Toxic shock syndrome due to Clostridium sordellii: a dramatic postpartum and postabortion disease

Clostridium sordellii: A Cause of Toxic Shock Syndrome After a Breach in the GI Tract

Clostridium sordellii is a highly virulent microorganism that causes serious infections, most commonly of the uterus and perineum. It has a high associated mortality rate due to the various toxins that it produces. A review of the literature suggests that knowledge surrounding its proper management is limited. This report describes a case of Clostridium sordellii causing toxic shock syndrome posttranslocation through the GI tract. A 69-year-old man with a past medical history of renal cell carcinoma and small bowl obstruction complicating transverse colostomy presented to the emergency room with back pain and rigors. Vital signs showed that he was in hemodynamic shock, and imaging revealed a left renal mass invading the adjacent splenic flexure of the colon. There was also a significant leukemoid reaction. After receiving a series of antibiotics, blood cultures revealed Clostridium sordellii as the pathogen of interest. As the first report of its kind, we identify a unique presentation of this organism, serving as a primary example of a different setting that clinicians should be aware of while at the same time highlighting a successful course of therapy for this often deadly organism.

Severe Skin and Soft-Tissue Infections

Skin and soft-tissue infections (SSTIs) are a common reason for hospital admission. Severe SSTIs, particularly necrotizing infections, often require intensive care. Source control (often with surgical debridement) and broad-spectrum antimicrobials are paramount for minimizing significant morbidity and mortality. Rapid diagnostic tests may help in selection and de-escalation of antimicrobials for SSTIs. Besides early source control and early effective antimicrobial therapy, other patient-level factors such as comorbidities and immune status play a role in clinical outcomes. Intravenous immunoglobulin continues to be studied for severe SSTI, though recruitment in trials continues to be an issue. Severe SSTIs are complex to manage, due in part to regional variation in predominant pathogens and antimicrobial resistance patterns, as well as variations in host immune responses. This review includes descriptions of source control, antimicrobial therapies, intravenous immunoglobulin, and hyperbaric oxygen therapy, as well as host factors in severe SSTIs.

Toxic shock syndrome complicated with symmetrical peripheral gangrene after liposuction and fat transfer: a case report and literature review

BACKGROUND

Liposuction is one of the most commonly performed aesthetic procedures. Toxic shock syndrome(TSS) is a rare, life-threatening complication. The incidence rate of TSS is very low in the plastic surgery field, especially after liposuction and fat transfer.

CASE PRESENTATION

A 23-year-old female patient was transferred to our emergency department from an aesthetic clinic with sepsis shock features after received liposuction and fat transfer. The patient underwent TSS, disseminated intravascular coagulation(DIC), multiple organ dysfunction syndrome (MODS), symmetrical peripheral gangrene (SPG), and necrotizing soft tissue infection of the buttocks in the next 10 days. Authors used a series of debridement and reconstructive surgery including vacuum sealing drainage (VSD) treatment, artificial dermis grafts,split-thickness skin grafts, amputation surgeries when her vital signs were stable. The patient experienced desquamation of the hand on the 26th day. The skin grafts survived and the function of both fingers and toes recovered. She was discharged 2 months after admission and was in good health.

CONCLUSION

TSS is extremely rare in the field of liposuction and autologous fat transfer. The mortality rate of TSS is very high. Early diagnosis and operative treatment, as well as correction of systemic abnormalities, are the important keys to save a patient's life.

Characterization of Paeniclostridium sordellii Metalloproteinase-1 in vitro and in an experimental model of infection

OBJECTIVE

Paeniclostridium sordellii is a pathogen that causes rapidly fatal infections characterized by severe edema, extreme leukemoid reaction and lack of an innate immune response. We recently identified a metalloproteinase of P. sordellii-1 (Mcs1) that cleaves human vascular cell adhesion molecule 1, an adhesion molecule important to hematopoietic precursor retention and leukocyte diapedesis. In the current study, we further characterize Mcs1 activity and investigate its role in pathogenesis.

METHODS

Mcs1 peptide cleavage sequence and activity conditions were identified using a semi-quantitative fluorescence-based reporter assay. Additional host targets for Mcs1 protease activity were tested and confirmed by gel electrophoreses and western blots. Finally, Mcs1 knock out (ΔMcs1) and complemented (cMcs1) strains were developed for assessment in our animal model of myonecrosis.

RESULTS

Data show that Mcs1 prefers aliphatic amino acid residues, I or L, especially when adjacent to negatively charged or noncharged-polar residues. In vitro, Mcs1 cleaved or partially cleaved human cell adhesion molecules, E-selectin and intracellular adhesion molecule-1 (ICAM-1), and mediators of innate immune infection defense, complement protein-3 and antimicrobial peptide LL-37. In vivo, infection with the ΔMcs1 P. sordellii strain had little effect on animal survival, tissue destruction or circulating white blood cell counts compared to wild type and cMcs1 strains.

CONCLUSIONS

Similar to proteolytic virulence factors from other pathogens, Mcs1 is a promiscuous protease that cleaves multiple human-host factors. Despite minimal impact of Mcs1 on the murine model of P. sordellii infection, it is worth considering its role in humans and other animal models.

Management of Postabortion Complications for the Emergency Medicine Clinician

Although induced abortion is generally a safe outpatient procedure, many patients subsequently present to the emergency department, concerned about a postabortion complication. It is helpful for emergency physicians to understand the medications and procedures used in abortion care in the United States to effectively and efficiently triage and treat women presenting with potential complications from an abortion. Furthermore, because many states are experiencing increased abortion restrictions that limit access to care, emergency medicine physicians may encounter more patients presenting after self-managed abortions, which presents additional challenges. This article reviews the epidemiology and background of abortion care, including the range of symptoms and adverse effects that are within the scope of an uncomplicated procedure. This review also offers a comprehensive overview of management of abortion complications, including algorithms for more common complications and descriptions of less common but more severe adverse events. The article concludes with a recognition of the social stigma and legal regulations unique to abortion care.

Rapidly fatal necrotizing soft tissue infection due to Clostridium sordellii in an injection drug user

Clostridium sordellii infections are known to be associated with high morbidity and mortality. To date, only a small number of cases with necrotizing soft tissue infection due to C. Sordellii have been reported. We report a case presented with necrotizing soft tissue infection of the right upper extremity caused by C. sordellii in a patient with known use of injected heroin. Despite broad spectrum antibiotics and surgical debridement, the patient's clinical course became rapidly fatal, within 24 h of admission. C. sordellii necrotizing soft tissue infections are particularly virulent. Even in the context of appropriate surgical debridement, these infections can be rapidly fatal. This case highlights the importance of high suspicion for C. sordellii as potential pathogen of necrotizing soft tissue infection in injection drug users.

Treatment of severe skin and soft tissue infections: a review

PURPOSE OF REVIEW

To review the salient features of the management of severe skin and soft tissue infections (SSTIs), including toxic shock syndrome, myonecrosis/gas gangrene, and necrotizing fasciitis.

RECENT FINDINGS

For severe SSTIs, intensive care, source control, and broad-spectrum antimicrobials are required for the initial phase of illness. There is an increasing focus on the utility of rapid diagnostic tests to help in selection and de-escalation of antimicrobials for SSTIs. In addition, clinical prediction scores have shown promise in helping predict patients who do not require antimicrobials directed against methicillin-resistant Staphylococcus aureus. Immune status has been shown to be important in clinical outcomes of some, but not all types of SSTIs. The debate for benefits of intravenous immunoglobulin continues to be waged in the recent literature.

SUMMARY

Severe SSTIs are common and their management complex due to regional variation in predominant pathogens and antimicrobial resistance patterns, as well variations in host immune responses. Unique aspects of care for severe SSTIs are discussed including the role of surgical consultation and source control. The unique features of SSTIs in immunocompromised hosts are also described.

The Heroin Epidemic in America: A Surgeon's Perspective

Background: The United States is currently experiencing a heroin epidemic. Recent reports have demonstrated a three-fold increase in heroin use among Americans since 2007 with a shift in demographics to more women and white Americans. Furthermore, there has been a correlation between the recent opioid epidemic and an increase in heroin abuse. Much has been written about epidemiology and prevention of heroin abuse, but little has been dedicated to the surgical implications, complications, and resource utilization. Discussion: This article focuses on the surgical problems encountered from heroin abuse and how to manage them in a constant effort to improve morbidity and mortality for these heroin abusers.

Septic Shock Due to Clostridium perfringens

Clostridium perfringens is an anaerobic Gram-positive bacterium. We present the case of a 75-year-old female presented to the emergency department with progressively worsening acute on chronic left hip pain. It was not until the third day of hospitalization when the initial blood cultures finalized as Clostridium perfringens, antibiotics were changed to piperacillin-tazobactam and clindamycin. Despite the latest measurements, the patient continued getting hypotensive and progressed to multiorgan failure resulting in death by the end of the third day. The recognition of risk factors in addition to gram-positive rod cultures in the setting of septic shock reinforces the importance of appropriate and early empiric antibiotics management and infectious disease consultation to avoid fatal complications.

Survival from Clostridium toxic shock syndrome: Case report and review of the literature

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This case is a rare presentation of C. sordellii toxic shock syndrome resulting from a Caesarian section.

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This is the only obstetric case of C. sordellii to have survived.

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Extreme levels of a leukocytosis and hypotension without fevers raises suspiscion for this severe infection.

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Broad spectrum antibiotics, including coverage for anaerobic organisms, and surgical intervention is the standard of care.

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At the moment, no early detection or antitoxins are commercially available.

Introduction

Clostridial toxic shock is a rare syndrome traditionally described in case studies and reviews as a uniformly fatal condition associated with post-partum and post-abortion. Clostridium sordellii was first mentioned in scientific literature as a human pathogen in 1922 when Argentinian microbiologist Alfredo Sordellii identified the organism in gangrenous wounds. Over the past century, there has been infrequent discussion and little awareness surrounding this serious condition. Information about patients who survived C. sordellii toxic shock is essentially nonexistent.

Presentation of case

A 31-year old post-partum female who underwent caesarian section 17 days prior, presented with abdominal pain and septic features. She underwent six operations/procedures over the next 17 days and was hospitalized for 25 days before discharge to her home with a successful outcome.

Discussion

This case provides insight on the process of identifying and managing complications associated with clostridial toxic shock syndrome. Out of now, 16 reported cases of C sordellii gynecologic infections in the world literature, our patient is the second patient to survive infection by this organism. More research is needed to provide clinicians with evidence-based approaches for managing these unique cases.

Conclusion

We present a case report of a rare toxic shock syndrome in a post-partum female caused by Clostridium sordellii. Her survival is notable among 16 patients with whom this infection now has a documented 87.5% mortality rate. Aggressive surgical measures and optimized intensive care management may have contributed to this patient’s survival.

The Evaluation and Management of Toxic Shock Syndrome in the Emergency Department: A Review of the Literature

BACKGROUND

Toxic shock syndrome (TSS) is a severe, toxin-mediated illness that can mimic several other diseases and is lethal if not recognized and treated appropriately.

OBJECTIVE

This review provides an emergency medicine evidence-based summary of the current evaluation and treatment of TSS.

DISCUSSION

The most common etiologic agents are Staphylococcus aureus and Streptococcus pyogenes. Sources of TSS include postsurgical wounds, postpartum, postabortion, burns, soft tissue injuries, pharyngitis, and focal infections. Symptoms are due to toxin production and infection focus. Early symptoms include fever, chills, malaise, rash, vomiting, diarrhea, and hypotension. Diffuse erythema and desquamation may occur later in the disease course. Laboratory assessment may demonstrate anemia, thrombocytopenia, elevated liver enzymes, and abnormal coagulation studies. Diagnostic criteria are available to facilitate the diagnosis, but they should not be relied on for definitive diagnosis. Rather, specific situations should trigger consideration of this disease process. Treatment involves intravenous fluids, source control, and antibiotics. Antibiotics should include a penicillinase-resistant penicillin, cephalosporin, or vancomycin (in methicillin-resistant S. aureus prevalent areas) along with either clindamycin or linezolid.

CONCLUSION

TSS is a potentially deadly disease requiring prompt recognition and treatment. Focused history, physical examination, and laboratory testing are important for the diagnosis and management of this disease. Understanding the evaluation and treatment of TSS can assist providers with effectively managing these patients.

Experimental identification and computational characterization of a novel extracellular metalloproteinase produced by Clostridium sordellii

The open (white, green) vs. closed (purple, cyan) structures of Clostridium sordellii metalloproteinase.

Clostridium sordellii is a lethal pathogen for both animals and humans. Severe capillary leakage, toxic shock syndrome, and an extreme leukemoid reaction (LR), are hallmark features of C. sordellii infections and contribute to its high mortality rate. Here we report the discovery of a previously unknown and uncharacterized metalloproteinase of C. sordellii (referred as Mcs1) that cleaves human vascular cell adhesion molecule (VCAM)-1 in vitro, an adhesion molecule critical to hematopoietic precursor retention and leukocyte diapedesis. We successfully identified the open reading frame encoding Mcs1 within the ATCC 9714 genome and developed an Δmcs1 mutant strain using the ClosTron mutagenesis technology. No VCAM-1 proteolysis was observed from exotoxins collected from mutant strain cultures. Using advanced protein structural modeling and molecular dynamics simulation techniques, the 3D molecular structure and conformational features of Mcs1 were also characterized. Our data demonstrates that Mcs1 proteolytic activity is controlled by the electrostatic interactions between Glu113 and Arg227 residues and the gating motions within its cleft region. This pilot interdisciplinary investigation provided crucial experimental evidence of the existence of Mcs1 in C. sordellii and molecular insights into its 3D structure and proteolytic activity. These findings have the potential to help advance new therapeutics and diagnostics against deadly C. sordellii infections. Follow-up in vitro and in vivo work is under way to further characterize Mcs1 enzymatic kinetics and its role in C. sordellii pathogenesis.

Diagnosis and management of skin and soft tissue infections in the intensive care unit: a review

PURPOSE

To review the salient features of the diagnosis and management of the most common skin and soft tissue infections (SSTI). This review focuses on severe SSTIs that require care in an intensive care unit (ICU), including toxic shock syndrome, myonecrosis/gas gangrene, and necrotizing fasciitis.

METHODS

Guidelines, expert opinion, and local institutional policies were reviewed.

RESULTS

Severe SSTIs are common and their management complex due to regional variation in predominant pathogens and antimicrobial resistance patterns, as well as variations in host immune responses. Unique aspects of care for SSTIs in the ICU are discussed, including the role of prosthetic devices, risk factors for bacteremia, and the need for surgical consultation. SSTI mimetics, the role of dermatologic consultation, and the unique features of SSTIs in immunocompromised hosts are also described.

CONCLUSIONS

We provide recommendations for clinicians regarding optimal SSTI management in the ICU setting.

Medical Abortion

OBJECTIVE

This guideline reviews the evidence relating to the provision of first-trimester medical induced abortion, including patient eligibility, counselling, and consent; evidence-based regimens; and special considerations for clinicians providing medical abortion care.

INTENDED USERS

Gynaecologists, family physicians, registered nurses, midwives, residents, and other healthcare providers who currently or intend to provide pregnancy options counselling, medical abortion care, or family planning services.

TARGET POPULATION

Women with an unintended first trimester pregnancy.

EVIDENCE

Published literature was retrieved through searches of PubMed, MEDLINE, and Cochrane Library between July 2015 and November 2015 using appropriately controlled vocabulary (MeSH search terms: Induced Abortion, Medical Abortion, Mifepristone, Misoprostol, Methotrexate). Results were restricted to systematic reviews, randomized controlled trials, clinical trials, and observational studies published from June 1986 to November 2015 in English. Additionally, existing guidelines from other countries were consulted for review. A grey literature search was not required.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force for Preventive Medicine rating scale (Table 1).

BENEFITS, HARMS AND/OR COSTS

Medical abortion is safe and effective. Complications from medical abortion are rare. Access and costs will be dependent on provincial and territorial funding for combination mifepristone/misoprostol and provider availability.

SUMMARY STATEMENTS

Introduction Pre-procedure care Medical abortion regimens Providing medical abortion Post-abortion care

RECOMMENDATIONS

Introduction Pre-procedure care Medical abortion regimens Providing medical abortion Post-abortion care.

A novel murine model of Clostridium sordellii myonecrosis: Insights into the pathogenesis of disease

Clostridium sordellii infections have been reported in women following natural childbirth and spontaneous or medically-induced abortion, injection drug users and patients with trauma. Death is rapid and mortality ranges from 70 to 100%. Clinical features include an extreme leukemoid reaction, the absence of fever, and only minimal pain or erythema at the infected site. In the current study, we developed a murine model of C. sordellii soft tissue infection to elucidate the pathogenic mechanisms. Mice received 0.5, 1.0 or 2.0 × 10(6) CFU C. sordellii (ATCC 9714 type strain) in the right thigh muscle. All doses caused fatal infection characterized by intense swelling of the infected limb but no erythema or visible perfusion deficits. Survival rates and time to death were inoculum dose-dependent. Mice developed a granulocytic leukocytosis with left shift, the onset of which directly correlated with disease severity. Histopathology of infected tissue showed widespread edema, moderate muscle damage and minimal neutrophil infiltration. Circulating levels of granulocyte colony-stimulating factor (G-CSF), soluble tumor necrosis factor receptor I (sTNF-RI) and interlukin-6 (IL-6) were significantly increased in infected animals, while TNF-α, and IL-1β levels were only mildly elevated, suggesting these host factors likely mediate the leukocytosis and innate immune dysfunction characteristic of this infection. Thus, this model mimics many of the salient features of this infection in humans and has allowed us to identify novel targets for intervention.

Vaginal and Rectal Clostridium sordellii and Clostridium perfringens Presence Among Women in the United States

OBJECTIVE

To characterize the presence of Clostridium sordellii and Clostridium perfringens in the vagina and rectum, identify correlates of presence, and describe strain diversity and presence of key toxins.

METHODS

We conducted an observational cohort study in which we screened a diverse cohort of reproductive-aged women in the United States up to three times using vaginal and rectal swabs analyzed by molecular and culture methods. We used multivariate regression models to explore predictors of presence. Strains were characterized by pulsed-field gel electrophoresis and tested for known virulence factors by polymerase chain reaction assays.

RESULTS

Of 4,152 participants enrolled between 2010 and 2013, 3.4% (95% confidence interval [CI] 2.9-4.0) were positive for C sordellii and 10.4% (95% CI 9.5-11.3) were positive for C perfringens at baseline. Among the 66% with follow-up data, 94.7% (95% CI 88.0-98.3) of those positive for C sordellii and 74.4% (95% CI 69.0-79.3) of those positive for C perfringens at baseline were negative at follow-up. At baseline, recent gynecologic surgery was associated with C sordellii presence, whereas a high body mass index was associated with C perfringens presence in adjusted models. Two of 238 C sordellii isolates contained the lethal toxin gene, and none contained the hemorrhagic toxin gene. Substantial strain diversity was observed in both species with few clusters and no dominant clones identified.

CONCLUSION

The relatively rare and transient nature of C sordellii and C perfringens presence in the vagina and rectum makes it inadvisable to use any screening or prophylactic approach to try to prevent clostridial infection.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT01283828.

The catalytic domains of Clostridium sordellii lethal toxin and related large clostridial glucosylating toxins specifically recognize the negatively charged phospholipids phosphatidylserine and phosphatidic acid

Clostridium sordellii lethal toxin (TcsL) is a potent virulence factor belonging to the large clostridial glucosylating toxin family. TcsL enters target cells via receptor-mediated endocytosis and delivers the N-terminal catalytic domain (TcsL-cat) into the cytosol upon an autoproteolytic process. TcsL-cat inactivates small GTPases including Rac and Ras by glucosylation with uridine-diphosphate (UDP)-glucose as cofactor leading to drastic changes in cytoskeleton and cell viability. TcsL-cat was found to preferentially bind to phosphatidylserine (PS)-containing membranes and to increase the glucosylation of Rac anchored to lipid membrane. We here report binding affinity measurements of TcsL-cat for brain PS-containing membranes by surface plasmon resonance and enzyme-linked immunosorbent assay (ELISA). In addition, TcsL-cat bound to phosphatidic acid (PA) and, to a lesser extent, to other anionic lipids, but not to neutral lipids, sphingolipids or sterol. We further show that the lipid unsaturation status influenced TcsL-cat binding to phospholipids, PS with unsaturated acyl chains and PA with saturated acyl chains being the preferred bindingsubstrates. Phospholipid binding site is localized at the N-terminal four helical bundle structure (1-93 domain). However, TcsL-1-93 bound to a broad range of substrates, whereas TcsL-cat, which is the active domain physiologically delivered into the cytosol, selectively bound to PS and PA. Similar findings were observed with the other large clostridial glucosylating toxins from C. difficile, C. novyi and C. perfringens.

Foot infection by Clostridium sordellii: case report and review of 15 cases in France

We report a case of foot infection by Clostridium sordellii and review 15 human infections registered at a Reference Center in France during the period 1998 to 2011. All strains were found nontoxigenic, lacking the lethal toxin gene coding for TcsL. Like Clostridium septicum, several C. sordellii infections were associated with intestinal neoplasms.

Antibiotic resistance, virulence factors and genetics of Clostridium sordellii

Clostridium sordellii is gram positive bacterial pathogen of humans and animals. While the incidence of human-related C. sordellii infection is low, the mortality rate associated with infection is high. Of particular concern are C. sordellii infections after child-birth or medical abortion, which have an almost 100% mortality rate. Recent genetic and epidemiological work has increased our understanding of how this pathogen has evolved and how it causes disease. This review will summarise studies involving the genetics of C. sordellii, including an antibiotic resistance profile, the genetic determinants of virulence and mutagenesis of C. sordellii.

What happens when we routinely give doxycycline to medical abortion patients?

OBJECTIVES

Routine provision of antibiotics following medical abortion is common yet practitioners and professional societies differ on its utility. Our study compares the side effects experienced by women who were prescribed doxycycline following medical abortion to those who were not and assesses the adherence to one prescribed regimen.

STUDY DESIGN

This was a prospective, observational, open-label study from a convenience sample. Women seeking medical abortion were enrolled in nine study sites, including four clinics that routinely prescribe a seven-day course of doxycycline (Doxycycline arm) and five clinics that do not routinely prescribe any antibiotics (No Doxycycline arm). Seven to fourteen days following the administration of mifepristone, women were asked to self-administer a computer-based survey. The survey asked about side effects experienced (both arms) and adherence to the regimen (Doxycycline arm only).

RESULTS

Five hundred eighty-one women were enrolled (278 in the Doxycycline arm and 303 in the No Doxycycline arm). There was a trend toward increased nausea in the Doxycycline arm (47.8% vs. 40.9%; p=.056) and a statistically significant difference in vomiting (25.2% vs. 18.5%; p=.032). Almost all women in the Doxycycline arm reported taking at least one pill, however only 28.3% reported "perfect adherence." The most common reasons reported for taking fewer pills than instructed were that participants were still taking them (beyond 7 days) or that they forgot to take them.

CONCLUSION

Women who were prescribed doxycycline following medical abortion reported moderate adherence and experienced significantly more vomiting than their counterparts.

IMPLICATIONS

In the absence of robust evidence that prescribing 7 days of doxycycline following medical abortion is effective at reducing serious infections, these data can assist the public health community with deciding whether routine provision is the most appropriate strategy.

Haemorrhagic toxin and lethal toxin from Clostridium sordellii strain vpi9048: molecular characterization and comparative analysis of substrate specificity of the large clostridial glucosylating toxins

Large clostridial glucosylating toxins (LCGTs) are produced by toxigenic strains of Clostridium difficile, Clostridium perfringens, Clostridium novyi and Clostridium sordellii. While most C. sordellii strains solely produce lethal toxin (TcsL), C. sordellii strain VPI9048 co-produces both hemorrhagic toxin (TcsH) and TcsL. Here, the sequences of TcsH-9048 and TcsL-9048 are provided, showing that both toxins retain conserved LCGT features and that TcsL and TcsH are highly related to Toxin A (TcdA) and Toxin B (TcdB) from C. difficile strain VPI10463. The substrate profile of the toxins was investigated with recombinant LCGT transferase domains (rN) and a wide panel of small GTPases. rN-TcsH-9048 and rN-TcdA-10463 glucosylated preferably Rho-GTPases but also Ras-GTPases to some extent. In this respect, rN-TcsH-9048 and rN-TcdA-10463 differ from the respective full-length TcsH-9048 and TcdA-10463, which exclusively glucosylate Rho-GTPases. rN-TcsL-9048 and full length TcsL-9048 glucosylate both Rho- and Ras-GTPases, whereas rN-TcdB-10463 and full length TcdB-10463 exclusively glucosylate Rho-GTPases. Vero cells treated with full length TcsH-9048 or TcdA-10463 also showed glucosylation of Ras, albeit to a lower extent than of Rho-GTPases. Thus, in vitro analysis of substrate spectra using recombinant transferase domains corresponding to the auto-proteolytically cleaved domains, predicts more precisely the in vivo substrates than the full length toxins. Except for TcdB-1470, all LCGTs evoked increased expression of the small GTPase RhoB, which exhibited cytoprotective activity in cells treated with TcsL isoforms, but pro-apoptotic activity in cells treated with TcdA, TcdB, and TcsH. All LCGTs induced a rapid dephosphorylation of pY118-paxillin and of pS144/141-PAK1/2 prior to actin filament depolymerization indicating that disassembly of focal adhesions is an early event leading to the disorganization of the actin cytoskeleton.

A case of toxic shock due to clandestine abortion by misoprostol self-administration

Maternal mortality and morbidity are the leading causes of death and illness, respectively, among women of reproductive age in many countries throughout the world. Of all maternal deaths, those related to unsafe abortions are the most widely underestimated, but they are also the most largely preventable. Medical abortion is a safe and reliable method for termination of a pregnancy in early gestation, although it is important to be aware of signs and symptoms of severe infection and toxic shock syndrome after the medical termination of pregnancy; case studies in literature are rarely fatal events. We report the first case of septic shock syndrome following a clandestine pregnancy termination with a misoprostol-only regimen (12 tablets 200 μg each). Autopsy findings and histopathological examination proved that the woman died from septic shock. This case suggests to improve the forensic investigations in case of unsafe, often clandestine, abortion is suspected.

Bacterial factors exploit eukaryotic Rho GTPase signaling cascades to promote invasion and proliferation within their host

Actin cytoskeleton is a main target of many bacterial pathogens. Among the multiple regulation steps of the actin cytoskeleton, bacterial factors interact preferentially with RhoGTPases. Pathogens secrete either toxins which diffuse in the surrounding environment, or directly inject virulence factors into target cells. Bacterial toxins, which interfere with RhoGTPases, and to some extent with RasGTPases, catalyze a covalent modification (ADPribosylation, glucosylation, deamidation, adenylation, proteolysis) blocking these molecules in their active or inactive state, resulting in alteration of epithelial and/or endothelial barriers, which contributes to dissemination of bacteria in the host. Injected bacterial virulence factors preferentially manipulate the RhoGTPase signaling cascade by mimicry of eukaryotic regulatory proteins leading to local actin cytoskeleton rearrangement, which mediates bacterial entry into host cells or in contrast escape to phagocytosis and immune defense. Invasive bacteria can also manipulate RhoGTPase signaling through recognition and stimulation of cell surface receptor(s). Changes in RhoGTPase activation state is sensed by the innate immunity pathways and allows the host cell to adapt an appropriate defense response.

Serious infection associated with induced abortion in the United States

Though serious infection after induced abortion is rare, infections account for one third of abortion-related deaths in the United States. Most fatal cases of infection after induced medical abortion have involved clostridial species. These reported cases share important clinical features that may guide clinicians to earlier recognition and institution of therapy. This article reviews our current knowledge regarding serious clostridial infections postabortion including the typical clinical presentation, pathophysiology, modes of diagnosis, and available treatment.

Fulminant leukemoid reaction due to postpartum Clostridium sordellii infection

Clostridium sordellii is gram positive anaerobic spore forming rod and it has been demonstrated to cause gas gangrene, refractory shock, leukemoid reaction, and pleuroperitoneal effusion due to capillary leak. We report here a case of postpartum female who presented with leukemoid reaction, ascites, pleural effusion, and shock without fever 7 days after normal vaginal home delivery.

Gynecologic clostridial toxic shock in women of reproductive age

Clostridial toxic shock, caused by Clostridium sordellii or Clostridium perfringens, is a rare and largely fatal syndrome among reproductive-aged women with genital tract infection, and may occur following various pregnancy outcomes or without pregnancy. Clinicians should be aware of common clinical features of this very rapidly-progressing syndrome including abdominal pain, tachycardia, hypotension, third-space fluid accumulations, hemoconcentration, and marked leukemoid response, often with lack of fever. In this review, we summarize known cases through mid-2011 and information on clinical presentation, diagnosis, treatment, and results of recent investigations regarding pathogenesis, including germination, toxins, and host response that may have important implications for development of preventive or therapeutic interventions.

Progesterone analogs influence germination of Clostridium sordellii and Clostridium difficile spores in vitro

Clostridium sordellii and Clostridium difficile are closely related anaerobic Gram-positive, spore-forming human pathogens. C. sordellii and C. difficile form spores that are believed to be the infectious form of these bacteria. These spores return to toxin-producing vegetative cells upon binding to small molecule germinants. The endogenous compounds that regulate clostridial spore germination are not fully understood. While C. sordellii spores require three structurally distinct amino acids to germinate, the occurrence of postpregnancy C. sordellii infections suggests that steroidal sex hormones might regulate its capacity to germinate. On the other hand, C. difficile spores require taurocholate (a bile salt) and glycine (an amino acid) to germinate. Bile salts and steroid hormones are biosynthesized from cholesterol, suggesting that the common sterane structure can affect the germination of both C. sordellii and C. difficile spores. Therefore, we tested the effect of sterane compounds on C. sordellii and C. difficile spore germination. Our results show that both steroid hormones and bile salts are able to increase C. sordellii spore germination rates. In contrast, a subset of steroid hormones acted as competitive inhibitors of C. difficile spore germination. Thus, even though C. sordellii and C. difficile are phylogenetically related, the two species' spores respond differently to steroidal compounds.

Rho/Ras-GTPase-dependent and -independent activity of clostridial glucosylating toxins

Clostridial glucosylating toxins are the main virulence factors of clostridia responsible for gangrene and/or colitis. These toxins have been well characterized to inactivate Rho/Ras-GTPases through glucosylation. However, the signalling pathways downstream of Rho/Ras-GTPases leading to the intracellular effects of these toxins are only partially known. Rac-dependent modification of focal adhesion complexes and phosphoinositide metabolism seem to be key processes involved in actin filament depolymerization and disorganization of intercellular junctions. In addition, clostridial glucosylating toxins induce Rho/Ras-independent intracellular effects such as activation of mitogen-activated protein kinase pathways, which are used by some of these toxins to trigger an inflammatory response.

Functional implications of lethal toxin-catalysed glucosylation of (H/K/N)Ras and Rac1 in Clostridium sordellii-associated disease

Clostridium sordellii-based diseases in humans and livestock rely on the activity of the major virulence factors, the single-chain protein toxins TcsL and TcsH, both belonging to the large clostridial glucosylating toxins. TcsL exclusively glucosylates Rho and Ras low molecular weight GTP-binding proteins. TcsL-induced loss of barrier function in epithelial (diarrhoea) and endothelial cells (extravasation of blood fluid) is based on Rac glucosylation whereas induction of apoptosis results from glucosylation of Ras. Intracellular glucosylation of Rac and Ras can be tracked by immunoblot applying the glucosylation-sensitive antibodies Rac1(Mab 102) and Ras(Mab 27H5). Induction of apoptosis especially of phagocytotic cells is crucial for the severity of C. sordellii-associated disease. The inhibition of TcsL-induced apoptosis by tauroursodeoxycholic acid (TUDCA) may be a promising therapeutic option.

The class A scavenger receptor, macrophage receptor with collagenous structure, is the major phagocytic receptor for Clostridium sordellii expressed by human decidual macrophages

Clostridium sordellii is an emerging pathogen associated with highly lethal female reproductive tract infections following childbirth, abortion, or cervical instrumentation. Gaps in our understanding of the pathogenesis of C. sordellii infections present major challenges to the development of better preventive and therapeutic strategies against this problem. We sought to determine the mechanisms whereby uterine decidual macrophages phagocytose this bacterium and tested the hypothesis that human decidual macrophages use class A scavenger receptors to internalize unopsonized C. sordellii. In vitro phagocytosis assays with human decidual macrophages incubated with pharmacological inhibitors of class A scavenger receptors (fucoidan, polyinosinic acid, and dextran sulfate) revealed a role for these receptors in C. sordellii phagocytosis. Soluble macrophage receptor with collagenous structure (MARCO) receptor prevented C. sordellii internalization, suggesting that MARCO is an important class A scavenger receptor in decidual macrophage phagocytosis of this microbe. Peritoneal macrophages from MARCO-deficient mice, but not wild-type or scavenger receptor AI/II-deficient mice, showed impaired C. sordellii phagocytosis. MARCO-null mice were more susceptible to death from C. sordellii uterine infection than wild-type mice and exhibited impaired clearance of this bacterium from the infected uterus. Thus, MARCO is an important phagocytic receptor used by human and mouse macrophages to clear C. sordellii from the infected uterus.

Killing of rat basophilic leukemia cells by lethal toxin from Clostridium sordellii: critical role of phosphatidylinositide 3'-OH kinase/Akt signaling

Clostridium sordellii lethal toxin (TcsL) belongs to the family of clostridial glucosylating toxins. TcsL exhibits glucosyltransferase activity to inactivate Rho and Ras proteins. On cultured cells, TcsL causes actin reorganization ("cytopathic effect") and apoptotic cell death ("cytotoxic effect"). This study is based on the concept that the cytotoxic effects of TcsL depend on the glucosylation of critical substrate proteins rather than on the glucosyltransferase activity per se. The cytotoxic effects of TcsL depend on the glucosyltransferase activity of TcsL, as neither chemically inactivated TcsL nor a glucosyltransferase-deficient mutant version of TcsL caused it. The TcsL homologous toxin B from Clostridium difficile serotype F strain 1470 (TcdBF) also failed to cause cytotoxic effects. Correlation of the toxins' respective protein substrate specificities highlighted (H/K/N)Ras as critical substrate proteins for the cytotoxic effects. (H/K/N)Ras are critical upstream regulators of phosphatidylinositide 3'-OH kinase (PI3K)/Akt survival signaling. Tauroursodeoxycholic acid (TUDCA) classified to activate PI3K/Akt signaling downstream of apoptosis-inducing stimuli prevented the cytotoxic effects of TcsL. In conclusion, (H/K/N)Ras glucosylation and subsequent inhibition of PI3K/Akt signaling are critical for the cytotoxic effects of TcsL.

The glucocorticoid receptor: a revisited target for toxins

The hypothalamic-pituitary-adrenal (HPA) axis activation and glucocorticoid responses are critical for survival from a number of bacterial, viral and toxic insults, demonstrated by the fact that removal of the HPA axis or GR blockade enhances mortality rates. Replacement with synthetic glucocorticoids reverses these effects by providing protection against lethal effects. Glucocorticoid resistance/insensitivity is a common problem in the treatment of many diseases. Much research has focused on the molecular mechanism behind this resistance, but an area that has been neglected is the role of infectious agents and toxins. We have recently shown that the anthrax lethal toxin is able to repress glucocorticoid receptor function. Data suggesting that the glucocorticoid receptor may be a target for a variety of toxins is reviewed here. These studies have important implications for glucocorticoid therapy.

Severe skin and soft tissue infections and associated critical illness

Skin and soft tissue infections (SSTIs) span a broad spectrum of clinical entities from limited cellulitis to rapidly progressive necrotizing fasciitis, which may be associated with septic shock or a toxic shock-like syndrome. These infections may be the primary instigators of critical illness requiring hospitalization and management in the intensive care unit. Alternatively, these infections may arise from metastatic spread of microorganisms from a distant focus. Regardless of the source, SSTIs may lead to critical illness. The complex interplay of environment, host, and pathogen are important to consider when evaluating SSTIs and planning therapy. This second of a two-part review focuses on severe SSTIs due to Clostridium spp, microorganisms associated with water sources, and polymicrobial/mixed infections. The key to a successful outcome is early identification of risk factors for specific pathogens and early initiation of empiric antimicrobial therapy. For some SSTIs, surgical intervention for diagnosis and/or therapy is also required.

Lethal toxin is a critical determinant of rapid mortality in rodent models of Clostridium sordellii endometritis

The toxigenic anaerobe Clostridium sordellii is an uncommon but highly lethal cause of human infection and toxic shock syndrome, yet few studies have addressed its pathogenetic mechanisms. To better characterize the microbial determinants of rapid death from infection both in vitro and in vivo studies were performed to compare a clinical strain of C. sordellii (DA-108), isolated from a patient who survived a disseminated infection unaccompanied by toxic shock syndrome, to a virulent reference strain (ATCC9714). Rodent models of endometrial and peritoneal infection with C. sordellii ATCC9714 were rapidly lethal, while infections with DA-108 were not. Extensive genetic and functional comparisons of virulence factor and toxin expression between these two bacterial strains yielded many similarities, with the noted exception that strain DA-108 lacked the tcsL gene, which encodes the large clostridial glucosyltransferase enzyme lethal toxin (TcsL). The targeted removal by immunoprecipitation of TcsL protected animals from death following injection of crude culture supernatants from strain ATCC9714. Injections of a monoclonal anti-TcsL IgG protected animals from death during C. sordellii ATCC9714 infection, suggesting that such an approach might improve the treatment of patients with C. sordellii-induced toxic shock syndrome.

Septic shock due to Klebsiella pneumoniae after medical abortion with misoprostol-only regimen

OBJECTIVE

To report a case of a healthy woman who was admitted to the hospital with septic shock caused by a common uropathogen after self-administration of misoprostol for pregnancy termination.

DESIGN

Case report.

SETTING

Tertiary hospital.

PATIENT(S)

A 38-year-old woman, gravida 5, para 3, who developed septic shock after medical termination of pregnancy.

INTERVENTION(S)

Suction curettage, antibiotic treatment, plasma and platelet transfusions.

MAIN OUTCOME MEASURE(S)

Klebsiella pneumoniae was isolated from blood samples.

RESULT

Ten days after her admission she was discharged home in good condition on oral antibiotics.

CONCLUSION(S)

Severe infections leading to septic shock from common pathogen bacteria can occur after medical termination of pregnancy, independently of the regimen used.

Clostridial toxins

Clostridia produce the highest number of toxins of any type of bacteria and are involved in severe diseases in humans and other animals. Most of the clostridial toxins are pore-forming toxins responsible for gangrenes and gastrointestinal diseases. Among them, perfringolysin has been extensively studied and it is the paradigm of the cholesterol-dependent cytolysins, whereas Clostridium perfringens epsilon-toxin and Clostridium septicum alpha-toxin, which are related to aerolysin, are the prototypes of clostridial toxins that form small pores. Other toxins active on the cell surface possess an enzymatic activity, such as phospholipase C and collagenase, and are involved in the degradation of specific cell-membrane or extracellular-matrix components. Three groups of clostridial toxins have the ability to enter cells: large clostridial glucosylating toxins, binary toxins and neurotoxins. The binary and large clostridial glucosylating toxins alter the actin cytoskeleton by enzymatically modifying the actin monomers and the regulatory proteins from the Rho family, respectively. Clostridial neurotoxins proteolyse key components of neuroexocytosis. Botulinum neurotoxins inhibit neurotransmission at neuromuscular junctions, whereas tetanus toxin targets the inhibitory interneurons of the CNS. The high potency of clostridial toxins results from their specific targets, which have an essential cellular function, and from the type of modification that they induce. In addition, clostridial toxins are useful pharmacological and biological tools.

Requirements for germination of Clostridium sordellii spores in vitro

Clostridium sordellii is a spore-forming, obligately anaerobic, Gram-positive bacterium that can cause toxic shock syndrome after gynecological procedures. Although the incidence of C. sordellii infection is low, it is fatal in most cases. Since spore germination is believed to be the first step in the establishment of Bacilli and Clostridia infections, we analyzed the requirements for C. sordellii spore germination in vitro. Our data showed that C. sordellii spores require three structurally different amino acids and bicarbonate for maximum germination. Unlike the case for Bacilli species, d-alanine had no effect on C. sordellii spore germination. C. sordellii spores germinated only in a narrow pH range between 5.7 and 6.5. In contrast, C. sordellii spore germination was significantly less sensitive to temperature changes than that of the Bacilli. The analysis of the kinetics of C. sordellii spore germination showed strong allosteric behavior in the binding of l-phenylalanine and l-alanine but not in that of bicarbonate or l-arginine. By comparing germinant apparent binding affinities to their known in vivo concentrations, we postulated a mechanism for differential C. sordellii spore activation in the female reproductive tract.

Undiagnosed cases of fatal Clostridium-associated toxic shock in Californian women of childbearing age

OBJECTIVE

In 2005, 4 Clostridium sordellii-associated toxic shock fatalities were reported in young Californian women after medical abortions. The true incidence of this rare disease is unknown, and a population-based study has never been performed. Additional clostridia-associated deaths were sought to describe associated clinical characteristics.

STUDY DESIGN

Population-based death certificate review and a clinical case definition for clostridial-associated toxic shock identified women with likelihood of dying from a Clostridium infection. Formalin-fixed autopsy tissues underwent immunohistochemical and polymerase chain reaction assays.

RESULTS

Thirty-eight women were suspected of having C sordellii-associated death. Five tested positive for Clostridium species: 3 for Clostridium perfringens, 1 for C sordellii, and 1 for both. Deaths occurred after the medical procedures for cervical dysplasia (n = 2), surgical abortion (n = 1), stillborn delivery (n = 1), and term live birth (n = 1). None had a medical abortion.

CONCLUSION

C sordellii and C perfringens are associated with undiagnosed catastrophic infectious gynecologic illnesses among women of childbearing age.

Prevention of Clostridium sordellii lethal toxin-induced apoptotic cell death by tauroursodeoxycholic acid

Virulent strains of Clostridium sordellii cause gangrenous myonecrosis in humans. The released lethal toxin (TcsL) and hemorrhagic toxin (TcsH) are regarded as the major virulence factors. TcsL inactivates low molecular weight GTP-binding proteins of the Rho/Ras subfamilies by monoglucosylation. In cultured cell lines, glucosylation, i.e., inactivation of Rho/Ras proteins, results in actin reorganization ("cytopathic effect") and apoptotic cell death ("cytotoxic effect"). Apoptotic cell death induced by TcsL is suggested to be based on inhibition of the phosphoinositide 3-kinase (PI3K)/Akt-survival pathway. In this study, we analyze the critical role of PI3K/Akt signaling in TcsL-induced apoptosis using the antiapoptotic bile acid tauroursodeoxycholic acid (TUDCA) as the pharmacological tool. TUDCA preserved the TcsL-induced decrease of the cellular level of phospho-Akt, suggesting that TUDCA activated PI3K/Akt signaling downstream of inhibited Ras signaling. TcsL-induced apoptosis was prevented by TUDCA treatment. The antiapoptotic effect of TUDCA was abolished by the PI3K inhibitor LY294002 and the Akt inhibitor, showing that the antiapoptotic effect depends on PI3K/Akt signaling. Inhibition of Ras/Rho signaling by TcsL resulted in activation of p38 MAP kinase. Inhibition of p38 MAP kinase by SB203580 protected cells from TcsL-induced apoptosis. TUDCA induced activation of p38 MAP kinase as well, an aspect of the TUDCA effects that most likely did not contribute to its antiapoptotic activity. Due to its antiapoptotic activity, TUDCA is under investigation for its potential application as a therapeutic modulator of apoptosis-related diseases. TUDCA may represent a new concept for the treatment of disease associated with toxigenic C. sordellii.