Background: Lack of insurance is associated with poorer outcomes in hospitalized patients. However, few studies have explored this association in hospitalizations for necrotizing soft tissue infections (NSTIs). This study examined the impact of insurance status on the outcome of NSTI admissions. Methods: All adult hospitalizations for necrotizing fasciitis, gas gangrene, and Fournier gangrene between 2016 and 2018 were examined using the Nationwide Inpatient Sample database. Insurance status was categorized as insured (including Medicare, Medicaid, and Private, including Health maintenance organization (HMO) or uninsured (Self-pay). Outcome measures included mortality rates, limb loss, length of hospital stay, prolonged hospital stay, and critical care admissions. Statistical analysis included weighted sample analysis, chi-square tests, multivariate regression analysis, and negative binomial regression modeling. Results: Approximately 29,705 adult hospitalizations for NSTIs were analyzed. Of these, 57.4% (17,065) were due to necrotizing fasciitis, 22% (6,545) to gas gangrene, and 20.5% (6,095) to Fournier gangrene. Approximately 9.7% (2,875) were uninsured, whereas 70% (26,780) had insurance coverage. Among the insured, Medicare covered 39.6% (10,605), Medicaid 29% (7,775), and private insurance 31.4% (8,400). After adjustments, Medicare insurance was associated with greater odds of mortality (adjusted odds ratio [aOR]: 1.81; 95% confidence interval [CI]: 1.33-2.47; p = 0.001). Medicaid insurance was associated with increased odds of amputation (aOR: 1.81; 95% CI: 1.33-2.47; p < 0.001), whereas private insurance was associated with lower odds of amputation (aOR: 0.70; 95% CI: 0.51-0.97; p = 0.030). Medicaid insurance was associated with greater odds of prolonged hospital stay (aOR: 1.34; 95% CI: 1.09-1.64; p < 0.001). No significant association was observed between the lack of insurance or self-pay and the odds of primary or secondary outcomes. Conclusion: Medicare insurance was correlated with greater odds of mortality, whereas Medicaid insurance was associated with increased odds of amputation and longer hospital stay. Uninsured status was not associated with significant differences in NSTI outcomes.

Gas gangrene is a lethal necrotic infection resulting in gas production within tissue. It is typically associated with trauma and is especially lethal during pregnancy, resulting in severe maternal infection and fetal death. We report the case of a 31-year-old G3P2 female who presented to the emergency department with abdominal bloating, vaginal cramping, and brown vaginal discharge. Physical examination showed that the patient was hypertensive, tachycardic, and tachypneic, and laboratory examination showed a downtrending beta-human chorionic gonadotropin and leukocytosis, with elevated inflammatory markers. Ultrasound showed copious gas located within the lower abdomen and the fetus was not visualized. Computed tomography (CT) of the abdomen and pelvis showed a gravid uterus with a single fetus and extensive air locules in the fetus, amniotic cavity, and placenta. The findings were consistent with gas gangrene of a mature fetus in the third trimester. Fetal gas gangrene is a potentially lethal condition during pregnancy, and early diagnosis is imperative in management. CT was utilized in this case to outline the increased gas production within the amniotic cavity and fetal organs and proved crucial in determining the next steps of management.

OBJECTIVE: Gas gangrene (GG) is a rare severe infection with a very high mortality rate mainly caused by Clostridium species. It develops suddenly, often as a complication of abdominal surgery or liver transplantation. We report a case of GG of the liver occurred after percutaneous microwave (MW) ablation of an hepatocellular carcinoma (HCC) successfully treated with percutaneous Radiofrequency ablation (RFA).
METHODS: A 76-year-old female patient was treated with MW ablation for a large HCC in the VIII segment; 2 days later she developed fever, weakness, abdominal swelling and was hospitalized with diagnosis of anaerobic liver abscess. Despite antibiotic therapy, the patient conditions worsened, and she was moved to the intensive care unit (ICU). Percutaneous drainage was attempted, but was unsuccessful. The surgeon and the anesthesiologist excluded any indication of surgical resection. We performed RFA of the GG by 3 cool-tip needles into the infected area. The procedure was well tolerated by the patient, who left the hospital for follow-up.
CONCLUSIONS: Percutaneous RFA could be a valuable therapy of focal GG of the liver in patients refractory to antibiotics and when surgery and OLT are not feasible. A fast and early indication is needed in case of rapid worsening of the patient\'s conditions.

Absent in melanoma 2 (AIM2), a key component of the IFI20X/IFI16 (PYHIN) protein family, is characterized as a DNA sensor to detect cytosolic bacteria and DNA viruses. However, little is known about its immunological role during pathogenic Clostridium perfringens (C. perfringens) infection, an extracellular bacterial pathogen. In a pathogenic C. perfringens gas gangrene model, Aim2-/- mice are more susceptible to pathogenic C. perfringens soft tissue infection, revealing the importance of AIM2 in host protection. Notably, Aim2 deficiency leads to a defect in bacterial killing and clearance. Our in vivo and in vitro findings further establish that inflammasome signaling is impaired in the absence of Aim2 in response to pathogenic C. perfringens. Mechanistically, inflammasome signaling downstream of active AIM2 promotes pathogen control. Importantly, pathogenic C. perfringens-derived genomic DNA triggers inflammasome signaling activation in an AIM2-dependent manner. Thus, these observations uncover a central role for AIM2 in host defense and triggering innate immunity to combat pathogenic C. perfringens infections.

A transtibial amputation is the traditional primary staged amputation for source control in the setting of non-salvageable lower extremity infection, trauma, or avascularity prior to progression to proximal amputation. The primary aim of the study is to compare preoperative risk factors and postoperative outcomes between patients who underwent transtibial amputation versus ankle disarticulation in staged amputations. A retrospective review of 152 patients that underwent staged below the knee amputation were compared between those that primarily underwent transtibial amputation (N = 70) versus ankle disarticulation (N = 82). The mean follow-up for all 152 patients was 2.1 years (range = 0.04-7.9 years). The odds of incisional healing were 3.2 times higher for patients with guillotine amputation compared to patients with ankle disarticulation (odds ratio [OR] = 3.2, 95% confidence interval [CI] = 1.437-7.057). The odds of postoperative infection is 7.4 times higher with ankle disarticulation compared to patients with guillotine amputation (OR = 7.345, 95% CI = 1.505-35.834). There were improved outcomes in patients that underwent staged below the knee amputation with primarily guillotine transtibial amputation compared to primarily ankle disarticulation. Ankle disarticulation should be reserved for more distal infections, to allow for adequate infectious control, in the aims of decreasing postoperative infection and improving incisional healing rates.Levels of Evidence: 3, Retrospective study.

A patient presented with fever, severe pain and edematous tight due to hip trauma and was scheduled for urgent fasciotomy. Following physical examination, laboratory analyses were requested, and results revealed anemia and severe infection. As the patient\'s condition was serious, a new set of samples was sent to the laboratory four hours later. Following centrifugation, severely hemolyzed dark-colored serum and plasma samples were obtained and in vitro hemolysis was suspected. The collection of samples was repeated, but a new set of samples was also hemolyzed with a significant decrease in the hemoglobin value. At that point, in vivo hemolysis was suspected, and samples were processed according to standard laboratory procedures for hemolytic samples. Following confirmation of the gas gangrene diagnosis by clinicians, the cause of hemolysis was attributed to the cytotoxic activity of α-toxin produced by the anaerobic gram-positive bacterium Clostridium perfringens. An insight into the laboratory procedure that could help to narrow down the causes of hemolysis and single out C. perfringens as a cause of intravascular hemolysis was given.

UNASSIGNED: There are inconsistencies in outcome reporting for patients with necrotising soft tissue infections (NSTI). The aim of this study was to evaluate reported outcome measures in NSTI literature that could inform a core outcome set (COS) such as could be used in a study of hyperbaric oxygen in this indication.
UNASSIGNED: A systematic review of all NSTI literature identified from Cochrane, Ovid MEDLINE and Scopus databases as well as grey literature sources OpenGrey and the New York Academy of Medicine databases which met inclusion criteria and were published between 2010 and 2020 was performed. Studies were included if they reported on > 5 cases and presented clinical endpoints, patient related outcomes, or resource utilisation in NSTI patients. Studies did not have to include intervention. Two independent researchers then extracted reported outcome measures. Similar outcomes were grouped and classified into domains to produce a structured inventory. An attempt was made to identify trends in outcome measures over time and by study design.
UNASSIGNED: Three hundred and seventy-five studies were identified and included a total of 311 outcome measures. Forty eight percent (150/311) of outcome measures were reported by two or more studies. The four most frequently reported outcome measures were mortality without time specified, length of hospital stay, amputation performed, and number of debridements, reported in 298 (79.5%), 260 (69.3%), 156 (41.6%) and 151 (40.3%) studies respectively. Mortality outcomes were reported in 23 different ways. Randomised controlled trials (RCTs) were more likely to report 28-day mortality or 90-day mortality. The second most frequent amputation related outcome was level of amputation, reported in 7.5% (28/375) of studies. The most commonly reported patient-centred outcome was the SF-36 which was reported in 1.6% (6/375) of all studies and in 2/10 RCTs.
UNASSIGNED: There was wide variance in outcome measures in NSTI studies, further highlighting the need for a COS.

Clostridium perfringens causes gas gangrene and food poisoning in humans, and monitoring this bacterium is important for public health. Although whole-genome sequencing is useful to comprehensively understand the virulence, resistome, and global genetic relatedness of bacteria, limited genomic data from environmental sources and developing countries hamper our understanding of the richness of the intrinsic genomic diversity of this pathogen. Here, we successfully accumulated the genetic data on C. perfringens strains isolated from hospital effluent and provided the first evidence that predicted pathogenic C. perfringens may be disseminated in the clinical environment in Ghana. Our findings suggest the importance of risk assessment in the environment as well as the clinical setting to mitigate the potential outbreak of C. perfringens food poisoning in Ghana.

Neutrophil extracellular traps (NETs) are networks of DNA and various microbicidal proteins released to kill invading microorganisms and prevent their dissemination. However, a NETs excess is detrimental to the host and involved in the pathogenesis of various inflammatory and immunothrombotic diseases. Clostridium perfringens is a widely distributed pathogen associated with several animal and human diseases, that produces many exotoxins, including the phospholipase C (CpPLC), the main virulence factor in gas gangrene. During this disease, CpPLC generates the formation of neutrophil/platelet aggregates within the vasculature, favoring an anaerobic environment for C. perfringens growth. This work demonstrates that CpPLC induces NETosis in human neutrophils. Antibodies against CpPLC completely abrogate the NETosis-inducing activity of recombinant CpPLC and C. perfringens secretome. CpPLC induces suicidal NETosis through a mechanism that requires calcium release from inositol trisphosphate receptor (IP3) sensitive stores, activation of protein kinase C (PKC), and the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) pathways, as well as the production of reactive oxygen species (ROS) by the metabolism of arachidonic acid. Proteomic analysis of the C. perfringens secretome identified 40 proteins, including a DNAse and two 5´-nucleotidases homologous to virulence factors that could be relevant in evading NETs. We suggested that in gas gangrene this pathogen benefits from having access to the metabolic resources of the tissue injured by a dysregulated intravascular NETosis and then escapes and spreads to deeper tissues. Understanding the role of NETs in gas gangrene could help develop novel therapeutic strategies to reduce mortality, improve muscle regeneration, and prevent deleterious patient outcomes.

OBJECTIVE: Clostridium perfringens causes food poisoning and gas gangrene, a serious wound-associated infection. C. perfringens cells adhere to collagen via fibronectin (Fn). We investigated whether the peptidoglycan hydrolase of C. perfringens, i.e., autolysin (Acp), is implicated in Fn binding to C. perfringens cells.
METHODS: This study used recombinant Acp fragments, human Fn and knockout mutants (C. perfringens 13 acp::erm and HN13 ΔfbpC ΔfbpD). Ligand blotting, Western blotting analysis, and complementation tests were performed. The Fn-binding activity of each mutant was evaluated by ELISA.
RESULTS: From an Fn-binding assay using recombinant Acp fragments, Fn was found to bind to the catalytic domain of Acp. In mutant cells lacking Acp, Fn binding was significantly decreased, but was restored by the complementation of the acp gene. There are three known kinds of Fn-binding proteins in C. perfringens: FbpC, FbpD, and glyceraldehyde-3-phosphate dehydrogenase. We found no difference in Fn-binding activity between the mutant cells lacking both FbpC and FbpD (SAK3 cells) and the wild-type cells, indicating that these Fn-binding proteins are not involved in Fn binding to C. perfringens cells.
CONCLUSIONS: We found that the Acp is an Fn-binding protein that acts as an Fn receptor on the surface of C. perfringens cells.