Fatal Clostridium sordellii infections after medical abortions

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.

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.

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.

Clostridium sordellii outer spore proteins maintain spore structural integrity and promote bacterial clearance from the gastrointestinal tract

Bacterial spores play an important role in disease initiation, transmission and persistence. In some species, the exosporium forms the outermost structure of the spore and provides the first point of contact between the spore and the environment. The exosporium may also be involved in spore adherence, protection and germination. Clostridium sordellii is a highly lethal, spore forming pathogen that causes soft-tissue infections, enteritis and toxic-shock syndrome. Despite the importance of C. sordellii spores in disease, spore proteins from this bacterium have not been defined or interrogated functionally. In this study, we identified the C. sordellii outer spore proteome and two of the identified proteins, CsA and CsB, were characterised using a genetic and phenotypic approach. Both proteins were essential for the correct formation and positioning of the C. sordellii spore coat and exosporium. The absence of CsA reduced sporulation levels and increased spore sensitivity to heat, sodium hydroxide and hydrochloric acid. By comparison, CsB was required for normal levels of spore adherence to cervical, but not vaginal, cells, with csB mutant spores having increased adherence properties. The establishment of a mouse infection model of the gastrointestinal tract for C. sordellii allowed the role of CsA and CsB to be interrogated in an infected host. Following the oral administration of spores to mice, the wild-type strain efficiently colonized the gastrointestinal tract, with the peak of bacterial numbers occurring at one day post-infection. Colonization was reduced by two logs at four days post-infection. By comparison, mice infected with the csB mutant did not show a reduction in bacterial numbers. We conclude that C. sordellii outer spore proteins are important for the structural and functional integrity of spores. Furthermore, outer spore proteins are required for wild-type levels of colonization during infection, possibly as a result of the role that the proteins play in spore structure and morphology.

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.

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.

Clostridial Infections in Children: Spectrum and Management

Clostridia can cause unique histotoxic syndromes produced by specific toxins (e.g., gas gangrene and food poisoning) as well as non-syndromic infections (e.g., abscess, local infections, and blood born infection). Clostridia can also be recovered from various body sites as part of polymicrobial aerobic-anaerobic infection. These include intra-abdominal (peritonitis and abscess), biliary tract, female genital tract, abscess (rectal area and oropharyngeal), pleuropulmonary, central nervous system, and skin and soft-tissue infections. Clostridia were recovered from children with bacteremia of gastrointestinal origin, necrotizing enterocolitis, and sickle cell disease. They have also been isolated in acute and chronic otitis media, chronic sinusitis and mastoiditis, peritonsillar abscesses, and neonatal conjunctivitis. Early and aggressive surgical debridement, decompression, and drainage of affected tissues are critical to successful outcome of histotoxic infections. Effective antimicrobials include penicillin, clindamycin, chloramphenicol, third-generation cephalosporins, carbapenems, and vancomycin.

Comparative genomic and phenomic analysis of Clostridium difficile and Clostridium sordellii, two related pathogens with differing host tissue preference

Background

Clostridium difficile and C. sordellii are two anaerobic, spore forming, gram positive pathogens with a broad host range and the ability to cause lethal infections. Despite strong similarities between the two Clostridial strains, differences in their host tissue preference place C. difficile infections in the gastrointestinal tract and C. sordellii infections in soft tissues.

Results

In this study, to improve our understanding of C. sordellii and C. difficile virulence and pathogenesis, we have performed a comparative genomic and phenomic analysis of the two. The global phenomes of C. difficile and C. sordellii were compared using Biolog Phenotype microarrays. When compared to C. difficile, C. sordellii was found to better utilize more complex sources of carbon and nitrogen, including peptides. Phenotype microarray comparison also revealed that C. sordellii was better able to grow in acidic pH conditions. Using next generation sequencing technology, we determined the draft genome of C. sordellii strain 8483 and performed comparative genome analysis with C. difficile and other Clostridial genomes. Comparative genome analysis revealed the presence of several enzymes, including the urease gene cluster, specific to the C. sordellii genome that confer the ability of expanded peptide utilization and survival in acidic pH.

Conclusions

The identified phenotypes of C. sordellii might be important in causing wound and vaginal infections respectively. Proteins involved in the metabolic differences between C. sordellii and C. difficile should be targets for further studies aimed at understanding C. difficile and C. sordellii infection site specificity and pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1663-5) contains supplementary material, which is available to authorized users.

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.

Is It Safe to Provide Abortion Pills over the Counter? A Study on Outcome Following Self-Medication with Abortion Pills

BACKGROUND

Medical abortion is a safe method of termination of pregnancy when performed as per guidelines with a success rate of 92-97 %. But self-administration of abortion pills is rampant throughout the country due to over the counter availability of these drugs and complications are not uncommon due to this practice. The society perceives unsupervised medical abortion as a very safe method of termination and women use this as a method of spacing.

AIM OF THE STUDY

The aim of this study was to study the implications of self-administration of abortion pills by pregnant women.

MATERIALS AND METHODS

Retrospective observational study done in Sri Manakula Vinayagar Medical College & Hospital between the period of July 2013 to June2014. Case sheets were analysed to obtain data regarding self-administration of abortion pills and complications secondary to its administration. The following data were collected. Age, marital status, parity, duration of pregnancy as perceived by the women, confirmation of pregnancy, duration between pill intake and visit to hospital, whether any intervention done elsewhere, any known medical or surgical complications, Hb level on admission, whether patient was in shock, USG findings, evidence of sepsis, blood transfusion, treatment given and duration of hospital stay. Descriptive analysis of the collected data was done.

RESULTS

Among the 128 cases of abortion in the study period, 40 (31.25%) patients had self-administered abortion pills. Among these 40 patients 27.5% had consumed abortion pills after the approved time period of 63 days of which 17.5% had consumed pills after 12 weeks of gestation. The most common presentation was excessive bleeding (77.5%) Severe anaemia was found in 12.5% of the patients and 5% of patients presented with shock. The outcome was as follows : 62.5% of the patients were found to have incomplete abortion, 22.5% had failed abortion and 7.5% of patients had incomplete abortion with sepsis. Surgical evacuation was performed in 67.5% of the patients whereas 12.5% of the patients required surgical evacuation with blood transfusion. Medical methods were used in 15% of the patients whereas 2.5% required transfusion along with medical methods.

CONCLUSION

Unsupervised medical abortion can lead to increased maternal morbidity and mortality. To curtail this harmful practice, strict legislations are required to monitor and also to restrict the sales of abortion pills over the counter and access to abortion pills for the public should be only through centers approved for MTP. Large scale prospective studies are required to assess the actual magnitude of this problem.

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.

[Pharmacology of misoprostol (pharmacokinetic data, adverse effects and teratogenic effects)]

Misoprostol is a synthetic analogue of prostaglandin E1. It is used in gynaecology because of its properties of myometrium smooth muscle cells contraction and its effects on the cervix. Misoprostol oral bioavailability is low and several authors have assessed whether the administration by other routes increased its pharmacodynamic effects. This paper summarizes the pharmacokinetic studies after other routes of administration: vaginal, sublingual, buccal or rectal. It also provides an update on its adverse effects and teratogenic effects.

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.

The immninent dawn of SPRMs in obstetrics and gynecology

Selective progesterone receptor modulators (SPRMs) have been developed since the late 70s when mifepristone was first described. They act through nuclear progesterone receptors and can have agonist or mixed agonist antagonist actions depending on the cell and tissue. Mifepristone has unique major antagonist properties allowing its use for pregnancy termination. Ulipristal acetate has been marketed in 2009 for emergency contraception and has been recently approved for preoperative myoma treatment. Further perspectives for SPRMs use include long term estrogen free contraception, endometriosis treatment. However long term applications will be possible only after confirmation of endometrial safety.

Rapid, simultaneous detection of Clostridium sordellii and Clostridium perfringens in archived tissues by a novel PCR-based microsphere assay: diagnostic implications for pregnancy-associated toxic shock syndrome cases

Clostridium sordellii and Clostridium perfringens are infrequent human pathogens; however, the case-fatality rates for the infections are very high, particularly in obstetric C. sordellii infections (>90%). Deaths from Clostridium sordellii and Clostridium perfringens toxic shock (CTS) are sudden, and diagnosis is often challenging. Formalin-fixed, paraffin-embedded (FFPE) tissues usually are the only specimens available for sudden fatal cases, and immunohistochemistry (IHC) for Clostridia is generally performed but it cannot identify species. A clear need exists for a rapid, species-specific diagnostic assay for FFPE tissues. We developed a duplex PCR-based microsphere assay for simultaneous detection of C. sordellii and C. perfringens and evaluated DNA extracted from 42 Clostridium isolates and FFPE tissues of 28 patients with toxic shock/endometritis (20 CTS, 8 non-CTS, as confirmed by PCR and sequencing). The microsphere assay correctly identified C. sordellii and C. perfringens in all known isolates and in all CTS patients (10 C. sordellii, 8 C. perfringens, 2 both) and showed 100% concordance with PCR and sequencing results. The microsphere assay is a rapid, specific, and cost-effective method for the diagnosis of CTS and offers the advantage of simultaneous testing for C. sordellii and C. perfringens in FFPE tissues using a limited amount of DNA.

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.

Non-toxigenic Clostridium sordellii: clinical and microbiological features of a case of cholangitis-associated bacteremia

Toxigenic Clostridium sordellii strains are increasingly recognized to cause highly lethal infections in humans that are typified by a toxic shock syndrome (TSS). Two glucosylating toxins, lethal toxin (TcsL) and hemorrhagic toxin (TcsH) are believed to be important in the pathogenesis of TSS. While non-toxigenic strains of C. sordellii demonstrate reduced cytotoxicity in vitro and lower virulence in animal models of infection, there are few data regarding their behavior in humans. Here we report a non-TSS C. sordellii infection in the context of a polymicrobial bacterial cholangitis. The C. sordellii strain associated with this infection did not carry either the TcsL-encoding tcsL gene or the tcsH gene for TcsH. In addition, the strain was neither cytotoxic in vitro nor lethal in a murine sepsis model. These results provide additional correlative evidence that TcsL and TcsH increase the risk of mortality during C. sordellii infections.

Clostridial infection in children

A survey of the isolation of Clostridium spp. from 1543 specimens sent to anaerobic microbiology laboratories revealed 113 isolates from 107 specimens (7.0% of all specimens) from 96 children. The isolates comprised 43 (38%) unidentified Clostridium spp., 37 (33%) C. perfringens, 13 (12%) C. ramosum, five (4%) C. innocuum, six (5%) C. botulinum, three (3%) C. difficile, two (2%) C. butyricum, and one isolate each of C. bifermentans, C. clostridiiforme, C. limosum and C. paraputrificum. Most clostridial isolates were from abscesses (38), peritonitis (26), bacteraemia (10), and chronic otitis media (7). Predisposing or underlying conditions were present in 31 (32%) cases. These were immunodeficiency (12), malignancy (9), diabetes (7), trauma (7), presence of a foreign body (6) and previous surgery (6). The clostridia were the only bacterial isolates in 14 (15%) cases; 82 (85%) cases had mixed infection. The species most commonly isolated with clostridia were anaerobic cocci (57); Bacteroides spp. (B. fragilis group) (50), Escherichia coli (22), pigmented Prevotella or Porphyromonas spp. (18) and Fusobacterium spp. (10). Most Bacteroides and Escherichia coli isolates with clostridia were from abdominal infections and skin and soft tissue infections adjacent to the rectal area; most pigmented Prevotella and Porphyromonas isolates were from oropharyngeal, pulmonary, and head and neck sites. Antimicrobial therapy was given to all patients, in conjunction with surgical drainage in 34 (35%). Only two patients died. These data illustrate the importance of Clostridium spp. in paediatric infections.