Therapeutic Approaches to Streptococcal Toxic Shock Syndrome

Streptococcal toxic shock syndrome following total thyroidectomy

Group A streptococcal toxic shock syndrome following clean surgery is a rare occurrence. Its incidence following thyroid surgery has not been described in the literature. We report on the presentation and management of severe streptococcal toxic shock syndrome following a total thyroidectomy for a multinodular goitre in a patient with Cowden syndrome. This report presents an overview of streptococcal toxic shock syndrome with a focus on the management issues to consider so as to improve patient outcome. All surgeons must maintain a high index of suspicion for this rare but dangerous entity.

A peptide antagonist of CD28 signaling attenuates toxic shock and necrotizing soft-tissue infection induced by Streptococcus pyogenes

Staphylococcus aureus and group A Streptococcus pyogenes (GAS) express superantigen (SAg) exotoxin proteins capable of inducing lethal shock. To induce toxicity, SAgs must bind not only to the major histocompatibility complex II molecule of antigen-presenting cells and the variable β chain of the T-cell receptor but also to the dimer interface of the T-cell costimulatory receptor CD28. Here, we show that the CD28-mimetic peptide AB103 (originally designated "p2TA") protects mice from lethal challenge with streptococcal exotoxin A, as well as from lethal GAS bacterial infection in a murine model of necrotizing soft-tissue infection. Administration of a single dose of AB103 increased survival when given up to 5 hours after infection, reduced inflammatory cytokine expression and bacterial burden at the site of infection, and improved muscle inflammation in a dose-dependent manner, without compromising cellular and humoral immunity. Thus, AB103 merits further investigation as a potential therapeutic in SAg-mediated necrotizing soft-tissue infection.

Streptococcal m1 protein triggers farnesyltransferase-dependent formation of CXC chemokines in alveolar macrophages and neutrophil infiltration of the lungs

The M1 serotype of Streptococcus pyogenes plays an important role in streptococcal toxic shock syndrome. Simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has been shown to inhibit streptococcal M1 protein-induced acute lung damage, although downstream mechanisms remain elusive. Protein isoprenylation, such as farnesylation and geranylgeranylation, has been suggested to regulate anti-inflammatory effects exerted by statins. Here, we examined the effect of a farnesyltransferase inhibitor (FTI-277) on M1 protein-triggered lung inflammation. Male C57BL/6 mice were treated with FTI-277 prior to M1 protein challenge. Bronchoalveolar fluid and lung tissue were harvested for quantification of neutrophil recruitment, edema, and CXC chemokine formation. Flow cytometry was used to determine Mac-1 expression on neutrophils. The gene expression of CXC chemokines was determined in alveolar macrophages by using quantitative reverse transcription (RT)-PCR. We found that the administration of FTI-277 markedly decreased M1 protein-induced accumulation of neutrophils, edema formation, and tissue damage in the lung. Notably, inhibition of farnesyltransferase abolished M1 protein-evoked production of CXC chemokines in the lung and gene expression of CXC chemokines in alveolar macrophages. Moreover, FTI-277 completely inhibited chemokine-induced neutrophil migration in vitro. However, farnesyltransferase inhibition had no effect on M1 protein-induced expression of Mac-1 on neutrophils. Our findings suggest that farnesyltransferase is a potent regulator of CXC chemokine formation in alveolar macrophages and that inhibition of farnesyltransferase not only reduces neutrophil recruitment but also attenuates acute lung injury provoked by streptococcal M1 protein. We conclude that farnesyltransferase activity is a potential target in order to attenuate acute lung damage in streptococcal infections.

A case of necrotizing fasciitis caused by coagulase-negative staphylococcus: utility of magnetic resonance imaging for the preoperative diagnosis of necrotizing fasciitis

A 70-year-old woman presented with fever and pain in the right lower extremity. Fat-suppressed gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI) showed contrast-enhanced fascia, fluid accumulation, and hypointense signals in the muscles. Surgical interventions including incisions and insertion of drainage tubes were performed on the basis of the MRI findings. The histopathological examinations of surgically obtained biopsy specimens demonstrated suppurative fasciitis, widespread myonecrosis, and thromboses of the vessels, all of which were compatible with a diagnosis of necrotizing fasciitis. The bacterial cultures were positive for a coagulase-negative staphylococcus. Following the surgical interventions, the patient was successfully treated by aggressive antimicrobial therapy. MRI can thus be useful for differentiating necrotizing fasciitis from nonnecrotizing soft tissue infection and for planning the treatment of necrotizing fasciitis.

Mass antibiotic treatment for group A streptococcus outbreaks in two long-term care facilities

Outbreaks of invasive infections caused by group A β-hemolytic streptococcus (GAS) may occur in long-term care settings and are associated with a high case-fatality rate in debilitated adults. Targeted antibiotic treatment only to residents and staff known to be at specific risk of GAS may be an ineffective outbreak control measure. We describe two institutional outbreaks in which mass antibiotic treatment was used as a control measure. In the first instance, mass treatment was used after targeted antibiotic treatment was not successful. In the second instance, mass treatment was used to control a rapidly evolving outbreak with a high case-fatality rate. Although no further clinical cases were seen after the introduction of mass antibiotic treatment, persistence of the outbreak strain was documented in one institution >1 year after cases had ceased. Strain persistence was associated with the presence of a chronically colonized resident and poor infection control practices.

Necrotizing soft tissue infections: are we making any progress?

BACKGROUND

Necrotizing soft tissue infections are a group of diseases with significant associated mortality. A wide spectrum of bacteria can be involved, and diagnosis can be difficult.

METHODS

Review of pertinent literature of the diagnosis and therapy of necrotizing soft-tissue infection.

RESULTS

Mortality and other adverse outcomes are directly related to advanced age, the presence of organ system failure, lactic acidemia, the percentage of body surface area involved with infection, and delays in operative management. Patients usually die early from the consequences of septic shock, whereas late mortality is related to multiple organ failure.

CONCLUSION

Early recognition and treatment can lower mortality from necrotizing soft tissue infection. Prompt operative debridement, broad-spectrum antimicrobials, and physiologic support are important components of treatment.

Fulminant group A streptococcal necrotizing fasciitis: clinical and pathologic findings in 7 patients

BACKGROUND

Necrotizing fasciitis is a rapidly progressive soft tissue infection with high morbidity and mortality rates. Examination of deep incisional biopsy specimens can provide prompt diagnosis and improve survival. We describe 7 patients with necrotizing fasciitis caused by group A Streptococcus species.

OBJECTIVE

Our purpose was to describe the unique dermatopathology and clinical features in 7 patients with necrotizing fasciitis caused by group A Streptococcus.

METHODS

We conducted a retrospective review.

RESULTS

The average age of the patients was 47 years. Fasciitis occurred on an extremity in all cases. All 5 patients with streptococcal toxic shock syndrome died of their disease. The histopathologic findings from early fascial disease revealed superficial epidermal necrosis, edema, and hemorrhage with few inflammatory cells, whereas clinically advanced, necrotic skin lesions revealed diffuse necrosis, thrombosis, neutrophilia, and numerous gram-positive diplococci.

CONCLUSIONS

Patients with clinical features of necrotizing fasciitis should have a deep incisional biopsy specimen obtained from the central area of ecchymotic, necrotic plaques to confirm the diagnosis. Immediate surgical intervention is necessary to reduce the morbidity and mortality rates associated with necrotizing fasciitis.