Search PubMed⌕ Search

Biomedical subjects

M S Bergdoll

Publications and source records attributed to M S Bergdoll.

At least 19 recordsLinked to original sources

[Occurrence and characteristics of staphylococcal enterotoxin antibodies in gynecologic patients].

OBJECTIVE: To control the occurrence of the antibodies against Staphylococcal type A and type B enterotoxin in gynaecological patients and in selected patients to determine the thermodynamic parameters of antibodies against Staphylococcal enterotoxins in their blood samples. DESIGN: Retrospective clinical study. SETTING: 2nd Department of Obstetrics and Gynaecology, P. J. Safárik University Kosice, Slovak Republic; Research Institute of Veterinary Medicine, Kosice, Slovak Republic; Department of Microbiology and Immunology, University of Veterinary Medicine, Kosice, Slovak Republic; Department of Food Microbiology and Toxicology, Food Research Institute, University of Wisconsin, Madison, USA. METHODS: The occurrence of antibodies against Staphylococcal type A and type B enterotoxin was determined in 68 patients hospitalized in Department of Obstetrics and Gynecology in Kosice. RESULTS: The occurrence of antibodies against Staphylococcal enterotoxins was determined by radioimmunoassay (RIA) in blood samples of 45 (66%) patients. The antibodies against Staphylococcal type A enterotoxin were determined in 36 (53%) patients and the antibodies against Staphylococcal type B enterotoxin were determined in 9 (13%) patients. The antibodies against both type A and type B enterotoxins were determined simultaneously in blood samples of 10% of all patients. The thermodynamic parameters of the antibodies were determined in 5 patients with positive serum findings. CONCLUSION: With regard to the existence of heterogeneous clinical findings in large amount of patients with antibodies against Staphylococcal enterotoxins, the next study of Staphylococcal enterotoxins role in pathogenesis of wide spectrum of diseases is necessary.

Adult↗

Staphylococci from dental personnel.

Thirty dental students and five professors were cultured in nares, throat, and hands for the presence of staphylococci. Twenty-four students and two professors were colonized with staphylococci that were classified as S. aureus. Twelve students and one professor were colonized with staphylococci that produced enterotoxin. Care needs to be taken to avoid contaminating patients during dental examination, particularly during any type of surgery.

Dental Staff↗

Production of staphylococcal enterotoxin A in cream-filled cake.

Cakes were baked with normal ingredients and filled with cream, inoculated with different size enterotoxigenic-staphylococcal inocula. Samples of the cakes were incubated at room temperature and put in the refrigerator. Samples of cake and filling were taken at different times and analyzed for staphylococcal count and presence of enterotoxin. The smaller the inoculum, the longer the time required for sufficient growth (10(6)) to occur for production of detectable enterotoxin. Enterotoxin added to the cake dough before baking (210 degrees C, 45 min) did not survive the baking. The presence of enterotoxin in the contaminated cream filling indicated this as the cause of staphylococcal food poisoning from cream-filled cakes. Refrigeration of the cakes prevented the growth of the staphylococci.

Animals↗

Importance of staphylococci that produce nanogram quantities of enterotoxin.

Many staphylococcal strains produce enterotoxin, the toxin that is the cause of staphylococcal food poisoning. If a strain is enterotoxigenic it is possible for it to be involved in food poisoning. The gel diffusion methods were the first methods developed for detection of the enterotoxins and were thought adequate to detect their production. However, they were not adequate to detect enterotoxin in foods involved in food poisoning. When researchers began using the sensitive methods, such as enzyme-linked immunosorbent assay (ELISA) and reversed passive latex agglutination (RPLA), to check strains for enterotoxin production, some strains produced nanogram quantities of enterotoxin. When it was reported that several coagulase-negative species produced less than 10 ng/ml of enterotoxin, it was imperative to determine whether these strains produced enough enterotoxin in foods to cause food poisoning. At the present time research is under way to determine whether these strains produce enough enterotoxin in foods to cause food poisoning.

Animals↗

Staphylococcal food poisoning from cream-filled cake in a metropolitan area of south-eastern Brazil.

Twelve people became ill with vomiting and diarrhoea approximately four hours after eating cake with a cream filling at a birthday party and on the day following. The cake had been prepared by a food handler who had long experience in preparing foods for such functions. Staphylococcus aureus that produced enterotoxin A was isolated from the nose, the fingernails, and a healed infection on the neck of the food handler, and from the cake. Enterotoxin A was detected in the remaining portion of the cake. The cake, while still warm, had been refrigerated for one hour after it was prepared before it was removed for the party; it was refrigerated after the party. The cake was large (6 kg) and hence it was not adequately cooled in the hour during which it was refrigerated before the party. The conclusion is that the cake was accidentally contaminated by the food handler and inadequately cooled before it was eaten.

Adult↗

Production of staphylococcal enterotoxin D in foods by low-enterotoxin-producing staphylococci.

The goal of this investigation was to determine whether staphylococcal strains producing enterotoxins at nanogram levels per milliliter in laboratory medium, not detectable by gel diffusion methods, could produce sufficient enterotoxin in foods to result in food poisoning. Three low-enterotoxin D (SED)-producing strains were selected for this research because this enterotoxin is produced in smaller amounts than the other enterotoxins. The foods used were cream pie and cooked ham, divided into two portions, sterile and non-sterile. Each portion was inoculated with known concentrations of the staphylococcal strains under study and incubated for 48 h at 25, 30, and 37 degrees C. Samples were taken after 24 and 48 h. Enterotoxin was detectable in both sterilized and unsterilized cream and ham after 24 h at 37 degrees C with an inoculum of 10(3)/g. Some strains produced detectable amounts of enterotoxin in the sterilized foods after 24 h at 30 degrees C and some produced detectable amounts of enterotoxin in the sterilized foods after 24 h at 25 degrees C with inocula of 10(4)/g. It can be concluded that staphylococcal strains producing enterotoxin at ng/ml levels in laboratory medium, not detectable by gel diffusion methods, can produce sufficient enterotoxin (ng/g) in foods to cause food poisoning.

Animals↗

Production of staphylococcal enterotoxins C1 and C2 and thermonuclease throughout the growth cycle.

Synthesis of enterotoxins C1 and C2 and thermonuclease throughout the growth cycle was investigated with Staphylococcus aureus type strains FRI137 and FRI361 and S. aureus isolates M5 (C1) and L2 (C2) of animal origin. Both enterotoxins were produced during the exponential growth phase or at the beginning of the stationary phase. The minimal incubation time (7 to 12 h) and the lowest population (10(7) to 2 x 10(9) CFU/ml) associated with detectable enterotoxin (1 to 6.5 ng/ml) were related to the total amount of toxin produced after 24 h. Thermonuclease was detected in all samples whenever enterotoxins were detected. Furthermore, strain FRI137 produced thermonuclease earlier and at lower cell populations than it did enterotoxin C1. Patterns of enterotoxin and thermonuclease synthesis did not correlate. The concentration of toxins increased throughout the growth cycle, while the concentration of thermonuclease remained constant during the last hours of the growth cycle.

Animals↗

Effect of environmental conditions on production of toxic shock syndrome toxin 1 by Staphylococcus aureus.

The kinetics of toxic shock syndrome toxin 1 (TSST-1) production by Staphylococcus aureus was studied in a fermentor in which aeration rate, atmospheric composition, pH, and temperature were controlled. The toxin was synthesized at a maximal rate during the exponential phase. High bacterial populations were not necessarily accompanied by high TSST-1 yields. Aerobiosis increased TSST-1 production, but excessive aeration had an adverse effect. Addition of CO2 enhanced TSST-1 yield by increasing toxin production rate and efficiency. Cultures with no pH control made more TSST-1 than those maintained at pH 5.5 to 7.5. Maximum TSST-1 yields were obtained when cultures were supplied with air (20 cm3/min) and CO2 (5 cm3/min) via a sintered glass sparger.

Bacterial Toxins↗

Effect of chemical modification of histidine and tyrosine residues in toxic shock syndrome toxin 1 on the serologic and mitogenic activities of the toxin.

Modification of three or four of the five histidine residues in the toxic shock syndrome toxin 1 (TSST-1) with diethylpyrocarbonate did not inhibit the precipitin reaction of the modified TSST-1 with polyvalent antisera to the toxin. Monoclonal antibody 7T did not react with the modified TSST-1, but monoclonal antibody 8T did react with the toxin. Up to 50% of the mitogenic reaction of TSST-1 was inhibited by the histidine modification. Modification of one or two of the nine tyrosine residues in TSST-1 did not inhibit the precipitin reaction with polyclonal antisera to the toxin but did inhibit 85% of the mitogenic reaction.

Animals↗

Production of a toxic shock syndrome toxin variant by Staphylococcus aureus strains associated with sheep, goats, and cows.

A toxic shock syndrome toxin (TSST) variant with an isoelectric point (pI) of 8.6 produced by an ovine-associated Staphylococcus aureus strain was described previously. Analysis of additional strains associated with sheep, goats, cows, and humans by isoelectric focusing with immunoblotting using monoclonal antibodies revealed that all 18 strains associated with sheep and all 12 strains associated with goats produced the TSST variant. Only 1 of 10 bovine-associated strains and no human-associated strains produced the variant, whereas the others produced TSST-1 (pI between 7.0 and 7.2). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis with immunoblotting indicated that both TSST-1 and the TSST variant had a molecular size of 24 kilodaltons.

Animals↗

Estimation of human dose of staphylococcal enterotoxin A from a large outbreak of staphylococcal food poisoning involving chocolate milk.

An outbreak of gastroenteritis in a school district in the United States was determined to be staphylococcal food poisoning due to 2% chocolate milk containing staphylococcal enterotoxin A (SEA). Twelve one-half pint (approx 0.28 l) cartons of the 2% chocolate milk from this outbreak were analyzed for the quantity of SEA present in the milk. The amount of SEA in the cartons varied from 94 to 184 ng with the average being 144 ng (mean = 139 +/- 45). The attack rate for vomiting among those who consumed more than one carton was greater (38.3%) than among those who consumed only one carton (31.5%) with the highest attack rate among those who consumed three or more cartons (44.4%).

Animals↗

Molecular topography of toxic shock syndrome toxin 1 as revealed by spectroscopic studies.

Molecular characterization of toxic shock syndrome toxin 1 has been carried out and compared with a group of functionally related staphylococcal enterotoxins. The secondary structure analysis of the far-UV circular dichroic spectrum of toxic shock syndrome toxin 1 revealed 6.25% alpha-helix, 51.25% beta-pleated sheets, 9.0% beta-turns, and 33.5% random coils. The pattern, in general, was similar to the staphylococcal enterotoxins. Four antigenic sites have been predicted for toxic shock syndrome toxin 1 by using the secondary structure information in combination with the hydrophilicity calculation. The location of the antigenic sites, in general, agrees with the experimental results. Topographical analysis of the tyrosine residues as determined by second-derivative UV spectroscopy [Ragone, R., Colonna, G., Balestrieri, C., Servillo, L., & Irace, G. (1984) Biochemistry 23, 1871-1875] showed that six of nine tyrosine residues are exposed to aqueous solvent. Tryptophan fluorescence quenching studies with an anionic surface quencher, I-, and a neutral quencher, acrylamide, revealed that almost all of the tryptophan residues are buried in the protein matrix as their accessibility to the surface quencher is very low (17%). Since there are only three tryptophan residues in the amino acid sequence of the toxic shock syndrome toxin 1 and there is a tyrosine residue (Tyr-15, Tyr-115, and Tyr-153) next to each of the tryptophan residues (Trp-14, Trp-116, and Trp-154), it appears the tyrosine residues not exposed to the aqueous solvent are those next to the tryptophan residues. Functional implications of the topography of the tryptophan and tyrosine residues are assessed.

Bacterial Toxins↗

Structural analysis of staphylococcal enterotoxins B and C1 using circular dichroism and fluorescence spectroscopy.

Secondary and tertiary structural parameters of two functionally and serologically related proteins, staphylococcal enterotoxins B and C1, have been determined by using circular dichroism and fluorescence spectroscopy. The secondary structures derived from the respective far-UV circular dichroic spectra were 9.5% alpha-helix, 55.0% beta-pleated sheets, 16.5% beta-turns, and 19.0% random coils for enterotoxin B and 15.0% alpha-helix, 38.0% beta-pleated sheets, 25.5% beta-turns, and 21.5% random coils for staphylococcal enterotoxin C1. The values matched well with the secondary structures derived from the amino acid sequences (Chou and Fasman method). Seven antigenic sites have been predicted for both staphylococcal enterotoxins B and C1 by using the hydrophilicity and the secondary structure information. Three of these antigenic sites appear similar. Fluorescence quantum yield of the single tryptophan residue (Trp-197) of both the enterotoxins showed the tryptophan residue in staphylococcal enterotoxin B to be approximately 46% more fluorescent than in staphylococcal enterotoxin C1. Tryptophan fluorescence quenching by the surface quencher I- and the neutral quencher acrylamide revealed that the single tryptophan residue in each of the enterotoxins is buried in the protein matrix and is not accessible to the surface quencher I-. The tryptophan residue in staphylococcal enterotoxin C1 is 14% less accessible to acrylamide than in staphylococcal enterotoxin B. The data, in general, reflect several similarities and significant differences between the two related enterotoxins.

Amino Acid Sequence↗

Enterotoxigenicity of Staphylococcus intermedius of canine origin.

Seventy-three staphylococcal strains isolated from pyrodermatitis in dogs were classified as Staphylococcus intermedius (52 strains) or Staphylococcus aureus (21 strains) on the basis of acetoin formation, anaerobic mannitol fermentation, aerobic maltose fermentation, pigmentation, coagulation of human plasma, and reaction on crystal violet agar. Enterotoxin was produced by 13 of the 52 S. intermedius strains and 6 of the S. aureus strains. The highest percentage of enterotoxigenic strains produced enterotoxins C (6 strains), D (7 strains), and E (6 strains). Four strains produced the toxic shock syndrome toxin-1. There was little difference in the antibiotic susceptibility between the enterotoxigenic and non-enterotoxigenic strains.

Animals↗