Clinical significance and outcomes of Clostridium perfringens bacteremia--a 10-year experience at a tertiary care hospital

Metronidazole-Loaded Chitosan Nanoparticles with Antimicrobial Activity Against Clostridium perfringens

Background/Objectives: Even with improvements in surgical techniques and the application of appropriate antibiotic prophylaxis, wound infections are still major public health problems in low- and middle-income countries. This study proposes the design of new particulate polymeric matrices based on chitosan (CS) for the controlled release of Metronidazole (MTZ), in order for it to be used for the treatment of Clostridium perfringens infections. Methods: The nanoparticles were prepared via inverse emulsion using tannic acid (TA) and sodium tripolyphosphate (TPP) as cross-linking agents. The ratio of CS to TPP, the concentration of CS solution, and the ratio of CS to TA were varied to optimize the synthesis procedure. Nanoparticles have been characterized based on several points of view in order to correctly correlate their properties with synthesis parameters. Results: The FTIR spectra of the analyzed nanoparticles confirmed both the formation of hydrogen bonds between CS and TA and the ionic cross-linking of CS with TPP. The average diameters of the nanoparticles ranged from 70 to 170 nm, whereas the zeta potential values were around 8 mV. Their swelling degree in a weak basic environment, as well as the drug loading/release capacity was influenced, as expected, by the synthesis parameters. The obtained nanoparticles were tested in vitro to evaluate their behavior in the blood environment, the cytotoxic effect, and the antimicrobial activity of nanoparticles loaded with MTZ against Clostridium perfringens cultures. Conclusions: The in vitro obtained results demonstrate that these non-hemolytic and non-cytotoxic particles can be efficient drug delivery systems for the treatment of Clostridium perfringens in wound infections.

Epidemiology and risk factors for mortality in clostridial bacteremia in Japan: A retrospective multicenter observational study

OBJECTIVES

Clostridium species are ubiquitous in nature and commonly cause infections, including bacteremia. C. perfringens is often the causative species, while the epidemiology of other clostridial species remains unclear. This study aimed to examine the epidemiology and risk factors for mortality among patients with clostridial bacteremia in Japan.

METHODS

This multicenter, retrospective cohort study analyzed patients with Clostridium spp. in blood cultures from four tertiary hospitals in Japan. Data on demographics, underlying conditions, clinical and laboratory values, and in-hospital mortality were included. Multivariate logistic regression analysis identified independent risk factors for in-hospital mortality.

RESULTS

Of 349 patients with Clostridium spp. in blood cultures, 278 (79.7%) had clinically significant clostridial bacteremia: C. perfringens was the most common species (52.9%), followed by C. ramosum (9.7%) and C. clostridioforme (4.3%). The median patient age was 77 years, and 61.9% were male. The in-hospital mortality rate was 25.9%, with 34.7% of deaths occurring within 3 days of the date of the positive blood culture. Independent risk factors for mortality were hepato-pancreato-biliary malignancy, chronic heart failure, acute renal failure, Pitt bacteremia score, and pneumonia.

CONCLUSIONS

Mortality from clostridial bacteremia is high, particularly among patients with pneumonia, comorbidities, or severe acute conditions. To improve mortality, early-stage treatment strategies are needed.

A subanalysis of Clostridium perfringens bloodstream infections from a 5-year retrospective nationwide survey (ITANAEROBY)

Clostridium perfingens bloodstream infections (BSIs) can be associated with high mortality rates. We performed a subanalysis of all C. perfringens BSIs enrolled during a multicentric retrospective observational study (ITANAEROBY). Data were collected from January 2016 to December 2020. C. perfringens BSIs were 134 (134/1960, 6.8 %). The highest resistance rate was observed for clindamycin (26/120, 21.6 %), penicillin (11/71, 15.4 %) and metronidazole (14/131, 10.7 %). In conclusion, C. perfringens reduced susceptibility phenotype to first-line therapy.

Clostridium perfringens sepsis after comprehensive multicourse treatment of hepatocellular carcinoma: A case report and review

Introduction

Clostridium perfringens sepsis is a rare but serious clinical syndrome that is typically triggered by gastrointestinal disorders. We present a case of bloodstream infection caused by Clostridium perfringens in a liver cancer patient after comprehensive multicourse treatment.

Case presentations

The patient, a 68-year-old male, experienced nausea, decreased appetite, and abdominal distension on the 15th day after receiving comprehensive multicourse treatment and transcatheter arterial chemoembolization (TACE). During admission, he developed fever, and blood culture results confirmed the presence of Clostridium perfringens. The patient was discharged with improved symptoms.

Conclusion

Our findings underscore the rarity of Clostridium perfringens sepsis. For liver cancer patients, particularly those who have undergone TACE or radiofrequency ablation and who experience post treatment fever, vigilance for Clostridium perfringens bloodstream infection is crucial. Timely diagnostic assessments and proactive treatment can significantly enhance the survival prospects of these patients.

Survival in a Case of Emphysematous Cholecystitis With Sepsis Caused by Clostridium perfringens

A 77-year-old man presented to the Department of Internal Medicine with a chief complaint of abdominal pain. During the outpatient examination, a computed tomography (CT) scan showed gallstones. The patient developed worsening abdominal pain and fever and was admitted to the emergency department. He was diagnosed with cholecystitis and hospitalized. Treatment with antimicrobial agents was initiated. On the second day of hospitalization, the patient developed a fever of 39°C, hypotension, and oliguria. An emergency CT scan was performed, which showed gas production in the gallbladder. He was diagnosed with emphysematous cholecystitis, and emergency percutaneous transhepatic gallbladder drainage was performed. The patient was transferred to the high-care unit, and intensive care was initiated. On the eighth day, a follow-up CT scan showed an abscess in the gallbladder bed, and drainage was performed percutaneously. His general condition gradually improved, and he was discharged from the hospital on day 24. The patient was readmitted for cholecystectomy three months after the initial admission. The prognosis of sepsis caused by Clostridium perfringens is extremely poor, with a mortality rate of 70%-100%. We present a case of emphysematous cholecystitis successfully treated with multimodal treatment despite the presence of sepsis due to Clostridium perfringens and discuss the possible prognostic factors by reviewing the literature.

Foodborne Clostridioides Species: Pathogenicity, Virulence and Biocontrol Options

Clostridioides species possess many virulence factors and alarming levels of muti-drug resistance which make them a significant risk to public health safety and a causative agent of livestock disease. Clostridioides result in serious systemic and gastrointestinal diseases such as myonecrosis, colitis, food poisoning and gastroenteritis. As foodborne pathogens, Clostridioides species are associated with significant incidences of morbidity and mortality where the application of broad-spectrum antibiotics predisposes patients to virulent Clostridioides colonisation. As part of the One Health approach, there is an urgent need to eliminate the use of antibiotics in food production to safeguard animals, humans and the environment. Alternative options are warranted to control foodborne pathogens at all stages of food production. Antimicrobial peptides and bacteriophages have demonstrated efficacy against Clostridioides species and may offer antimicrobial biocontrol options. The bacteriocin nisin, for example, has been implemented as a biopreservative for the control of Listeria, Staphylococcus and Clostridia species in food. Bacteriophage preparations have also gained recognition for the antibacterial action against highly virulent bacterial species including foodborne pathogens. Studies are warranted to mitigate the formulation and administration limitations associated with the application of such antimicrobials as biocontrol strategies. This review outlines foodborne Clostridioides species, their virulence factors, and potential biocontrol options for application in food production.

First successful treatment of Clostridium perfringens-associated emphysematous hepatitis: a case report

Emphysematous diseases of the abdomen are rare with an often inconspicuous presentation of symptoms and rapid lethal outcome if untreated. We report the first successfully treated case of Clostridium perfringens-associated emphysematous hepatitis. In the emergency room, a 79-year-old man presented with shortness of breath and deteriorated general condition since the morning of admission. Initial CT scans showed a small but rapidly expanding gas collection in liver segment 6. Emergency surgery with atypical liver resection was performed immediately. With early resection and prolonged administration of antibiotics in the presence of sepsis, the patient recovered successfully and was discharged 37 days after admission. As in our case, prompt diagnosis with early surgical treatment is crucial for the management of emphysematous hepatitis.

Clinical and Microbiological Features of Fulminant Haemolysis Caused by Clostridium perfringens Bacteraemia: Unknown Pathogenesis

Bacteraemia brought on by Clostridium perfringens has a very low incidence but is severe and fatal in fifty per cent of cases. C. perfringens is a commensal anaerobic bacterium found in the environment and in the intestinal tracts of animals; it is known to produce six major toxins: α-toxin, β-toxin, ε-toxin, and others. C. perfringens is classified into seven types, A, B, C, D, E, F and G, according to its ability to produce α-toxin, enterotoxin, and necrotising enterotoxin. The bacterial isolates from humans include types A and F, which cause gas gangrene, hepatobiliary infection, and sepsis; massive intravascular haemolysis (MIH) occurs in 7-15% of C. perfringens bacteraemia cases, resulting in a rapid progression to death. We treated six patients with MIH at a single centre in Japan; however, unfortunately, they all passed away. From a clinical perspective, MIH patients tended to be younger and were more frequently male; however, there was no difference in the toxin type or genes of the bacterial isolates. In MIH cases, the level of θ-toxin in the culture supernatant of clinical isolates was proportional to the production of inflammatory cytokines in the peripheral blood, suggesting the occurrence of an intense cytokine storm. Severe and systemic haemolysis is considered an evolutionary maladaptation as it leads to the host's death before the bacterium obtains the benefit of iron utilisation from erythrocytes. The disease's extraordinarily quick progression and dismal prognosis necessitate a straightforward and expedient diagnosis and treatment. However, a reliable standard of diagnosis and treatment has yet to be put forward due to the lack of sufficient case analysis.

Massive intravascular hemolysis is an important factor in Clostridium perfringens-induced bacteremia

Clostridium perfringens bacteremia is rare but often fatal. In particular, once bacteremia with massive intravascular hemolysis (MIH) occurs, the mortality rate is extremely high. However, because of its rarity, the detailed pathophysiology of this fulminant form of bacteremia is unclear. To elucidate the detailed pathogenesis of MIH, we retrospectively reviewed the data of all patients with C. perfringens bacteremia from two university hospitals from 2000 to 2014. The medical records and laboratory data of 60 patients with bacteremia, including 6 patients with MIH and 54 patients without MIH, were analyzed. Patients with MIH had higher rates of intense pain at onset, impaired consciousness, shock at presentation, hematuria, metabolic acidosis, and gas formation than patients without MIH. The antibiotic susceptibility of the clinical isolates was not significantly different between the two groups. All patients with MIH, although treated with appropriate antimicrobial agents, died within 26 h of admission due to rapidly progressive acute lung injury or acute respiratory distress syndrome, and the median time from arrival at the hospital to death was only 4 h and 20 min. When clinicians observe intravascular hemolysis in blood samples from patients with characteristic symptoms of MIH, they should prepare for a severe disease outcome. The underlying pathophysiology of fulminant cases must be investigated.

Structural Changes in Trabecular Bone, Cortical Bone and Hyaline Cartilage as Well as Disturbances in Bone Metabolism and Mineralization in an Animal Model of Secondary Osteoporosis in Clostridium perfringens Infection

There is no information regarding whether changes in the microbiological balance of the gastrointestinal tract as a result of an infection with Clostridium perfringens influence the development of metabolic bone disorders. The experiment was carried out on male broiler chickens divided into two groups: control (n = 10) and experimental (n = 10). The experimental animals were infected with Clostridium perfringens between 17 and 20 days of age. The animals were euthanized at 42 days of age. The structural parameters of the trabecular bone, cortical bone, and hyaline cartilage as well as the mineralization of the bone were determined. The metabolism of the skeletal system was assessed by determining the levels of bone turnover markers, hormones, and minerals in the blood serum. The results confirm that the disturbed composition of the gastrointestinal microflora has an impact on the mineralization and metabolism of bone tissue, leading to the structural changes in cortical bone, trabecular bone, and hyaline cartilage. On the basis of the obtained results, it can be concluded that changes in the microenvironment of the gastrointestinal tract by infection with C. perfringens may have an impact on the earlier development of osteoporosis.

Non-C. difficile Clostridioides Bacteremia in Intensive Care Patients, France

Article Summary: This multicenter study focusing on critically ill patients showed a strong relationship between hemolysis and mortality.

Usually responsible for soft tissue infections, Clostridioides species can also cause bacteremia, life-threatening infections often requiring intensive care unit (ICU) admission. We conducted a multicenter retrospective study to investigate Clostridioides bacteremia in ICUs to describe the clinical and biologic characteristics and outcomes in critically ill patients. We identified 135 patients with Clostridioides bacteremia, which occurred almost exclusively (96%) in patients with underlying conditions. Septic shock and digestive symptoms were the hallmarks of Clostridioides bacteremia in the ICU. We identified 16 different species of Clostridioides, among which C. perfringens accounted for 31% of cases. Despite the high sensitivity of Clostridioides to common antimicrobial drugs, mortality rates were high: 52% for ICU patients and 71% overall at 3 months. In multivariate analysis, the most important factor associated with increased risk for death was the presence of hemolysis. Clostridioides bacteremia often leads to multiple organ failures, which have high mortality rates.

Application of MALDI-TOF MS to assess clinical characteristics, risk factors, and outcomes associated with anaerobic bloodstream infection: a retrospective observational study

Background

Correctly identifying anaerobic bloodstream infections (BSIs) is difficult. However, a new technique, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), enables more accurate identification and appropriate treatment. Anaerobic BSIs identified by MALDI-TOF MS were retrospectively analyzed to determine the clinical and microbiological features and patient outcomes based on the anaerobic genera or group.

Methods

Medical records of patients with anaerobic BSIs were used to conduct a single-center retrospective cohort study from January 2016 to December 2020 in Nagoya, Japan. Multivariate logistic regression analysis was performed to determine the independent risk factors for in-hospital mortality.

Results

Of the 215 patients with anaerobic BSIs, 31 had multiple anaerobic organisms in the blood culture, including 264 total episodes of anaerobic BSIs. Bacteroides spp. were isolated the most (n = 74), followed by gram-positive non-spore-forming bacilli (n = 57), Clostridium spp. (n = 52), gram-positive anaerobic cocci (GPAC) (n = 27), and gram-negative cocci (n = 7). The median patient age was 76 years; 56.7% were male. The most common focal infection site was intra-abdominal (36.7%). The in-hospital mortality caused by anaerobic BSIs was 21.3%, and was highest with Clostridium spp. (36.5%) and lowest with GPAC (3.7%). Age, solid tumors, and Clostridium spp. were independent risk factors for in-hospital mortality.

Conclusions

We identified current anaerobic BSI trends using MALDI-TOF MS and reported that mortality in patients with anaerobic BSIs patients was highest with Clostridium spp. infections.

Clostridium Perfringens Septic Arthritis of the Sternoclavicular Joint

BACKGROUND

Clostridium perfringens septic arthritis of the sternoclavicular joint has not been reported previously.

CASE REPORT

We present the case of a 70-year-old patient with a history of stage IV colon cancer who presented to the emergency department with chest and neck pain for 3 days. After assessment, he was discharged home on analgesics. Within 24 h he returned, critically ill with C. perfringens septic arthritis of the left sternoclavicular joint and septic shock. Why Should an Emergency Physician Be Aware of This? Emergency physicians should be aware of the possibility of C. perfringens sternoclavicular joint septic arthritis in patients with unexplained chest, shoulder, or neck pain, especially when associated with a history of colorectal carcinoma or immunosuppression. A finding of C. perfringens bacteremia should prompt a search for occult gastrointestinal malignancy.

A 64-Year-Old Man with Low Back Pain Due to Clostridium perfringens Lumbar Discitis

Patient: Male, 64-year-old

Final Diagnosis: Clostridium perfringens infection

Symptoms: Lower back pain

Medication:—

Clinical Procedure: —

Specialty: Infectious Diseases • General and Internal Medicine

Clostridium perfringens sepsis in three patients with acute leukemia and review of the literature

In this study, we aimed to improve understanding of the clinical manifestations, laboratory findings, and risk factors of Clostridium perfringens sepsis in patients with acute leukemia and to analyze treatment strategies for improving prognosis. We analyzed clinical manifestations, laboratory data, diagnosis, and treatment strategies in three cases of C. perfringens sepsis in patients with acute leukemia. We also reviewed and analyzed the relevant literature, incorporating our findings into the discussion. All three patients developed septic shock with neutropenia following chemotherapy. Analysis of blood samples confirmed the presence of C. perfringens, and two patients had fulminant intravascular hemolysis and developed multiple organ dysfunction syndrome. Two patients survived and one died despite timely and full-dose antibacterial treatments, blood purification, and noninvasive positive pressure ventilation. Overall, our findings showed that C. perfringens sepsis is rare in patients with acute leukemia but progresses rapidly. A high mortality rate was observed, and patients often experienced refractory shock and intravascular hemolysis. This demonstrates the importance of early detection and diagnosis. Multimodal treatments, including fluid resuscitation, antibiotics, organ support, and blood purification, are essential for success.

Multiorgan failure following gastroenteritis: a case report

Background

This report highlights the first published case of fatal septic shock associated with Clostridium perfringens and Enterococcus avium bacteremia due to infective gastroenteritis.

Case presentation

We report a case of hepatic infarction, abscess, and death following gastroenteritis in a 63-year-old Aboriginal man who initially presented to a rural hospital with suspected food poisoning. The patient had persistent fever and was commenced on empirical antibiotics. His blood culture results were positive for Clostridium perfringens and Enterococcus avium. He was transferred to a tertiary center but developed organ failure and refractory shock. Initial computed tomography of the abdomen was unremarkable, but repeat imaging showed small bowel enteritis, hepatic abscess, and infarction as a result of portal vein septic thromboembolism. Despite maximal intensive care treatment, including percutaneous drainage of hepatic abscess and broad antibiotic cover, the patient died 6 days after initial presentation.

Conclusions

This case highlights the rare but commonly fatal course of sepsis associated with Clostridium perfringens bacteremia and demonstrates detrimental effects of coinfection with Enterococcus avium, including potential for rapidly seeding abscess formation. Lessons for rural practice are highlighted, including the need for urgent and early referral for intensive care support, particularly for patients with complex comorbidities.

Clinical relevance of Clostridium bacteremia: An 8-year retrospective study

Clostridium spp. are recovered from 25% of the blood culture positive with anaerobes. However, the clinical relevance of Clostridium bacteremia has been controverted in the literature, particularly for C. perfringens. We aimed to evaluate the clinical relevance of Clostridium bacteremia, either due to C. perfringens or other Clostridium species, and to identify the risk factors of mortality in these patients. A retrospective cohort study was conducted from January 2010 to April 2018. All the patients with at least one blood culture positive with any Clostridium species were included. Eighty-one patients with a least one blood culture positive with any Clostridium species were included. Seventy patients (86.4%) fulfilled the criteria for clinically relevant bacteremia. Bacteremia due to C. perfringens tended to be less clinically relevant than other Clostridium species but this was not statistically significant (76% vs 91.2%, P = 0.09). In case of clinically relevant bacteremia, the 30-day mortality rate was 31.4%. In multivariate analysis, adequate empiric antimicrobial therapy was significantly associated with survival (P = 0.03). In conclusion, bacteremia due to C. perfringens or other Clostridium species is usually clinically relevant. This finding was also supported by an improved survival at 30 days when adequate empiric antimicrobial therapy was administered.

Subphrenic abscess due to Clostridium perfringens after hepatic resection for hepatocellular carcinoma following emphysematous cholecystitis: Report of a case

BACKGROUND

Subphrenic abscess caused by Clostridium perfringens is rare after hepatic resection. We herein report such a case after hepatic resection for hepatocellular carcinoma following treatment of emphysematous cholecystitis.

CASE PRESENTATION

A 69-years-old man with chronic hepatitis B, was admitted to our hospital for right subcostal pain and loss of appetite. Computed tomography (CT) revealed emphysematous cholecystitis, for which percutaneous transhepatic gallbladder drainage was performed. Clostridium perfringens was identified from the culture of the bile. Imaging studies immediately demonstrated hepatocellular carcinoma with right lobe of the liver, for which the patients underwent hepatic resection and cholecystectomy concomitantly. After operation, the patient developed emphysematous subphrenic abscess on postoperative day 15, for which CT-guided percutaneous drainage was performed. Clostridium perfringens was identified from the culture of the abscess fluid. The patient was given Ciprofloxacin and Clindamycin and made a satisfactory recovery. The patient was discharged on POD 95 and remains well with no evidence of tumor recurrence as of 8 years after resection.

CONCLUSION

We herein reported a subphrenic abscess due to Clostridium perfringens after hepatic resection for hepatocellular carcinoma following emphysematous cholecystitis.

A rare case of non-clostridial infection in a non-diabetic patient

A 76-year-old man presented with neck swelling associated with pain and fever. On examination, there was a submental neck swelling. His initial CT scan showed multiloculated abscess centred in the left submandibular gland. He remained febrile despite on intravenous ceftriaxone and metronidazole. A repeat CT scan revealed significant worsening with multiple pockets of fluids with gas locules in the deep neck spaces. He subsequently underwent neck exploration and drainage of neck abscess. Extensive necrotic tissue was found intraoperatively and thick pus was drained from the bilateral parapharyngeal, submental spaces and anterior mediastium. Pus culture profusely grew of Eggerthella species. Patient recovered well following further intravenous antibiotic therapy. Diabetes mellitus and odontogenic infections are the common risk factors in deep neck infections. Our patient is however non-diabetic and edentulous. Current case is presented to serve as a rare case of neck abscess with unusual cause in a non-diabetic patient.

Fatal Liver Infection Caused By Clostridium perfringens After Common Bile Duct Stenting Due To Pancreatic Cancer: A Case Report

Background

Intra-abdominal Clostridium perfringens, especially liver infection, is rare and fatal. It often occurs in patients with immunodeficiency due to various factors, such as cancer, diabetes mellitus, and organ transplantation. The identification of gram-positive bacilli in septicemia, the presence of gas-forming liver damage and intravascular hemolysis are manifestations of Clostridium perfringens infection. The episode deteriorates rapidly and has a high mortality rate.

Case presentation

This case involved a 60-year-old man with infection onset 2 weeks after common bile duct stenting for obstructive jaundice caused by unresectable pancreatic cancer. Abdominal computed tomography (CT) revealed gas-containing lesions in the liver. Blood culture showed Clostridium perfringens. Though aggressively rescued, he died within 24 hrs after admission.

Conclusion

Clostridium perfringens liver infection is rare but leads to a severe prognosis rapidly. High awareness of this condition is key for early diagnosis and effective treatment.

Continuous venovenous hemodiafiltration using cytokine-adsorbing hemofilters as adjuvant therapy for anaerobic descending necrotizing mediastinitis: a case report

Background

We describe a combinatorial intensive care approach and discuss the critical factors that allowed us to successfully manage a life-threatening case of acute anaerobic septic shock triggered by descending necrotizing mediastinitis.

Case presentation

We admitted a 38-year-old critically ill Kosovar Albanian man to our intensive care unit because of clinical manifestations of severe sepsis. His condition had worsened in the previous 2 weeks following unsuccessful antibiotic therapy for tonsillitis complicated by retropharyngeal abscesses. Computed tomography and intraoperative observations identified abscesses in the anterior and middle mediastinum regions and the distal part of the neck, directly on the border with the left lobe of the thyroid gland. Cultures indicated infections with α-hemolytic Streptococcus and Clostridium species: High procalcitonin and lactate levels, blood gas analysis, poor peripheral capillary oxygen saturation, and severe hemodynamic instability pointed to a case of acute septic shock. The entire treatment consisted of an aggressive antibiotic regimen, transthoracic and mediastinal surgical evacuation of the abscess, vacuum sealing drainage with a pleural chest tube, continuous venovenous hemodiafiltration using cytokine-adsorbing hemofilters, and extracorporeal blood hyperoxygenation.

Conclusions

Efficient treatment of severe anaerobic sepsis resulting from descending necrotizing mediastinitis should build on a multidisciplinary approach. In support of first-line therapies with targeted antibiotics and surgical debridement, clinicians should consider alternative therapies such as continuous venovenous hemodiafiltration with cytokine-adsorbing hemofilters and hyperoxygenation.

Electronic supplementary material

The online version of this article (10.1186/s13256-019-2123-7) contains supplementary material, which is available to authorized users.

Clostridium perfringens α-toxin impairs granulocyte colony-stimulating factor receptor-mediated granulocyte production while triggering septic shock

During bacterial infection, granulocyte colony-stimulating factor (G-CSF) is produced and accelerates neutrophil production from their progenitors. This process, termed granulopoiesis, strengthens host defense, but Clostridium perfringens α-toxin impairs granulopoiesis via an unknown mechanism. Here, we tested whether G-CSF accounts for the α-toxin-mediated impairment of granulopoiesis. We find that α-toxin dramatically accelerates G-CSF production from endothelial cells in response to Toll-like receptor 2 (TLR2) agonists through activation of the c-Jun N-terminal kinase (JNK) signaling pathway. Meanwhile, α-toxin inhibits G-CSF-mediated cell proliferation of Ly-6G+ neutrophils by inducing degradation of G-CSF receptor (G-CSFR). During sepsis, administration of α-toxin promotes lethality and tissue injury accompanied by accelerated production of inflammatory cytokines in a TLR4-dependent manner. Together, our results illustrate that α-toxin disturbs G-CSF-mediated granulopoiesis by reducing the expression of G-CSFR on neutrophils while augmenting septic shock due to excess inflammatory cytokine release, which provides a new mechanism to explain how pathogenic bacteria modulate the host immune system.

Abdominal aortic aneurysm in the setting of Clostridium perfringens pancreatitis

We report a case of a 56-year-old woman who presented with worsening abdominal pain located in the left upper quadrant together with abdominal distention, nausea and anorexia. One month prior to this admission, she had presented and had been diagnosed with concurrent acute pancreatitis and rapidly expanding abdominal aortic aneurysm. The aneurysm was prioritised over the pancreatitis and she underwent uncomplicated endovascular repair. Cross-sectional imaging was consistent with infected pancreatic necrosis and also revealed a large collection located in the anterior pararenal space with extensive gas formation. An image-guided fluid aspiration revealed Clostridium perfringens as the causative organism. She was treated by placement of large bore drains along with irrigation and targeted intravenous antibiotic for 6 weeks. The collections resolved completely and at 6 months follow-up she was well and symptom free.

Discitis and Clostridium perfringens bacteraemia

The authors present a case involving an 80-year-old man with infectious T10/T11 discitis on the background of a recent Clostridium perfringens bacteraemia. This case report describes a case of probable C. perfringens discitis as further investigations failed to identify any causative agents. He was treated with intravenous piperacillin/tazobactam to good effect, achieving favourable clinical outcome. Diagnosis of discitis/osteomyelitis can often be delayed and mismanaged due to its non-specific presentations. Timing of empirical antimicrobial therapy requires careful consideration based on haemodynamic stability and neurological function to maximise microbiological yield.

There may be more than meets the eye with Clostridium perfringens bacteremia

We present the case of an 89-year-old man with a 1 month history of fevers and fatigue. Blood cultures were positive for Clostridium perfringens. The patient had worsening abdominal distension in which an abdominal computed tomography scan uncovered a colonic mass, and further work-up revealed poorly differentiated adenocarcinoma. The patient was treated with antibiotics, but unfortunately, given his age and the new malignancy, he was discharged to hospice care. The association between clostridial bacteremia and colon cancer has been well described in the literature and is further discussed in this article. This case highlights the importance of recognizing possible occult malignancy in the right clinical setting in patients found to have clostridial bacteremia.

Clostridium perfringens bacteraemia, an analysis of 28 cases over 10 years in a university hospital of Madrid

Bacteraemia caused by anaerobic bacteria is rare in the hospital setting. The Clostridium genus is the second most common cause of these infections, particularly Clostridium perfringens, which has a high mortality rate. However, reviews in the literature of these infections are scarce. The aim of this study was to retrospectively document the incidence, clinical characteristics and risk factors involved in the acquisition of bacteraemia caused by C. perfringens among patients treated at our hospital over a 10-year period. Twenty-eight patients with C. perfringens bacteraemia were included in the study. We evaluated pre-existing comorbidities, the source of bacteraemia, clinical features, the antimicrobial treatment administered and patient outcome. C. perfringens bacteraemia occurs rarely in our setting, but with a very high mortality rate. This rate is associated with old age and pre-existing, largely gastrointestinal malignancies. It presents with few specific symptoms but requires rapid and appropriate diagnosis and treatment to reduce the high mortality of this infection.

Anaerobic Bacteremia: Impact of Inappropriate Therapy on Mortality

BACKGROUND

Investigation on incidence and mortality of anaerobic bacteremia (AB) is clinically relevant in spite of its infrequent occurrence and not often explored, which report varies according to period and institutions. Therefore, it is necessary to analyze the incidence and risk factors related to mortality and assess clinical outcomes of AB in current aspect.

MATERIALS AND METHODS

Characteristics of AB patients and anaerobic bacteria from blood culture at a university hospital in 2012 were reviewed retrospectively. The correlation between risk factors and 28-day patient mortality was analyzed.

RESULTS

A total of 70 non-duplicated anaerobic bacteria were isolated from blood of 70 bacteremia patients in 2012. The history of cardiovascular disease as host's risk factor was statistically significant (P = 0.0344) in univariate and multivariate analysis. Although the inappropriate therapy was not statistically significant in univariate and multivariate analysis, the survival rate of bacteremia was significantly worse in patients who had inappropriate therapy compared with those underwent appropriate therapy (hazard ratio, 5.4; 95% confidence interval, 1.7-6.9; P = 0.004). The most frequently isolated organism was Bacteroides fragilis (32 isolates, 46%), followed by Bacteroides thetaiotaomicron (10, 14%), and non-perfringens Clostridium (7, 10%).

CONCLUSION

The incidence of AB in 2012 was 2.3% (number of AB patients per 100 positive blood culture patients) and the mortality rate in patients with clinically significant AB was 21.4%. In addition, AB was frequently noted in patients having malignancy and the survival rate of AB was significantly worse in patients who received inappropriate therapy compared with those underwent appropriate therapy.

The Exosporium Layer of Bacterial Spores: a Connection to the Environment and the Infected Host

Much of what we know regarding bacterial spore structure and function has been learned from studies of the genetically well-characterized bacterium Bacillus subtilis. Molecular aspects of spore structure, assembly, and function are well defined. However, certain bacteria produce spores with an outer spore layer, the exosporium, which is not present on B. subtilis spores. Our understanding of the composition and biological functions of the exosporium layer is much more limited than that of other aspects of the spore. Because the bacterial spore surface is important for the spore's interactions with the environment, as well as being the site of interaction of the spore with the host's innate immune system in the case of spore-forming bacterial pathogens, the exosporium is worthy of continued investigation. Recent exosporium studies have focused largely on members of the Bacillus cereus family, principally Bacillus anthracis and Bacillus cereus. Our understanding of the composition of the exosporium, the pathway of its assembly, and its role in spore biology is now coming into sharper focus. This review expands on a 2007 review of spore surface layers which provided an excellent conceptual framework of exosporium structure and function (A. O. Henriques and C. P. Moran, Jr., Annu Rev Microbiol 61:555-588, 2007, http://dx.doi.org/10.1146/annurev.micro.61.080706.093224). That review began a process of considering outer spore layers as an integrated, multilayered structure rather than simply regarding the outer spore components as independent parts.

Severe Sepsis due to Clostridium perfringens Bacteremia of Urinary Origin: A Case Report and Systematic Review

Clostridium perfringens bacteremia is an uncommon yet serious clinical syndrome that typically arises from a gastrointestinal source. However, clinicians should consider nongastrointestinal sources as well. We present a rare case of C. perfringens bacteremia of urinary origin that required surgical intervention for definitive treatment. A 61-year-old male presented with acute nausea and vomiting, altered mental status, and chronic diarrhea. His physical exam revealed right costovertebral tenderness and his laboratory work-up revealed acute renal failure. Percutaneous blood cultures grew C. perfringens. Cross-sectional imaging revealed a right-sided ureteral stone with hydronephrosis, which required nephrostomy placement. On placement of the nephrostomy tube, purulent drainage was identified and Gram stain of the drainage revealed Gram-variable rods. A urinary source of C. perfringens was clinically supported. Although it is not a common presentation, nongastrointestinal sources such as a urinary source should be considered in C. perfringens bacteremia because failure to recognize a nongastrointestinal source can delay appropriate treatment, which may include surgical intervention.

Beta Lactamase Producing Clostridium perfringens Bacteremia in an Elderly Man with Acute Pancreatitis

Clostridium perfringens bacteremia is associated with adverse outcomes. Known risk factors include chronic kidney disease, malignancy, diabetes mellitus, and gastrointestinal disease. We present a 74-year-old man admitted with confusion, vomiting, and abdominal pain. Exam revealed tachycardia, hypotension, lethargy, distended abdomen, and cold extremities. He required intubation and aggressive resuscitation for septic shock. Laboratory data showed leukocytosis, metabolic acidosis, acute kidney injury, and elevated lipase. CT scan of abdomen revealed acute pancreatitis and small bowel ileus. He was started on vancomycin and piperacillin-tazobactam. Initial blood cultures were positive for C. perfringens on day five. Metronidazole and clindamycin were added to the regimen. Repeat CT (day 7) revealed pancreatic necrosis. The patient developed profound circulatory shock requiring multiple vasopressors, renal failure requiring dialysis, and bacteremia with vancomycin-resistant enterococci. Hemodynamic instability precluded surgical intervention and he succumbed to multiorgan failure. Interestingly, our isolate was beta lactamase producing. We review the epidemiology, risk factors, presentation, and management of C. perfringens bacteremia. This case indicates a need for high clinical suspicion for clostridial sepsis and that extended spectrum beta lactam antibiotic coverage may be inadequate and should be supplemented with use of clindamycin or metronidazole if culture is positive, until sensitivities are known.

Acute Hemolysis with Renal Failure due toClostridiumBacteremia in a Patient with AML

We present a case of acute hemolytic anemia, renal failure, and Clostridium perfringens bacteremia in a patient with acute myelogenous leukemia. The high fatality of C. perfringens bacteremia requires that clinicians recognize and rapidly treat patients at risk for this infection. Although other hemolytic processes are in the differential diagnosis of these events, the presence of high fever, chills, and rapidly positive blood cultures may help narrow the diagnosis. Most cases of C. perfringens bacteremia have a concomitant coinfection, which makes broad spectrum empiric therapy essential. There is a high mortality rate of C. perfringens infections associated with leukemia.

Clostridium perfringens infection after transarterial chemoembolization for large hepatocellular carcinoma

We report an unusual case of Clostridium perfringens liver abscess formation after transcatheter arterial chemoembolization (TACE) for large hepatocellular carcinoma. Severe deterioration in liver and renal function accompanied with hemocytolysis was found on the 2^nd day after TACE. Blood culture found Clostridium perfringens and abdominal computed tomography revealed a gas-containing abscess in the liver. Following antibiotics administration and support care, the infection was controlled and the liver and renal function turned normal. The 2^nd TACE procedure was performed 1.5 mo later and no recurrent Clostridium perfringens infection was found.

Gas-forming liver abscess associated with rapid hemolysis in a diabetic patient

We experienced a case of liver abscess due to Clostridium perfringens (CP) complicated with massive hemolysis and rapid death in an adequately controlled type 2 diabetic patient. The patient died 6 h after his first visit to the hospital. CP was later detected in a blood culture. We searched for case reports of CP septicemia and found 124 cases. Fifty patients survived, and 74 died. Of the 30 patients with liver abscess, only 3 cases survived following treatment with emergency surgical drainage. For the early detection of CP infection, detection of Gram-positive rods in the blood or drainage fluid is important. Spherocytes and ghost cells indicate intravascular hemolysis. The prognosis is very poor once massive hemolysis occurs. The major causative organisms of gas-forming liver abscess in diabetic patients are Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli). Although CP is relatively rare, the survival rate is very poor compared with those of K. pneumoniae and E. coli. Therefore, for every case that presents with a gas-forming liver abscess, the possibility of CP should be considered, and immediate aspiration of the abscess and Gram staining are important.