Phenotypic distinctiveness of Staphylococcus aureus strains associated with toxic shock syndrome

Infectious Diseases and the Kidney in Children

The kidney is involved in a wide range of bacterial, viral, fungal, and parasitic diseases. In most systemic infections, renal involvement is a minor component of the illness, but in some, renal failure may be the presenting feature and the major problem in management. Although individual infectious processes may have a predilection to involve the renal vasculature, glomeruli, interstitium, or collecting systems, a purely anatomic approach to the classification of infectious diseases affecting the kidney is rarely helpful because most infections may involve several different aspects of renal function. In this chapter, a microbiological classification of the organisms affecting the kidney is adopted. Although they are important causes of renal dysfunction in infectious diseases, urinary tract infections and hemolytic uremic syndrome (HUS) are not discussed in detail because they are considered separately in chapters XX and XX, respectively.

Bacteremic nonmenstrual staphylococcal toxic shock syndrome associated with enterotoxins A and C

We report a case of bacteremic nonmenstrual staphylococcal toxic shock syndrome (STSS) producing staphylococcal enterotoxins A and C. The bloodstream isolation of Staphylococcus aureus, as well as the production of enterotoxins A and C, are unusual as separate entities, and distinctly uncommon when found together.

Toxin-mediated streptococcal and staphylococcal disease

After several decades of seemingly decreasing virulence, streptococcal and staphylococcal infections have reemerged as a major source of morbidity and mortality. Within the past 2 decades, not only have well-established diseases such as rheumatic fever begun to reappear. but also many new entities, such as toxic shock syndrome, streptococcal toxic shock syndrome, recurrent toxin-mediated perineal erythema, and recalcitrant erythematous desquamating disorder have been described. Central to the renewed importance of these bacteria has been the production of circulating toxins, which often function as superantigens in causing the clinical manifestations, morbidity and mortality associated with these diseases.

A comparison of phenotypic properties of Staphylococcus aureus isolated from burned children and other patient groups

This study aimed to determine whether strains of Staph. aureus isolated from children on our paediatric burns unit were different from strains isolated from other patient groups. Of particular interest was the incidence of toxin production amongst the different patient groups and the potential association with toxic shock syndrome (TSS). Wound isolates of Staph. aureus were collected from three patient groups: (1) hospital inpatients, (2) community patients and (3) patients from a regional burns unit. One hundred isolates were collected from each group (n = 300). Each isolate was tested for enterotoxin and TSST-1 production, phage type, antibiogram and tryptophan dependence. The results were compared, to determine whether there were any differences between the isolates from each of these patient groups. There were some variations in antibiotic sensitivity patterns and phage type of the isolates between the different patient groups but there was no significant difference in the incidence of toxin production, which was an important observation. The 100 isolates collected from this burns unit were derived from 58 patients. The colonization patterns of the Staph. aureus showed that 12 patients were colonized by more than one isolate and that these were a mixture of toxin-positive and toxin-negative strains. The medical records were examined for evidence of TSS; there was a higher incidence of toxic episodes in the patients colonized with strains which produced TSST-1 toxin.

New perspectives on the management of septic shock in the cancer patient

Septic shock is a common life-threatening problem, usually presenting with fever, tachycardia, tachypnea, and often a source of infection. The cardiac index is increased, with a decreased systemic vascular resistance, and a reversibly decreased ejection fraction with an increased end diastolic volume. The myocardial depression is most likely caused by a circulating humoral substance that depresses myocardial contractility. The initial treatment of septic shock is aggressive fluid resuscitation and antibiotic therapy, with vasopressors and inotropes being indicated in those patients who do not respond adequately to fluids. Therapy directed against the mediators of septic shock is theoretically promising, but to date has not been successful.

Lipoteichoic acid from Staphylococcus aureus depresses contractile function of human arteries in vitro due to the induction of nitric oxide synthase

The aim of this study was to clarify the role of Gram-positive organisms in the genesis of sepsis. In the present study, we investigated the effect of lipoteichoic acid (LTA) from the cell wall of Staphylococcus aureus on contractions elicited by norepinephrine (NE) in rings cut from human gastroepiploic arteries. LTA diminished the contractile response to NE. This attenuation began after several hours of exposure, whether or not endothelium was present. The cyclic guanosine monophosphate content of LTA-treated rings was higher than that of control rings, whether there was a functional endothelium. These LTA-mediated responses were reduced significantly by inhibitors of nitric oxide (NO) synthase and guanylate cyclase. All of this indicates that the main underlying cause of the vascular hyporeactivity to NE was a massive generation of No. In addition, cycloheximide, an inhibitor of inducible NO synthase, prevented the attenuation of NE-induced contractions caused by LTA. Thus, our results offer strong supporting evidence that the important factor in the genesis by Gram-positive organisms of a diminished contractile response to pressor drugs is their induction of inducible NO synthase in smooth muscle.

Syndromes with renal failure and shock

Renal failure occurs commonly in children with shock, coagulopathy and multi-organ failure. Successful management of these patients requires not only management of the renal failure, but recognition and treatment of the underlying process. In addition to common and well-recognised causes of renal failure and shock, such as Gram-negative sepsis, there are a number of syndromes which are either less well recognised or confined to specific geographic locations. This article reviews the clinical and epidemiological features of the syndromes with shock and renal failure, focusing on the more recently recognised syndromes such as staphylococcal and streptococcal toxic shock syndrome, haemorrhagic shock and encephalopathy syndrome and viral haemorrhagic fevers.

Toxic shock syndrome toxin-secreting Staphylococcus aureus in Kawasaki syndrome

Kawasaki syndrome (KS), the main cause of acquired heart disease in children, is associated with the selective expansion of V beta 2+ T cells in peripheral blood. Our study suggests that KS may be caused by a superantigen--a staphylococcal or streptococcal toxin. Bacteria were cultured without knowledge of their origin, from the throat, rectum, axilla, and groin of 16 patients with untreated acute KS and 15 controls. Bacteria producing toxins were isolated from 13 of 16 KS patients but from only 1 of 15 controls (p < 0.0001). Toxic shock syndrome toxin (TSST) secreting Staphylococcus aureus was isolated from 11 of the 13 toxin-positive cultures, and streptococcal pyogenic exotoxin (SPE) B and C were found in the other 2. These toxins are known to stimulate V beta 2+ T cells. All TSST-producing KS isolates were tryptophan auxotrophs indicating they were clonally related. S aureus isolates from acute KS patients were unusual because they produced less lipase, haemolysin, and protease compared to other isolates (p < 0.01). S aureus colonies from KS patients were white, and could be easily mistaken for coagulase-negative staphylococci, whereas colonies of non-KS isolates were gold. These observations suggest that the expansion of V beta 2+ T cells in most patients with KS may be caused by a new clone of TSST-producing S aureus, and, in a minority of patients, SPEB-producing or SPEC-producing streptococci.

Streptococcus associated toxic shock

In the past few years, there appears to have been a change in the spectrum of disease caused by group A beta-haemolytic streptococcus (GABHS), and a toxic shock-like syndrome caused by this organism has recently been described in adults. We report four children with an acute illness characterised by rapid progression of shock, erythematous rash, multisystem organ involvement, electrolyte derangements, and desquamation who fulfil the previously established diagnostic criteria for toxic shock syndrome. Three of the children had extensive cutaneous and soft tissue infection and the fourth had peritonitis. All four developed bacteraemia. Treatment included aggressive cardiovascular resuscitation and antibiotic therapy. Although no patient died, they suffered multiple and severe complications requiring prolonged treatment and hospitalisation. Streptococcal toxic shock syndrome is a separate and clearly defined entity occurring in previously healthy children.

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.

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.

Synergism of Candida albicans and delta toxin producing Staphylococcus aureus on mouse mortality and morbidity: protection by indomethacin

Twelve Staphylococcus aureus strains, six positive and six negative for delta-toxin production, were studied for synergistic effects on mouse mortality and morbidity when combined with Candida albicans and inoculated intraperitoneally (i.p.). S. aureus strains producing delta-toxin were found to exhibit a relatively great synergistic decrease (between near 10(3)-10(5)-fold) in LD50 (dose necessary to kill 50% of exposed animals in five days) when combined with a nonlethal dose of C. albicans and injected i.p. S. aureus strains which did not produce delta showed less of a synergistic effect with C. albicans (10-10(2)-fold drop in LD50). A synergistic effect on mortality could also be produced when animals were dually injected with C. albicans and sterile growth filtrates from the delta-toxin producing strains or the purified delta-toxin. The lethal agent in the culture filtrate was, like delta-toxin, sensitive to lecithin and insensitive to heat. Indomethacin protected animals from the C. albicans-filtrate induced death. Blood measurements made following i.p. injection of delta-toxin and C. albicans revealed chemistry changes indicative of shock, kidney and liver damage; delta-toxin alone caused no significant chemistry changes whereas C. albicans alone caused some blood chemistry changes but liver and kidney damage was not indicated. No synergism on mortality was found between C. albicans and purified alpha-toxin or toxic shock syndrome 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.

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.

Regulation of staphylococcal toxic shock syndrome toxin-1 and total exoprotein production by magnesium ion

The effect of Mg2+ on in vitro production of extracellular proteins and, specifically, of toxic shock syndrome toxin-1 (TSST-1), by Staphylococcus aureus in a chemically defined medium was examined. As previously observed, the organisms did not proliferate in the absence of divalent cations. Low levels of Mg2+ (0.02 to 0.04 mM) permitted submaximal proliferation and elevated production of exoproteins. When the Mg2+ concentration was raised to 0.4 mM, multiplication was optimal and exoprotein levels were depressed. Ca2+ and Mn2+ diminished the effect of limiting Mg2+. The increased levels of exoproteins were not due to cell lysis or leakage since intracellular TSST-1 levels were not high enough to account for the increase in extracellular TSST-1 and since the intracellular enzyme, lactate dehydrogenase, was not found in culture supernatants. Cells cultured in low levels of Mg2+ remained in logarithmic growth longer than did those cultured in high concentrations of Mg2+ and, unlike the latter, produced exoproteins throughout the logarithmic growth phase. Low Mg2+ had no effect on cultures in the stationary phase, and organisms cultured in low Mg2+ recovered fully when transferred to high Mg2+. We conclude that, when cultured in medium deficient in Mg2+, S. aureus responds early in the growth cycle by increasing production of many extracellular proteins, including TSST-1.

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).

Toxic shock syndrome

Presenting features and clinical manifestations of six patients with toxic shock syndrome are reported. In four of the six cutaneous injury, sometimes trivial, occurred before the onset of symptoms and may have been a causal factor. All six children recovered. The need for early recognition and intensive management in this life threatening condition is discussed.