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Atchade E, De Tymowski C, Grall N, Tanaka S, Montravers P. Toxic Shock Syndrome: A Literature Review. Antibiotics (Basel) 2024; 13:96. [PMID: 38247655 PMCID: PMC10812596 DOI: 10.3390/antibiotics13010096] [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: 12/14/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 01/23/2024] Open
Abstract
Toxic shock syndrome (TSS) is a rare, life-threatening, toxin-mediated infectious process linked, in the vast majority of cases, to toxin-producing strains of Staphylococcus aureus or Streptococcus pyogenes. The pathophysiology, epidemiology, clinical presentation, microbiological features, management and outcome of TSS are described in this review. Bacterial superantigenic exotoxins induces unconventional polyclonal lymphocyte activation, which leads to rapid shock, multiple organ failure syndrome, and death. The main described superantigenic exotoxins are toxic shock syndrome toxin-1 (TSST-1) and enterotoxins for Staphylococcus aureus and Streptococcal pyrogenic exotoxins (SpE) A, B, and C and streptococcal superantigen A (SsA) for Streptococcus pyogenes. Staphylococcal TSS can be menstrual or nonmenstrual. Streptococcal TSS is linked to a severe group A streptococcal infection and, most frequently, to a necrotizing soft tissue infection. Management of TSS is a medical emergency and relies on early detection, immediate resuscitation, source control and eradication of toxin production, bactericidal antibiotic treatment, and protein synthesis inhibiting antibiotic administration. The interest of polyclonal intravenous immunoglobulin G administration as an adjunctive treatment for TSS requires further evaluation. Scientific literature on TSS mainly consists of observational studies, clinical cases, and in vitro data; although more data on TSS are required, additional studies will be difficult to conduct due to the low incidence of the disease.
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Affiliation(s)
- Enora Atchade
- DMU PARABOL, Bichat-Claude Bernard Hospital, AP-HP, 75018 Paris, France; (C.D.T.); (S.T.); (P.M.)
| | - Christian De Tymowski
- DMU PARABOL, Bichat-Claude Bernard Hospital, AP-HP, 75018 Paris, France; (C.D.T.); (S.T.); (P.M.)
- UFR Diderot, Paris Cité University, 75018 Paris, France;
- INSERM UMR 1149, Immunoreceptor and Renal Immunopathology, Bichat-Claude Bernard Hospital, 75018 Paris, France
| | - Nathalie Grall
- UFR Diderot, Paris Cité University, 75018 Paris, France;
- Bacteriology Department, Bichat Claude Bernard Hospital, AP-HP, Paris Cité University, 75018 Paris, France
- INSERM UMR 1137 Infection, Antimicrobials, Modelling, Evolution, 75018 Paris, France
| | - Sébastien Tanaka
- DMU PARABOL, Bichat-Claude Bernard Hospital, AP-HP, 75018 Paris, France; (C.D.T.); (S.T.); (P.M.)
- INSERM, UMR 1188, Diabetes Atherothrombosis Réunion Océan Indien (DéTROI), la Réunion University, 97400 Saint-Denis de la Réunion, France
| | - Philippe Montravers
- DMU PARABOL, Bichat-Claude Bernard Hospital, AP-HP, 75018 Paris, France; (C.D.T.); (S.T.); (P.M.)
- UFR Diderot, Paris Cité University, 75018 Paris, France;
- INSERM UMR 1152 ANR 10—LABX-17, Pathophysiology and Epidemiology of Respiratory Diseases, 75018 Paris, France
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Kamala K, Sivaperumal P. Prevalence of enterotoxin genes of Staphylococcus sp. isolated from marine fish to reveal seafood contamination. MARINE POLLUTION BULLETIN 2023; 195:115464. [PMID: 37666137 DOI: 10.1016/j.marpolbul.2023.115464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/22/2023] [Accepted: 08/26/2023] [Indexed: 09/06/2023]
Abstract
Seafood is a valuable nutritional source, but it is highly susceptible to bacterial contamination, posing a severe health risk to humans. Enterotoxin-producing genes carrying Staphylococcus sp. are a significant concern in marine fish. This study aimed to investigate the prevalence of enterotoxin genes in Staphylococcus sp. isolated from 17 common fish species and emphasise the need for improving seafood quality and hygiene. The potential risks of contamination by enterotoxin-producing Staphylococcus sp. were assessed. The results indicated the risk associated with the consumption of contaminated seafood, especially from marketed and frozen samples. Gene expression analysis on a heat map revealed that samples stored in markets are heavily loaded with Staphylococcus enterotoxin genes due to the unhygienic water that was used from the local markets for fish processing. To enhance seafood quality, effective measures on handling and storage should be regularly monitored, and they must be implemented throughout the local seafood markets.
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Affiliation(s)
- Kannan Kamala
- Centre for Marine Actinobacterial Research (CMAR), Department of Physiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical & Technical Sciences, Saveetha University, Chennai 600077, Tamil Nadu, India
| | - Pitchiah Sivaperumal
- Marine Biomedical Research Lab & Environmental Toxicology Unit, Centre for Marine Research and Conservation, Saveetha Dental College and Hospitals, Saveetha Institute of Medical & Technical Sciences, Saveetha University, Chennai 600077, Tamil Nadu, India.
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Armeftis C, Ioannou A, Lazarou T, Giannopoulos A, Dimitriadou E, Makrides K, Pana ZD. Staphylococcus epidermidis induced toxic shock syndrome (TSS) secondary to influenza infection. BMC Infect Dis 2023; 23:583. [PMID: 37674134 PMCID: PMC10481523 DOI: 10.1186/s12879-023-08487-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 07/27/2023] [Indexed: 09/08/2023] Open
Abstract
BACKGROUND To date, few cases of TSS caused by coagulase negative (CoN) staphylococci have been reported in the literature. Recent data show that CoN staphylococci are capable of secreting a number of enterotoxins and cytotoxins, normally produced by S. aureus. Herewith, we describe a case of TSS caused by Staphylococcus epidermidis with a favorable outcome. CASE PRESENTATION We report a case of a 46-year-old man who developed TSS from S. epidermidis. The patient was admitted for a 7-day history of general malaise and headache following a recent influenza infection and a 3-day history of vomiting, diarrhea, diffuse erythroderma, and fever. The main laboratory findings on admission were leukopenia (WBC 800/mm3), thrombocytopenia (Plt count 78.000/mm3), elevated urea, creatine levels and increased inflammatory markers (CRP 368 mg/ml). The patient had clinical and radiological evidence of pneumonia with chest computed tomography (CT) showing diffuse bilateral airspace opacifications with air bronchogram. On the second day, a methicillin resistant S. epidermidis (MRSE) strain was detected in both sets of blood cultures, but the organism was unavailable for toxin testing. All other cultures and diagnostic PCR tests were negative. His clinical signs and symptoms fulfilled at that stage four out of five clinical criteria of TSS with a fever of 39 °C, diffuse erythroderma, multisystem involvement and hypotension. On the same day the patient was admitted to the ICU due to acute respiratory failure. The initial treatment was meropenem, vancomycin, levofloxacin, clindamycin, IVIG and steroids. Finger desquamation appeared on the 9th day of hospitalization, fulfilling all five clinical criteria for TSS. CONCLUSIONS To our knowledge, this is the first adult case with TSS induced by CoNS (MRSE) secondary to an influenza type B infection, who had favorable progression and outcome. Further research is warranted to determine how TSS is induced by the CoNS infections.
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Affiliation(s)
- Charis Armeftis
- Ygia Polyclinic Private Hospital, 21 Nafpliou Str, Limassol, 3025, Cyprus
- Medical School, European University, 6, Diogenous Str, Engomi, 2404, Nicosia, Cyprus
| | - Andreas Ioannou
- Ygia Polyclinic Private Hospital, 21 Nafpliou Str, Limassol, 3025, Cyprus
| | | | | | | | | | - Zoi Dorothea Pana
- Medical School, European University, 6, Diogenous Str, Engomi, 2404, Nicosia, Cyprus.
- Infection Control and Antimicrobial Stewardship Medical School, EUC, Engomi, Nicosia, Cyprus.
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Pomputius WF, Kilgore SH, Schlievert PM. Probable enterotoxin-associated toxic shock syndrome caused by Staphylococcus epidermidis. BMC Pediatr 2023; 23:108. [PMID: 36882717 PMCID: PMC9989563 DOI: 10.1186/s12887-023-03914-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/17/2023] [Indexed: 03/09/2023] Open
Abstract
BACKGROUND We describe a case of a toxic shock-like syndrome in a child, which was associated with Staphylococcus epidermidis instead of Staphylococcus aureus or Streptococcus pyogenes, the usual causes of toxic shock syndrome. CASE PRESENTATION The patient was an 8-year-old boy who developed a toxic shock syndrome-like illness, including fever, hypotension, and rash. The Staphylococcus epidermidis isolate was cultured from urine, but this organism was unavailable for toxin testing. Multiple blood cultures were negative. Instead, a highly novel assay was used on acute plasma from the patient which demonstrated the presence of the genes for superantigens, staphylococcal enterotoxins A, C, D, and E. Superantigens are the known causes of toxic shock syndrome. CONCLUSIONS Our study suggests strongly that Staphylococcus epidermidis was causing the TSS symptoms through the known Staphylococcus aureus superantigens. It is unknown how many other such patients exist; this should be explored. Of great importance is that PCR performed directly on blood plasma in the absence of microbial isolation could be used to demonstrate superantigen genes.
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Affiliation(s)
- William F Pomputius
- Division of Infectious Disease, Children's Minnesota, Minneapolis, MN, 55455, USA
| | - Samuel H Kilgore
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa, 52242, USA
| | - Patrick M Schlievert
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa, 52242, USA. .,Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
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Abstract
Many bacterial and fungal pathogens cause disease across mucosal surfaces, and to a lesser extent through skin surfaces. Pathogens that potentially cause disease vaginally across epithelial cells include Staphylococcus aureus, group A and B streptococci, Escherichia coli, Neisseria gonorrhoeae, and Candida albicans. We have previously shown that staphylococcal and streptococcal superantigens induce inflammatory chemokines from vaginal epithelial cells through the immune costimulatory molecule CD40 through use of a CRISPR cas9 knockout mutant and complemented epithelial cell line. In this study, we show that the potential vaginal pathogens S. aureus, group A and B streptococci, E. coli, an Enterococcus faecalis strain, and C. albicans in part use CD40 to stimulate interleukin-8 (IL-8) production from human vaginal epithelial cells. In contrast, N. gonorrhoeae does not appear to use CD40 to signal IL-8 production. Normal flora Lactobacillus crispatus and an Enterococcus faecalis strain that produces reutericyclin do not induce IL-8. These data indicate that many potential pathogens, but no normal commensals, induce IL-8 to help disrupt the human vaginal epithelial barrier through CD40, thus providing a potential therapeutic target for drug development. IMPORTANCE Most bacterial and fungal pathogens cause disease across mucosal, and to a lesser extent, skin barriers with the help of induced chemokines from epithelial cells. In this study, we showed that potential vaginal pathogens Staphylococcus aureus, group A and B streptococci, some Enterococcus faecalis strains, Escherichia coli, and Candida albicans use the immune costimulatory molecule CD40 to induce the chemokine interleukin-8 production. In contrast, Neisseria gonorrhoeae does not use CD40 to stimulate interleukin-8. Normal flora lactobacilli and at least one E. faecalis strain do not induce interleukin-8.
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Al-Haqan A, Boswihi SS, Pathan S, Udo EE. Antimicrobial resistance and virulence determinants in coagulase-negative staphylococci isolated mainly from preterm neonates. PLoS One 2020; 15:e0236713. [PMID: 32750089 PMCID: PMC7402503 DOI: 10.1371/journal.pone.0236713] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 07/13/2020] [Indexed: 12/22/2022] Open
Abstract
Coagulase-negative staphylococci (CoNS) are the most common isolates from blood culture in neonates resulting in high mortality and morbidity. This study investigated CoNS obtained from blood cultures of neonates for antibiotic resistance and virulence factors, and possible association with inflammatory response (C-reactive protein). A total of 93 CoNS isolates were collected from 76 blood cultures of neonates at the Maternity hospital in Kuwait in a six-month period and investigated for susceptibility to antibiotics, carriage of staphylococcal cassette chromosome mec (SCCmec), and virulence-associated genes. The 93 CoNS isolates consisted of S. epidermidis (76; 81.7%), S. capitis (12; 12.9%), S. hominis (2; 2.1%), S. warneri (2; 2.1%) and S. haemolyticus (1; 1.0%). Eighty-six (92.4%) of the isolates were resistant to cefoxitin (MR-CoNS) while 49 (52.7%) expressed multi-antibiotic resistance. The methicillin-resistant isolates (MR-CoNS) carried SCCmec III, SCCmec IVa and four combinations of SCCmec types including SCCmec types I+IVa (one S. warneri and 25 S. epidermidis isolates), types I+III (one S. epidermidis isolate), types III+IVa (six S. epidermidis isolates) and types I+III+IVa (one S. epidermidis isolate). The most common virulence-related genes were icaC, seb, arc detected in 69.7%, 60.5%, 40.8% of the isolates respectively. Two isolates were positive for tst1. No association between C-reactive protein and antibiotic resistance or virulence factors was established. This study revealed that S. epidermidis carrying different SCCmec genetic elements, was the dominant CoNS species isolated from neonatal blood cultures with 90.3% and 36.6% of the isolates positive for genes for biofilm and ACME production respectively.
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Affiliation(s)
- Aishah Al-Haqan
- Microbiology Laboratory, Maternity Hospital, Kuwait city, Kuwait
| | - Samar S. Boswihi
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait city, Kuwait
| | - Seema Pathan
- Microbiology Laboratory, Maternity Hospital, Kuwait city, Kuwait
| | - Edet E. Udo
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait city, Kuwait
- * E-mail:
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Banaszkiewicz S, Calland JK, Mourkas E, Sheppard SK, Pascoe B, Bania J. Genetic Diversity of Composite Enterotoxigenic Staphylococcus epidermidis Pathogenicity Islands. Genome Biol Evol 2020; 11:3498-3509. [PMID: 31769803 PMCID: PMC6931896 DOI: 10.1093/gbe/evz259] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2019] [Indexed: 02/07/2023] Open
Abstract
The only known elements encoding enterotoxins in coagulase-negative staphylococci are composite Staphylococcus epidermidis pathogenicity islands (SePIs), including SePI and S. epidermidis composite insertion (SeCI) regions. We investigated 1545 Staphylococcus spp. genomes using whole-genome MLST, and queried them for genes of staphylococcal enterotoxin family and for 29 ORFs identified in prototype SePI from S. epidermidis FRI909. Enterotoxin-encoding genes were identified in 97% of Staphylococcus aureus genomes, in one Staphylococcus argenteus genome and in nine S. epidermidis genomes. All enterotoxigenic S. epidermidis strains carried composite SePI, encoding sec and sel enterotoxin genes, and were assigned to a discrete wgMLST cluster also containing genomes with incomplete islands located in the same region as complete SePI in enterotoxigenic strains. Staphylococcus epidermidis strains without SeCI and SePI genes, and strains with complete SeCI and no SePI genes were identified but no strains were found to carry only SePI and not SeCI genes. The systematic differences between SePI and SeCI regions imply a lineage-specific pattern of inheritance and support independent acquisition of the two elements in S. epidermidis. We provided evidence of reticulate evolution of mobile elements that contain elements with different putative ancestry, including composite SePI that contains genes found in other coagulase-negative staphylococci (SeCI), as well as in S. aureus (SePI-like elements). We conclude that SePI-associated elements present in nonenterotoxigenic S. epidermidis represent a scaffold associated with acquisition of virulence-associated genes. Gene exchange between S. aureus and S. epidermidis may promote emergence of new pathogenic S. epidermidis clones.
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Affiliation(s)
- Sylwia Banaszkiewicz
- Department of Food Hygiene and Consumer Health Protection, Wrocław University of Environmental and Life Sciences, Poland
| | | | | | | | - Ben Pascoe
- The Milner Centre for Evolution, University of Bath, United Kingdom
| | - Jacek Bania
- Department of Food Hygiene and Consumer Health Protection, Wrocław University of Environmental and Life Sciences, Poland
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Dendritic Cells Internalize Staphylococcus aureus More Efficiently than Staphylococcus epidermidis, but Do Not Differ in Induction of Antigen-Specific T Cell Proliferation. Microorganisms 2019; 8:microorganisms8010019. [PMID: 31861881 PMCID: PMC7022728 DOI: 10.3390/microorganisms8010019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/05/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus and Staphylococcus epidermidis are related species which can cause predominantly acute and subacute infections, respectively. Differences in human adaptive immune responses to these two species are not well understood. Dendritic cells (DCs) have an important role in the control and regulation of anti-staphylococcal T cell responses. Therefore, we aimed to compare the ability of S. aureus and S. epidermidis to influence the essential steps in human DC activation and subsequent antigen-specific CD4+ T cell proliferation, and to investigate the underlying mechanisms. Using multiple strains of both species, we observed that S. aureus was internalized more effectively than S. epidermidis by DCs but that both species were equally potent in activating these host cells, as evidenced by similar induction of DC maturation marker expression and antigen loading onto MHC-II molecules. The DCs stimulated by S. aureus strains not harboring superantigen (SAg) genes or by any of the S. epidermidis strains, induced low, likely physiological levels of T cell proliferation. Only DCs stimulated with S. aureus strains harboring SAg genes induced high levels of T cell proliferation. Taken together, S. aureus and S. epidermidis do not differently affect DC activation and ensuing antigen-specific T cell proliferation, unless a strain has the capacity to produce SAgs.
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Chun S, Kang CI, Kim YJ, Lee NY. Clinical Significance of Isolates Known to Be Blood Culture Contaminants in Pediatric Patients. ACTA ACUST UNITED AC 2019; 55:medicina55100696. [PMID: 31627324 PMCID: PMC6843289 DOI: 10.3390/medicina55100696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/26/2019] [Accepted: 10/15/2019] [Indexed: 11/30/2022]
Abstract
Background and objectives: The objective of this study was to investigate the clinical significance of isolates from blood stream infection known to be blood culture contaminants in pediatric patients. Materials and Methods: Microbiological reports and medical records of all blood culture tests issued from 2002 to 2012 (n = 76,331) were retrospectively reviewed. Evaluation for potential contaminants were done by reviewing medical records of patients with the following isolates: coagulase-negative Staphylococcus, viridans group Streptococcus, Bacillus, Corynebacterium, Micrococcus, Aerococcus, and Proprionibacterium species. Repeated cultures with same isolates were considered as a single case. Cases were evaluated for their status as a pathogen. Results: Coagulase-negative Staphylococcus had clinical significance in 23.8% of all cases. Its rate of being a true pathogen was particularly high in patients with malignancy (43.7%). Viridans group Streptococcus showed clinical significance in 46.2% of all cases. Its rate of being a true pathogen was similar regardless of the underlying morbidity of the patient. The rate of being a true pathogens for remaining isolates was 27.7% for Bacillus and 19.0% for Corynebacterium species. Conclusions: Coagulase-negative Staphylococcus and viridans group Streptococcus isolates showed high probability of being true pathogens in the pediatric population, especially in patients with underlying malignancy.
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Affiliation(s)
- Sejong Chun
- Department of Laboratory Medicine, Chonnam National University Medical School & Hospital, Gwangju 61469, Korea.
- Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
| | - Cheol-In Kang
- Division of Infectious Diseases, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
| | - Yae-Jean Kim
- Division of Infectious Diseases and Immunodeficiency, Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
| | - Nam Yong Lee
- Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
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Characterization of Human Type C Enterotoxin Produced by Clinical S. epidermidis Isolates. Toxins (Basel) 2018; 10:toxins10040139. [PMID: 29584685 PMCID: PMC5923305 DOI: 10.3390/toxins10040139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 11/17/2022] Open
Abstract
Staphylococcal Enterotoxins (SEs) are superantigens (SAg) originally produced by S. aureus, but their presence in coagulase negative staphylococci (CNS) has long been suspected. This study aims to better characterize a novel C-like enterotoxin expressed by clinical S. epidermidis strains, called SECepi. We isolated and characterized SECepi for its molecular and functional properties. The toxin was structurally modeled according to its significant similarity with S. aureus SEC3. Most of SEC amino acid residues important for the formation of the trimolecular Major Histocompatibility Complex II MHCII-SEC-T Cell Receptor TCR complex are conserved in SECepi. The functional properties of SECepi were estimated after cloning, expression in E. coli, and purification. The recombinant SECepi toxin exhibits biological characteristics of a SAg including stimulation of human T-cell mitogenicity, inducing and releasing high cytokines levels: IL-2, -4, -6, -8, -10, IFN-γ, TNF-α and GM-CSF at a dose as low as 3.7 pM. Compared to SECaureus, the production of pro-sepsis cytokine IL-6 is significantly higher with SECepi-activated lymphocytes. Furthermore, SECepi is stable to heat, pepsin or trypsin hydrolysis. The SECepi superantigen produced by CNS is functionally very close to that of S. aureus, possibly inducing a systemic inflammatory response at least comparable to that of SECaureus, and may account for S. epidermidis pathogenicity.
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Pathogenic features of clinically significant coagulase-negative staphylococci in hospital and community infections in Benin. Int J Med Microbiol 2016; 307:75-82. [PMID: 27876296 DOI: 10.1016/j.ijmm.2016.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/14/2016] [Accepted: 11/08/2016] [Indexed: 11/21/2022] Open
Abstract
In West Africa, very little consideration has been given to coagulase negative Staphylococci (CNS). Herein, we describe the features contributing to the pathogenicity of 99 clinically-significant independent CNS isolates associated with infections encountered at the National Teaching Hospital Center of Cotonou (Benin). The pathogenic potentials of nosocomial strains were compared with community strains. S. haemolyticus (44%), S. epidermidis (22%) and S. hominis (7%) were the most frequently isolated while bacteremia (66.7%) and urinary tract infections (24.2%) were the most commonly encountered infections. Most strains were resistant to multiple antibiotics, including penicillin (92%), fosfomycin (81%), methicillin (74%) and trimethoprim-sulfamethoxazole (72%). The most frequently isolated species were also the most frequently resistant to methicillin: S. hominis (100%), S. haemolyticus (93%) and S. epidermidis (67%). Screening of toxic functions or toxin presence revealed hemolytic potential in 25% of strains in over 50% of human erythrocytes in 1h. Twenty-six percent of strains exhibited protease activity with low (5%), moderate (10%) and high activity (11%), while 25% of strains displayed esterase activity. Three percent of strain supernatants were able to lyse 100% of human polymorphonuclear cells after 30min. Polymerase chain reaction and latex agglutination methods revealed staphylococcal enterotoxin C gene expression in 9% of S. epidermidis. A majority of hospital-associated CNS strains (68%) had at least one important virulence feature, compared with only 32% for community-acquired strains. The present investigation confirms that these microorganisms can be virulent, at least in some individual cases, possibly through genetic transfer from S. aureus.
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