raw milk cream and analyzed saturation of the cream layer by natural creaming assay. We used 12 STEC strains and 3 strains belonging to another pathotype to assess the effects of serotypes on this phenomenon. We performed sucrose density gradient centrifugation assays with 2 STEC model strains to confirm the results obtained by natural creaming. The localization of STEC within MFG-enriched creams was observed by confocal and electron microscopy. We recovered approximately 10 times more STEC from the cream layer after natural creaming than from raw bovine milk. The concentration of STEC required to saturate the cream layer (the saturation concentration) was estimated for each strain by nonlinear regression, highlighting a strain and serotype effect. Moreover, the concentration of STEC in the cream was milk fat level dependent. However, even in nonsaturating conditions, a high level of STEC was still present in the aqueous phase, after fat separation. Thus, natural creaming should not be used as the sole preventive measure to remove STEC from naturally contaminated raw milk. The results of our study suggest that cream saturation is a complex mechanism, most likely involving specific interactions between STEC and raw MFG.
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Affiliation(s)
- A Bagel
- Bacterial Opportunistic Pathogens and Environment Research Group, Université de Lyon, UMR 5557 Ecologie Microbienne Lyon, National Center of Scientific Research, VetAgro Sup, 69280 Marcy-l'Etoile, France
| | - M-L Delignette-Muller
- Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, Université de Lyon, VetAgro Sup, National Center of Scientific Research, 69622 Villeurbanne, France
| | - C Lopez
- INRAE, UR BIA, F-44316, Nantes, France
| | - V Michel
- Actalia, 74800 La Roche-sur-Foron, France
| | - D Sergentet
- Bacterial Opportunistic Pathogens and Environment Research Group, Université de Lyon, UMR 5557 Ecologie Microbienne Lyon, National Center of Scientific Research, VetAgro Sup, 69280 Marcy-l'Etoile, France; VetAgro Sup-Campus Vétérinaire, Laboratoire d'Etudes des Microorganismes Alimentaires Pathogènes-French National Reference Laboratory for Escherichia coli including Shiga toxin-producing E. coli (NRL-STEC), Université de Lyon, 69280, Marcy-l'Etoile, France.
| | - T Douellou
- Bacterial Opportunistic Pathogens and Environment Research Group, Université de Lyon, UMR 5557 Ecologie Microbienne Lyon, National Center of Scientific Research, VetAgro Sup, 69280 Marcy-l'Etoile, France
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Bagel A, Sergentet D. Shiga Toxin-Producing Escherichia coli and Milk Fat Globules. Microorganisms 2022; 10:microorganisms10030496. [PMID: 35336072 PMCID: PMC8953591 DOI: 10.3390/microorganisms10030496] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/09/2022] [Accepted: 02/17/2022] [Indexed: 02/04/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) are zoonotic Gram-negative bacteria. While raw milk cheese consumption is healthful, contamination with pathogens such as STEC can occur due to poor hygiene practices at the farm level. STEC infections cause mild to serious symptoms in humans. The raw milk cheese-making process concentrates certain milk macromolecules such as proteins and milk fat globules (MFGs), allowing the intrinsic beneficial and pathogenic microflora to continue to thrive. MFGs are surrounded by a biological membrane, the milk fat globule membrane (MFGM), which has a globally positive health effect, including inhibition of pathogen adhesion. In this review, we provide an update on the adhesion between STEC and raw MFGs and highlight the consequences of this interaction in terms of food safety, pathogen detection, and therapeutic development.
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Affiliation(s)
- Arthur Bagel
- ‘Bacterial Opportunistic Pathogens and Environment’ Research Team, Université de Lyon, UMR5557 Ecologie Microbienne Lyon, CNRS (National Center of Scientific Research), VetAgro Sup, Marcy-l’Etoile, 69280 Lyon, France;
| | - Delphine Sergentet
- ‘Bacterial Opportunistic Pathogens and Environment’ Research Team, Université de Lyon, UMR5557 Ecologie Microbienne Lyon, CNRS (National Center of Scientific Research), VetAgro Sup, Marcy-l’Etoile, 69280 Lyon, France;
- Laboratoire d’Etudes des Microorganismes Alimentaires Pathogènes-French National Reference Laboratory for Escherichia coli Including Shiga Toxin-Producing E. coli (NRL-STEC), VetAgro Sup—Campus Vétérinaire, Université de Lyon, Marcy-l’Etoile, 69280 Lyon, France
- Correspondence:
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