Acute Interstitial Inflammation on Skin Biopsies and Positive Tissue Cultures in Cellulitis Patients Are Associated a Worse Prognosis

BACKGROUND

Cellulitis is a significant public health burden and lacks a gold standard for diagnosis. Up to 1/3 of patients are incorrectly diagnosed. The skin biopsy has been proposed as the gold standard.

OBJECTIVE

In this study, we evaluate the histopathologic characteristics and tissue culture positivity of biopsies in patients diagnosed with cellulitis seen by our inpatient dermatology consultation service.

METHODS

This retrospective cohort study examined patients who were hospitalized with a skin and soft tissue infection at our institution between 2011 and 2020 and underwent a skin biopsy.

RESULTS

Those with a positive tissue culture were more likely to die within 30 days compared with those with negative tissue cultures (26% vs. 6%, P = 0.048). Patients who died within 30 days were more likely to have acute interstitial inflammation as a feature on histopathology (38%, P = 0.03).

LIMITATIONS

Single institutional design, unintentional exclusion of patients with organism-specific diagnosis, and selection for a medically complex patient population because of the nonroutine collection of biopsies.

CONCLUSION

Positive tissue cultures and histopathology showing acute interstitial space inflammation on skin and soft tissue infection (SSTI) biopsies are associated with increased mortality and thus may serve as indicators of poor prognosis.

The ever-changing microenvironment of Staphylococcus aureus in cutaneous infections

BACKGROUND

Staphylococcus aureus is responsible for the majority of skin and soft tissue infections, which are often diagnosed at a late stage, thereby impacting treatment efficacy. Our study was designed to reveal the physiological changes at different stages of infection by S. aureus through the combined analysis of variations in the skin microenvironment, providing insights for the diagnosis and treatment of S. aureus infections.

METHODS

We established a murine model of skin and soft tissue infection with S. aureus as the infectious agent to investigate the differences in the microenvironment at different stages of infection. By combining analysis of the host immune status and histological observations, we elucidate the progression of S. aureus infection in mice.

RESULTS

The results indicate that the infection process in mice can be divided into at least two stages: early infection (1-3 days post-infection) and late infection (5-7 days post-infection). During the early stage of infection, notable symptoms such as erythema and abundant exudate at the infection site were observed. Histological examination revealed infiltration of numerous neutrophils and bacterial clusters, accompanied by elevated levels of cytokines (IL-6, IL-10). There was a decrease in microbial alpha diversity within the microenvironment (Shannon, Faith's PD, Chao1, Observed species, Simpson, Pielou's E). In contrast, during the late stage of infection, a reduction or even absence of exudate was observed at the infected site, accompanied by the formation of scabs. Additionally, there was evidence of fibroblast proliferation and neovascularization. The levels of cytokines and microbial composition gradually returned to a healthy state.

CONCLUSION

This study reveals synchrony between microbial composition and histological/immunological changes during S. aureus-induced SSTIs.

[Necrotizing soft tissue infections]

Necrotizing soft tissue infections are a heterogeneous group of severe infections of the skin, connective tissue and muscles in which necrotic destruction of the tissue occurs at the site of infection. Various bacteria are known as "typical" triggering pathogens and the infection can occur on the entire surface of the body. Necrotizing soft tissue infections are always a time-sensitive emergency associated with high mortality. Many affected patients are critically ill and require treatment in an intensive care unit. The rapid and radical surgical treatment is an essential part of management and in addition an adequate and timely antimicrobial treatment is of great importance. The health consequences for surviving patients are often severe, as extensive soft tissue damage leads to functional impairments. In many cases extensive plastic surgery follow-up is necessary. Therefore, necrotizing soft tissue infections are "complicated" in every phase of the disease and require interprofessional treatment. This review article provides a current overview of various aspects of the diagnostics, treatment and aftercare of necrotizing soft tissue infections.

Glucose transporter 1 is essential for the resolution of methicillin-resistant S. aureus skin and soft tissue infections

Skin/soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) pose a major healthcare burden. Distinct inflammatory and resolution phases comprise the host immune response to SSTIs. Resolution is a myeloid PPARγ-dependent anti-inflammatory phase that is essential for the clearance of MRSA. However, the signals activating PPARγ to induce resolution remain unknown. Here, we demonstrate that myeloid glucose transporter 1 (GLUT-1) is essential for the onset of resolution. MRSA-challenged macrophages are unsuccessful in generating an oxidative burst or immune radicals in the absence of GLUT-1 due to a reduction in the cellular NADPH pool. This translates in vivo as a significant reduction in lipid peroxidation products required for the activation of PPARγ in MRSA-infected mice lacking myeloid GLUT-1. Chemical induction of PPARγ during infection circumvents this GLUT-1 requirement and improves resolution. Thus, GLUT-1-dependent oxidative burst is essential for the activation of PPARγ and subsequent resolution of SSTIs.

Sarcopenia Is Associated With Increased Mortality in Patients With Necrotizing Soft Tissue Infections

INTRODUCTION

Necrotizing soft tissue infections (NSTIs) are surgical emergencies associated with high morbidity and mortality. Identifying risk factors for poor outcome is a critical part of preoperative decision-making and counseling. Sarcopenia, the loss of lean muscle mass, has been associated with an increased risk of mortality and can be measured using cross-sectional imaging. Our aim was to determine the impact of sarcopenia on mortality in patients with NSTI. We hypothesized that sarcopenia would be associated with an increased risk of mortality in patients with NSTI.

METHODS

This is a retrospective cohort study of NSTI patients admitted from 1995 to 2015 to two academic institutions. Operative and pathology reports were reviewed to confirm the diagnosis in all cases. Average bilateral psoas muscle cross-sectional area at L4, normalized for height (Total Psoas Index [TPI]), was calculated using computed tomography (CT). Sarcopenia was defined as TPI in the lowest sex-specific quartile. Primary outcome was in-hospital mortality. Multivariate logistic regression was performed to assess the association between sarcopenia and in-hospital mortality.

RESULTS

There were 115 patients with preoperative imaging, 61% male and a median age of 57 y interquartile range (IQR 46.6-67.0). Overall in-hospital mortality was 12.1%. There was no significant difference in sex, body mass index (BMI), comorbidities and American Society of Anesthesiologists classification (Table 1). After multivariate analysis, sarcopenia was independently associated with increased in-hospital mortality (Odds ratio, 3.5; 95% Confidence Interval [CI], 1.05-11.8).

CONCLUSIONS

Sarcopenia is associated with increased risk of in-hospital mortality in patients with NSTIs. Sarcopenia identifies patients with higher likelihood of poor outcomes, which can possibly help surgeons in counseling their patients and families.

A dose response model for Staphylococcus aureus

Dose-response models (DRMs) are used to predict the probability of microbial infection when a person is exposed to a given number of pathogens. In this study, we propose a new DRM for Staphylococcus aureus (SA), which causes skin and soft-tissue infections. The current approach to SA dose-response is only partially mechanistic and assumes that individual bacteria do not interact with each other. Our proposed two-compartment (2C) model assumes that bacteria that have not adjusted to the host environment decay. After adjusting to the host, they exhibit logistic/cooperative growth, eventually causing disease. The transition between the adjusted and un-adjusted states is a stochastic process, which the 2C DRM explicitly models to predict response probabilities. By fitting the 2C model to SA pathogenesis data, we show that cooperation between individual SA bacteria is sufficient (and, within the scope of the 2C model, necessary) to characterize the dose-response. This is a departure from the classical single-hit theory of dose-response, where complete independence is assumed between individual pathogens. From a quantitative microbial risk assessment standpoint, the mechanistic basis of the 2C DRM enables transparent modeling of dose-response of antibiotic-resistant SA that has not been possible before. It also enables the modeling of scenarios having multiple/non-instantaneous exposures, with minimal assumptions.

Necrotizing soft tissue infection of the upper extremities in patients with diabetes mellitus in a tertiary care center-a retrospective study

BACKGROUND

Necrotizing soft tissue infection (NSTI) of the upper extremities is a rare, but potentially life-threatening infection in patients with type 2 diabetes mellitus (T2DM). We analyzed the clinical characteristics and the outcome of NSTI of upper extremities in these patients.

METHODS

This was a retrospective study analyzing the clinical characteristics and the outcomes of 33 T2DM patients with NSTI of upper extremities, who were treated in the department of hand surgery between January 2011 and December 2017.

RESULTS

Predisposing factors for NSTI were recognized in 16 (48.5%) patients. Eleven (33.3)% patients had septic shock while ten (30.3%) had acute renal insufficiency at the time of presentation, of which six required dialysis. The mean glycosylated hemoglobin was 9.6(±2.6)% and the random plasma glucose at admission was 271(±96) mg/dl. Monomicrobial infection was seen in 16(49%) patients and polymicrobial infection in 9(27%) patients. Gram-positive causation was found in 25(66%) patients. Twelve (36.4%) patients required amputation, six (18.2%) of which were major. Death occurred in more than one-fifth (21.2%) of the patients during treatment.

CONCLUSION

Necrotizing soft tissue infection of the upper extremities in T2DM is associated with increased risk of severe infection, amputation and mortality.

Analyzing Outcomes Among Older Adults With Necrotizing Soft-Tissue Infections in the United States

BACKGROUND

Necrotizing soft-tissue infections (NSTIs) encompass a group of severe, life-threatening diseases with high morbidity and mortality. Evidence suggests advanced age is associated with worse outcomes. To date, no large data sets exist describing outcomes in older individuals, and risk factor identification is lacking.

METHODS

Retrospective data were obtained from the 2015 Medicare 100% sample. Included in the analysis were those aged ≥65 y with a primary diagnosis of an NSTI (gas gangrene, necrotizing fasciitis, cutaneous gangrene, or Fournier's gangrene). Risk factors for in-hospital mortality and discharge disposition were examined. Continuous variables were assessed using central tendency, t-tests, and Wilcoxon rank-sum tests. Categorical variables were assessed using the chi-squared and Fisher's exact tests. Statistical significance was defined as P < 0.05.

RESULTS

1427 patient records were reviewed. 59% of patients were male, and the overall mean age was 75.4±8.6 y. 1385 (97.0%) patients required emergency surgery for their NSTI diagnosis. The overall mortality was 5.3%. Several underlying comorbidities were associated with higher rates of mortality including cancer (OR: 3.50, P = 0.0009), liver disease (OR: 2.97, P = 0.03), and kidney disease (OR: 2.15, P = 0.01). While associated with high in-hospital mortality, these diagnoses were not associated with a difference in the rate of discharge to home compared with skilled nursing or rehab. Overall, patients discharged to skilled nursing facilities or rehab had higher rates of underlying comorbidities than patients who were discharged home (3 or more comorbid illness 84.3% versus 68.6%, P < 0.0001); however, no individual comorbid illness was associated with discharge location.

CONCLUSIONS

In our Medicare data set, we identified several medical comorbidities that are associated with increased rates of in-hospital mortality. Patients with underlying cancers had the highest odds of increased mortality. The effect on outcomes of the potentially immunosuppressive cancer treatments in these patients is unknown. These data suggest that patients with underlying illnesses, especially cancer, kidney disease, or liver disease have higher mortalities and are more likely to be discharged to skilled nursing facilities or rehab. It is unclear why these illnesses were associated with these worse outcomes while others including diabetes and heart disease were not. These data suggest that these particular comorbid illnesses may have special prognostic implications, although further analysis is necessary to identify the causative factors.

Association of Negative Pressure Wound Therapy and Dermatotraction for Management of Necrotizing Soft Tissue Infections: A Case Series

INTRODUCTION

Soft tissue infections (STIs), which include infections of the skin, subcutaneous tissue, fascia, and muscle, encompass a wide variety of heterogeneous pathologies. Treatment of STIs is based on surgical debridement of the affected area. One such treatment, negative pressure wound therapy (NPWT), has improved the management of STIs.

OBJECTIVE

The purpose of this study is to assess the safety and utility of NPWT in conjunction with dermatotraction in the early stage management of necrotizing STIs.

MATERIALS AND METHODS

The authors report a retrospective series of 3 cases in which NPWT and dermatotraction (NPWT-D) were used in an attempt to manage necrotizing STI. The NPWT-D device combination was employed to approximate the edges of the wounds. The NPWT device was changed every 2 or 3 days, and dermatotraction tension was adjusted concurrently.

RESULTS

The NPWT-D device changes ranged from 3 to 4 times for 2 of the 3 patients, as 1 patient passed away secondary to STIs and therefore did not receive complete treatment. The total treatment ranged from 8 to 10 days in the remaining 2 patients. In both cases, complete wound closure was achieved while avoiding skin grafts. After 5 days of therapy in the incomplete treatment case, the wound area was reduced by about half.

CONCLUSIONS

Based on the experiences herein, NPWT-D may be a safe and useful alternative surgical treatment for the management of necrotizing STIs. In the present cases, NPWT-D improved and shortened the wound healing process, and it achieved a tertiary wound closure, thereby avoiding the need for skin grafts.

An unexpected host in a soft-tissue lesion of thigh

Rhinosporidiosis is an enigmatic entity and poses a major health problem in the developing countries of South-East Asia. A soft friable polypoid nasal mass is the most common presentation, while sparse literature is available on extranasal involvement. We describe the case of a 35-year-old female patient who presented with a slow-growing soft-tissue swelling with ulceration over the thigh. On clinical and radiological examination, a provisional diagnosis of soft-tissue neoplasm was made. After resection, histopathological sections showed a closely packed cyst with innumerable endospores. The present case report documents the rare occurrence of an incidentally detected cutaneous rhinosporidiosis causing diagnostic difficulty.

Panton-Valentine leukocidin-positive Staphylococcus aureus in skin and soft tissue infections from primary care patients

OBJECTIVES

To characterize deep skin and soft tissue infections (dSSTI) caused by Panton-Valentine leukocidin (PVL)-positive versus PVL-negative Staphylococcus aureus isolates.

METHODS

We performed a retrospective analysis of patients' records including S. aureus isolates from outpatients with dSSTI. Samples had been submitted by primary care physicians, i.e. general practitioners, surgeons, dermatologists and paediatricians, located in Berlin, Germany, in 2007-2017. Bacterial isolates were identified and tested for antimicrobial susceptibility by VITEK 2; PVL was detected by PCR.

RESULTS

In total, 1199 S. aureus isolates from 1074 patients with dSSTI were identified, and 613 (51.1%) of 1199 samples were PVL⁺. The median age of patients with PVL⁺S. aureus was lower than in patients with PVL- S. aureus (34 years, range 0-88 years, vs. 44 years, range 0-98 years; p < 0.0001). PVL was associated with repeated/multiple samples compared to single sample submission (69/92, 75% vs. 448/982, 45.6%, p < 0.0001; odds ratio (OR), 3.6; 95% confidence interval (CI), 2.2-5.8). Interestingly, the highest PVL positivity rate was found in isolates from gluteal (82/108, 75.9%; OR, 3.6; 95% CI, 2-5) or axillary (76/123, 61.8%; OR, 2; 95% CI, 1.1-3.3) localizations compared to isolates from the arm. The PVL positivity rate did not increase over time. Yet we noticed an increase in the trimethoprim/sulfamethoxazole (SXT) resistance rate in PVL⁺ isolates, mainly methicillin-sensitive S. aureus, when considering SXT resistance rates of 2007-2012 versus 2013-2017 (35/226, 15.5% vs. 74/289, 25.6%; p 0.01).

CONCLUSIONS

In outpatients, gluteal and axillary dSSTI are indicative of PVL⁺S. aureus. Providing SXT as a complementary treatment for dSSTI should be based on susceptibility testing.

Diagnostic Value of Laboratory Parameters for Distinguishing Between Herpes Zoster and Bacterial Superficial Skin and Soft Tissue Infections

Clinical differentiation between herpes zoster and bacterial superficial skin and soft tissue infections of the face can be difficult. In addition, diagnosis can be complicated by bacterial superinfection of lesional herpes zoster. The aim of this study was to determine whether inflammatory parameters, such as C-reactive protein (CRP) and blood counts, might be reliable biomarkers to distinguish between skin and soft tissue infections and herpes zoster when the face is infected. The study data (multivariate analysis and area under the curve) identified CRP (0.880) and leukocytes (0.730) together as the parameters that best discriminate between skin and soft tissue infections and herpes zoster. A CRP threshold ≥ 2.05 mg/dl indicated a diagnosis of skin and soft tissue infection with a sensitivity of 80% and specificity of 83.8%. For leukocytes ≥ 7.3×109/l, diagnosis of skin and soft tissue infection had a sensitivity of 75% and specificity of 67.6%. Thus, when differential diagnosis is difficult, CRP and leukocytes should be determined, while parameters such as neutrophils or immature granulocytes do not add diagnostic value.

CRISPR-Cas9 modified bacteriophage for treatment of Staphylococcus aureus induced osteomyelitis and soft tissue infection

Osteomyelitis, or bone infection, is often induced by antibiotic resistant Staphylococcus aureus strains of bacteria. Although debridement and long-term administration of antibiotics are the gold standard for osteomyelitis treatment, the increase in prevalence of antibiotic resistant bacterial strains limits the ability of clinicians to effectively treat infection. Bacteriophages (phages), viruses that in a lytic state can effectively kill bacteria, have gained recent attention for their high specificity, abundance in nature, and minimal risk of host toxicity. Previously, we have shown that CRISPR-Cas9 genomic editing techniques could be utilized to expand temperate bacteriophage host range and enhance bactericidal activity through modification of the tail fiber protein. In a dermal infection study, these CRISPR-Cas9 phages reduced bacterial load relative to unmodified phage. Thus we hypothesized this temperate bacteriophage, equipped with the CRISPR-Cas9 bactericidal machinery, would be effective at mitigating infection from a biofilm forming S. aureus strain in vitro and in vivo. In vitro, qualitative fluorescent imaging demonstrated superiority of phage to conventional vancomycin and fosfomycin antibiotics against S. aureus biofilm. Quantitative antibiofilm effects increased over time, at least partially, for all fosfomycin, phage, and fosfomycin-phage (dual) therapeutics delivered via alginate hydrogel. We developed an in vivo rat model of osteomyelitis and soft tissue infection that was reproducible and challenging and enabled longitudinal monitoring of infection progression. Using this model, phage (with and without fosfomycin) delivered via alginate hydrogel were successful in reducing soft tissue infection but not bone infection, based on bacteriological, histological, and scanning electron microscopy analyses. Notably, the efficacy of phage at mitigating soft tissue infection was equal to that of high dose fosfomycin. Future research may utilize this model as a platform for evaluation of therapeutic type and dose, and alternate delivery vehicles for osteomyelitis mitigation.

Wound Culture Utility in Negative Surgical Exploration for Necrotizing Soft Tissue Infection

Early surgical intervention decreases mortality in necrotizing soft tissue infections (NSTIs). Yet, a subset of patients will not have NSTIs (non-NSTIs) at the time of exploration. We hypothesized that NSTI and non-NSTI patients had similar causative organisms and that intraoperative wound cultures could help guide management. Culture results and outcomes were compared for all patients undergoing surgery for suspected NSTIs over a seven-year-period. Of 295 patients, 240 (81.4%) had NSTIs. Of the 55 non-NSTI patients (18.6%), 50 had cellulitis and 5 had abscesses. NSTI and non-NSTI patients had similar rates of bacteremia (20.4% vs 17.6%, P = 0.66), septic shock (15.9% vs 12.7%, P = 0.68), and mortality (10.4% vs 7.2%, P = 0.62). Wound cultures were collected more often in NSTI patients (229/240, 95.4%) than in non-NSTI patients (42/55, 76.4%, P < 0.01). Non-NSTI patients had positive deep wound cultures more than half of the time (23/42, 54.8%). The microbiologic profile was similar between groups, with Methicillin Resistant Staphylococcus aureus and Group A Streptococcus occurring with the same frequency. We advocate for deep wound cultures in all patients being evaluated operatively for NSTIs even if the exploration is considered negative because these patients have similar clinical characteristics and virulent microbiology, and culture results can help guide antimicrobial therapy.

Distinguishing bone and soft tissue infections mimicking sarcomas requires multimodal multidisciplinary team assessment

INTRODUCTION

The aims of this study were to report the presenting characteristics and identify how best to distinguish bone and soft-tissue infections that mimic sarcomas.

MATERIALS AND METHODS

A total of 238 (211 osteomyelitis and 27 soft-tissue infections) patients referred to a tertiary sarcoma multidisciplinary team with suspected sarcoma who were ultimately diagnosed with a bone or soft tissue infection were included. Data from a prospectively collated database was analysed retrospectively.

RESULTS

Of all possible bone and soft-tissue sarcoma referrals, a diagnosis of infection was made in 2.1% and 0.7%, respectively. Median age was 18 years in the osteomyelitis group and 46 years in the soft-tissue infection group. In the osteomyelitis group, the most common presenting features were pain (85.8%) and swelling (32.7%). In the soft-tissue infection group, the most common clinical features were swelling (96.3%) and pain (70.4%). Those in the soft-tissue group were more likely to have raised inflammatory markers. Radiological investigations were unable to discern between tumour or infection in 59.7% of osteomyelitis and 81.5% of soft-tissue infection cases. No organism was identified in 64.9% of those who had a percutaneous biopsy culture.

CONCLUSIONS

This study has highlighted that infection is frequently clinically indistinguishable from sarcoma and remains a principle non-neoplastic differential diagnosis. When patients are investigated for suspected sarcoma, infections can be missed due to falsely negative radiological investigations and percutaneous biopsy. As no single clinical, biochemical or radiological feature or investigation can be relied upon for diagnosis, clinicians should have a low threshold for tissue biopsy and discussion in a sarcoma multidisciplinary team meeting.

Necrotizing Myositis: A Rare Necrotizing Soft Tissue Infection Involving Muscle

INTRODUCTION

Necrotizing myositis (NM) is an extremely rare necrotizing soft tissue infection involving muscle. Unlike similar infections (eg, necrotizing fasciitis, clostridial myonecrosis) that can be more readily diagnosed, NM can have a benign presentation then rapidly progress into a life-threatening condition with a mortality rate of 100% without surgical intervention.

CASE REPORT

A 74-year-old man with a history of prostate cancer with radiation therapy, seed implants, and 2 transurethral resection procedures presented to the emergency department after a fall. He was initially diagnosed and treated for urosepsis. Sixteen hours after presentation, he complained of pain and swelling of his right groin. Computed tomography of the abdomen and pelvis showed gas findings suspicious for necrotizing infection of the bilateral thighs. Surgical exploration revealed NM. Separate cultures from the left thigh and bladder grew Streptococcus intermedius, Clostridium clostridioforme, and Peptostreptococcus, suggesting a possible common source of infection from the prostate gland or the osteomyelitic pubic symphysis, which subsequently spread to the bilateral thighs.

CONCLUSIONS

To the best of the authors' knowledge, this is the first reported case of S intermedius and C clostridioforme causing NM. A high index of suspicion is required for extremely rare conditions like NM, because early diagnosis and surgical intervention significantly reduce mortality.

Efficacy of Wound Coverage Techniques in Extremity Necrotizing Soft Tissue Infections

Little data exist about management of wounds created by debridement in necrotizing soft tissue infections (NSTIs). Multiple wound coverage techniques exist, including complete primary wound closure, split-thickness skin grafting, secondary intention, and flap creation. We hypothesized that all wound coverage techniques would be associated with high rates of successful wound coverage and low crossover rates to other wound coverage techniques. NSTIs over a three-year period were retrospectively reviewed. Both the initial and secondary wound coverage techniques (if necessary) were recorded. The primary outcome was the ability to achieve complete wound coverage. Overall, 46 patients with NSTIs had long-term data available. Of the patients undergoing split-thickness skin grafting as the initial wound coverage technique, 8/8 (100%) achieved complete wound coverage; and of those undergoing flap creation, 1/1 (100%) achieved complete wound coverage; and of those undergoing complete primary wound closure, 4/4 (100%) achieved complete wound coverage. Of the patients undergoing secondary intention as the initial wound coverage technique, 5/33 (15.2%) achieved complete wound coverage and 28/33 (84.8%) required a secondary wound coverage technique with split-thickness skin grafting. All 46 patients achieved long-term successful wound coverage. Time to wound coverage did not vary with initial wound coverage technique (P = 0.44). Split-thickness skin grafting, flap creation, complete primary wound closure, and secondary intention are all reasonable choices for initial wound coverage for NSTIs. Although secondary intention had a low success rate as an initial wound coverage technique, all patients ultimately achieved complete wound coverage without a significant increase in time to coverage.

Mycobacterial skin and soft tissue infections: TB or not TB?

Non-tuberculous mycobacteria are a known cause of skin and soft tissue infections. However, only too often it takes inordinately long to arrive at the appropriate diagnosis and start treatment. Actively searching for predilection factors, exposure risks and specific clinical clues may speed up the diagnostic process. Deep tissue biopsy cultures are indispensable to determine the species and strain of mycobacterium, with important consequences for treatment. Less well known as a causative agent of prolonged tenosynovitis is Mycobacterium tuberculosis. We present a case series and performed a literature search concerning mycobacterial tenosynovitis.

Surveillance of Extrapulmonary Nontuberculous Mycobacteria Infections, Oregon, USA, 2007-2012

Limited data are available describing extrapulmonary nontuberculous mycobacteria (NTM) infections in the general population. We describe results from statewide population-based laboratory surveillance in Oregon, USA, during 2007–2012. We defined a case of extrapulmonary NTM infection as >1 isolate from skin/soft tissue, disseminated sites, lymph node, joint, or other sites. The annual incidence of extrapulmonary NTM infection (other than Mycobacterium gordonae) was stable, averaging 1.5 cases/100,000 population. Median age of the 334 patients was 51 years, and 53% of patients were female. Half of cases were caused by M. avium complex, but rapid-growing NTM species accounted for one third of cases. Most extrapulmonary NTM infections are skin/soft tissue. Compared with pulmonary NTM infection, more extrapulmonary infections are caused by rapid-growing NTM species. the designation of NTM as a reportable disease in Oregon in 2014 will result in better detection of changes in the incidence and patterns of disease in the future.

A Fatal Case of Super-super Obesity (BMI >80) in a Patient with a Necrotic Soft Tissue Infection

A 35-year-old man (height, 169 cm; body weight, 240 kg; BMI, 84) visited the Department of Dermatology due to left leg pain and swelling. Focused enhanced computed tomography (CT) of the left leg ruled out complications of deep venous thrombosis. Surgical exploration of the left leg resulted in a diagnosis of necrotic soft tissue infection, but amputation was ruled out due to his weight. The patient ultimately died of multiple organ failure on the fourth day of hospitalization. A culture of the surgical material revealed Streptococcus dysgalactiae. The present case suggests that super-obese patients should be aggressively treated before lethal complications occur.

A Woman with a Necrotizing Soft-Tissue Infection

[Full article available at http://rimed.org/rimedicaljournal-2017-12.asp].

Virulence Inhibitors from Brazilian Peppertree Block Quorum Sensing and Abate Dermonecrosis in Skin Infection Models

Widespread antibiotic resistance is on the rise and current therapies are becoming increasingly limited in both scope and efficacy. Methicillin-resistant Staphylococcus aureus (MRSA) represents a major contributor to this trend. Quorum sensing controlled virulence factors include secreted toxins responsible for extensive damage to host tissues and evasion of the immune system response; they are major contributors to morbidity and mortality. Investigation of botanical folk medicines for wounds and infections led us to study Schinus terebinthifolia (Brazilian Peppertree) as a potential source of virulence inhibitors. Here, we report the inhibitory activity of a flavone rich extract "430D-F5" against all S. aureus accessory gene regulator (agr) alleles in the absence of growth inhibition. Evidence for this activity is supported by its agr-quenching activity (IC50 2-32 μg mL-1) in transcriptional reporters, direct protein outputs (α-hemolysin and δ-toxin), and an in vivo skin challenge model. Importantly, 430D-F5 was well tolerated by human keratinocytes in cell culture and mouse skin in vivo; it also demonstrated significant reduction in dermonecrosis following skin challenge with a virulent strain of MRSA. This study provides an explanation for the anti-infective activity of peppertree remedies and yields insight into the potential utility of non-biocide virulence inhibitors in treating skin infections.