Spontaneous, nontraumatic gangrene due to Clostridium septicum

Case report: A severe case of generalized tetanus in a young cat

A 10-month-old, 3 kg, female spayed Domestic Shorthair cat was presented with a chronic, infected wound at the level of the proximo-lateral left pelvic limb. General physical examination revealed a weight-bearing lameness of the left pelvic limb, which was moderately and circumferentially swollen and edematous proximal to the tarsal joint. On the lateral aspect of the proximal thigh, there was a chronic wound of 1 cm in diameter and an additional exudative skin lesion was present throughout the whole length of the caudo-lateral thigh. Complete blood count and serum biochemistry profile revealed mild anemia, increased serum amyloid A, hyponatraemia, hypochloraemia, hypocalcaemia, hyperkalaemia, hypermagnesaemia, hyperglycaemia, increased creatine kinase, and increased liver parameters. Surgical exploration of the wound was performed, and necrotizing fasciitis was suspected. The affected limb was amputated and swabs for bacterial culture were taken from both the skin lesions and surgical site before wound closure. One day after surgery, mild muscular contractions on the forehead and an increased muscle tone of the right pelvic limb were evident. One day later, the cat developed a generalized increase in extensor tone, with intermittent opisthotonos, resulting in lateral recumbency. Based on these clinical signs, a diagnosis of generalized tetanus was made and treatment with midazolam, methocarbamol, and metronidazole was started. Despite an improvement of all blood parameters, the cat progressively deteriorated and 4 days after surgery, it developed episodes of tetanic convulsions, associated with hyperthermia and ventricular arrhythmias. Despite intensive care and medical management, the cat died following a cardio-respiratory arrest 3 days later. This case report describes a rare case of severe generalized tetanus in a young cat.

Clostridium myonecrosis - a rare and underdiagnosed condition in the elderly: a case with severe skipping lesions and an overview of treatment guidelines

We present an unusual and severe case of spontaneous clostridial myonecrosis (SCM) in an elderly patient, with severe skipping lesions spread throughout the body. CT imaging, combined with postmortem available blood cultures, confirmed the diagnosis. We noted an underrepresentation of SCM in the cohort of elderly patients (≥ 85 years), upon a review of case reports in the literature over the last decade. Given the worldwide demographic change resulting in an increase in the number of visits to emergency departments for this age group, it is likely that SCM is underdiagnosed in these elderly patients. This case report aims to increase awareness among emergency physicians to recognize the disease as well as to provide a treatment guideline, in order to provide better care and outcome.

Spontaneous gas gangrene of the lower limb in a patient with rectal cancer: A fatal diagnostic pitfall

Spontaneous gas gangrene of lower limb is rare. It may complicate digestive cancer or neutropenia. We report a case of spontaneous gas gangrene of the lower limb complicating a rectal cancer, initially diagnosed as deep vein thrombosis. The diagnostic delay was fatal.

Fatal Clostridium septicum myonecrosis from gastric perforation: A case report

Clostridial myonecrosis is a medical and surgical emergency which requires early and aggressive intervention to reduce mortality. We report a rare case of Clostridium septicum myonecrosis that disseminated hematogenously from a gastric perforation. The patient was afebrile and hemodynamically stable upon admission. He rapidly developed spontaneous clostridial myonecrosis and succumbed to septic shock 36 hours after presentation. In our extensive literature review this is the only case with blood cultures confirming Clostridium septicum bacteremia with a surgically confirmed gastric perforation source in the setting of spontaneous clostridial myonecrosis.

Clostridium septicum endophthalmitis as the first manifestation of a colon adenocarcinoma: A case report

Clostridium septicum endophthalmitis is an extremely rare infection with only a few cases reported in the literature. It has an endogenous origin and is associated with gastrointestinal and haematological malignancies. We present the case of a 62-year-old male who presented this infection as the first manifestation of a colon adenocarcinoma.

Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections occur after traumatic injuries, minor skin lesions, nonpenetrating injuries, natural childbirth, and in postsurgical and immunocompromised patients. Infections can be severe, rapidly progressive, and life threatening. Survivors often endure multiple surgeries and prolonged hospitalization and rehabilitation. Despite subtle nuances that may distinguish one entity from another, clinical approaches to diagnosis and treatment are highly similar. This review describes the clinical and laboratory features of necrotizing soft tissue infections and addresses recommended diagnostic and treatment modalities. It discusses the impact of delays in surgical debridement, antibiotic use, and resuscitation on mortality, and summarizes key pathogenic mechanisms.

Clostridial Gas Gangrene - A Rare but Deadly Infection: Case series and Comparison to Other Necrotizing Soft Tissue Infections

Objective

Clostridial gas gangrene (GG) or clostridial myonecrosis is a very rare but life‐threatening necrotizing soft tissue infection (NSTI) caused by anaerobic, spore‐forming, and gas‐producing clostridium subspecies. It is the most rapidly spreading and lethal infection in humans, also affecting muscle tissue. The high mortality, of up to 100%, in clostridial GG is mediated by potent bacterial exotoxins. Necrotizing fasciitis (NF) is an important differential diagnosis, most often caused by group A streptococci, primarily not affecting musculature but the subcutaneous tissue and fascia. In the early stages of the infection, it is difficult to distinguish between GG and NF. Therefore, we compare both infection types, identify relevant differences in initial clinical presentation and later course, and present the results of our patients in a retrospective review.

Methods

Patients diagnosed with GG from 2008 to 2018 in our level one trauma center were identified. Their charts were reviewed retrospectively and data analyzed in terms of demographic information, microbiological and histological results, therapeutic course, outcome, and mortality rates. The laboratory risk indicator for NF (LRINEC) score was applied on the first blood work acquired. Results were compared to those of a second group diagnosed with NF.

Results

Five patients with GG and nine patients with NF were included in the present study. Patients with GG had a mortality rate of 80% compared to 0% in patients with NF. In eight patients with NF, affected limbs could be salvaged; one NF underwent amputation. LRINEC did not show significant differences between the groups; however, C‐reactive protein was significantly increased (P = 0.009) and hemoglobin (Hb) was significantly decreased (P = 0.02) in patients with GG. Interleukin‐6 and procalcitonin levels did not show significant difference. Patients with GG were older (70.2 vs 50 years). Of the isolated bacteria, 86% were sensitive to the initial calculated antibiotic treatment with ampicillin‐sulbactam or imipenem plus metronidazole plus clindamycin.

Conclusion

Both GG and NF need full‐scale surgical, antibiotic, and intensive care treatment, especially within the first days. Among patients with NSTI, those with clostridial GG have a significantly increased mortality risk due to early septic shock caused by clostridial toxins. In the initial stages, clinical differences are hardly detectable. Immediate surgical debridement is the key to successful therapy for NSTI and needs to be performed as early as possible. However, patients should be treated in a center with an experienced interdisciplinary intensive care team based on a predetermined treatment plan.

A Middle-Aged Woman With Hematochezia, Hypotension, and Leg Cramps

CASE PRESENTATION

A 57-year-old woman with a history of mantle cell lymphoma presented to the ED with complaints of vomiting, bleeding per rectum, and leg cramps, that started 6 h prior to her arrival. She had received chemotherapy a week prior. Her leg cramps were not associated with pain or swelling of the legs; she also denied any trauma to the legs. She did complain of mild lower abdominal pain at presentation. Review of systems was negative for fever, chills, diarrhea, chest pain, and dizziness. She denied using alcohol or nonsteroidal anti-inflammatory drugs. The patient was tachycardic with a systolic BP (SBP) of 85 mm Hg and was administered 1-L normal saline, with improvement in her SBP to 90 mm Hg. The hematocrit level was 24%, the WBC count was 0.3 × 10⁹/L, and the platelet count was 6 × 10⁹/L in the ED. On arrival in the ICU, she was noted to have an SBP of 70 mm Hg. Resuscitation with IV fluids was initiated, followed by transfusion of packed RBCs and platelets, based on the blood counts. Despite aggressive fluid resuscitation and improvement in her hemoglobin, the patient remained persistently hypotensive. The diagnosis of underlying septic shock because of neutropenia was considered; the patient was started on vasopressors and empirical broad-spectrum antibiotics, with improvement in her BP. After this, the patient was sent to radiology for a CT scan of the abdomen and pelvis with contrast to evaluate for mesenteric infarction, enteric or colonic bleeding, and the need for arterial embolization.

Histotoxic Clostridial Infections

The pathogenesis of clostridial myonecrosis or gas gangrene involves an interruption to the blood supply to the infected tissues, often via a traumatic wound, anaerobic growth of the infecting clostridial cells, the production of extracellular toxins, and toxin-mediated cell and tissue damage. This review focuses on host-pathogen interactions in Clostridium perfringens-mediated and Clostridium septicum-mediated myonecrosis. The major toxins involved are C. perfringens α-toxin, which has phospholipase C and sphingomyelinase activity, and C. septicum α-toxin, a β-pore-forming toxin that belongs to the aerolysin family. Although these toxins are cytotoxic, their effects on host cells are quite complex, with a range of intracellular cell signaling pathways induced by their action on host cell membranes.

Sudden death due to gas gangrene caused by Clostridium septicum in goats

Background

Even though gas gangrene caused by Clostridium septicum in goats is mentioned in the classical textbooks, we have not managed to find any case description in the literature.

Case presentation

Clinical signs resembling gas gangrene such as subcutaneous bloating, edema and crepitation were detected at various body parts of nine pregnant animals at the ages of 2–3 years on a hair goat farm (n = 170) located in Bingol province, Eastern Turkey. Five of these suspected animals with severe clinical symptoms died within 2 days. Various samples such as internal organs, edematous skin and edema fluid collected from dead and live animals were analyzed for the presence of clostridial agents by histopathological and microbiological methods. As a result of macroscopic and microscopic examination, lesions of gas gangrene were detected. The suspected isolates were identified and confirmed as C. septicum by bacteriological and molecular methods.

Conclusion

The present study was the first to report identification of C. septicum as primary agent in the gas gangrene of goats.

Clostridium septicum arthroplasty infection: beware of occult aortitis and malignancy

Introduction

The Clostridia species are responsible for life-threatening conditions such as tetanus, botulism and gas gangrene. Clostridium septicum is a rare cause of clinical infection, accounting for less than 1% of blood culture samples that test positive for Clostridia. However, C. septicum bacteraemia is associated with greater than 60% mortality and in over 80% of cases is associated with an underlying malignancy.

Case presentation

We present a review of the literature and the first case of an acute arthroplasty infection and concurrent infective aortitis caused by this organism in the absence of an identified underlying malignancy. Early diagnosis and multi-disciplinary input resulted in the patient surviving a rare and potentially fatal infective aortitis and septic arthritis.

Conclusion

This case demonstrates the importance of early systemic investigation to exclude occult infective aortitis in C. septicum infection. The key role of multi-disciplinary input into the management of this often fatal infection is also discussed along with the requirement to exclude occult gastrointestinal and haematological malignancy.

Atraumatic Clostridial Myonecrosis in an Immunocompromised Host

BACKGROUND

Necrotizing fasciitis is usually associated with a surgical or traumatic wound. Clostridial myonecrosis is an uncommon but deadly infection that can develop in the absence of a wound and is often associated with occult gastrointestinal cancer or immunocompromise, or both.

CASE REPORT

We report a case of catastrophic atraumatic Clostridium septicum infection in an immunocompromised host. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians most commonly associate necrotizing fasciitis with superinfection of an open wound. This case reminds physicians that patients with acquired neutropenia can present with spontaneous gas gangrene due to C. septicum. Providers should consider this diagnosis in immunocompromised patients who present with acute onset of severe atraumatic limb pain.

Deadly combination: Clostridium septicum and colorectal malignancy

Gas gangrene is a life-threatening, necrotising soft tissue infection. Colorectal malignancy-associated Clostridiumsepticum is a rare cause of gas gangrene. This case outlines an initial presentation of colonic malignancy as gas gangrene from C.septicum infection.A 69-year-old man presented with abdominal pain, vomiting and constipation. Abdominal X-ray revealed dilated small bowel loops. Lactate was elevated. A diagnosis of small bowel obstruction was made. Subsequent CT revealed caecal thickening and subcutaneous emphysema overlying the left flank. Clinically, he became haemodynamically unstable. Examination revealed crepitus overlying the left flank in keeping with gas gangrene. The patient required immediate surgical debridement. Tissue specimens cultured C.septicum Following a complicated postoperative period, he was transferred to the plastic surgery team for further tissue debridement and reconstruction. A colonoscopy was later performed which was suspicious for malignancy. Colorectal multidisciplinary team discussion is awaited.

Spontaneous C. septicum gas gangrene: A literature review

As the infectious disease paradigm undergoes a subtle shift, unusual infections associated with malignancy and immunosuppression are being increasingly reported. Spontaneous or non-traumatic Clostridium septicum infection is one such unusual infection which has gained prominence. This article aims to understand the pathophysiology, clinical manifestations and current trends in diagnosing and treating this rare but deadly infection. To understand the multifactorial causation of this infection a review of published cases of spontaneous C. septicum gas gangrene was performed and a total of 94 such cases were identified. Several factors were analyzed for each case: age, infection location and underlying illness, presenting signs and symptoms, neutropenia, gross pathology of the colon, antibiotic use, surgical intervention, and survival. A known or occult malignancy was present in 71% patients and an overall mortality of 67% was observed.

Clostridium septicum Pneumocephalus

BACKGROUND

Spontaneous pneumocephalus in the nontraumatic setting is distinctly unusual. Pneumocephalus from central nervous system infection with Clostridium septicum has been rarely reported, and more commonly reflects a later stage of abscess formation. We present an unusual case of invasive C. septicum infection without an associated diagnosed malignancy presenting with rapidly progressive CNS pathology and resultant early pneumocephalus.

METHODS

Medical records, radiologic imaging, and microbiological specimens of a case were reviewed.

RESULTS

A 66-year-old male presented with a history of two witnessed generalized tonic-clonic seizures on awakening. He was found unresponsive at the scene by paramedics and subsequently intubated. There was no reported antecedent symptomatology, such as headache, fever, chills, focal weakness, and speech or gait disturbances. Medical history was remarkable only for diet-controlled hypertension. Computed tomography (CT) head imaging revealed an abnormal right parietal hypodensity. The patient was evaluated per the acute stroke protocol but was not deemed a candidate for intervention or thrombolytic therapy given the uncertainty of his clinical presentation; intravenous antibiotics were administered for possible sepsis. Follow-up CT imaging of the head performed 8 h later revealed right parieto-temporal pneumocephalus with extensive cerebral edema and effacement of basilar cisterns. Neurosurgical intervention was not deemed appropriate given the catastrophic nature of his injury and the patient subsequently expired 14 h after presentation. Blood cultures grew gram-positive rods in three of four bottles identified as C. septicum.

CONCLUSIONS

Clostridium septicum is an uncommon and often fatal cause of nontraumatic pneumocephalus. This underscores the need for a high index of clinical suspicion in cases with unexplained pneumocephalus, as early diagnosis remains the key to survival. In survivors of C. septicum infection, subsequent colonoscopy should be considered to exclude undiagnosed or occult gastrointestinal malignancy.

Massive gas gangrene secondary to occult colon carcinoma

Gas gangrene is a rare but often fatal soft-tissue infection. Because it is uncommon and the classic symptom of crepitus does not appear until the infection is advanced, prompt diagnosis requires a high index of suspicion. We present a case report of a middle-aged man who presented with acute onset lower-extremity pain that was initially thought to be due to deep vein thrombosis. After undergoing workup for pulmonary embolism, he was found to have massive gas gangrene of the lower extremity secondary to an occult colon adenocarcinoma and died within hours of presentation from multisystem organ failure.

Interventions for treating gas gangrene

BACKGROUND

Gas gangrene is a rapidly progressive and severe disease that results from bacterial infection, usually as the result of an injury; it has a high incidence of amputation and a poor prognosis. It requires early diagnosis and comprehensive treatments, which may involve immediate wound debridement, antibiotic treatment, hyperbaric oxygen therapy, Chinese herbal medicine, systemic support, and other interventions. The efficacy and safety of many of the available therapies have not been confirmed.

OBJECTIVES

To evaluate the efficacy and safety of potential interventions in the treatment of gas gangrene compared with alternative interventions or no interventions.

SEARCH METHODS

In March 2015 we searched: The Cochrane Wounds Group Specialized Register, The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), Ovid MEDLINE, Ovid EMBASE, EBSCO CINAHL, Science Citation Index, the China Biological Medicine Database (CBM-disc), the China National Knowledge Infrastructure (CNKI), and the Chinese scientific periodical database of VIP INFORMATION (VIP) for relevant trials. We also searched reference lists of all identified trials and relevant reviews and four trials registries for eligible research. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) and quasi-RCTs that compared one treatment for gas gangrene with another treatment, or with no treatment.

DATA COLLECTION AND ANALYSIS

Independently, two review authors selected potentially eligible studies by reviewing their titles, abstracts and full-texts. The two review authors extracted data using a pre-designed extraction form and assessed the risk of bias of each included study. Any disagreement in this process was solved by the third reviewer via consensus. We could not perform a meta-analysis due to the small number of studies included in the review and the substantial clinical heterogeneity between them, so we produced a narrative review instead.

MAIN RESULTS

We included two RCTs with a total of 90 participants. Both RCTs assessed the effect of interventions on the 'cure rate' of gas gangrene; 'cure rate' was defined differently in each study, and differently to the way we defined it in this review.One trial compared the addition of Chinese herbs to standard treatment (debridement and antibiotic treatment; 26 participants) against standard treatment alone (20 participants). At the end of the trial the estimated risk ratio (RR) of 3.08 (95% confidence intervals (CI) 1.00 to 9.46) favoured Chinese herbs. The other trial compared standard treatment (debridement and antibiotic treatment) plus topical hyperbaric oxygen therapy (HBOT; 21 participants) with standard treatment plus systemic HBOT (23 participants). There was no evidence of difference between the two groups; RR of 1.10 (95% CI 0.25 to 4.84). For both comparisons the GRADE assessment was very low quality evidence due to risk of bias and imprecision so further trials are needed to confirm these results.Neither trial reported on this review's primary outcomes of quality of life, and amputation and death due to gas gangrene, or on adverse events. Trials that addressed other therapies such as immediate debridement, antibiotic treatment, systemic support, and other possible treatments were not available.

AUTHORS' CONCLUSIONS

Re-analysis of the cure rate based on the definition used in our review did not show beneficial effects of additional use of Chinese herbs or topical HBOT on treating gas gangrene. The absence of robust evidence meant we could not determine which interventions are safe and effective for treating gas gangrene. Further rigorous RCTs with appropriate randomisation, allocation concealment and blinding, which focus on cornerstone treatments and the most important clinical outcomes, are required to provide useful evidence in this area.

Low prevalence of Clostridium septicum fecal carriage in an adult population

Clostridium septicum is an uncommon cause of severe infection. Real-time PCR against the C. septicum-specific alpha-toxin gene (csa) was used to estimate the prevalence of this microbe in human stool from 161 asymptomatic community-dwelling adults and 192 hospitalized patients with diarrhea. All samples were negative, suggesting a low prevalence.

Development of Clostridium septicum gas gangrene as an adverse effect of clindamycin-induced Clostridium difficile infection in a pediatric patient

Clostridium myonecrosis or gas gangrene is a life-threatening infection characterized by either traumatic or atraumatic etiology. It has been widely described in patients with traumatic open wounds and in immunocompromised patients, including malignancy. A third source can result from natural flora in the gastrointestinal tract after bowel ischemia. This is a rare occurrence and is even less commonly described in the pediatric population. We present a pediatric patient who developed Clostridium septicum myonecrosis as an iatrogenic complication from clindamycin-induced Clostridium difficile ischemic colitis.

Necrotizing gastritis associated with Clostridium septicum in a rabbit

Clostridium septicum is the causative agent of histotoxic infections, including malignant edema and braxy (necrotizing abomasitis) in several animal species. The carcass of a 2-year–old, female New Zealand white rabbit with a history of acute depression and obtundation followed by death was received at the California Animal Health and Food Safety Laboratory System (San Bernardino, California) for necropsy and diagnostic workup. No gross lesions were detected at necropsy. Microscopically, there was moderate to severe, multifocal fibrinonecrotizing, transmural gastritis with numerous intralesional Gram-positive, sporulated rods, and disseminated thrombosis of the brain, lungs, heart, and liver, with occasional intravascular rods. The rods observed within the gastric wall and thrombi in the stomach and lung were positive for C. septicum by immunohistochemical staining. However, this microorganism was not isolated from stomach content. Clostridium septicum should be included in the list of possible etiologies of gastritis in rabbits.

Gas gangrene presenting with back pain

A 61-year-old Caucasian man (previously fit and well) presented to the emergency department with 2 days of non-traumatic, non-radiating lower back pain. He was admitted to our department having been provisionally diagnosed with discitis. Later that night, while being reassessed, a skin lesion on his thigh appeared and gas could be palpated. The patient was then taken immediately to theatre and a radical surgical debridement was performed. The organism that grew from tissue samples was Clostridium septicum, which when identified is an indication to exclude colonic neoplasms. The patient managed to preserve his limb on this occasion, however, he underwent a right hemicolectomy for what proved to be a colonic tumour at a later date.

Necrotizing Fasciitis and Toxic Shock Syndrome from Clostridium septicum following a Term Cesarean Delivery

Necrotizing fasciitis and toxic shock syndrome are life-threatening conditions that can be seen after any surgical procedure. With only 4 previous published case reports in the obstetrics and gynecology literature of these two conditions occurring secondary to Clostridium septicum, we describe a case of necrotizing fasciitis and toxic shock syndrome occurring after a term cesarean delivery caused by this microorganism, requiring aggressive medical and surgical intervention.

Opioid analgesics stop the development of clostridial gas gangrene

Gas gangrene is a potentially fatal disease that is primarily caused by the ubiquitous, anaerobic bacteria Clostridium perfringens and Clostridium septicum. Treatment is limited to antibiotic therapy, debridement of the infected tissue, and, in severe cases, amputation. The need for new treatment approaches is compelling. Opioid-based analgesics such as buprenorphine and morphine also have immunomodulatory properties, usually leading to faster disease progression. However, here we show that mice pretreated with buprenorphine and morphine do not die from clostridial myonecrosis. Treatment with buprenorphine after the onset of infection also arrested disease development. Protection against myonecrotic disease was specific to C. perfringens-mediated myonecrosis; buprenorphine did not protect against disease caused by C. septicum infection even though infections due to both species are very similar. These data provide the first evidence of a protective role for opioids during infection and suggest that new therapeutic strategies may be possible for the treatment of C. perfringens-mediated myonecrosis.

Analysis of tryptophan-rich region in Clostridium septicum alpha-toxin involved with binding to glycosylphosphatidylinositol-anchored proteins

Clostridium septicum alpha-toxin has a unique tryptophan-rich region ((302)NGYSEWDWKWV(312)) that consists of 11 amino acid residues near the C-terminus. Using mutant toxins, the contribution of individual amino acids in the tryptophan-rich region to cytotoxicity and binding to glycosylphosphatidylinositol (GPI)-anchored proteins was examined. For retention of maximum cytotoxic activity, W307 and W311 are essential residues and residue 309 has to be hydrophobic and possess an aromatic side chain, such as tryptophan or phenylalanine. When residue 308, which lies between tryptophans (W307 and W309) is changed from an acidic to a basic amino acid, the cytotoxic activity of the mutant is reduced to less than that of the wild type. It was shown by a toxin overlay assay that the cytotoxic activity of each mutant toxin correlates closely with affinity to GPI-anchored proteins. These findings indicate that the WDW_W sequence in the tryptophan-rich region plays an important role in the cytotoxic mechanism of alpha-toxin, especially in the binding to GPI-anchored proteins as cell receptors.

Life-threatening clostridial infections

Life-threatening soft tissue infections caused by Clostridium species have been described in the medical literature for hundreds of years largely because of their fulminant nature, distinctive clinical presentations and complex management issues. The Clostridium species perfringens, septicum and histolyticum are the principal causes of trauma-associated gas gangrene and their incidence increases dramatically in times of war, hurricanes, earthquakes and other mass casualty conditions. Recently, there has also been an increased incidence of spontaneous gas gangrene caused by Clostridium septicum in association with gastrointestinal abnormalities and neutropenia. Similarly, over the last 15 years there has been increased recognition of a toxic shock-like syndrome associated with Clostridium sordellii in individuals skin-popping black tar heroin, in women undergoing childbirth or other gynecologic procedures including medically-induced abortion. Like their cousins Clostridium tetanus and Clostridium botulinum, the pathogenesis of these clostridial infections is largely the consequence of potent exotoxin production. Strategies to inhibit toxin production, neutralize circulating toxins and prevent their interaction with cells of the innate immune response are sorely needed. Recent studies have elucidated novel targets that may hold promise for newer therapeutic modalities.

Clostridial myonecrosis: new insights in pathogenesis and management

Clostridial myonecrosis remains an important cause of human morbidity and mortality worldwide. Although traumatic gas gangrene can be readily diagnosed from clinical findings and widely available technologies, spontaneous gas gangrene is more insidious, and gynecologic infections due to Clostridium sordellii progress so rapidly that death often precedes diagnosis. In each case, extensive tissue destruction and the subsequent systemic manifestations are mediated directly and indirectly by potent bacterial exotoxins. The management triumvirate of timely diagnosis, thorough surgical removal of necrotic tissue, and treatment with antibiotics that inhibit toxin synthesis remains the gold standard of care. Yet, despite these measures, mortality remains 30% to 100% and survivors often must cope with life-altering amputations. Recent insights regarding the genetic regulation of toxin production, the molecular mechanisms of toxin-induced host cell dysfunction, and the roles of newly described toxins in pathogenesis suggest that novel prevention, diagnostic, and treatment modalities may be on the horizon for these devastating infections.

Non-traumatic gas gangrene presenting as left buttock and thigh pain in a patient with metastatic non-small cell lung cancer

We report a case of Clostridium septicum myonecrosis in a patient with metastatic non-small cell lung cancer receiving palliative chemotherapy. This is a rare but important differential diagnosis in patients with known malignancy presenting with acute pain. It is critical that the diagnosis is considered and confirmed promptly due to rapid deterioration and a potentially fatal outcome in the absence of aggressive treatment.

Spontaneous occurrence of gangrene due to clostridium septicum in a patient with advanced endometrial carcinoma

Background: We report the first known case of spontaneous, atraumatic Clostridium septicum gangrene occurring in a patient with recurrent endometrial adenocarcinoma.

Case: A 63-year-old white female undergoing chemotherapy for recurrent endometrial adenocarcinoma presented with right “arthritis-like” shoulder pain. She denied fever, chills, or shoulder trauma. The patient was afebrile and her blood pressure was 100/50. Her right shoulder and upper extremity were remarkable for an area of dark blue discoloration with crepitus. The white blood cell (WBC) count was 8,200/μl with left shift. Serum creatinine, platelet count, and coagulation studies were normal. Computed tomography revealed gas in the right shoulder tissues. A Gram stain of fluid aspirated from the shoulder demonstrated gram-positive spore-forming rods. She declined surgical intervention and expired within hours of admission. Cultures of the right shoulder eventually grew Clostridium septicum.

Conclusion: It is imperative to consider clostridial gangrene in the differential diagnosis for any patient with cancer and a fever of unknown origin.

Quantitative real-time PCR assay for Clostridium septicum in poultry gangrenous dermatitis associated samples

Clostridium septicum is a spore-forming anaerobe frequently implicated in cases of gangrenous dermatitis (GD) and other spontaneously occurring myonecrotic infections of poultry. Although C. septicum is readily cultured from diseased tissues it can be difficult to enumerate due to its tendency to swarm over the surface of agar plates. In this study a quantitative real-time PCR assay was developed in order to more accurately measure the levels of C. septicum in healthy as well as GD associated poultry samples. The assay was specifically designed to target the C. septicum alpha toxin gene, csa, which is, to our knowledge, carried by all strains of C. septicum and has been shown to be essential for virulence. Genomic DNAs from a diverse collection of bacterial species, including closely related Clostridium chauvoei, Clostridium carnis, Clostridium tertium as well as several strains of Clostridium perfringens, all failed to produce a positive reaction. An approximate reproducible limit of detection in spiked extracts of at least 10(3) cfu/g of C. septicum was observed for a variety of different sample types. C. septicum levels in broiler chicken field samples estimated from the results of qPCR were statistically correlated to culture based enumerations obtained from those same tissues.

Clostridial toxins

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