Vaginal isolates of Staphylococcus aureus associated with toxic shock syndrome

Discovery of the Lyme Disease Agent

A detailed first-hand account of the events leading up to the discovery of the Lyme disease agent has been lacking. Nearly 40 years have elapsed since the discovery of the organism that was named Borrelia burgdorferi There are thousands of articles in the scientific and medical literature on this organism and the disease that it causes. In the interval since the organism's discovery, however, misconceptions have arisen regarding not only the disease but the discovery itself. Accordingly, with this paper, we aim to fill in the details of this episode in medical history with a joint introduction, first-person accounts by the two authors, a summary of contemporaneous events, and concluding comments. The history of the discovery of the Lyme disease agent has threads originating in different places in the United States. Studies on Long Island, NY, provided the epidemiological thread of studies on rickettsial diseases and babesiosis, linking the latter with the cutaneous manifestation of Lyme disease, now known as erythema migrans. The Long Island thread intersected Montana's Rocky Mountain Laboratories thread of studies on a relapsing fever Borrelia and its cultivation and expertise in vector biology. This intersection made possible the discovery of the spirochete and its recovery from patients. This paper stresses that what may seem to have been an individual scientific discovery is actually the product of several threads coming together and is attributable to more people than appreciated.

Co-production of staphylococcal enterotoxin A with toxic shock syndrome toxin-1 (TSST-1) enhances TSST-1 mediated mortality in a D-galactosamine sensitized mouse model of lethal shock

It has previously been reported that staphylococcal enterotoxin A (SEA) is frequently co-expressed with toxic shock syndrome toxin-1 (TSST-1) in menstrual Toxic Shock Syndrome (MTSS)-associated Staphylococcus aureus. It was hypothesized that co-production of SEA and TSST-1 might yield a more virulent strain than one that produced TSST-1 but not SEA. To test this hypothesis, a TSST-1+/SEA- derivative of S. aureus RN3984 (TSST-1+/SEA+) was constructed by plasmid integration, and the isogenic pair were introduced into a D-galactosamine sensitized mouse model of lethal shock. At 72 h, 27 out of 30 (90%) mice inoculated with the parental strain died, as compared to 21 out of 30 (70%) mice inoculated with the isogenic derivative (P=0.05, Fisher's exact test; 1-tailed; 95% confidence limits, 0.80-20.80). Our results suggest that co-production of SEA with TSST-1 does enhance the ability of this strain of S. aureus to induce lethal shock in vivo. This enhanced virulence could be due to an additive or synergistic activity of the toxin combination on T cell proliferation and cytokine production in the animal model.

Staphylococcus aureusisogenic mutant, deficient in toxic shock syndrome toxin-1 but not staphylococcal enterotoxin A production, exhibits attenuated virulence in a tampon-associated vaginal infection model of toxic shock syndrome

Since menstrual toxic shock syndrome (MTSS) is associated with a predominant clone of Staphylococcus aureus which produces both toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin A (SEA), we sought to clarify the role of TSST-1 in a tampon-associated vaginal infection model in New Zealand White (NZW) rabbits, using isogenic tst+/sea+S. aureus mutants in which tst was inactivated by allelic replacement. Rabbits infected with the tst-/sea+strain became ill within 3 days, with fever, weight loss, conjunctival hyperemia, and lethargy. Mortality was significantly higher with the tst+/sea+strain compared to its tst-/sea+isogenic derivative (4/13 vs. 0/14; p < 0.05, Fisher's exact test, 2-tailed). Mean fever index was higher (p < 0.005; t test, 2-tailed) and weight loss more sustained among survivors in the tst+/sea+group. Furthermore, culture filtrates from the tst+/sea+strain induced a significantly greater response in mitogenesis and TNFalpha secretion from rabbit splenocytes in vitro compared to the tst-/sea+isogenic derivative. Thus, regardless of the role of SEA, TSST-1 significantly contributed to both morbidity and mortality in this tampon-associated vaginal infection model in NZW rabbits. This is the first demonstration of the potential role of TSST-1 and SEA in the pathogenesis of MTSS with a MTSS-associated clinical S. aureus strain in a relevant animal model.Key words: toxic-shock syndrome toxin-1, superantigens, rabbit model.

Staphylococcal toxic shock syndrome in a paediatric burn unit

A case of staphylococcal toxic shock syndrome (TSS) in a 15-year-old patient undergoing reconstructive burn surgery is reported. This syndrome, first described in menstruating women using tampons, can also occur as a postsurgical complication. The epidemiology, microbiology, clinical presentation and management of non-menstrual TSS are discussed and correlated with the patient present. We advise caution in the use of occlusive dressings and recommend constant isolation of patients with open wounds colonized with a TSST-1 producing strain of Staph. aureus.

Expression of type 8 capsular polysaccharide and production of toxic shock syndrome toxin 1 are associated among vaginal isolates of Staphylococcus aureus

A colony immunoblot method was developed for serotyping the capsular polysaccharides expressed by Staphylococcus aureus isolates. The method was rapid and specific and was performed with either polyclonal or monoclonal antibodies specific for each of the capsule types. S. aureus isolates were obtained from patients with toxic shock syndrome (TSS) or other staphylococcal infections and from asymptomatic women with vaginal colonization. Among the vaginal isolates of S. aureus, expression of the type 8 capsule was significantly (P less than 0.001) more frequent among strains that produced TSS toxin 1 (TSST-1) than it was among TSST-1-negative strains. In contrast, the frequency of type 8 capsule expression was similar among both TSST-1-positive and -negative strains of S. aureus from patients with nonvaginal TSS. When all vaginal and nonvaginal isolates were compared, TSST-1-negative S. aureus strains were equally distributed among the type 5 and 8 and nontypeable capsule groups, whereas TSST-1-positive strains were predominantly capsule type 8.

A single clone of Staphylococcus aureus causes the majority of cases of toxic shock syndrome

Genetic relationships among 315 isolates of the bacterium Staphylococcus aureus expressing toxic shock syndrome toxin-1 (TSST-1) recovered primarily from humans with toxic shock syndrome (TSS) in five countries on two continents were determined by analyzing electrophoretically demonstrable allelic variation at 20 chromosomal enzyme loci. Forty-nine distinctive electrophoretic types (ETs), representing multilocus enzyme genotypes, were identified. Cluster analysis of the ETs revealed two major phylogenetic divisions separated at a genetic distance of 0.35 and seven branches diverging from one another at distances greater than or equal to 0.20. A single clone (ET 41) accounted for 88% of cases of TSS with a female urogenital focus and 53% of TSS cases involving nonurogenital (predominantly wound) infections. With few exceptions, strains representing different phylogenetic lines had characteristic TSST-1 gene (tst) restriction fragment length polymorphism patterns obtained by digestion of genomic DNA with Cla I. Strains recovered from ovine and bovine hosts with mastitis were genotypically distinct from the major human TSS clone. The expression of TSST-1 in cell lineages representing the total breadth of multilocus genotypic diversity in the species S. aureus as a whole is interpreted as evidence that the TSST-1 gene is evolutionarily old. The recovery of a single clone from the majority of individuals afflicted with TSS having a urogenital focus and from the genital tract of a large proportion of asymptomatic female carriers strongly suggests that this clone is especially well adapted for colonization of these anatomic sites.

Staphylococcal and streptococcal pyrogenic toxins involved in toxic shock syndrome and related illnesses

Toxic-shock syndrome (TSS) is an acute onset, multiorgan illness which resembles severe scarlet fever. The illness is caused by Staphylococcus aureus strains that express TSS toxin-1 (TSST-1), enterotoxin B, or enterotoxin C. TSST-1 is associated with menstrual TSS and approximately one-half of nonmenstrual cases; the other two toxins cause nonmenstrual cases, 47% and 3%, respectively. The three toxins are expressed in culture media under similar environmental conditions. These conditions may explain the association of certain tampons with menstrual TSS. Biochemically, the toxins are all relatively low molecular weight and fairly heat and protease stable. Enterotoxins B and C, share nearly 50% sequence homology with streptococcal scarlet fever toxin A; they share no homology with TSST-1 despite sharing numerous biological properties. Numerous animal models for development of TSS have suggested mechanisms of toxin action, though the exact molecular action is not known. The toxins are all potent pyrogens, induce T lymphocyte proliferation, requiring interleukin 1 release from macrophages, suppress immunoglobulin production, enhance endotoxin shock, and enhance hypersensitivity skin reactions. The genetic control of the toxins has been studied and suggests the exotoxins are variable traits. Some additional properties of TSS S. aureus which facilitate disease causation have been clarified.

Colony immunoblot assay for the detection of staphylococcal toxic shock syndrome toxin 1 (TSST-1) with anti-TSST-1 F(ab')2 fragments

Toxic shock syndrome toxin 1 (TSST-1), an exoprotein of Staphylococcus aureus, is strongly implicated in the pathogenesis of TSS. Detection of TSST-1, however, is often hindered in immunoassays because of the cosecretion of protein A, a genetic trait which appears to be coordinately expressed with other exoproteins in S. aureus. We developed a colony immunoblot assay for rapid screening of TSST-1-producing S. aureus using TSST-1-specific rabbit F(ab')2 fragments. The sensitivity and specificity of this method were compared with those of a quantitative noncompetitive enzyme-linked immunosorbent assay (ELISA) for 34 S. aureus isolates (17 TSS-associated and 17 non-TSS-associated isolates). Cosecreted protein A in culture supernatants was evaluated by a quantitative competitive ELISA. The results clearly indicated the superiority of F(ab')2 fragments in eliminating nonspecific reactivity of protein A in the colony immunoblot assay. The sensitivity of the immunoblot with TSST-1-specific F(ab')2 was similar to that with whole immunoglobulin G (94 versus 82%, respectively; P = 0.601, Fisher's exact test), but the specificity was markedly improved (94 versus 59%, respectively; P = 0.039). Among TSST-1-negative isolates (as determined by ELISA), strains which gave false-positive results in the immunoglobulin G immunoblot assay produced higher amounts of protein A than strains which gave true-negative results (P = 0.08, Mann-Whitney rank sum test, one tailed). Among strains positive for TSST-1, the level of TSST-1 detected in culture supernatants correlated inversely with the amount of protein A secreted (rs = -0.64; P less than 0.01, Spearman rank correlation). These findings validate the utility of a rapid screening method for the detection of TSST-1-producing S. aureus and support the concept of coordinate secretion of exoproteins in S. aureus.

Characterization of staphylococci from patients with toxic shock syndrome

Fifty staphylococcal strains that produced toxic shock syndrome (TSS) toxin 1 and that were isolated from patients with TSS were characterized. One strain had more properties that were characteristic of Staphylococcus hyicus than of Staphylococcus aureus. Forty-four strains had the same properties or differed in only one property. Thirty-five of the 50 strains produced either enterotoxin A or C or both in addition to TSS toxin 1.

Association of toxic shock toxin-1 determinant with a heterologous insertion at multiple loci in the Staphylococcus aureus chromosome

Most Staphylococcus aureus strains associated with toxic shock syndrome and producing toxic shock syndrome toxin 1 (TSST-1) require tryptophan because of a genetic defect in tryptophan biosynthesis. The association between TSST-1 production and tryptophan auxotrophy was not correlated with the phage type, the colonization site, or the disease status of the patient from whom the isolate came. Protoplast fusion and transformation mapping located the genetic determinant of TSST-1 production (tst) very close to the trp operon in such strains and very close to tyrB in a Trp+ TSST-1+ strain. Southern blot hybridization of ClaI-restricted chromosomal DNA with a tst-specific probe revealed a common homologous segment in all of the Trp+ strains with tst linked to tyrB. These results confirmed that the tst determinant in Trp- strains is located at one site, whereas in Trp+ TSST-1+ strains the determinant is located elsewhere on the S. aureus chromosome. It is suggested that the TSST-1 determinant is associated with the insertion of a transposonlike segment into several sites on the S. aureus chromosome.

Toxic shock syndrome

In the past 10 years, we have learned much about TSS and S. aureus and its toxins. A number of important biologic principles have been reemphasized in this first decade of TSS research: S. aureus is a very complex organism, one not likely to yield quick answers; in vitro observations must always be confirmed in the patient; animal models may not always be reliable replicates of human disease; and epidemiologic associations cannot be equated with causation. Toxic shock is an intricate phenomenon with many interesting scientific facets. Unraveling its mysteries will undoubtedly teach us more about the complex interaction of patients and microorganisms.

Two-site monoclonal antibody quantitative ELISA for toxic shock syndrome toxin-1

A two-site monoclonal antibody (MAB) quantitative enzyme-linked immunosorbent assay (ELISA) was developed that enables quantitation of toxic shock syndrome toxin-1 (TSST-1) down to 0.25 ng/ml and detection of TSST-1 to 0.06 ng/ml. Interference by Staphylococcus protein A was eliminated by incorporating normal rabbit serum into the test sample diluent. In the process of selecting an MAB pair for a two-site 'sandwich'-type ELISA, the MABs were screened for inhibition or common epitope binding. Some MABs that reacted with antigen that was adsorbed to a polystyrene well would not bind to antigen that was presented in a more natural configuration, as in the case of antigen immobilized by trapping antibody. Conversely, MABs that reacted with antigen that was immobilized by another antibody did not all function as trapping antibodies when adsorbed directly to a polystyrene surface. ELISAs that used polyclonal antibodies in the capture mode and MAB conjugate as the second antibody were generally more sensitive than were those that used polyclonal antibodies for both capture and indicator functions. MAB screening and selection schemes should be carefully designed to evaluate MABs in the mode in which they will be used in the final assay.

Production of gamma-hemolysin and lack of production of alpha-hemolysin by Staphylococcus aureus strains associated with toxic shock syndrome

The hemolytic activity of toxic shock syndrome isolates of Staphylococcus aureus is enhanced when agarose is substituted for agar in blood plates or when strains are grown in liquid culture in the presence of 20% (vol/vol) CO2 in air. Hemolytic activity of a representative panel of toxic shock syndrome isolates was rigorously assessed both on blood agar and in liquid culture to unequivocally identify the predominant hemolysins produced. As determined by isoelectric focusing and Western immunoblotting, 15 of 15 TSS isolates produced gamma-lysin and 10 of 15 produced delta-lysin. None produced beta-lysin, and only 2 of 15 produced alpha-lysin. The low rate of alpha-lysin production was a most striking characteristic, since all strains were found to have the alpha-lysin gene by Southern blot hybridization.

Reinfection of bovine mammary glands following dry-cow antibiotic therapy

Dry-cow antibiotic therapy (DCT) was administered to quarters with Staphylococcus aureus or streptococcal infections and the quarters were closely monitored for the presence of new or reactivated mammary infections throughout the dry period and the following lactation. Strains of S. aureus were characterized using a selection of biotyping tests to allow a comparison of S. aureus strains isolated before and after DCT. Cows with 3-4 quarters infected prior to DCT had a high susceptibility to reinfection in the following year. In contrast, for cows with 1-2 quarters infected prior to DCT and for heifers with no previous history of infection, the susceptibility to reinfection or new infection was very low. The majority of the S. aureus infections appearing in the lactation following DCT were due to S. aureus strains which differed from strains isolated prior to DCT, suggesting that these were new infections. Histopathological examination of quarters which had had recurrent S. aureus infections revealed lesions typical of chronic S. aureus mastitis, including extensive lobular fibrosis and atrophy.

Production and characterization of monoclonal antibodies to toxic shock syndrome toxin 1 and use of a monoclonal antibody in a rapid, one-step enzyme-linked immunosorbent assay for detection of picogram quantities of toxic shock syndrome toxin 1

Twenty-six hybridoma cell lines that produced monoclonal antibodies to toxic shock syndrome toxin 1 (TSST-1) were generated by immunizing mice with a highly purified preparation of TSST-1 and fusing their splenic lymphocytes with SP2/0-Ag-14 cells. One monoclonal antibody of the immunoglobulin G1 isotype, designated as PEC-1 10-2SCH, was selected for extensive study. The specificity of this antibody was determined by testing spent culture fluid filtrates of TSST-1- and non-TSST-1-producing strains of Staphylococcus aureus by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and enzyme-linked immunoelectrotransfer blot techniques. Monoclonal antibody PEC-1-10-2SCH was specific for TSST-1-producing strains of S. aureus, reacting with TSST-1 and two other proteins which appear to be unique to S. aureus strains that produce TSST-1. Monoclonal antibody PEC-1-10-2SCH was used in conjunction with polyclonal rabbit antibodies to TSST-1 in a rapid, one-step, sensitive, specific, and quantitative enzyme-linked immunosorbent assay. This assay was shown to be more sensitive, faster, and simpler to perform than previously described isoelectric focusing, immunodiffusion, and solid-phase radioimmunoassays for TSST-1. Monoclonal antibody PEC-1-10-2SCH was not reactive with Staphylococcus protein A under the conditions of the test.

Characterization of clinical strains of Staphylococcus aureus associated with pneumonia

A total of 5 Staphylococcus aureus strains from patients with postinfluenzal staphylococcal pneumonia, 7 from burn patients with staphylococcal pneumonia, and 21 from the nasopharynx of carriers were phenotypically characterized. All or most strains produced coagulase, clumping factor, DNase, thermostable DNase, protease, gelatinase, lipase, and pigment; the strains were low to moderate producers of extracellular protein A, fibrinolysin, and alpha-hemolysin. All strains were sensitive to mercury, half were sensitive to arsenate and cadmium, and 67 to 92% were resistant to penicillin. Differences between strains were not statistically significant. Cell surface hydrophobicity was determined by measuring percent adsorption to hexadecane. Hydrophobicity of postinfluenzal staphylococcal pneumonia strains was significantly lower than that of pneumonia strains from burn patients and carriers (P less than 0.005). Immunoblot experiments with sera immune to one clinical test strain allowed the separation of all strains into three groups based on probe-positive reactions with primarily four staphylococcal polypeptides (154,200, 130,000, 77,100, and 64,400 molecular weight). The difference in distribution of clinical and carrier strains was highly significant (P = 0.007).

Acquired ability of Staphylococcus aureus to produce toxic shock-associated protein and resulting illness in a rabbit model

Staphylococcus aureus from patients with toxic shock syndrome (TSS) produce TSS toxin 1. We transferred, by a bacteriophage, the ability to produce TSS toxin 1 from a TSS toxin 1-positive to a TSS toxin 1-negative strain of S. aureus. This recombinant strain produced TSS toxin 1 as confirmed by isoelectric focusing, immunodiffusion, radioimmunoassay, and autoradiography. The recombinant produced TSS-like illness in rabbits, and was significantly (P less than 0.001) more lethal than the recipient strain. Both strains produced fever and diarrhea, but, in addition, rabbits challenged with the recombinant also developed lowered blood pressure (P = 0.002), conjunctival hyperemia, erythroderma, and respiratory distress. Histopathological findings in rabbits challenged with the recombinant strain were remarkably similar to those described for humans with TSS, e.g., erythrophagocytosis, liver "triaditis," and vasodilatation. This study demonstrates that this protein may contribute to the pathogenesis of the TSS.

Animal studies of toxic shock syndrome

Toxic shock syndrome (TSS) was first described in 1978 and since that year over 2990 cases have been reported to the Communicable Disease Center. The estimated case-fatality rate is 5.6%. The disease is characterized by fever, hypotension, rash, desquamation, and involvement of at least three other organ systems. Approximately 85% of the cases are menstrually related and tampon use has been identified as a risk factor. The remaining 15% of the cases occur in both sexes and are not specifically related to age or geographic location. In all cases where sought there is evidence for infection by Staphylococcus aureus. Nearly all S. aureus isolates are phage type 52/29 and elaborate a unique exotoxin (toxic shock toxin). This review explores both the successful and unsuccessful attempts to induce toxic shock or a TSS-like syndrome in animals other than man. The review identifies the baboon as an animal model of TSS and discusses the clinical and pathologic sequellae, in this species, after exposure to purified toxic shock toxin.

Presence of toxic shock toxin in toxic shock and other clinical strains of Staphylococcus aureus

Toxic shock toxin (TST), also known as pyrogenic exotoxin C (Schlievert et al., J. Infect. Dis. 143:509-516, 1981) and staphylococcal enterotoxin F (Bergdoll et al., Lancet i:1017-1021, 1981), was purified from toxic shock strains of Staphylococcus aureus by preparative isoelectric focusing and by chromatofocusing. Neither method produced an absolutely pure protein as determined by silver staining of sodium dodecyl sulfate-acrylamide gels, although chromatofocusing was the better method of the two. Three molecular weight variants of the protein were found in the two toxic shock syndrome strains that were studied, regardless of the purification method that was used. An isoelectric point of 7.15 and molecular weights of 21,400, 22,100, and 23,200 were determined for the different forms of the protein from electrophoresis data. A sedimentation coefficient of 2.3S was determined by sucrose gradient centrifugation, and a Stokes radius of 2 X 10(-7) cm was determined by gel filtration. An average molecular weight of 18,900 for all of the TST forms was calculated from these data by the Stokes-Einstein equation. A survey for TST in 32 control and 46 toxic shock strains of S. aureus by isoelectric focusing and by agarose gel double immunodiffusion with specific rabbit antiserum revealed that the isoelectric focusing method tends to overestimate the number of TST-positive strains because of the detection of non-TST, neutral staphylococcal proteins. Based on immunodiffusion data, the association of TST with toxic shock strains was found to be 100% in vaginal isolates and 62% in non-vaginal isolates. In the control strains, TST was found in 16% of the vaginal strains and 23% of the non-vaginal strains. The value of this toxin as a marker for toxic shock and its relationship to the pathogenesis of this disease are discussed.

Phenotypic distinctiveness of Staphylococcus aureus strains associated with toxic shock syndrome

Twenty Staphylococcus aureus strains from patients with toxic shock syndrome (TSS) and 20 from control patients (non-TSS) with infection but no clinical evidence of TSS were compared phenotypically in a collaborative, blinded, randomized study. TSS strains were significantly (P less than 0.05) more likely than non-TSS strains to produce various previously described but related toxic shock-associated proteins (pyrogenic exotoxin C, enterotoxin F, and TSS marker protein), as well as differing in other distinctive phenotypic characteristics, such as hemolysis, bacteriocin susceptibility, arsenate resistance, pigment production, and casein proteolysis. TSS strains were significantly less likely to carry plasmids than control strains. A combination of two variables--proteolysis and toxic shock-associated protein production--statistically accounted for all other phenotypic variations between TSS and non-TSS strains. Only proteolysis covaried with all other significant variables, suggesting a primary role in the phenotypic distinctiveness of TSS S. aureus strains and possibly in the pathogenesis of TSS.

Two coagulase-variant forms of Staphylococcus aureus isolated from blood cultures

Two coagulase-variant forms of Staphylococcus aureus were isolated from blood cultures of a patient with infective endocarditis. The coagulase-positive isolate was hemolytic, whereas the coagulase-negative isolate was nonhemolytic. All other properties examined were identical in both strains. Since coagulase-negative S. aureus strains have been isolated from clinical specimens, laboratories should consider using a combination of other biological properties along with coagulase production for the identification of S. aureus.

Production of toxic-shock-associated protein(s) in Staphylococcus aureus strains isolated from 1956 through 1982

A total of 281 Staphylococcus aureus strains selected from those submitted to the Centers for Disease Control for phage typing between 1956 and 1982 were tested for the production of toxic-shock-associated protein (TSAP) by isoelectric focusing (IEF) and solid-phase radioimmunoassay. The results suggest that the observed temporal trends in the incidence of toxic-shock syndrome were not primarily due to changes in the distribution of TSAP-positive strains of S. aureus. Overall, 39 (14%) were TSAP positive by both methods. The earliest positive strain was an isolate submitted in 1957. TSAP-positive strains were most prevalent in the group of isolates submitted in 1976 for which 29% reacted, but the percent positive subsequently declined for isolates submitted in later years. TSAP production was more frequent among strains of phage types 29, 29/52, and 52 than among other strains. The use of IEF to identify TSAP detected false-positive proteins. Seven strains were positive by IEF and negative by solid-phase radioimmunoassay, whereas only one was positive by solid-phase radioimmunoassay and negative by IEF.

Association of high levels of serum antibody to staphylococcal toxic shock antigen with nasal carriage of toxic shock antigen-producing strains of Staphylococcus aureus

Forty-four asymptomatic male subjects were examined for their nasal carriage of strains of Staphylococcus aureus capable of producing staphylococcal toxic shock antigen (TSA), an exotoxin implicated in the pathogenesis of toxic shock syndrome. In addition, the levels of antibody to TSA in sera from these subjects were determined by an enzyme-linked immunosorbent assay. S. aureus was isolated from the anterior nares of 23 subjects. Of those 23 isolates of S. aureus, 9 were found to produce TSA. All individuals carrying strains of S. aureus capable of producing TSA had high to moderate levels of antibody to TSA. In contrast, those individuals carrying strains not producing TSA had levels of antibody to TSA ranging from high to nondetectable. A second examination of nasal samples from 42 of these subjects revealed that 86% of those carrying S. aureus initially still carried S. aureus after a period of 3 months; all subjects found to carry TSA-producing strains initially and that were examined a second time yielded TSA-producing strains once again.

Toxic shock syndrome--an adolescent disease

Over the past 3 years, toxic shock syndrome (TSS) has emerged from virtual obscurity to become a household word. The syndrome, which most commonly occurs in previously healthy women during menses, is characterized by the sudden onset of headache, malaise, high fever, myalgia, diarrhea, syncope, skin rash, and evidence of multisystem involvement with progression to desquamation of skin, nails, and hair. Death has occurred in 5%-10% of cases. Use of highly absorbent tampons and the presence of toxin-producing staphylococcus aureus have been implicated in the pathogenesis of this syndrome. Treatment with beta-lactamase-resistant antibiotics and discontinuation of tampon use are associated with reduction in the risk of recurrence. To date, 42% of cases have occurred in females under the age of 19 years. Accordingly, physicians who care for adolescents should be knowledgeable about the syndrome's myriad manifestations and treatment, as well as the possibility of prevention through education about menstrual practices.

Effect of strain of Staphylococcus aureus on synergism with Candida albicans resulting in mouse mortality and morbidity

Nine Staphylococcus aureus strains isolated from patients with toxic shock syndrome (TSS), two strains from non-disease-associated sources, and four strains from disease (not TSS)-associated sources were characterized for the intraperitoneal dose necessary to kill 50% of exposed animals (LD50) and toxic shock toxin production and studied for synergistic effects on mouse mortality and morbidity when combined with a sublethal dose of Candida albicans and inoculated intraperitoneally. Representative toxic shock toxin-producing strains (free of other enterotoxins) exhibited the following unique set of characteristics when inoculated intraperitoneally into mice and compared with all other strains tested: (i) lowest virulence when inoculated alone into mice as determined by the LD50; (ii) greatest synergistic decrease in LD50 (up to 70,000-fold as compared to up to 200-fold for other strains) when combined with C. albicans and injected intraperitoneally; and (iii) induced a characteristic, dose-independent, temporal death pattern in dually injected animals. When sublethal dual doses were used, animals receiving disease (TSS and not TSS)-associated S. aureus in combination with C. albicans developed symptoms, but some differences in symptomatologies, depending on the strain, were observed. The symptoms included conjunctivitis; gastrointestinal, neurological, and circulatory abnormalities; rash followed by desquamation; and patchy baldness. Although overlap in symptoms between animal treatment groups was observed, certain symptoms (neurological sequeae and petechial hemorrhages) were observed only in animals inoculated with a specific S. aureus strain combined with C. albicans. Animals receiving sublethal dual doses, which included non-disease-associated S. aureus, did not develop symptoms. When Staphylococcus epidermidis was combined with C. albicans and inoculated into mice, no synergistic effects on morbidity or mortality were observed.

Toxic-shock syndrome: a commentary and review of the characteristics of Staphylococcus aureus strains

Toxic-shock syndrome (TSS) was first identified in 1978 in children as a toxin-mediated illness associated with Staphylococcus aureus. Extensive publicity ensued when the strong association of this disease with menses and tampon use was recognized in 1980. Since that time, investigation into the epidemiology, clinical manifestations and pathogenesis of TSS has coincided with a decreasing incidence of disease. A unique exotoxin has been isolated under varying physico-chemical conditions from TSS-associated strains of S. aureus and its effect on immune function and other parameters both in vitro and in vivo described. In addition, TSS-associated S. aureus strains have been found to have characteristic heavy metal susceptibility patterns, to be lysogenized and to show decreased hemolysis on sheep blood agar. Preliminary results of the prevalence of TSS-associated strains of S. aureus and of the theories of pathogenesis are reviewed.

Production of staphylococcal enterotoxin F and pyrogenic exotoxin C by Staphylococcus aureus isolates from toxic shock syndrome-associated sources

A total of 136 isolates of Staphylococcus aureus were tested for production of staphylococcal enterotoxin F (SEF) and pyrogenic exotoxin C (PEC), both of which have been identified as reliable indicators of toxic shock syndrome (TSS)-associated strains. SEF and PEC production by isolates from TSS-associated and other sources was tested independently in two laboratories, after which the two sets of data were compared. A 100% concordance between SEF and PEC production was obtained. The TSS toxin candidates were produced by 30 of 136 isolates, and in all instances SEF and PEC were made concurrently by the same strains; in no case was one toxin made and not the other. In the five groups of S. aureus tested, toxins were detected as follows: 23 of 25 (92%) acute TSS isolates, 2 of 48 (4.2%) genital non-TSS isolates, 2 of 16 (12.5%) recovered TSS isolates, 1 of 23 (4.3%) clinical nongenital isolates, and 2 of 24 (8.3%) enterotoxigenic food outbreak isolates. Comparison of purified SEF and purified PEC by immunological and biochemical criteria by immunodiffusion, isoelectric focusing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blot analysis show that the toxins are immunologically identical and strongly suggest that the two nominal TSS toxins are in fact a single protein.

Characterization of the hemolytic activity of Staphylococcus aureus strains associated with toxic shock syndrome

The hemolytic activity of 32 vaginal isolates of Staphylococcus aureus from patients with typical toxic shock syndrome (TSS) was contrasted with that of 50 vaginal isolates from patients without TSS, using a standardized inoculum (10(5) CFU) on 5% sheep blood agar after 48 h of incubation under 30% CO2. Additionally, 7 nongenital isolates from patients with nonmenstrual TSS and 57 strains of nongenital control isolates were included for comparison. Vaginal TSS strains were significantly less hemolytic than non-TSS S. aureus strains of either genital (P less than 0.001) or nongenital (P less than 0.01) origin. Vaginal TSS S. aureus strains were also less hemolytic than were nongenital TSS S. aureus strains (P less than 0.02). This reduced hemolytic activity of genital TSS S. aureus strains may provide a useful marker for screening and further delineation of toxigenic S. aureus associated with menstrually related TSS.

Characterization of Staphylococcus aureus isolates from patients with toxic shock syndrome, using polyethylene infection chambers in rabbits

Isolates of Staphylococcus aureus from patients with toxic shock syndrome (TSS) were compared with non-TSS strains of S. aureus with respect to their virulence in rabbits. When the organisms were injected into subcutaneous chambers (perforated polyethylene golf balls) to assess virulence, a rapid mortality was observed with TSS but not with non-TSS strains. Of 16 TSS strains, 11 caused lethal infections in 33 rabbits tested, and none of the 5 control strains caused mortality in 10 rabbits. This evidence of enhanced virulence associated with TSS strains did not appear to be associated with the size of the inoculum. In addition, strains which produced lethal infections appeared to do so despite a reduction in the size of the original inoculum during the first 24 h. All of the TSS strains and none of the non-TSS strains elaborated extracellular protein(s) with a neutral pI when grown in a dialyzed beef heart medium. No other physiological difference was noted between the TSS and non-TSS strains.

A simple purification method for enterotoxin F produced by Staphylococcus aureus and some properties of the toxin

Staphyloccoccus aureus enterotoxin F (SEF), which is associated with S. aureus strains isolated from toxic-shock-syndrome patients, was purified by successive chromatography on CM sephadex C-25 and gelfiltration on sephadex G-75. When tested by disc-polyacrylamide gel-electrophoresis the toxin migrated as a homogeneous protein. In SDS-polyacrylamide gel-electrophoresis three protein bands were observed. The main component had a mol wt of 23 000 and the two minor components had a mol wt less than 13 000. By iso-electric focussing a main protein band with an iso-electric point of 7.2 was obtained. The LD50 for rabbits (3-3.5 kg) by subcutaneous and intravenous application of SEF was 6 micrograms and 180 micrograms, respectively. Antibodies to SEF prepared in a sheep did not react with other staphylococcal enterotoxins (A to E).

The effect of menses and use of catamenial products on cervical carriage of Staphylococcus aureus

Cervical specimens for culturing for Staphylococcus aureus were obtained during menstruation and at midcycle from 40 users of tampons and twelve users of pads. Nine women (two users of pads and seven users of tampons) were colonized by S. aureus. Colonization rates of the cervix were similar for users of tampons and users of pads (18% and 17%, respectively). S. aureus was isolated more frequently during menstruation (17%) than at midcycle (5.8%). Six women had positive menstrual cultures without a positive midcycle culture, whereas no women had positive midcycle cultures and negative menstrual cultures. These observations indicate a significant (p less than 0.05) association of menses with staphylococcal colonization of the cervix.