Exfoliative toxin E, a new Staphylococcus aureus virulence factor with host-specific activity

Imanishi, Ichiro; Nicolas, Aurélie; Caetano, Ana-Carolina Barbosa; Castro, Thiago Luiz de Paula; Tartaglia, Natayme Rocha; Mariutti, Ricardo Barros; Guédon, Éric; Even, Sergine; Berkova, Nadia; Arni, R.K.; Seyffert, Núbia; Azevedo, Vasco; Nishifuji, Koji; Loir, Yves Le

doi:10.1038/s41598-019-52777-3

Cited by 22 publications

(19 citation statements)

References 53 publications

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“…S. aureus strains of bovine and ovine origins have evolved to adapt to their animal hosts and differ from human strains at the genotypic and genomic levels 45,46 . In some cases, species-specific traits are also observed at the molecular level, as exemplified for example by the bovine variant of von Willebrand factor-binding protein 47 , or ovine-specific exfoliative toxin type E 48 . Here, none of the EV proteins specifically associated with ovine (n = 6), bovine (n = 6) or human (n = 5) strains presented any functions that could be related specifically to their host origin, with the exception of beta-lactamase for strain MW2.…”

Section: Discussionmentioning

confidence: 99%

Extracellular vesicles produced by human and animal Staphylococcus aureus strains share a highly conserved core proteome

Tartaglia

Nicolas

Rodovalho

et al. 2020

Sci Rep

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Staphylococcus aureus is an important opportunistic pathogen of humans and animals. it produces extracellular vesicles (EVs) that are involved in cellular communication and enable inter-kingdom crosstalk, the delivery of virulence factors and modulation of the host immune response. The protein content of EVs determines their biological functions. Clarifying which proteins are selected, and how, is of crucial value to understanding the role of EVs in pathogenesis and the development of molecular delivery systems. Here, we postulated that S. aureus EVs share a common proteome containing components involved in cargo sorting. The EV proteomes of five S. aureus strains originating from human, bovine, and ovine hosts were characterised. The clustering of EV proteomes reflected the diversity of the producing strains. A total of 253 proteins were identified, 119 of which composed a core EV proteome with functions in bacterial survival, pathogenesis, and putatively in EV biology. We also identified features in the sequences of EV proteins and the corresponding genes that could account for their packaging into EVs. Our findings corroborate the hypothesis of a selective sorting of proteins into EVs and offer new perspectives concerning the roles of EVs in S. aureus pathogenesis in specific host niches. Staphylococcus aureus is a Gram-positive opportunistic pathogen that causes a broad spectrum of infections in humans and animals. In humans, these diseases range from superficial skin and soft tissue infections to life-threatening conditions that require hospitalisation and extensive medical support 1,2. This bacterium is also one of the main causative agents of nosocomial infections. In animals, S. aureus is notably responsible for ruminant mastitis, an inflammation of the mammary glands that dramatically affects animal health and welfare, milk quality and the economics of milk production 3. Mastitis is also the principal reason for the use of antibiotics in dairy herds 4. The wide range of clinical manifestations of S. aureus infections is likely associated with its huge arsenal of virulence factors, which include structural components and extracellular factors such as enzymes and toxins 5. Despite considerable efforts, the precise mechanisms underlying host adaptation, colonisation and interactions are not yet fully understood 6. Extracellular vesicles (EVs) are used by many pathogenic bacteria as a secretory route to deliver toxic compounds to infected cells 7,8. EVs are lipid bilayer nanoparticles that range in size from 20 to 300 nm and are released by almost all cells in all domains of life 9. In Gram-positive bacteria, they are formed by budding and shedding of the cytoplasmic membrane. They play a pivotal role in cell-to-cell communication through their ability to transport bioactive molecules (proteins, nucleic acids, lipids, metabolites) from donor to recipient cells. The EVs produced by S. aureus can mediate the pathogenesis of infection in a variety of ways. They may be cytotoxic to host cells 10-12 , induce the ...

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Section: Discussionmentioning

confidence: 99%

Extracellular vesicles produced by human and animal Staphylococcus aureus strains share a highly conserved core proteome

Tartaglia

Nicolas

Rodovalho

et al. 2020

Sci Rep

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“…Three different ETs (ETA, ETB, and ETD) are associated with skin exfoliation in different hosts, but with varied effects, indicating at least some degree of host specificity; a caveat is that this specificity was only studied in bacterial strains associated with mild mastitis in ewes. A new exfoliative toxin, ETE, was recently identified from sheep suffering from mastitis caused by S. aureus O46; the implication is that ETE could contribute to bacterial colonization of stratified epithelia [6].…”

Section: Role Of Staphylococcus Aureus Toxic Proteins In Mastitismentioning

confidence: 99%

“…S. aureus enterotoxins include toxic shock syndrome toxin 1 (TSST-1), exfoliative toxins, and staphylococcal enterotoxins (SEs) ( Table 1 ). Exfoliative toxins (ETs) are serine proteases with affinity towards desmoglein 1 (Dsg1) that help S. aureus colonize the skin of mammals [ 6 ]. Hemolysins, such as β, α, and δ toxins ( Table 1 ), attack cell membranes and cause platelet damage, lysosome destruction, ischemia, and necrosis.…”

Section: Role Of Staphylococcus Aureus Toxic Prmentioning

confidence: 99%

“…The latter destroy white blood cells, while enterotoxins can stimulate the host T cells and cause a cytokine storm [5]. In milk-producing ruminants, S. aureus is normally the major cause of mammary gland inflammation, referred to as mastitis [6]. Although S. aureus is responsible for 95% of the coagulase positive tests in bovine-mastitis samples, this test is not sufficient to identify the bacterium, requiring additional diagnostic confirmation.…”

Section: Introductionmentioning

confidence: 99%

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Staphylococcus aureus Exotoxins and Their Detection in the Dairy Industry and Mastitis

Abril

Villa

Barros‐Velázquez

et al. 2020

Toxins

100

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Staphylococcus aureus constitutes a major food-borne pathogen, as well as one of the main causative agents of mastitis in dairy ruminants. This pathogen can produce a variety of extracellular toxins; these include the shock syndrome toxin 1 (TSST-1), exfoliative toxins, staphylococcal enterotoxins (SE), hemolysins, and leukocidins. S. aureus expresses many virulence proteins, involved in evading the host defenses, hence facilitating microbial colonization of the mammary glands of the animals. In addition, S. aureus exotoxins play a role in the development of both skin infections and mastitis. Indeed, if these toxins remain in dairy products for human consumption, they can cause staphylococcal food poisoning (SFP) outbreaks. As a result, there is a need for procedures to identify the presence of exotoxins in human food, and the methods used must be fast, sensitive, reliable, and accurate. It is also essential to determine the best medical therapy for human patients suffering from S. aureus infections, as well as establishing the relevant veterinary treatment for infected ruminants, to avoid economic losses in the dairy industry. This review summarizes the role of S. aureus toxins in the development of mastitis in ruminants, their negative effects in the food and dairy industries, and the different methods used for the identification of these toxins in food destined for human consumption.

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“…and Klebsiella pneumoniae as well [42,43]. Another recent study on S. aureus also suggests the importance of GIs in the host specificity [44].…”

Section: Gis and Their Importance In La-sa Genomesmentioning

confidence: 88%

Genomic islands and the evolution of livestock-associatedStaphylococcus aureusgenomes

et al. 2020

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Background: Genomic Islands (GIs) are commonly believed to be relics of horizontal transfer and associated with specific metabolic capacities, including virulence of the strain. Horizontal gene transfer (HGT) plays a vital role in the acquisition of GIs and the evolution and adaptation of bacterial genomes. Objective: The present study was designed to predict the GIs and role of HGT in evolution of livestock-associated Staphylococcus aureus (LA-SA). Methods: GIs were predicted with two methods namely, Ensemble algorithm for Genomic Island Detection (EGID) tool, and Seq word Sniffer script. Functional characterization of GI elements was performed with clustering of orthologs. The putative donor predictions of GIs was done with the aid of the pre_GI database. Results: The present study predicted a pan of 46 GIs across the LA-SA genomes. Functional characterization of GI sequences revealed few unique results like the presence of metabolic operons like leuABCD and folPK genes in GIs and showed the importance of GIs in the adaptation to the host niche. The developed framework for GI donor prediction results revealed Rickettsia and Mycoplasma as the major donors of GI elements. Conclusions: The role of GIs during the evolutionary race of LA-SA could be concluded from the present study. Niche adaptation of LA-SA enhanced presumably due to these GIs. Future studies could focus on the evolutionary relationships between Rickettsia and Mycoplasma sp. with S. aureus and also the evolution of Leucine/Isoleucine mosaic operon (leuABCD).

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Exfoliative toxin E, a new Staphylococcus aureus virulence factor with host-specific activity

Cited by 22 publications

References 53 publications

Extracellular vesicles produced by human and animal Staphylococcus aureus strains share a highly conserved core proteome

Extracellular vesicles produced by human and animal Staphylococcus aureus strains share a highly conserved core proteome

Staphylococcus aureus Exotoxins and Their Detection in the Dairy Industry and Mastitis

Genomic islands and the evolution of livestock-associatedStaphylococcus aureusgenomes

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