Fatal toxic shock syndrome associated with Clostridium sordellii after medical abortion

Molecular basis of TMPRSS2 recognition by Paeniclostridium sordellii hemorrhagic toxin

Hemorrhagic toxin (TcsH) is a major virulence factor produced by Paeniclostridium sordellii, which is a non-negligible threat to women undergoing childbirth or abortions. Recently, Transmembrane Serine Protease 2 (TMPRSS2) was identified as a host receptor of TcsH. Here, we show the cryo-EM structures of the TcsH-TMPRSS2 complex and uncover that TcsH binds to the serine protease domain (SPD) of TMPRSS2 through the CROP unit-VI. This receptor binding mode is unique among LCTs. Five top surface loops of TMPRSS2SPD, which also determine the protease substrate specificity, constitute the structural determinants recognized by TcsH. The binding of TcsH inhibits the proteolytic activity of TMPRSS2, whereas its implication in disease manifestations remains unclear. We further show that mutations selectively disrupting TMPRSS2-binding reduce TcsH toxicity in the intestinal epithelium of the female mice. These findings together shed light on the distinct molecular basis of TcsH-TMPRSS2 interactions, which expands our knowledge of host recognition mechanisms employed by LCTs and provides novel targets for developing therapeutics against P. sordellii infections.

Structural dynamics of the CROPs domain control stability and toxicity of Paeniclostridium sordellii lethal toxin

Paeniclostridium sordellii lethal toxin (TcsL) is a potent exotoxin that causes lethal toxic shock syndrome associated with fulminant bacterial infections. TcsL belongs to the large clostridial toxin (LCT) family. Here, we report that TcsL with varied lengths of combined repetitive oligopeptides (CROPs) deleted show increased autoproteolysis as well as higher cytotoxicity. We next present cryo-EM structures of full-length TcsL, at neutral (pH 7.4) and acidic (pH 5.0) conditions. The TcsL at neutral pH exhibits in the open conformation, which resembles reported TcdB structures. Low pH induces the conformational change of partial TcsL to the closed form. Two intracellular interfaces are observed in the closed conformation, which possibly locks the cysteine protease domain and hinders the binding of the host receptor. Our findings provide insights into the structure and function of TcsL and reveal mechanisms for CROPs-mediated modulation of autoproteolysis and cytotoxicity, which could be common across the LCT family.

Medication Abortion: A Comprehensive Review

This chapter provides an overview of evidence-based guidelines for medication abortion in the first trimester. We discuss regimens, both FDA-approved and other clinical-based protocols, and will briefly discuss novel self-managed abortion techniques taking place outside the formal health care system. Overview of patient counseling and pain management are presented with care to include guidance on "no touch" regimens that have proven both feasible and effective. We hope that this comprehensive review helps the health care community make strides to increase access to abortion in a time when reproductive health care is continuously restricted.

Under the Skin: A Case Series of Clostridium sordellii Necrotizing Soft Tissue Infections in Patients Who Inject Drugs

Clostridium sordellii has been well-associated as a cause of obstetric infections but is a less commonly recognized organism of necrotizing skin and soft tissue infections (NSTI). C. sordelli infections are rare with only 14 cases reported in the literature to date. These infections are often associated with profound septic shock and the mortality rate remains high. We report four patients who presented with C. sordellii NSTI over a period of two years at an academic medical center. Notably, injection drug use was the main risk factor for infection in these patients. Appropriate management of C. sordellii NSTI necessitates a combination of antibiotics and emergent surgical intervention. However, despite these efforts, the mortality rate remains high, with three of the four patients dying. Clinicians should consider NSTI in the differential diagnosis when evaluating skin and soft tissue infections in people who inject drugs. Furthermore, it is imperative to educate patients who engage in injection drug use on the potential risks associated with NSTI and inform them of warning signs that warrant immediate medical attention. The devastating consequences of C. sordellii-associated NSTI in this vulnerable population can be mitigated by enhancing awareness and facilitating early intervention.

Abortion Care in the United States - Current Evidence and Future Directions

Abortion Care in the United StatesAbortion services are a vital component of reproductive health care. Jung and colleagues review medication abortion and procedural abortion as well as implications of increasing restrictions on access in the United States.

Infections caused by Clostridium perfringens and Paeniclostridium sordellii after unsafe abortion

After the legalisation of abortion in the USA in 1973, the risk of infectious morbidity and mortality from this procedure notably decreased. With increasingly restrictive legislation targeting access to safe abortion services, reviewing infectious complications of unsafe pregnancy termination is crucial, particularly the diagnosis and management of life-threatening clostridial (and related anaerobic bacterial) infections that can complicate unsafe abortion. This Review deals with two especially devastating infections that are well-documented causes of septic abortion: the anaerobic, spore-forming pathogens Clostridium perfringens and Paeniclostridium sordellii. We seek to familiarise the reader with these bacteria, the clinical syndromes they can cause (with a focus on toxic shock syndrome), and provide a review of diagnosis and treatment options.

Forensic Toxicological Aspects of Misoprostol Use in Pharmacological Abortions

The aim of this study was establishment of an UHPLC-QqQ-MS/MS method for the deter-mination of misoprostol acid in biological specimens in cases of pharmacological abortions. Forensic toxicological examination was performed in three different biological samples (whole blood, placenta and fetal liver). The validation parameters of the method were as follows: limit of detection: 25 pg/mL; limit of quantification: 50 pg/mL, coefficient of determination: >0.999 (R2), intra- and interday accuracy and precision: not greater than 13.7%. The recovery and matrix effect were in the range of 88.3−95.1% and from −11.7 to −4.9%, respectively. Toxicological analysis of the mother’s blood (collected two days after pregnancy termination) did not reveal any abortifacients; however, misoprostol acid was found in the placenta (793 pg/g) and fetal liver (309 pg/g). The second case involved a fetus found near a garbage container. The concentration of misoprostol acid in the placenta was 2332 pg/g. In the presented study, an extensive literature review of misoprostol pharmacokinetics studies was performed. To our knowledge, the UHPLC-QqQ-MS/MS technique presented in this paper is the first quantitative method applied for forensic toxicological purposes. In addition, postmortem concentrations of misoprostol acid in miscarried fetuses due to illegal abortions were reported for the first time.

Mifepristone (RU-486®) as a Schedule IV Controlled Drug—Implications for a Misleading Drug Policy on Women’s Health Care

Background: Mifepristone (RU-486) has been approved for abortion in Taiwan since 2000. Mifepristone was the first non-addictive medicine to be classified as a schedule IV controlled drug. As a case of the “misuse” of “misuse of drugs laws,” the policy and consequences of mifepristone-assisted abortion for pregnant women could be compared with those of illicit drug use for drug addicts. Methods: The rule-making process of mifepristone regulation was analyzed from various aspects of legitimacy, social stigma, women’s human rights, and access to health care. Results and Discussion: The restriction policy on mifepristone regulation in Taiwan has raised concerns over the legitimacy of listing a non-addictive substance as a controlled drug, which may produce stigma and negatively affect women’s reproductive and privacy rights. Such a restriction policy and social stigma may lead to the unwillingness of pregnant women to utilize safe abortion services. Under the threat of the COVID-19 pandemic, the US FDA’s action on mifepristone prescription and dispensing reminds us it is time to consider a change of policy. Conclusions: Listing mifepristone as a controlled drug could impede the acceptability and accessibility of safe mifepristone use and violates women’s right to health care.

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.

Analysis of Complications and Management After Self-Administration of Medical Termination of Pregnancy Pills

Background Medical abortion up to seven weeks of pregnancy by using a combination of mifepristone and misoprostol with careful follow-up is approved by WHO guidelines. But due to the counter sale of medical termination of pregnancy (MTP) pills, in our country, pregnant women have easy access to use them landing upon serious complications. The present study aims to assess the outcome of self-medicated MTP pills in pregnant women. Method This prospective observational study includes pregnant women who presented to our hospital for medical assistance due to complications after using the counter of MTP pills without medical consultation. Findings of ultra-sonographic and physical examination were noted along with analysis of subsequent management. Results The major complaint at presentation was excessive bleeding (78%). Out of 100 patients, 66% of cases were diagnosed as incomplete abortion, 6% as missed abortion, and 6% as unaffected pregnancy. Ectopic pregnancy was detected in 12% of cases. Sixty patients of incomplete abortion were managed with suction and evacuation and six were supplemented with misoprostol. All patients with ectopic pregnancies were managed surgically. Conclusion The majority of the pregnant women who took MTP pills presented with serious complications in the form of bleeding, incomplete/missed abortion, and ectopic pregnancy. Restriction of the over-the-counter dispensation of abortion pills needs to be strictly implemented and knowledge of women regarding the unfavourable outcome of MTP pill intake without proper consultation needs to be improved.

Translocation of vaginal microbiota is involved in impairment and protection of uterine health

The vaginal and uterine microbiota play important roles in the health of the female reproductive system. However, the interactions among the microbes in these two niches and their effects on uterine health remain unclear. Here we profile the vaginal and uterine microbial samples of 145 women, and combine with deep mining of public data and animal experiments to characterize the microbial translocation in the female reproductive tract and its role in modulating uterine health. Synchronous variation and increasing convergence of the uterine and vaginal microbiome with advancing age are shown. We also find that transplanting certain strains of vaginal bacteria into the vagina of rats induces or reduces endometritis-like symptoms, and verify the damaging or protective effects of certain vaginal bacteria on endometrium. This study clarifies the interdependent relationship of vaginal bacterial translocation with uterine microecology and endometrial health, which will undoubtedly increase our understanding of female reproductive health.

Large Clostridial Toxins: Mechanisms and Roles in Disease

Large clostridial toxins (LCTs) are a family of bacterial exotoxins that infiltrate and destroy target cells. Members of the LCT family include Clostridioides difficile toxins TcdA and TcdB, Paeniclostridium sordellii toxins TcsL and TcsH, Clostridium novyi toxin TcnA, and Clostridium perfringens toxin TpeL. Since the 19th century, LCT-secreting bacteria have been isolated from the blood, organs, and wounds of diseased individuals, and LCTs have been implicated as the primary virulence factors in a variety of infections, including C. difficile infection and some cases of wound-associated gas gangrene. Clostridia express and secrete LCTs in response to various physiological signals. LCTs invade host cells by binding specific cell surface receptors, ultimately leading to internalization into acidified vesicles. Acidic pH promotes conformational changes within LCTs, which culminates in translocation of the N-terminal glycosyltransferase and cysteine protease domain across the endosomal membrane and into the cytosol, leading first to cytopathic effects and later to cytotoxic effects. The focus of this review is on the role of LCTs in infection and disease, the mechanism of LCT intoxication, with emphasis on recent structural work and toxin subtyping analysis, and the genomic discovery and characterization of LCT homologues. We provide a comprehensive review of these topics and offer our perspective on emerging questions and future research directions for this enigmatic family of toxins.

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.

Medication Abortion Up to 70 Days of Gestation

Medication abortion, also referred to as medical abortion, is a safe and effective method of providing abortion. Medication abortion involves the use of medicines rather than uterine aspiration to induce an abortion. The U.S. Food and Drug Administration (FDA)-approved medication abortion regimen includes mifepristone and misoprostol. The purpose of this document is to provide updated evidence-based guidance on the provision of medication abortion up to 70 days (or 10 weeks) of gestation. Information about medication abortion after 70 days of gestation is provided in other ACOG publications [1].

Medication to Manage Abortion and Miscarriage

Abortion and miscarriage are common, affecting millions of US women each year. By age 45, one in four women in the USA will have had an abortion, and at least as many will have had a miscarriage. Most individuals seeking abortion services do so before 10 weeks' gestation when medication abortions are a safe and effective option, using a regimen of oral mifepristone followed by misoprostol tablets. When a pregnancy is non-viable before 13 weeks' gestation, it is referred to as an early pregnancy loss or miscarriage and can be managed using the same mifepristone and misoprostol regimen. Given their safety and efficacy, mifepristone and misoprostol can be offered in ambulatory settings without special equipment or on-site emergency services. As more patients find it difficult to access clinical care when faced with an undesired pregnancy or a miscarriage, it is important for general internists and primary care providers to become familiar with how to use medications to manage these common conditions. We summarize the most recent evidence regarding the use of mifepristone with misoprostol for early abortion and miscarriage. We discuss clinical considerations and resources for integrating mifepristone and misoprostol into clinical practice. By learning to prescribe mifepristone and misoprostol, clinicians can expand access to time-sensitive health services for vulnerable populations.

Recognition of Semaphorin Proteins by P. sordellii Lethal Toxin Reveals Principles of Receptor Specificity in Clostridial Toxins

Pathogenic clostridial species secrete potent toxins that induce severe host tissue damage. Paeniclostridium sordellii lethal toxin (TcsL) causes an almost invariably lethal toxic shock syndrome associated with gynecological infections. TcsL is 87% similar to C. difficile TcdB, which enters host cells via Frizzled receptors in colon epithelium. However, P. sordellii infections target vascular endothelium, suggesting that TcsL exploits another receptor. Here, using CRISPR/Cas9 screening, we establish semaphorins SEMA6A and SEMA6B as TcsL receptors. We demonstrate that recombinant SEMA6A can protect mice from TcsL-induced edema. A 3.3 Å cryo-EM structure shows that TcsL binds SEMA6A with the same region that in TcdB binds structurally unrelated Frizzled. Remarkably, 15 mutations in this evolutionarily divergent surface are sufficient to switch binding specificity of TcsL to that of TcdB. Our findings establish semaphorins as physiologically relevant receptors for TcsL and reveal the molecular basis for the difference in tissue targeting and disease pathogenesis between highly related toxins.

Bacterial intracellularly active toxins: Membrane localisation of the active domain

Numerous bacterial toxins exert their activity by inactivating or modulating a specific intracellular host target. For this purpose, these toxins have developed efficient strategies to overcome the different host cell defences including specific binding to cell surface, internalisation, passage through the endosome or plasma membrane, exploiting intracellular trafficking and addressing to intracellular targets. Several intracellularly active toxins deliver an active domain into the cytosol that interacts with a target localised to the inner face of the plasma membrane. Thus, the large clostridial glucosylating toxins (LCGTs) target Rho/Ras-GTPases, certain virulence factors of Gram negative bacteria, Rho-GTPases, while Pasteurella multocida toxin (PMT) targets trimeric G-proteins. Others such as botulinum neurotoxins and tetanus neurotoxin have their substrate on synaptic vesicle membrane. LCGTs, PMT, and certain virulence factors from Vibrio sp. show a particular structure constituted of a four-helix bundle membrane (4HBM) protruding from the catalytic site that specifically binds to the membrane phospholipids and then trap the catalytic domain at the proximity of the membrane anchored substrate. Structural and functional analysis indicate that the 4HBM tip of the Clostridium sordellii lethal toxin (TcsL) from the LCGT family contain two loops forming a cavity that mediates the binding to phospholipids and more specifically to phosphatidylserine.

Genome-Wide CRISPR Screen Identifies Semaphorin 6A and 6B as Receptors for Paeniclostridium sordellii Toxin TcsL

The exotoxin TcsL is a major virulence factor in Paeniclostridium (Clostridium) sordellii and responsible for the high lethality rate associated with P. sordellii infection. Here, we present a genome-wide CRISPR-Cas9-mediated screen using a human lung carcinoma cell line and identify semaphorin (SEMA) 6A and 6B as receptors for TcsL. Disrupting SEMA6A/6B expression in several distinct human cell lines and primary human endothelial cells results in reduced TcsL sensitivity, while SEMA6A/6B over-expression increases their sensitivity. TcsL recognizes the extracellular domain (ECD) of SEMA6A/6B via a region homologous to the receptor-binding site in Clostridioides difficile toxin B (TcdB), which binds the human receptor Frizzled. Exchanging the receptor-binding interfaces between TcsL and TcdB switches their receptor-binding specificity. Finally, administration of SEMA6A-ECD proteins protects human cells from TcsL toxicity and reduces TcsL-induced damage to lung tissues and the lethality rate in mice. These findings establish SEMA6A and 6B as pathophysiologically relevant receptors for TcsL.

Bacteriemia por Clostridium sordellii en paciente con neoplasia gastrointestinal. Reporte de caso y revisión de literatura

La bacteriemia por Clostridium sordellii es infrecuente y usualmente se origina a partir de infecciones de etiología generalmente ginecológica y puerperal, con unamortalidad de aproximadamente el 70%. Existen pocas herramientas para el diagnóstico rápido y oportuno, siendo así la experiencia de tratamiento para este germen muy limitada en otros escenarios, lo que probablemente sea la causa de su alta mortalidad. Presentamos una paciente con antecedente de masa abdominal expansiva de larga data, con diagnóstico por histopatología e inmunohistoquimica compatibles con tumor del estroma gastrointestinal (GIST por sus siglas en inglés) y estudios de extensión que confirman compromiso metastásico hepático, en quien se documenta bacteriemia por Clostridium sordellii. 

Assessing the effectiveness of empiric antimicrobial regimens in cases of septic/infected abortions

INTRODUCTION

Infected abortion is a life-threatening condition that requires immediate surgical and medical interventions. We aimed to assess the common pathogens associated with infected abortion and to test the microbial coverage of various empiric antimicrobial regimens based on the bacteriological susceptibility results in women with infected abortions.

METHODS

A retrospective study in a single university-affiliated tertiary hospital. Electronic records were searched for clinical course, microbial characteristics, and antibiotic susceptibility of all patients diagnosed with an infected abortion. The effectiveness of five antibiotic regimens was analyzed according to bacteriological susceptibility results.

RESULTS

Overall, 84 patients were included in the study. The mean age of patients was 32.3(SD ± 5.8) years, and the median gestational age was 15 (IQR 8-19) weeks. Risk factors for infection were identified in 23 patients (27.3%), and included lack of medical insurance (n = 12), recent amniocentesis/chorionic villus sampling or fetal reduction due to multifetal pregnancies (n = 10). The most common pathogens isolated were Enterobacteriaceae (35%), Streptococci (31%), Staphylococci (9%) and Enterococci (9%). The combination of intravenous ampicillin, gentamicin and metronidazole showed significant superiority over all the other tested regimens according to the susceptibility test results. Piperacillin-tazobactam as an empiric single-agent drug of choice and provided a superior microbial coverage, with a coverage rate of 93.3%.

CONCLUSIONS

A combination of ampicillin, gentamicin, and metronidazole had a better spectrum of coverage as a first-line empiric choice for patients with infected abortion.

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.

[Prevention of postoperative or associated of care pelvic inflammatory diseases: CNGOF and SPILF Pelvic Inflammatory Diseases Guidelines]

Numerous prophylactic antibiotic regimens (PBR) have been evaluated particularly in surgical abortion, hysterosalpingography or caesarean section, but few randomized comparative trials are available. Recommendations for PBR should take into account, expected and demonstrated benefits that reduce the risk of surgical site infection, but also the impact on the microbiota, the risk of bacterial resistance selection, and the overall cost to the community. In addition, antibiotic prophylaxis is not the only one factor to reduce the risk of surgical site infection, such as preventive measures and good hygiene practices.

Paeniclostridium sordellii and Clostridioides difficile encode similar and clinically relevant tetracycline resistance loci in diverse genomic locations

BACKGROUND

With the current rise of antibiotic resistance in bacteria, it is important to monitor the efficacy of antimicrobials in clinical use. Paeniclostridium sordellii (previously Clostridium sordellii) is a bacterial pathogen that causes human uterine infection after spontaneous or medically induced abortion, for which mortality rates approach 100%. Prophylactic antibiotics have been recommended for individuals undergoing medically-induced abortion, one of which is doxycycline, a member of the tetracycline antibiotic family. However, tetracycline resistance had not been well characterized in P. sordellii. This study therefore aimed to determine the levels of tetracycline resistance in P. sordellii isolates, and to identify associated loci and their genomic locations.

RESULTS

Using a MIC assay, five of 24 P. sordellii isolates were found to be resistant to tetracycline, minocycline, and importantly, doxycycline. Analysis of genome sequence data from 46 isolates found that phenotypically resistant isolates encoded a variant of the Clostridium perfringens tetracycline resistance determinant Tet P. Bioinformatic analysis and comparison of the regions surrounding these determinants found variation in the genomic location of Tet P among P. sordellii isolates. The core genome comparison of the 46 isolates revealed genetic diversity and the absence of dominant genetic types among the isolates. There was no strong association between geographic location of isolation, animal host or Tet P carriage with isolate genetic type. Furthermore, the analysis of the Tet P genotype revealed that Tet P is encoded chromosomally, or on one of two, novel, small plasmids, all consistent with multiple acquisition and recombination events. BLAST analysis of Clostridioides difficile draft genome sequences also identified a Tet P locus, the genomic location of which demonstrated an evolutionary relationship with the P. sordellii locus.

CONCLUSIONS

The Tet P determinant is found in variable genomic locations within diverse human and animal isolates of P. sordellii and C. difficile, which suggests that it can undergo horizontal transfer, and may disseminate tetracycline resistance between clostridial species. Doxycycline is a suggested prophylactic treatment for P. sordellii infections, however, a small sub-set of the isolates tested are resistant to this antibiotic. Doxycycline may therefore not be an appropriate prophylactic treatment for P. sordellii infections.

Conservation of the "Outside-in" Germination Pathway in Paraclostridium bifermentans

Clostridium difficile spore germination is initiated in response to certain bile acids and amino acids (e.g., glycine). Though the amino acid-recognizing germinant receptor is unknown, the bile acid germinant receptor is the germination-specific, subtilisin-like pseudoprotease, CspC. In C. difficile the CspB, CspA, and CspC proteins are involved in spore germination. Of these, only CspB is predicted to have catalytic activity because the residues important for catalysis are mutated in the cspA and cspC sequence. The CspB, CspA, and CspC proteins are likely localized to the outer layers of the spore (e.g., the cortex or the coat layers) and not the inner membrane where the Ger-type germinant receptors are located. In C. difficile, germination proceeds in an “outside-in” direction, instead of the “‘inside-out” direction observed during the germination of Bacillus subtilis spores. During C. difficile spore germination, cortex fragments are released prior to the release of 2,4-dipicolinic acid (DPA) from the spore core. This is opposite to what occurs during B. subtilis spore germination. To understand if the mechanism C. difficile spore germination is unique or if spores from other organisms germinate in a similar fashion, we analyzed the germination of Paraclostridium bifermentans spores. We find that P. bifermentans spores release cortex fragments prior to DPA during germination and the DPA release from the P. bifermentans spore core can be blocked by high concentrations of osmolytes. Moreover, we find that P. bifermentans spores do not respond to steroid-like compounds (unlike the related C. difficile and P. sordellii organisms), indicating that the mere presence of the Csp proteins does permit germination in response to steroid compounds. Our findings indicate that the “outside in” mechanism of spore germination observed in C. difficile can be found in other bacteria suggesting that this mechanism is a novel pathway for endospore germination.

Bioresponsive Nanoparticles Targeted to Infectious Microenvironments for Sepsis Management

Sepsis is a life-threatening disease resulted from a dysregulated host immune response to bacterial infections, continuing to cause high morbidity and mortality worldwide. Despite discoveries of many potential therapeutic targets, effective treatments of sepsis are lacking. Here, a strategy is reported to target infectious microenvironments (IMEs) via bioresponsive nanoparticles that simultaneously eliminate bacteria and alleviate the host inflammation response, thus managing sepsis in mice. The nanoparticle is made of copolymers sensitive to pH and bacterial enzymes to self-assemble into a micelle loaded with both an antibiotic (ciprofloxacin) and an anti-inflammatory agent ((2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide). In addition, the nanoparticle is conjugated with intercellular adhesion molecule-1 antibodies to target IMEs. Nanoparticle targeting to IMEs and local cues as triggers to deliver therapeutics in on-demand manners is demonstrated using an acute lung bacterial infection mouse model. In the sepsis mouse model induced by peritonitis at a lethal dose of bacterial invasion, it is shown that concurrently targeting pathogens and excessive inflammation pathways is valuable to manage the sepsis. The study illustrates not only the development of a new delivery system but also the mechanism-based therapy of nanomedicine for infectious diseases.

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

•

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

•

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

•

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

•

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

•

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.

Clostridium sordelli causing malignant edema in a trauma patient: a case report and review of literature

Clostridium sordelli infection is a rare but potentially lethal infection associated with abortions, injury, contaminated wounds, and illicit drug use. It causes a recognizable syndrome with marked leukocytosis. Rapid diagnosis and aggressive sepsis management is required for optimal outcome. We report a case in a trauma patient with delayed presentation after sustaining facial trauma with soil contamination. The critical care management is summarized and a review of the literature.

Clostridium sordellii Pathogenicity Locus Plasmid pCS1-1 Encodes a Novel Clostridial Conjugation Locus

A major virulence factor in Clostridium sordellii-mediated infection is the toxin TcsL, which is encoded within a region of the genome called the pathogenicity locus (PaLoc). C. sordellii isolates carry the PaLoc on the pCS1 family of plasmids, of which there are four characterized members. Here, we determined the potential mobility of pCS1 plasmids and characterized a fifth unique pCS1 member. Using a derivative of the pCS1-1 plasmid from strain ATCC 9714 which had been marked with the ermB erythromycin resistance gene, conjugative transfer into a recipient C. sordellii isolate, R28058, was demonstrated. Bioinformatic analysis of pCS1-1 identified a novel conjugation gene cluster defined as the C. sordellii transfer (cst) locus. Interruption of genes within the cst locus resulted in loss of pCS1-1 transfer, which was restored upon complementation in trans. These studies provided clear evidence that genes within the cst locus are essential for the conjugative transfer of pCS1-1. The cst locus is present on all pCS1 subtypes, and homologous loci were identified on toxin-encoding plasmids from Clostridium perfringens and Clostridium botulinum and also carried within genomes of Clostridium difficile isolates, indicating that it is a widespread clostridial conjugation locus. The results of this study have broad implications for the dissemination of toxin genes and, potentially, antibiotic resistance genes among members of a diverse range of clostridial pathogens, providing these microorganisms with a survival advantage within the infected host.

C. sordellii is a bacterial pathogen that causes severe infections in humans and animals, with high mortality rates. While the pathogenesis of C. sordellii infections is not well understood, it is known that the toxin TcsL is an important virulence factor. Here, we have shown the ability of a plasmid carrying the tcsL gene to undergo conjugative transfer between distantly related strains of C. sordellii, which has far-reaching implications for the ability of C. sordellii to acquire the capacity to cause disease. Plasmids that carry tcsL encode a previously uncharacterized conjugation locus, and individual genes within this locus were shown to be required for conjugative transfer. Furthermore, homologues on toxin plasmids from other clostridial species were identified, indicating that this region represents a novel clostridial conjugation locus. The results of this study have broad implications for the dissemination of virulence genes among members of a diverse range of clostridial pathogens.

Structural Characterization of Clostridium sordellii Spores of Diverse Human, Animal, and Environmental Origin and Comparison to Clostridium difficile Spores

Clostridium sordellii is a significant pathogen with mortality rates approaching 100%. It is the bacterial spore that is critical in initiating infection and disease. An understanding of spore structures as well as spore morphology across a range of strains may lead to a better understanding of C. sordellii infection and disease. However, the structural characteristics of the C. sordellii spores are limited. In this work, we have addressed this lack of detail and characterized the C. sordellii spore morphology. The use of traditional and advanced microscopy techniques has provided detailed new observations of C. sordellii spore structural features, which serve as a reference point for structural studies of spores from other bacterial species.

Clostridium sordellii is an often-lethal bacterium causing human and animal disease. Crucial to the infectious cycle of C. sordellii is its ability to produce spores, which can germinate into toxin-producing vegetative bacteria under favorable conditions. However, structural details of the C. sordellii spore are lacking. Here, we used a range of electron microscopy techniques together with superresolution optical microscopy to characterize the C. sordellii spore morphology with an emphasis on the exosporium. The C. sordellii spore is made up of multiple layers with the exosporium presenting as a smooth balloon-like structure that is open at the spore poles. Focusing on the outer spore layers, we compared the morphologies of C. sordellii spores derived from different strains and determined that there is some variation between the spores, most notably with spores of some strains having tubular appendages. Since Clostridium difficile is a close relative of C. sordellii, their spores were compared by electron microscopy and their exosporia were found to be distinctly different from each other. This study therefore provides new structural details of the C. sordellii spore and offers insights into the physical structure of the exosporium across clostridial species.

IMPORTANCEClostridium sordellii is a significant pathogen with mortality rates approaching 100%. It is the bacterial spore that is critical in initiating infection and disease. An understanding of spore structures as well as spore morphology across a range of strains may lead to a better understanding of C. sordellii infection and disease. However, the structural characteristics of the C. sordellii spores are limited. In this work, we have addressed this lack of detail and characterized the C. sordellii spore morphology. The use of traditional and advanced microscopy techniques has provided detailed new observations of C. sordellii spore structural features, which serve as a reference point for structural studies of spores from other bacterial species.

Development of medical termination of pregnancy: a review

The synthesis of mifepristone, an antiprogestin blocking the action of progesterone at the receptor level, started a new era of medical termination of pregnancy (MTOP). The initial results of MTOP with mifepristone alone were disappointing; however, mifepristone can sensitise the myometrium to the action of prostaglandins. Clinical trials have shown that the sequential administration of mifepristone followed 1-2 days later by a prostaglandin analogue is a safe, effective, and acceptable method for MTOP. This article will review the events and challenges leading to the development of the current evidence-based and yet off-label regimen for first-trimester MTOP.

TWEETABLE ABSTRACT

This article reviews the events and challenges in the development of medical termination of pregnancy.

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.

[Complications of termination of pregnancy]

The legalization of abortion in France allowed to disappear almost maternal deaths caused by induced abortions. Nevertheless, the practice of abortion in a medical framework is encumbered with a number of immediate complications. Similarly, the late consequences of the practice of surgical abortion have generated an abundant literature, which it is important to analyse, both to meet the legitimate concerns of patients as to prevent any spread of false ideas under the influence of movements opposed to abortion.

Clostridium Sordellii as an Uncommon Cause of Fatal Toxic Shock Syndrome in a Postpartum 33-Year-Old Asian Woman, and the Need for Antepartum Screening for This Clostridia Species in the General Female Population

Clostridium sordellii (C. sordellii) is an anaerobic gram-positive rod most commonly found in the soil and sewage but also as part of the normal flora of the gastrointestinal tract and vagina of a small percentage of healthy individuals. C. sordellii infection is considered to result from childbirth, abortion, and/or gynecological procedures. Although many strains of C. sordellii are nonpathogenic, virulent toxin-producing strains exist. Infection with this organism typically manifests as a patient experiencing septic shock rapidly followed by end-organ failure. Identification of C. sordelli has been successful by traditional culture, mass spectrometry methods, and via molecular methods. Herein, we present a fatal case of C. sordellii infection of a postpartum 33-year-old Asian woman. The organism was isolated by culture and identified using matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) technology. With the advent of rapid detection methods, antepartum screening for the fatal Clostridium species should be implemented in the general female population.

Antibiotics for treating septic abortion

BACKGROUND

A septic abortion refers to any abortion (spontaneous or induced) complicated by upper genital tract infection including endometritis or parametritis. The mainstay of treatment of septic abortion is antibiotic therapy alone or in combination with evacuation of retained products of conception. Regimens including broad-spectrum antibiotics are routinely recommended for treatment. However, there is no consensus on the most effective antibiotics alone or in combination to treat septic abortion. This review aimed to bridge this gap in knowledge to inform policy and practice.

OBJECTIVES

To review the effectiveness of various individual antibiotics or antibiotic regimens in the treatment of septic abortion.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, and POPLINE using the following keywords: 'Abortion', 'septic abortion', 'Antibiotics', 'Infected abortion', 'postabortion infection'. We also searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov for ongoing trials on 19 April, 2016.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) and non-RCTs that compared antibiotic(s) to another antibiotic(s), irrespective of route of administration, dosage, and duration as well as studies comparing antibiotics alone with antibiotics in combination with other interventions such as dilation and curettage (D&C).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from included trials. We resolved disagreements through consultation with a third author. One review author entered extracted data into Review Manager 5.3, and a second review author cross-checked the entry for accuracy.

MAIN RESULTS

We included 3 small RCTs involving 233 women that were conducted over 3 decades ago.Clindamycin did not differ significantly from penicillin plus chloramphenicol in reducing fever in all women (mean difference (MD) -12.30, 95% confidence interval (CI) -25.12 to 0.52; women = 77; studies = 1). The evidence for this was of moderate quality. "Response to treatment was evaluated by the patient's 'fever index' expressed in degree-hour and defined as the total quantity of fever under the daily temperature curve with 99°F (37.2°C) as the baseline".There was no difference in duration of hospitalisation between clindamycin and penicillin plus chloramphenicol. The mean duration of hospital stay for women in each group was 5 days (MD 0.00, 95% CI -0.54 to 0.54; women = 77; studies = 1).One study evaluated the effect of penicillin plus chloramphenicol versus cephalothin plus kanamycin before and after D&C. Response to therapy was evaluated by "the time from start of antibiotics until fever lysis and time from D&C until patients become afebrile". Low-quality evidence suggested that the effect of penicillin plus chloramphenicol on fever did not differ from that of cephalothin plus kanamycin (MD -2.30, 95% CI -17.31 to 12.71; women = 56; studies = 1). There was no significant difference between penicillin plus chloramphenicol versus cephalothin plus kanamycin when D&C was performed during antibiotic therapy (MD -1.00, 95% CI -13.84 to 11.84; women = 56; studies = 1). The quality of evidence was low.A study with unclear risk of bias showed that the time for fever resolution (MD -5.03, 95% CI -5.77 to -4.29; women = 100; studies = 1) as well as time for resolution of leukocytosis (MD -4.88, 95% CI -5.98 to -3.78; women = 100; studies = 1) was significantly lower with tetracycline plus enzymes compared with intravenous penicillin G.Treatment failure and adverse events occurred infrequently, and the difference between groups was not statistically significant.

AUTHORS' CONCLUSIONS

We found no strong evidence that intravenous clindamycin alone was better than penicillin plus chloramphenicol for treating women with septic abortion. Similarly, available evidence did not suggest that penicillin plus chloramphenicol was better than cephalothin plus kanamycin for the treatment of women with septic abortion. Tetracyline enzyme antibiotic appeared to be more effective than intravenous penicillin G in reducing the time to fever defervescence, but this evidence was provided by only one study at low risk of bias.There is a need for high-quality RCTs providing reliable evidence for treatments of septic abortion with antibiotics that are currently in use. The three included studies were carried out over 30 years ago. There is also a need to include institutions in low-resource settings, such as sub-Saharan Africa, Latin America and the Caribbean, and South Asia, with a high burden of abortion and health systems challenges.

The Sialidase NanS Enhances Non-TcsL Mediated Cytotoxicity of Clostridium sordellii

The clostridia produce an arsenal of toxins to facilitate their survival within the host environment. TcsL is one of two major toxins produced by Clostridium sordellii, a human and animal pathogen, and is essential for disease pathogenesis of this bacterium. C. sordellii produces many other toxins, but the role that they play in disease is not known, although previous work has suggested that the sialidase enzyme NanS may be involved in the characteristic leukemoid reaction that occurs during severe disease. In this study we investigated the role of NanS in C. sordellii disease pathogenesis. We constructed a nanS mutant and showed that NanS is the only sialidase produced from C. sordellii strain ATCC9714 since sialidase activity could not be detected from the nanS mutant. Complementation with the wild-type gene restored sialidase production to the nanS mutant strain. Cytotoxicity assays using sialidase-enriched culture supernatants applied to gut (Caco2), vaginal (VK2), and cervical cell lines (End1/E6E7 and Ect1/E6E7) showed that NanS was not cytotoxic to these cells. However, the cytotoxic capacity of a toxin-enriched supernatant to the vaginal and cervical cell lines was substantially enhanced in the presence of NanS. TcsL was not the mediator of the observed cytotoxicity since supernatants harvested from a TcsL-deficient strain displayed similar cytotoxicity levels to TcsL-containing supernatants. This study suggests that NanS works synergistically with an unknown toxin or toxins to exacerbate C. sordellii-mediated tissue damage in the host.

Fatal Spontaneous Clostridium bifermentans Necrotizing Endometritis: A Case Report and Literature Review of the Pathogen

Clostridium bifermentans is a rare pathogen in humans. A fatal case of fulminant endometritis with toxic shock and capillary leak secondary to C bifermentans infection in a young woman is described, and this is compared to all 13 previously described cases of C bifermentans infection.

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.

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.

Abortion-Related Mortality in the United States: 1998-2010

OBJECTIVE

To examine characteristics and causes of legal induced abortion-related deaths in the United States between 1998 and 2010.

METHODS

Abortion-related deaths were identified through the national Pregnancy Mortality Surveillance System with enhanced case-finding. We calculated the abortion mortality rate by race, maternal age, and gestational age and the distribution of causes of death by gestational age and procedure.

RESULTS

During the period from 1998-2010, of approximately 16.1 million abortion procedures, 108 women died, for a mortality rate of 0.7 deaths per 100,000 procedures overall, 0.4 deaths for non-Hispanic white women, 0.5 deaths for Hispanic women, and 1.1 deaths for black women. The mortality rate increased with gestational age, from 0.3 to 6.7 deaths for procedures performed at 8 weeks or less and at 18 weeks or greater, respectively. A majority of abortion-related deaths at 13 weeks of gestation or less were associated with anesthesia complications and infection, whereas a majority of abortion-related deaths at more than 13 weeks of gestation were associated with infection and hemorrhage. In 20 of the 108 cases, the abortion was performed as a result of a severe medical condition where continuation of the pregnancy threatened the woman's life.

CONCLUSION

Deaths associated with legal induced abortion continue to be rare events-less than 1 per 100,000 procedures. Primary prevention of unintended pregnancy, including those in women with serious pre-existing medical conditions, and increased access to abortion services at early gestational ages may help to further decrease abortion-related mortality in the United States.

LEVEL OF EVIDENCE

III.

Mifepristone With Buccal Misoprostol for Medical Abortion: A Systematic Review

OBJECTIVE

To summarize clinical outcomes and adverse effects of medical abortion regimens consisting of mifepristone followed by buccal misoprostol in pregnancies through 70 days of gestation.

DATA SOURCES

We used PubMed, ClinicalTrials.gov, and reference lists from published reports to identify relevant studies published between November 2005 and January 2015 using the search terms "mifepristone and medical abortion" and "buccal and misoprostol."

METHODS OF STUDY SELECTION

Studies were included if they presented clinical outcomes of medical abortion using mifepristone and buccal misoprostol through 70 days of gestation. Studies with duplicate data were excluded.

TABULATION, INTEGRATION, AND RESULTS

We included 20 studies with a total of 33,846 women through 70 days of gestation. We abstracted efficacy and ongoing pregnancy rates as an overall rate and by gestational age in days in reference to completed weeks (eg, 49 days or less, 50-56 days, 57-63 days, 64-70 days) and adverse effects when reported. The overall efficacy of mifepristone followed by buccal misoprostol is 96.7% (95% confidence interval [CI] 96.5-96.8%) and the continuing pregnancy rate is 0.8% (95% CI 0.7-0.9%) in approximately 33,000 pregnancies through 63 days of gestation. Only 332 women with pregnancies between 64 and 70 days of gestation are reported in the literature with an overall efficacy of 93.1% (95% CI 89.6-95.5%) and a continuing pregnancy rate of 2.9% (95% CI 1.4-5.7%). Currently available data suggest that regimens with a 24-hour time interval between mifepristone and buccal misoprostol administration are slightly less effective than those with a 24- to 48-hour interval. Rates of surgical evacuation for reasons other than ongoing pregnancy range from 1.8% to 4.2%. Severe adverse events like blood transfusion (0.03-0.6%) and hospitalization (0.04-0.9%) are uncommon.

CONCLUSION

Outpatient medical abortion regimens with mifepristone followed in 24-48 hours by buccal misoprostol are highly effective for pregnancy termination through 63 days of gestation. More data are needed to evaluate clinical outcomes with regimens containing mifepristone followed in 24 hours by buccal misoprostol and in pregnancies beyond 63 days of gestation.

Treating spontaneous and induced septic abortions

Worldwide, abortion accounts for approximately 14% of pregnancy-related deaths, and septic abortion is a major cause of the deaths from abortion. Today, septic abortion is an uncommon event in the United States. The most critical treatment of septic abortion remains the prompt removal of infected tissue. Antibiotic administration and fluid resuscitation provide necessary secondary levels of treatment. Most young physicians have never treated septic abortion. Many obstetrician-gynecologists experience, or plan to experience, global health activities and will likely care for women with septic abortion. Thus, updated knowledge of the pathophysiology, clinical presentation, microbes, and proper treatment is needed to optimally treat this emergency condition when it exists. The pathophysiology of septic abortion involves infection of the placenta, especially the maternal villous space that leads to a high frequency of bacteremia. Symptoms and signs range from mild to severe. The microbes involved are usually common vaginal bacteria, including anaerobes, but occasionally potentially very serious and lethal infection is caused by bacteria that produce toxins. The primary treatment is early curettage to remove infected and devitalized tissue even in the face of continued fetal heart tones. Important secondary treatments are the administration of fluids and antibiotics. Updated references of sepsis and septic shock are reviewed.

Clostridium sordellii genome analysis reveals plasmid localized toxin genes encoded within pathogenicity loci

Background

Clostridium sordellii can cause severe infections in animals and humans, the latter associated with trauma, toxic shock and often-fatal gynaecological infections. Strains can produce two large clostridial cytotoxins (LCCs), TcsL and TcsH, related to those produced by Clostridium difficile, Clostridium novyi and Clostridium perfringens, but the genetic basis of toxin production remains uncharacterised.

Results

Phylogenetic analysis of the genome sequences of 44 strains isolated from human and animal infections in the UK, US and Australia placed the species into four clades. Although all strains originated from animal or clinical disease, only 5 strains contained LCC genes: 4 strains contain tcsL alone and one strain contains tcsL and tcsH. Four toxin-positive strains were found within one clade. Where present, tcsL and tcsH were localised in a pathogenicity locus, similar to but distinct from that present in C. difficile. In contrast to C. difficile, where the LCCs are chromosomally localised, the C. sordellii tcsL and tcsH genes are localised on plasmids. Our data suggest gain and loss of entire toxigenic plasmids in addition to horizontal transfer of the pathogenicity locus. A high quality, annotated sequence of ATCC9714 reveals many putative virulence factors including neuraminidase, phospholipase C and the cholesterol-dependent cytolysin sordellilysin that are highly conserved between all strains studied.

Conclusions

Genome analysis of C. sordellii reveals that the LCCs, the major virulence factors, are localised on plasmids. Many strains do not contain the LCC genes; it is probable that in several of these cases the plasmid has been lost upon laboratory subculture. Our data are consistent with LCCs being the primary virulence factors in the majority of infections, but LCC-negative strains may precipitate certain categories of infection. A high quality genome sequence reveals putative virulence factors whose role in virulence can be investigated.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1613-2) contains supplementary material, which is available to authorized users.