1
|
Cunha, Calsolari R. Toxigenicity in Staphylococcus aureus and Coagulase-Negative Staphylococci: Epidemiological and Molecular Aspects. Microbiol Insights 2008. [DOI: 10.4137/mbi.s796] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Representatives of the Staphylococcus genus are the most common pathogens found in hospital environments, and they are etiological agents for a large variety of infections. Various virulence factors are responsible for the symptoms and severity of infections caused by Staphylococcus aureus. Among them are staphylococcal enterotoxins (SEs), which cause staphylococcal food poisoning, and toxic shock syndrome toxin-1 (TSST-1). Some reports indicate that TSST-1 and staphylococcal enterotoxins are also produced by coagulase-negative staphylococci (CNS). The present review aimed to discuss general aspects of staphylococcal toxins as well as the epidemiology, genetics and detection of toxins in Staphylococcus aureus and coagulase-negative staphylococci, since these microorganisms are becoming more and more frequent in nosocomial infections.
Collapse
Affiliation(s)
- Cunha
- Department of Microbiology and Immunology, Biosciences Institute, São Paulo State University, Rubião Júnior, Botucatu, SP, 18.618-000, Brazil
| | - R.A.O. Calsolari
- Department of Tropical Diseases and Imaging Diagnosis, School of Medicine, São Paulo State University, Rubião Júnior, Botucatu, SP, 18.618–000, Brazil
| |
Collapse
|
2
|
Callahan JH, Shefcheck KJ, Williams TL, Musser SM. Detection, Confirmation, and Quantification of Staphylococcal Enterotoxin B in Food Matrixes Using Liquid Chromatography−Mass Spectrometry. Anal Chem 2006; 78:1789-800. [PMID: 16536413 DOI: 10.1021/ac051292v] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although immunoassay-based methods are sensitive and widely used for measuring protein toxins in food matrixes, there is a need for methods that can directly confirm the molecular identity of the toxin in situations where immunoassay tests yield a positive result. A method has been developed that uses mass spectrometry to identify a protein toxin, staphylococcal enterotoxin B (SEB), in a model food matrix, apple juice. The approach employs ultrafiltration to remove low molecular weight components from the sample, after which the remaining high molecular weight fraction, containing the protein, is digested with trypsin. The tryptic fragments are separated from residual biopolymers and analyzed by liquid chromatography-electrospray mass spectrometry. The background is still sufficiently complex that tandem mass spectrometry (MS/MS) is used to confirm the identity of target peptides. Limits of detection are 80 ng of SEB for MS and 100 ng for full scan MS/MS, using a tryptic fragment as the analytical target. Lower detection limits can be obtained using selected ion monitoring and multiple reaction monitoring. The presence of SEB can be confirmed at concentrations as low as 5 parts-per-billion by increasing the size of the sample to 10 mL. The method is applicable to the detection of SEB in other water-soluble food matrixes.
Collapse
Affiliation(s)
- John H Callahan
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, USA.
| | | | | | | |
Collapse
|
3
|
Shalita Z, Hertman I, Sarid S. Isolation and characterization of a plasmid involved with enterotoxin B production in Staphylococcus aureus. J Bacteriol 1977; 129:317-25. [PMID: 830641 PMCID: PMC234929 DOI: 10.1128/jb.129.1.317-325.1977] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Genetic analysis and molecular characterization of plasmid deoxyribonucleic acid (DNA) was performed in a toxigenic isolate of Staphylococcus aureus strain DU4916. Elimination, transduction, and transformation experiments provided us with a series of derivatives similar except for the presence or absence of genes mediating resistance to penicillin (penr), methicillin (mecr), and tetracycline (tetr) and enterotoxin type B (SEB) production (entB+). The derivatives were examined for the presence of a plasmid species which encodes for SEB production. Two distinct species of covalently closed circular DNA of about 2.8 X 10(6) and 0.75 X 10(6) daltons were identified in an ethidium bromide-cured, penicillinase-negative (pens) isolate, SN109 (mecr tetr emtB+). Further segregation of either methicillin resistance or tetracycline resistance or of both together resulted in the loss of SEB production and the disappearance of both plasmids. Transduction from strain SN109 showed that determinants for tetracycline resistance are carried by the 2.8 X 10(6) dalton plasmid. Transformation with covalently closed circular DNA from strain SN109 yielded mecs tetr entB- transformants harboring the tetracycline resistance plasmid alone and mecr tetr entB+ transformants harboring both the tetracycline resistance and the 0.75 X 10(6)-dalton plasmid. Further segregation of methicillin resistance in transformants was not associated with any change in plasmid DNA. The results indicate that a genetic determinant for SEB production is carried by the 0.75 X 10(6)-dalton plasmid. It is possible, however, that this plasmid cannot be maintained in the host independently from the tetracycline resistance plasmid. Methicillin resistance in the strains examined could not be ascribed to any of the covalently closed circular DNA components resolved in strain DU4916.
Collapse
|
4
|
Niskanen A, Lindroth S. Comparison of different purification procedure for extraction of staphylococcal enterotoxin A from foods. Appl Environ Microbiol 1976; 32:455-64. [PMID: 984824 PMCID: PMC170277 DOI: 10.1128/aem.32.4.455-464.1976] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Different procedures commonly used for extraction, purification, and concentration of staphylococcal enterotoxins from foods were investigated with 131I- and 125I-labeled staphylococcal enterotoxin A. Loss of labeled enterotoxin A was compared with loss of total nitrogen. The results showed that in most of the common procedures, such as gel filtration, ion exchange, and heat treatment, the percentage of loss of labeled enterotoxin A was greater than the loss of total nitrogen. Chloroform extraction and acid precipitation with hydrochloric acid had nearly the same effect on the purification of both labeled enterotoxin A and total nitrogen. Ammonium sulfate precipitation proved to be practical and was successfully used for purification of enterotoxin A from sausage extract. Simultaneous use of trypsin and Pseudomonas peptidase for treatment of food extracts considerably reduced food proteins capable of interfering with serological detection of enterotoxins but did not essentailly influence the loss of enterotoxin A.
Collapse
|
5
|
Genigeorgis C, Kuo JK. Recovery of staphylococcal enterotoxin from foods by affinity chromatography. Appl Environ Microbiol 1976; 31:274-9. [PMID: 999276 PMCID: PMC169759 DOI: 10.1128/aem.31.2.274-279.1976] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Extraction, concentration, and serological detection of staphylococcal enterotoxins from foods are laborious and time consuming. By exposing food extracts to an insoluble matrix tagged with specific anti-enterotoxin B, we have been able to recover the toxin from foods in a sensitive and rapid way. After mixing the reagents for 2 h at room temperature, immunoglobulin G antibodies were attached to CNBr-activated Sepharose 4B at pH 8.5 (0.1 M carbonate buffer with 0.5 M NaCl). Sepharose-antibody complex (1 ml) specifically recovered 0.1 to 30 mug of enterotoxin B from 400 ml of food extract (100 g of food) after mixing for 2 h at 4 C. The Sepharose-antibody-toxin complex was washed with 0.02 M phosphate-buffered saline at pH 7.2, and the toxin was dissociated by 2 to 4 ml of 0.2 M HCl-glycine plus 0.5 M NaCl buffer at pH 2.8. The recovered enterotoxin was free of interfering food components and could be detected serologically. Work to couple antibodies A, B, C, D, and E to Sepharose to recover all five toxins in one step is under study.
Collapse
|
6
|
Czop JK, Bergdoll MS. Staphylococcal enterotoxin synthesis during the exponential, transitional, and stationary growth phases. Infect Immun 1974; 9:229-35. [PMID: 4205941 PMCID: PMC414791 DOI: 10.1128/iai.9.2.229-235.1974] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Small inocula (1 to 10 colony-forming units per ml of broth) of Staphylococcus aureus strains S-6, S-6R, and FRI-100 were employed to study growth and enterotoxin synthesis in 4% protein hydrolysate powder broths. For each strain, the exponential growth phase ended once the population approached 10(9) to 2 x 10(9) colony-forming units per ml. By that time, the concentrations of enterotoxins A and B reached the minimal level (1 to 2 mug/ml) at which the single gel diffusion tube method becomes applicable. By microslides and reverse passive hemagglutination, enterotoxins A and B were found to be synthesized during the exponential growth phase, but at different exponential rates.
Collapse
|
7
|
Abstract
A short procedure for the extraction of staphylococcal enterotoxins from food materials has been developed. The procedure involves extraction of the food at pH 4.5, centrifugation, extraction of the supernatant with CHCl(3) (pH 7.5), extraction of the enterotoxin from the water layer with CG-50 ion exchange resin (pH 5.4 to 5.9), and treatment of the eluate with agar and concentration with Carbowax 20-M. The concentrate was extracted with CHCl(3), and the water layer was lyophilized. The dried material was dissolved in a 1% trypsin solution and placed on microslides, which were incubated 24 h at 37 C. The time required for enterotoxin analysis was 3 days with microslides and 1 day with the reversed passive hemagglutination technique.
Collapse
|
8
|
Uemura T, Sakaguchi G, Riemann HP. In vitro production of Clostridium perfringens enterotoxin and its detection by reversed passive hemagglutination. Appl Microbiol 1973; 26:381-5. [PMID: 4356461 PMCID: PMC379795 DOI: 10.1128/am.26.3.381-385.1973] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The reversed passive hemagglutination (RPHA) test yielded a positive reaction in 2 h with as little as 0.5 ng of purified Clostridium perfringens enterotoxin (CPE) per ml as well as with cultures of some C. perfringens grown in Duncan-Strong (DS) medium. This method is the most sensitive, the simplest, and the fastest among all reported. The time course of CPE production of Clostridium perfringens NCTC 8798 in DS was investigated by RPHA. CPE in culture was detectable at 4 h, increased gradually, reached a maximum at 12 to 14 h, and remained at a high level of 20 mug/ml through 48 h of incubation. CPE synthesized within cells is released easily by sonic disruption of young cultures and by aging the cultures 20 h or more. Heat shock of the cell inoculum was essential for CPE production by C. perfringens in DS.
Collapse
|
9
|
Collins WS, Johnson AD, Metzger JF, Bennett RW. Rapid solid-phase radioimmunoassay for staphylococcal enterotoxin A. Appl Microbiol 1973; 25:774-7. [PMID: 4715556 PMCID: PMC380910 DOI: 10.1128/am.25.5.774-777.1973] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A rapid solid-phase radioimmunoassay for staphylococcal enterotoxin A is described. The assay procedure requires 3 to 4 h for completion by using a competitive inhibition system in which the antibody is attached to bromacetyl cellulose particles. It is accurate to a level of 0.01 mug of enterotoxin A/ml in a variety of media such as ham, milk products, crab meat, custard, etc. No significant interference was found with any media or food product tested.
Collapse
|
10
|
Woodburn M, Morita TN, Venn SZ. Production of staphylococcal enterotoxins A, B, and C in colloidal dispersions. Appl Microbiol 1973; 25:825-33. [PMID: 4197641 PMCID: PMC380919 DOI: 10.1128/am.25.5.825-833.1973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Larger amounts of enterotoxin were produced when Staphylococcus aureus S-6 was grown under still (nonshaken) conditions in a medium that was a paste or gel than were produced in a liquid dispersion with the same colloidal ingredient or in control basal broth (4% NZ Amine-NAK containing 50 mug of thiamine per 100 ml and 1 mg of niacin per 100 ml). Four colloidal ingredients were used which had been previously demonstrated to not support enterotoxin production in buffer. The effect of the type of dispersion occurred earlier than that of the colloidal ingredient, but interactions were found. This effect was not observed when the cells were grown with aeration (shaken). Four other strains of S. aureus followed a similar pattern for enterotoxins A, B, and C, although liquid and paste with cornstarch and carrageenan were the only media compared to the control broth. Enterotoxins A and B were produced earlier by S. aureus S-6, and much greater quantities of enterotoxins were produced for all strains when incubated shaken.
Collapse
|
11
|
Kimble CE, Anderson AW. Rapid, sensitive assay for staphylococcal enterotoxin A by reversed immuno-osmophoresis. Appl Microbiol 1973; 25:693-4. [PMID: 4121541 PMCID: PMC380888 DOI: 10.1128/am.25.4.693-694.1973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Reversed immuno-osmophoresis using phenylsulfonated immune gamma(2)-globulin is a rapid sensitive method of assaying for staphylococcal enterotoxin A. The technique is compared with other serological methods.
Collapse
|
12
|
Johnson HM, Bukovic JA, Kauffman PE, Peeler JT. Staphylococcal enterotoxin B: solid-phase radioimmunoassay. Appl Microbiol 1971; 22:837-41. [PMID: 5002312 PMCID: PMC376429 DOI: 10.1128/am.22.5.837-841.1971] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
An immunoassay employing (125)I-labeled enterotoxin B and polystyrene tubes coated with specific antibody was used for assaying purified and crude enterotoxin. Antibody was adsorbed to untreated polystyrene tubes. Unlabeled enterotoxin competed with (125)I-labeled enterotoxin for antibody-combining sites. The uptake of (125)I-labeled toxin reflected the concentration of unlabeled toxin present. The test is sensitive to 1 to 5 ng of purified and crude enterotoxin B per ml, and cross-reactions with heterologous enterotoxins did not interfere with the specificity. This test possesses the combination of sensitivity and objectivity absent in current methods for assaying enterotoxin and provides a model for investigating other enterotoxin serotypes.
Collapse
|
13
|
Chesbro W, Kucic V. Beta hemolysin: a persistent impurity in preparations of staphylococcal nuclease and enterotoxin. Appl Microbiol 1971; 22:233-41. [PMID: 4999525 PMCID: PMC377420 DOI: 10.1128/am.22.2.233-241.1971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Purified staphylococcal nuclease and enterotoxin B from several sources contained beta hemolysin whose physicochemical resemblances to the other two proteins make its elimination difficult.
Collapse
|
14
|
Abstract
A simple assay is reported in which 1 mug of staphylococcal enterotoxins A, B, and D per ml was detected in less than 1 hr. Interfacial reaction of antisera and enterotoxin solutions in a 1-ml internal diameter capillary tube allowed rapid detection of sera type.
Collapse
|
15
|
Friedman ME, Howard MB. Induction of mutants of Staphylococcus aureus 100 with increased ability to produce enterotoxin A. J Bacteriol 1971; 106:289-91. [PMID: 4994600 PMCID: PMC248676 DOI: 10.1128/jb.106.1.289-291.1971] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
As a result of serial exposures to a mutagenic agent, N-methyl-N'-nitro-N-nitrosoguanidine, the yield of enterotoxin A produced by the last mutant in the series was increased nearly 20-fold over the amount produced by the parent Staphylococcus aureus 100.
Collapse
|