Practice guidelines for the diagnosis and management of skin and soft-tissue infections

Ceftaroline Fosamil for the Empiric Treatment of Hospitalized Adults with cSSTI: An Economic Analysis from the Perspective of the Spanish National Health System

Purpose

Complicated skin and soft tissue infections (cSSTI) are associated with high healthcare resource use and costs. The emergency nature of cSSTI hospitalizations requires starting immediate empiric intravenous (IV) antibiotic treatment, making the appropriate choice of initial antibiotic therapy crucial.

Patients and Methods

The use of ceftaroline fosamil (CFT) as an alternative to other IV antibiotic therapies for the empiric treatment of hospitalized adults with cSSTI (vancomycin, linezolid, daptomycin, cloxacillin, tedizolid) was evaluated through cost consequences analysis. The model structure was a decision tree accounting for four different pathways: patients demonstrating early response (ER) either discharged early (with oral antibiotic) or remaining in hospital to continue the initial therapy; non-responders either remaining on the initial IV therapy or switching to a second-line antibiotic. The model perspective was the Spanish National Health System.

Results

CFT resulted in average percentage of patients discharged early (PDE) of 24.6% (CI 19.49–30.2%) with average total cost per patient of €6763 (€6268–€7219). Vancomycin, linezolid, daptomycin and tedizolid resulted in average PDE of 22% (17.34–27.09%), 26.4% (20.5–32.32%), 28.6% (22.08–35.79%) and 26.5% (20.39–33.25%), respectively, for a total cost per patient of €6,619 (€5,902–€6,929), €6,394 (€5,881–€6,904), €6,855 (€5,800–€7,410) and €7,173 (€6,608–€7,763), respectively. Key model drivers were ER and antibiotic treatment duration, with hospital costs accounting for over 83% of the total expenditures.

Conclusion

Given its clinical and safety profile, CFT is an acceptable choice for cSSTI empiric therapy providing comparable ER and costs to other relevant antibiotic options.

Necrotizing Soft Tissue Infection of the Upper Extremity as a Manifestation of Hansen’s Disease

Hansen’s disease is a well-described, largely historic infection that is caused by Mycobacterium leprae. Lucio's phenomenon is an aggressive, rare form of untreated lepromatous leprosy characterized by diffuse cutaneous lesions and systemic symptoms. To date, cases of necrotizing soft tissue infection in the setting of leprosy have rarely been reported in the literature. We present the case of a 51-year-old man with no known past medical history who presented for the evaluation of acute-on-chronic left upper extremity ulceration, soft tissue swelling, and pain. The patient was diagnosed with necrotizing soft tissue infection of the left upper extremity and underlying multibacillary lepromatous leprosy with Lucio's phenomenon. He underwent dermatofasciectomy of the affected extremity, followed by staged soft tissue coverage, including dermal allograft placement. Proper antibiotic management was also undertaken. In this article, we describe a case of previously undiagnosed leprosy with Lucio's phenomenon manifesting as necrotizing fasciitis of the upper extremity.

[Soft tissue infections]

Acute skin and soft tissue infections are among the most frequent infections in medicine. There is a broad spectrum including simple local infections as well as severe and life-threatening diseases. Along with Staphylococcus aureus, group A Streptococci are mainly responsible for these illnesses. The therapeutic approach ranges from antiseptic local treatments to administering systemic antibiotics or emergency surgery. Treating physicians often face challenges when presented with soft tissue infections due to a great discrepancy between the first impression of the disease compared to a possibly quick progression as well as the wide range of sometimes confusing historic terms and definitions being used in the English and German language, for instance pyoderma, erysipelas or phlegmon. A recently more popular collective term emphasized by clinical trials is "acute bacterial skin and skin structure infections" (ABSSSI).

Infectious diseases associated with pediatric type 1 diabetes mellitus: A narrative review

Diabetes mellitus (DM) has been frequently associated with an impaired immune response against infectious agents, making affected patients at risk for more severe disease and sometimes causing worse outcomes. The recent COVID-19 pandemic has seriously affected patients with both diabetes, in particular those carrying comorbidities or with poor glycemic control. As regards pediatric diabetes mellitus, the availability of more accurate and technological tools for glycemic management and the improved markers of metabolic control might mitigate the negative impact of infections. Notably, good metabolic control of diabetes since its diagnosis reduces not only the risk of microangiopathic complications but also of impaired immune response to infectious diseases. Therefore, vaccinations are strongly recommended. Our paper aims to provide the most updated evidence regarding infectious diseases in type 1 pediatric DM.

Comparison of LRINEC Scoring System with Finger Test and Histopathological Examination for Necrotizing Fasciitis

Background  Necrotizing fasciitis (NF) is a life-threatening condition requiring urgent attention. It is clinically difficult to diagnose, linked to severe systemic toxicity, and has poor prognosis. In 2001, Andreasen and coworkers described the "Finger test" for the diagnosis of NF. Subsequent studies have suggested early recognition and management of NF. In this study, we compare the LRINEC-Laboratory Risk Indicator for Necrotizing Fasciitis-scoring system with the "Finger test" and histopathological examination for diagnosis of NF. Results  In our study, LRINEC scoring system and Finger test are statistically significant in the diagnosis of NF. Males are more frequently affected, and the most common organism causing NF is Staphylococcus . Histopathology remained the gold standard for diagnosis of NF, while LRINEC score and Finger test were good diagnostic tools for early diagnosis, with sensitivities of 83.33 and 86.11%, respectively. Conclusion  LRINEC laboratory-based scoring system is easy and reliable diagnostic tool though histopathology remains the gold standard. There is statistically significant correlation between histopathology and laboratory criteria. LRINEC test is independently better than bedside Finger test alone or combined LRINEC and bedside Finger test.

T-lymphocyte subtyping: an early warning and a potential prognostic indicator of active cytomegalovirus infection in patients with sepsis

Cytomegalovirus (CMV) infection is very common in patients suffering from sepsis and may cause poor prognosis. To explore the relationship between immune status of patients with sepsis and CMV infection, we assessed T lymphocyte subtyping and other commonly used clinical parameters in patients with sepsis upon admission to the intensive care unit (ICU) and evaluated their potential impact on diagnosis and outcomes of active CMV infection. In our study, 82 of 599 patients with sepsis were diagnosed with active CMV infection. The 28-day mortality was higher in active CMV-infected than nonactive CMV-infected patients (20.7% versus 9.9%); 51of 82 active CMV-infected patients with sepsis were assessed to have CMV-DNA-negative conversion, while 31 were persistently positive for CMV DNA. Higher CD8⁺ CD28⁺ T-cell counts at presentation were associated with CMV-DNA-negative conversion and lower 28-day mortality. The CMV-DNA-negative conversion and 28-day mortality of active CMV-infected patients with sepsis could be predicted using cutoff values of 151 (74.5% sensitivity and 87.1% specificity) and 64.5 (52.9% sensitivity and 92.3% specificity) CD8⁺ CD28⁺ T cells mL^-1 at ICU admission, respectively. Higher CD8⁺ CD28⁺ T-cell count was significantly associated with active CMV infection, higher CMV-DNA-negative conversion and lower 28-day mortality, which may be a potential marker for early warning of active CMV infection and outcome prediction.

Necrotizing Soft-Tissue Infections After Hip Arthroplasty

Necrotizing soft-tissue infections are a rare complication following hip arthroplasty procedures. These rapidly spreading infections have a high mortality rate and must be diagnosed and treated in an expeditious manner. This article discusses the epidemiology, classification, diagnosis, and treatment of these conditions and describes 2 related case reports.

'We dry contaminated meat to make it safe': An assessment of knowledge, attitude and practices on anthrax during an outbreak, Kisumu, Kenya, 2019

Introduction

Anthrax is the highest-ranked priority zoonotic disease in Kenya with about ten human cases annually. Anthrax outbreak was reported in Kisumu East Sub County after some villagers slaughtered and ate beef from a cow suspected to have died of anthrax. We aimed at establishing the magnitude of the outbreak, described associated factors, and assessed community knowledge, attitude, and practices on anthrax.

Methods

We reviewed human and animal records, conducted case search and contact tracing using standard case definitions in the period from July 1through to July 28, 2019. A cross-sectional study was conducted to assess community knowledge, attitude, and practices towards anthrax. The household selection was done using multistage sampling. We cleaned and analyzed data in Ms. Excel and Epi Info. Descriptive statistics were carried out for continuous and categorical variables while analytical statistics for the association between dependent and independent variables were calculated.

Results

Out of 53 persons exposed through consumption or contact with suspicious beef, 23 cases (confirmed: 1, probable: 4, suspected: 18) were reviewed. The proportion of females was 52.17% (12/23), median age 13.5 years and range 45 years. The attack rate was 43.4% (23/53) and the case fatality rate was 4.35% (1/23). Knowledge level, determined by dividing those considered to be ‘having good knowledge’ on anthrax (numerator) by the total number of respondents (denominator) in the population regarding cause, transmission, symptoms and prevention was 51% for human anthrax and 52% for animal anthrax. Having good knowledge on anthrax was associated with rural residence [OR = 5.5 (95% CI 2.1–14.4; p<0.001)], having seen a case of anthrax [OR = 6.2 (95% CI 2.8–14.2; p<0.001)] and among those who present cattle for vaccination [OR = 2.6 (95% CI 1.2–5.6; p = 0.02)]. About 23.2% (26/112) would slaughter and sell beef to neighbors while 63.4% (71/112) would bury or burn the carcass. Nearly 93.8% (105/112) believed vaccination prevents anthrax. However, 5.4% (62/112) present livestock for vaccination.

Conclusion

Most anthrax exposures were through meat consumption. Poor knowledge of the disease might hamper prevention and control efforts.

Short Courses of Antibiotics Are Safe in Necrotizing Soft Tissue Infections

INTRODUCTION

Necrotizing soft tissue infections (NSTIs) carry high morbidity and mortality. While early aggressive surgical debridement is well-accepted treatment for NSTIs, the optimum duration of adjunct antibiotic therapy is unclear. An increasing focus on safety and evidence-based antimicrobial stewardship suggests a value in addressing this knowledge gap.

OBJECTIVE

To determine whether shorter antibiotic courses have similar outcomes compared to longer courses in patients with NSTI following adequate source control.

POPULATION

142 consecutive patients with surgically managed NSTI were identified on retrospective chart review between December 2014 and December 2018 at two academic medical centers.

RESULTS

Patients were predominately male (74%) with a median age of 52 and similar baseline characteristics. The median number of debridements to definitive source control was 2 (IQR 1-3) with the short course group undergoing a greater number of debridements control 2.57 ± 1.8 vs 1.9 ± 1.2, (P = .01). Of 142 patients, 34.5% received a short course and the remaining 65.5% received a longer course of antibiotics. There was no significant difference in the incidence of bacteremia or wound culture positivity between groups. There was also no significant difference in in-hospital mortality, 8% vs 6% (P = .74), incidence of C. difficile infection, median length of stay, or 30-day readmission.

CONCLUSION

Provided adequate surgical debridement, similar outcomes in morbidity and mortality suggest antibiotic courses of 7 days or less are equally safe compared to longer courses.

Diagnosis and treatment of the invasive extension of bacteria (cellulitis) from chronic wounds utilising point-of-care fluorescence imaging

Early diagnosis of wound‐related cellulitis is challenging as many classical signs and symptoms of infection (erythema, pain, tenderness, or fever) may be absent. In addition, other conditions (ie, chronic stasis dermatitis) may present with similar clinical findings. Point‐of‐care fluorescence imaging detects elevated bacterial burden in and around wounds with high sensitivity. This prospective observational study examined the impact of incorporating fluorescence imaging into standard care for diagnosis and management of wound‐related cellulitis. Two hundred thirty‐six patients visiting an outpatient wound care centre between January 2020 and April 2021 were included in this study. Patients underwent routine fluorescence scans for bacteria (range: 1‐48 scans/patient). Wound‐related cellulitis was diagnosed in 6.4% (15/236) of patients. In these patients, fluorescence scans showed an irregular pattern of red (bacterial) fluorescence extending beyond the wound bed and periwound that could not be removed through cleansing or debridement, indicating the invasive extension of bacteria (wound‐related cellulitis). Point‐of‐care identification facilitated rapid initiation of treatments (source control and antibiotics, when warranted) that resolved the fluorescence. No patients had worsening of cellulitis requiring intravenous antibiotics and/or hospitalisation. These findings demonstrate the utility of point‐of‐care fluorescence imaging for efficient detection and proactive, targeted management of wound‐related cellulitis.

Necrotizing Soft Tissue Infections, the Challenge Remains

Background: Necrotizing Soft Tissue Infections (NSTIs) are uncommon rapidly spreading infection of the soft tissues for which prompt surgical treatment is vital for survival. Currently, even with sufficient awareness and facilities available, ambiguous symptoms frequently result in treatment delay.

Objectives: To illustrate the heterogeneity in presentation of NSTIs and the pitfalls entailing from this heterogeneity.

Discussion: NSTI symptoms appear on a spectrum with on one side the typical critically ill patient with fast onset and progression of symptoms combined with severe systemic toxicity resulting in severe physical derangement and sepsis. In these cases, the suspicion of a NSTI rises quickly. On the other far side of the spectrum is the less evident type of presentation of the patient with gradual but slow progression of non-specific symptoms over the past couple of days without clear signs of sepsis initially. This side of the spectrum is under represented in current literature and some physicians involved in the care for NSTI patients are still unaware of this heterogeneity in presentation.

Conclusion: The presentation of a critically ill patient with evident pain out of proportion, erythema, necrotic skin and bullae is the classical presentation of NSTIs. On the other hand, non-specific symptoms without systemic toxicity at presentation frequently result in a battery of diagnostics tests and imaging before the treatment strategy is determined. This may result in a delay in presentation, delay in diagnosis and delay in definitive treatment. This failure to perform an adequate exploration expeditiously can result in a preventable mortality.

Management of Infectious Lymphadenitis in Children

Lymphadenopathy is an irregularity in the size and texture of the lymph nodes, which is quite common in childhood. When the enlargement of lymph nodes is caused by inflammatory and infectious processes, it is called lymphadenitis. The main objective of this manuscript is to summarize the common infectious etiologies and presentations of lymphadenitis in children providing a management guide for clinical practice. PubMed was used to search for all of the studies published up to April 2021 using keywords such as "lymphadenitis" and "children". Literature analysis showed that the differential diagnosis for lymphadenitis in pediatrics is broad. Although lymph node enlargement in children is usually benign and self-limited, it is important to exclude malignant etiology. In most cases, history and physical examination allow to identify the correct diagnosis and start a proper treatment with a prompt resolution of the lymphadenopathy. However, particularly in the case of persistent lymphadenitis, determining the cause of lymph node enlargement may be difficult, and the exact etiology may not be identified despite extensive investigations. Further studies should develop and validate an algorithm to assist pediatricians in the diagnosis and timely treatment of lymphadenitis, suggesting situations in which a watchful waiting may be considered a safe approach, those in which empiric antibiotic therapy should be administered, and those requiring a timely diagnostic work-up.

The Needle and the Damage Done: A Retrospective Review of the Health Impact of Recreational Intravenous Drug Use and the Collateral Consequences for Vascular Surgery

BACKGROUND

The UK has one of the highest rates of recreational drug use and consequent deaths in Europe. Scotland is the "Drug deaths capital of Europe." Intravenous drug use can result in limb- and life-threatening pathology. This study aimed to characterise limb-related admissions associated with intravenous drug use, outcomes and healthcare expenditure.

METHODS

Retrospective data collection between December 2011 and August 2018. Patients were identified through discharge codes. Admission details were extracted from electronic records and a database compiled. Statistical analyses were performed using Statistical Package for the Social Science, P < 0.05 denoted significance.

RESULTS

There were 558 admissions for 330 patients (1-9 admissions/patient), mean age 37 years (+/-7.6 SD) and 196 (59.2%; 319 admissions, 57.2%) were male. Three hundred forty-eight (62.4%) admissions were to surgical specialties, predominantly Vascular Surgery (247). Including onward referrals, Vascular ultimately managed 54.8% of admissions. Patients presented with multiple pathologies: 249 groin abscesses; 38 other abscesses; 74 pseudoaneurysms; 102 necrotising soft tissue infections (NSTI); 85 cellulitis; 138 deep venous thrombosis (DVTs); 28 infected DVTs and 70 other diagnoses. Two hundred and seventy-seven admissions (220 patients) required operations, with 361 procedures performed (1-7 operations/admission). There were 24 major limb amputations and 74 arterial ligations. Eleven amputations were due to NSTI and 13 followed ligation (17.6% of ligations). During follow-up 50 (15.2%) patients died, of which 6 (12%) had amputations (OR 3.2, 95% CI 1.04-9.61, P = 0.043). Cumulative cost of acute care was £4,783,241.

CONCLUSIONS

Limb-related sequalae of intravenous drug use represents a substantial surgical workload, especially for Vascular. These are complex, high-risk patients with poor outcomes and high healthcare costs.

Patterns of antibiotic nonsusceptibility among invasive group A Streptococcus infections-United States, 2006-2017

BACKGROUND

Treatment of severe group A streptococcal infections requires timely and appropriate antibiotic therapy. We describe the epidemiology of antimicrobial-resistant invasive group A streptococcal (iGAS) infections in the U.S.

METHODS

We analyzed population-based iGAS surveillance data at 10 U.S. sites from 2006-2017. Cases were defined as infection with GAS isolated from normally sterile sites or wounds in patients with necrotizing fasciitis or streptococcal toxic shock syndrome. GAS isolates were emm typed. Antimicrobial susceptibility was determined using broth microdilution or whole genome sequencing. We compared characteristics among patients infected with erythromycin nonsusceptible (EryNS) and clindamycin nonsusceptible (CliNS) strains to those with susceptible infections. We analyzed proportions of EryNS and CliNS among isolates by site, year, risk factors and emm type.

RESULTS

Overall, 17,179 iGAS cases were reported; 14.5% were EryNS. Among isolates tested for both inducible and constitutive CliNS (2011-2017), 14.6% were CliNS. Most (99.8%) CliNS isolates were EryNS. Resistance was highest in 2017 (EryNS: 22.8%; CliNS: 22.0%). All isolates were susceptible to beta-lactams. EryNS and CliNS infections were most frequent among persons aged 18-34 years and in persons residing in long-term care facilities, experiencing homelessness, incarcerated, or who injected drugs. Patterns varied by site. Patients with nonsusceptible infections were significantly less likely to die. Emm types with >30% EryNS or CliNS included: 77, 58, 11, 83, 92.

CONCLUSION

Increasing prevalence of EryNS and CliNS iGAS infections in the U.S. is predominantly due to expansion of several emm types. Clinicians should consider local resistance patterns when treating iGAS infections.

Recent advances in gold nanoparticle-based lateral flow immunoassay for the detection of bacterial infection

Diagnosis of bacterial infections (BI) is becoming an increasingly difficult task in clinical practice due to their high prevalence and frequency, as well as the growth of antibiotic resistance worldwide. World Health Organization (WHO) reported antibiotic resistance is a major public health problem. BI becomes difficult or impossible to treat when the bacteria acquire immunity against antibiotics. Thus, there is a need for a quick and accurate technique to detect infection. Lateral flow immunoassay (LFIA) is an ideal technique for point-of-care testing of a disease or pathological changes inside the human body. In recent years, several LFIA based strips are being used for the detection of BI by targeting specific analytes which may range from the causative bacterium, whole-cell, DNA, or biomarker. Numerous nanoparticles like lipid-based nanoparticles, polymeric nanoparticles, and inorganic nanoparticles such as quantum dots, magnetic, ceramic, and metallic nanoparticles (copper, silver gold, iron) are widely being used in the advanced treatment of BI. Out of these gold nanoparticle (AuNPs), is being used for detection BI more effectively than other nanoparticles due to their surface functionalization, extraordinary chemical stability, biorecognition, and signal amplification properties and help to improve in conjugation with capture antibodies, and act as a color marker with unique optical properties on LFIA strips. Herein, a review that provides an overview of the principle of LFIA, how LFIA based strip is developed, and how it is helpful to detect a specific biomarker for bedside detection of the BI.

A Randomized Controlled Trial of an Electronic Clinical Decision Support Tool for Inpatient Antimicrobial Stewardship

BACKGROUND

The weighted incidence syndromic combination antibiogram (WISCA) is an antimicrobial stewardship tool that utilizes electronic medical record data to provide real-time clinical decision support regarding empiric antibiotic prescription in the hospital setting. The aim of this study was to determine the impact of WISCA utilization for empiric antibiotic prescription on hospital length of stay (LOS).

METHODS

We performed a crossover randomized controlled trial of the WISCA tool at 4 hospitals. Study participants included adult inpatients receiving empiric antibiotics for urinary tract infection (UTI), abdominal-biliary infection (ABI), pneumonia, or nonpurulent cellulitis. Antimicrobial stewardship (ASP) physicians utilized WISCA and clinical guidelines to provide empiric antibiotic recommendations. The primary outcome was LOS. Secondary outcomes included 30-day mortality, 30-day readmission, Clostridioides difficile infection, acquisition of multidrug-resistant gram-negative organism (MDRO), and antibiotics costs.

RESULTS

In total, 6849 participants enrolled in the study. There were no overall differences in outcomes among the intervention versus control groups. Participants with cellulitis in the intervention group had significantly shorter mean LOS compared to participants with cellulitis in the control group (coefficient estimate = 0.53 [-0.97, -0.09], P = .0186). For patients with community acquired pneumonia (CAP), the intervention group had significantly lower odds of 30-day mortality compared to the control group (adjusted odds ratio [aOR] .58, 95% confidence interval [CI], .396, .854, P = .02).

CONCLUSIONS

Use of WISCA was not associated with improved outcomes for UTI and ABI. Guidelines-based interventions were associated with decreased LOS for cellulitis and decreased mortality for CAP.

Unravelling the Impact of Pneumococcal Conjugate Vaccines on Ambulatory Antibiotic Drug Consumption in Young Children: An Interrupted Time Series Analysis

BACKGROUND

Pneumococcal conjugate vaccines (PCVs) reduce respiratory infections in young children, the main antibiotic consumers. Following PCV implementation, dispensed antibiotic prescription (DAP) rates in young children were expected to decline.

METHODS

Computerized data on DAP for children <5 years were examined during a 13-year period (including 4 pre-PCV years). All DAPs from clinics with ≥50 insured children, active both pre- and post-PCV implementation were included. Interrupted time series with segmented regression was applied to analyze monthly DAP rate trends, adjusted for age, ethnicity and season. Incidence rate ratios (IRR) DAPs during late PCV13 period vs. 4 years pre-PCV were calculated both as absolute rate ratios (aIRR) and relative to expected rates (rIRR).

RESULTS

Of 1,090,870 DAPs, 57% were in children <2 years. All-DAP rates peaked in the cold season. Post-PCV7/PCV13 implementation, all DAP-rates abruptly and significantly declined, reaching a plateau within 5 years. This was largely driven by amoxicillin/amoxicillin-clavulanate (75% of DAPs). Age <2 years and Bedouin ethnicity were significantly associated with higher pre-PCV DAP rates but with faster and greater decline post-PCV, achieving near elimination of gaps between ages and ethnic groups. Overall reduction (and 95% CIs) in DAP rates per 1,000 was estimated between aIRR value (344.7 [370.9-358.4]) and rIRR value (110.4 [96.9-123.7]).

CONCLUSIONS

Shortly following PCV implementation, overall DAP rates showed an abrupt and steep decline, stabilizing within 5 years, in parallel to post-PCV respiratory infection trends previously described in this population, suggesting causality. The variable patterns of certain drug categories suggest additional influences beyond PCV.

Afferent Lymphatic Transport and Peripheral Tissue Immunity

Lymphatic vessels provide an anatomical framework for immune surveillance and adaptive immune responses. Although appreciated as the route for Ag and dendritic cell transport, peripheral lymphatic vessels are often not considered active players in immune surveillance. Lymphatic vessels, however, integrate contextual cues that directly regulate transport, including changes in intrinsic pumping and capillary remodeling, and express a dynamic repertoire of inflammatory chemokines and adhesion molecules that facilitates leukocyte egress out of inflamed tissue. These mechanisms together contribute to the course of peripheral tissue immunity. In this review, we focus on context-dependent mechanisms that regulate fluid and cellular transport out of peripheral nonlymphoid tissues to provide a framework for understanding the effects of afferent lymphatic transport on immune surveillance, peripheral tissue inflammation, and adaptive immunity.

The Autocatalytic Cleavage Domain Is Not Required for the Activity of ScpC, a Virulence Protease from Streptococcus pyogenes: A Structural Insight

Group A Streptococcus (GAS, or Streptococcus pyogenes) is a leading human bacterial pathogen with diverse clinical manifestations, ranging from mild to life-threatening and to severe immune sequela. These diseases, combined, account for more than half a million deaths per year, globally. To accomplish its vast pathogenic potential, GAS expresses a multitude of virulent proteins, including the pivotal virulence factor ScpC. ScpC is a narrow-range surface-exposed subtilisin-like serine protease that cleaves the last 14 C-terminal amino acids of interleukin 8 (IL-8 or CXCL8) and impairs essential IL-8 signaling processes. As a result, neutrophil migration, bacterial killing, and the formation of neutrophil extracellular traps are strongly impaired. Also, ScpC has been identified as a potential vaccine candidate. ScpC undergoes an autocatalytic cleavage between Gln244 and Ser245, resulting in two polypeptide chains that assemble together forming the active protease. Previously, we reported that the region harboring the autocatalytic cleavage site, stretching from Gln213 to Asp272, is completely disordered. Here, we show that a deletion mutant (ScpC_Δ60) of this region forms a single polypeptide chain, whose crystal structure we determined at 2.9 Å resolution. Moreover, we show that ScpC_Δ60 is an active protease capable of cleaving its substrate IL-8 in a manner comparable to that of the wild type. These studies improve our understanding of the proteolytic activity of ScpC.

Necrotizing fasciitis secondary to lake water inoculation with Aeromonas sobria: A case report

RATIONALE

Necrotizing fasciitis (NF) is a rapidly progressing bacterial soft tissue infection with a high mortality rate. It is characterized by significant soft tissue destruction with associated sepsis. The mainstay of treatment is coverage with appropriate broad-spectrum antibiotic therapy and emergent surgical debridement.

PATIENT CONCERNS

A previously healthy 66-year-old female presented with a deep laceration to her right, posterior calf with subsequent contamination with lake water. After the wound was irrigated and closed, the patient developed NF.

DIAGNOSIS

Laceration of the right lower extremity complicated by NF secondary to Aeromonas sobria.

INTERVENTIONS

The patient underwent emergent surgical debridements with intravenous broad-spectrum antibiotics and negative pressure wound therapy. The lower extremity was reconstructed with split-thickness skin grafts.

OUTCOMES

The patient's initial penetrating trauma was closed in the emergency room, and the patient was discharged home with antibiotics. She returned the next day with unstable vitals and was admitted to the intensive care unit. Her condition continued to deteriorate, and she underwent serial surgical debridements. Her condition improved and was discharged home after 13 days in the hospital.

LESSONS LEARNED

Close monitoring for NF is important for tissue infections sustained in aquatic environments. Timely identification and surgical management of NF increases overall survival.

Occupational Skin Disease in Physicians: A Review of the Literature

OBJECTIVES

Occupational skin disease (OSD) arises from work-related activity. However, there is a paucity of literature on OSD in physicians. The aim of the this review was therefore to examine and summarize what types of symptomatic OSD physicians experience.

METHODS

We conducted a systematic literature search on Cochrane Library, Embase, and Pubmed.

RESULTS

Contact dermatitis from formaldehyde and glutaraldehyde were found in 11.5 and 13.5% of cases, respectively. In total 2.4-14.9% had latex allergy. The reported standardized incidence ratio of squamous cell carcinoma and melanoma was up to 2.15 [95% confidence interval (CI) 1.57-1.95] and 3.2 (95% CI 1.38-6.31). Transmission of human papilloma virus (HPV) particles during carbon dioxide laser wart ablation were found in 70% of samples collected from protective gloves and in 52% of samples from vapors.

CONCLUSIONS

The most frequently reported OSD in physicians is contact dermatitis from allergens in disinfectants and rubber gloves. There is also a risk of cutaneous reactions to latex. The incidence of skin cancer was higher in physicians than in the general population, and the reason for this remains unexplained and potentially biased. There are no reports of transmission of patient HPV to surgeons during wart ablation, possibly because of proper use of protective equipment.

Dynamic Changes in Microbial Composition During Necrotizing Soft-Tissue Infections in ICU Patients

Introduction: Recent studies described the threat of emerging multidrug-resistant (MDR) bacteria in intensive care unit (ICU) patients, but few data are available for necrotizing skin and soft tissue infections (NSTI). In a cohort of ICU patients admitted for NSTI, we describe the dynamic changes of microbial population during repeated surgeries.

Materials and Methods: This retrospective study compiled consecutive cases admitted for the management of severe NSTI. Clinical characteristics, NSTI features, morbidity and mortality data were collected. The microbiological characteristics of surgical samples obtained during initial surgery were compared with those obtained during the first reoperation, including persistence of initial pathogens and/or emergence of microorganisms. Risk factors for emergence of microorganisms and MDR bacteria were assessed by univariable and multivariable analyses.

Results: Among 100 patients {63% male, 58 years old [interquartile ratio (IQR) 50–68]} admitted for NSTI, 54 underwent reoperation with a median [IQR] delay of 3 (1–7) days. Decreased proportions of susceptible strains and emergence of Gram-negative bacteria, including Pseudomonas aeruginosa, staphylococci and enterococci strains, were reported based on the cultures of surgical specimen collected on reoperation. On reoperation, 22 (27%) of the isolated strains were MDR (p < 0.0001 vs. MDR bacteria cultured from the first samples). Broad-spectrum antibiotic therapy as first-line therapy was significantly associated with a decreased emergence of microorganisms. Adequate antibiotic therapy from the initial surgery did not modify the frequency of emergence of microorganisms (p = 0.79) and MDR bacteria (p = 1.0) or the 1-year survival rate.

Conclusion: The emergence of microorganisms, including MDR bacteria, is frequently noted in NSTI without affecting mortality.

The Clinical Utility of Maceration Dressings in the Treatment of Inpatient Hand Infections: An Evaluation of Treatment Outcomes Compared to Standard Care

Background: In cases of oral antibiotic-resistant infection of the hand, we propose utilizing a heated, moist maceration dressing to help shorten and simplify the in-hospital clinical course by increasing the efficacy of antibiotic deliverance to infection sites, increasing the success of nonoperative management, and decreasing eradication time of infection of the hand. Methods: Fifty-six patients older than 18 years of age who presented with hand infections requiring inpatient intravenous antibiotics at our suburban academic hospital over a 30-month period were included and randomly assigned to either the maceration dressing group or the standard treatment group. Maceration dressings included warm and moist gauze, kerlix, webril, Orthoglass, Aqua K Pad, and sling. Results: Fifty-two patients who were mostly male and younger than 60 years of age were included. Patients who used the maceration dressing had significantly shorter hospital lengths of stay (P = .02) and intravenous antibiotics duration before transition to oral antibiotics (P = .04), and decreased need for formal operating room irrigation and debridement to obtain source control (P = .02) compared to patients treated with the standard dressing. Post-hoc analysis yielded improved outcomes when using the maceration dressing regardless of whether initial bedside incision and drainage was needed to decompress a superficial abscess or not. Conclusion: The maceration dressing can be used along with proper intravenous antibiotic treatment to improve the treatment course of patients with hand infections regardless of whether the patient needs an initial bedside incision and drainage or not. Level of Evidence: Therapeutic Level II.

Surgical Infection Society 2020 Updated Guidelines on the Management of Complicated Skin and Soft Tissue Infections

Background: The Surgical Infection Society (SIS) Guidelines for the treatment of complicated skin and soft tissue infections (SSTIs) were published in October 2009 in Surgical Infections. The purpose of this project was to provide a succinct update on the earlier guidelines based on an additional decade of data. Methods: We reviewed the previous guidelines eliminating bite wounds and diabetic foot infections including their associated references. Relevant articles on the topic of complicated SSTIs from 2008-2020 were reviewed and graded individually. Comparisons were then made between the old and the new graded recommendations with review of the older references by two authors when there was disparity between the grades. Results: The majority of new studies addressed antimicrobial options and duration of therapy particularly in complicated abscesses. There were fewer updated studies on diagnosis and specific operative interventions. Many of the topics addressed in the original guidelines had no new literature to evaluate. Conclusions: Most recommendations remain unchanged from the original guidelines with the exception of increased support for adjuvant antimicrobial therapy after drainage of complex abscess and increased data for the use of alternative antimicrobial agents.

Essential oil combinations against Clostridium perfringens and Clostridium septicum - the causative agents of gas gangrene

AIMS

The inhibitory and bactericidal effect of a wide range of essential oils, and their selected combinations against two pathogens (Clostridium perfringens and Clostridium septicum), the causative pathogens of gas gangrenous infections were investigated. Fractional inhibitory indices were also calculated to determine the interactions.

METHODS AND RESULTS

The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays were used to determine the efficacy of the essential oils. Santalum austrocaledonicum demonstrated the highest activity inhibiting both Clostridial pathogens at the lowest concentration of 0·02 mg ml^-1 . Santalum austrocaledonicum combined with Cymbopogon martinii had the strongest inhibition against C. perfringens (MIC 0·02 mg ml^-1 ) and C. septicum (MIC 0·01 mg ml^-1 ). Selected combinations demonstrated synergy (ΣFIC ≤ 0·50) in combination against both pathogens tested. Antagonism was also observed in many combinations.

CONCLUSIONS

Selected essential oils, when studied either individually or in combination, have high inhibitory and bactericidal effects against both Clostridial strains. Nine combinations have proven to be synergistic with 23 combinations additive; 96 indifferent and 77 having an antagonistic effect against the pathogenic strains. Some combinations demonstrated extreme antagonism and as such, careful consideration needs to be given to essential oil selection against these pathogens.

SIGNIFICANT IMPACT OF THE STUDY

Very few essential oils have been antimicrobially screened (MIC and MBC) against Clostridial strains and furthermore, the efficacies in combination are not known.

Epidemiology, Disposition, and Treatment of Ambulatory Veterans With Skin and Soft Tissue Infections

BACKGROUND

Most skin and soft tissue infections (SSTIs) are managed in the outpatient setting, but data are lacking on treatment patterns outside the emergency department (ED). Available data suggest that there is poor adherence to SSTI treatment guidelines.

METHODS

We conducted a retrospective cohort study of Veterans diagnosed with SSTIs in the ED or outpatient clinics from 1 January 2005 through 30 June 2018. The incidence of SSTIs over time was modeled using Poisson regression using robust standard errors. Antibiotic selection and incision and drainage (I&D) were described and compared between ambulatory settings. Anti-methicillin-resistant Staphylococcus aureus (MRSA) antibiotic use was compared to SSTI treatment guidelines.

RESULTS

There were 1 740 992 incident SSTIs in 1 156 725 patients during the study period. The incidence of SSTIs significantly decreased from 4.58 per 1000 patient-years in 2005 to 3.27 per 1000 patient-years in 2018 (P < .001). There were lower rates of β-lactam prescribing (32.5% vs 51.7%) in the ED compared to primary care (PC), and higher rates of anti-MRSA therapy (51.4% vs 35.1%) in the ED compared to PC. The I&D rate in the ED was 8.1% compared to 2.6% in PC. Antibiotic regimens without MRSA activity were prescribed in 24.9% of purulent SSTIs. Anti-MRSA antibiotics were prescribed in 40.1% of nonpurulent SSTIs.

CONCLUSIONS

We found a decrease in the incidence of SSTIs in the outpatient setting over time. Treatment of SSTIs varied depending on the presenting ambulatory location. There is poor adherence to guidelines in regard to use of anti-MRSA therapies. Further study is needed to understand the impact of guideline nonadherence on patient outcomes.

Association of cfDNA levels and bothrops envenomation

In the Amazon, around 90% of snakebites are caused by the Bothrops genus. Complications arising from Bothrops envenomations result from the inflammatory and coagulotoxic activities of the venom. The aim of this study was to investigate the potential of cell-free DNA (cfDNA) as a biomarker of severity in Bothrops snakebites. Patients were treated at the Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, in the Brazilian Amazon. cfDNA plasma levels were measured by amplifying the human telomerase reverse transcriptase (hTERT) sequence using quantitative RT-PCR. Median levels of cfDNA were compared between envenomed and healthy volunteers and among patients presenting different complications, such as renal failure, bleeding and infection. Of the 76 patients included, 82.9% were male, with a mean age of 32.8 years, and envenomations were mainly classified as severe (39.5%). ROC curve analysis showed a good accuracy of cfDNA levels (AUROC of 0.745) in envenomation diagnosis. A correlation analysis using laboratory variables showed positive correlation with lactate dehydrogenase (p = 0.033) and platelet count (p = 0.003). When cfDNA levels were compared with clinical complications, significant statistical differences were only found among individuals with mild and severe pain (p < 0.05). In summary, our results demonstrated that cfDNA levels are sufficiently accurate for discriminating between envenomed and non-envenomed patients, but are not able to distinguish different complications and the level of severity among envenomed patients. Thus, the role of cfDNA in the pathogenesis of the snakebite envenomations needs to be further investigated.

Predictive ability of LRINEC score in the prediction of limb loss and mortality in diabetic foot infection

It was aimed to analyze the effectiveness of the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score in predicting amputation and mortality in diabetic foot infection (DFI). Data of 416 patients who were hospitalized for DFI were recorded retrospectively. LRINEC scores were calculated for each patient from laboratory data. The diagnostic performance of LRINEC score was investigated in amputated/nonamputated and survived/deceased patient groups. Median LRINEC score of patients who underwent amputation was higher than those without amputation (P < 0.001). The area under the curve (AUC) value for LRINEC score was 0.638 with the cut-off point of ≥5 in predicting amputation. Median LRINEC score of deceased patients was higher than those who survived (P= 0.022). AUC value for LRINEC score was 0.663 with the cut-off point of ≥7 in predicting mortality. LRINEC score may be a promising scoring system in predicting both amputation and mortality in DFI.

Intolerable Burden of Impetigo in Endemic Settings: A Review of the Current State of Play and Future Directions for Alternative Treatments

Impetigo (school sores) is a common superficial bacterial skin infection affecting around 162 million children worldwide, with the highest burden in Australian Aboriginal children. While impetigo itself is treatable, if left untreated, it can lead to life-threatening conditions, such as chronic heart and kidney diseases. Topical antibiotics are often considered the treatment of choice for impetigo, but the clinical efficacy of these treatments is declining at an alarming rate due to the rapid emergence and spread of resistant bacteria. In remote settings in Australia, topical antibiotics are no longer used for impetigo due to the troubling rise of antimicrobial resistance, demanding the use of oral and injectable antibiotic therapies. However, widespread use of these agents not only contributes to existing resistance, but also associated with adverse consequences for individuals and communities. These underscore the urgent need to reinvigorate the antibiotic discovery and alternative impetigo therapies in these settings. This review discusses the current impetigo treatment challenges in endemic settings in Australia and explores potential alternative antimicrobial therapies. The goals are to promote intensified research programs to facilitate effective use of currently available treatments, as well as developing new alternatives for impetigo.

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.

Recommendations for Improving Antimicrobial Stewardship in Long-Term Care Settings Through Collaboration

Antimicrobial stewardship is a collaborative venture and antimicrobial stewardship in long-term care (LTC) settings is no exception. There are many barriers to implementing effective antimicrobial stewardship programs in LTC settings, including constrained financial resources, limited access to physicians and pharmacists with antimicrobial stewardship training, minimal on-site infectious syndrome diagnostics and laboratory expertise, and high rates of staff turnover. This article suggests that collaboration at the level of health care facilities and systems, with public health departments, with laboratory partners, and among personnel, including nursing staff, prescribers, and pharmacists, can lead to effective antimicrobial stewardship programs in LTC settings.

Pediatric necrotizing soft tissue infection after elective surgery: A case report and literature review

INTRODUCTION

Necrotizing soft tissue infections (NSTIs) are rare but often lethal. Early diagnosis and aggressive surgical debridement are essential to achieve the best possible outcome.

CASE PRESENTATION

A 12-year old boy was diagnosed with a necrotizing soft tissue infection following elective revision surgery for functional impairment resulting from scar tissue of the neck. Fever and inflammation of the surgical wound manifested 24-36 hours postoperatively. Antibiotic therapy with amoxicillin-clavulanic acid was initiated, but the patient was unresponsive. Ultrasonography, a wound culture and surgical exploration confirmed the diagnosis. The culture was positive for a Streptococcus pyogenes infection and antibiotic treatment was switched to penicillin and clindamycin. Following the diagnosis, surgical debridement was performed subcutaneously, and only necrotic tissue was removed to preserve as much skin tissue as possible. After eradication of the infection, vacuum-assisted closure of the wound was used to close the subcutaneous space. The patient was discharged after 40 days.

CONCLUSION

In this patient, we treated a necrotizing soft tissue infection with antibiotics, skin sparing surgeries and negative pressure wound therapy (NPWT). We used ultrasonography as imaging technique to help with the diagnosis. The extensiveness of surgical debridement was rather limited. We focused on opening all affected fascial layers. The surgical debridement was subcutaneous, and only necrotic tissue was removed. Because of the location in the neck, we tried to avoid an aggressive skin debridement to preserve as much skin tissue as possible. Negative pressure wound therapy is not frequently used in this context but it contributed to an enhanced wound healing. Ultrasonography for diagnosing NSTIs is useful, but the clinical findings and an explorative surgery will remain most important.

Getting it Right the First Time: Frozen Sections for Diagnosing Necrotizing Soft Tissue Infections

Background

The aim of this study was to investigate which histopathologic findings are most indicative for necrotizing soft tissue infections (NSTIs) in ambivalent cases.

Methods

Patients undergoing surgical exploration for suspected NSTIs with obtainment of incisional biopsies for histopathological assessment were included from January 2013 until August 2019. The frozen sections and formalin-fixed paraffin-embedded (FFPE) samples were retrospectively re-assessed. The primary outcome was the discharge diagnosis.

Results

Twenty-seven (69%) biopsies of the 39 included samples were from patients with NSTIs. Microscopic bullae (p = 0.043), severe fascial inflammation (p < 0.001) and fascial necrosis (p < 0.001) were significantly more often present in the NSTI group compared to the non-NSTI group. Muscle edema (n = 5), severe muscle inflammation (n = 5), muscle necrosis (n = 8), thrombosis (n = 10) and vasculitis (n = 5) were most frequently only seen in the NSTI group. In thirteen tissues samples, there were some discrepancies between the severity of findings in the frozen section and the FFPE samples. None of these discrepancies resulted in a different diagnosis or treatment strategy.

Conclusion

Microscopic bullae, severe fascial or muscle inflammation, fascial or muscle necrosis, muscle edema, thrombosis and vasculitis upon histopathological evaluation all indicate a high probability of a NSTI. At our institution, diagnosing NSTIs is aided by using intra-operative frozen section as part of triple diagnostics in ambivalent cases. Based on the relation between histopathologic findings and final presence of NSTI, we recommend frozen section for diagnosing NSTIs in ambivalent cases.

Pitfalls of Breast Evaluation in the Emergency Department

Breast complaints in the emergency department (ED) include trauma, infection, pain, masses, and nipple discharge. Breast cancer mimics other inflammatory conditions such as mastitis and abscess. Differentiating infectious processes versus cancer can become problematic when no imaging is used. While mammogram is included in the initial imaging for outpatient breast evaluation, ultrasound is more available in the ED. We present a case of a patient seen in the ED for breast pain and mass. The patient had no imaging done, yet the ED physician attempted to drain the mass unsuccessfully and prescribed antibiotics. The patient followed up at a breast center where clinical Stage IIA right breast invasive ductal carcinoma (IDC) was diagnosed. This case highlights the importance of breast imaging before drainage for suspected abscess and the importance of follow-up for all breast complaints that present in the ED to rule out a malignancy.

Rare case of extensive streptococcal myositis

A rare case of extensive streptococcal myositis is reported. A 46-year-old man was admitted following acute swollen right elbow joint associated with localised pain, erythema and hypoaesthesia. Multiple tense blisters subsequently developed around the affected elbow joint extending to the axilla. He was treated for suspected soft tissue infection and septic arthritis. Blood test investigations demonstrated raised creatine kinase (894 U/L) and inflammatory markers (white cell count 21.1×10⁹/L; C reactive protein 370 mg/L). Emergency CT scan reported extensive myositis affecting the triceps, latissimus dorsi and pectoralis major muscle with no fascial involvement. He was escalated to intensive care unit and treated for infectious myositis. Further investigation revealed positive streptococcal antibody (anti-streptodornase B titre >1600 U/mL). He was managed conservatively with microbiologist specialist input and supportive care. The patient made good recovery after receiving 10 days of intravenous antibiotics and subsequently switched to oral antibiotics. He was discharged on day 30 of admission after receiving intensive inpatient physiotherapy.

Challenges in Tracking and Reporting Antibiotic Use in Long-Term Care

The contemporary long-term care provider and interdisciplinary team are well aware of the recent focus on antibiotic use in their settings. Regulatory changes implemented by Centers for Medicare and Medicaid Services beginning in 2016 have required long-term care settings to look at antibiotic use in a more comprehensive way and to align their programs with the Centers for Disease Control and Prevention's Core Elements for Antibiotic Stewardship for Nursing Homes. As long-term care settings have worked to develop antibiotic stewardship programs over the past several years, there have been many discoveries about the processes involved in gathering data about antibiotic use and associated attributes, including dose, duration of therapy, and indication for use. Attempts to align these attributes with appropriateness may require integration of data elements from pharmacy records and the individual resident's electronic medical record. In this article, we systematically discuss relevant antibiotic use metrics, sources of antibiotic use data, collecting and reporting antibiotic use data, concluding with implications for policy, practice, and research. Only by measuring antibiotic use can we start to assess the effectiveness of antibiotic stewardship program to induce meaningful change in the care of residents in long-term care.

Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) randomised clinical trial: study protocol

INTRODUCTION

Bloodstream infections are a leading cause of mortality and morbidity; the duration of treatment for these infections is understudied.

METHODS AND ANALYSIS

We will conduct an international, multicentre randomised clinical trial of shorter (7 days) versus longer (14 days) antibiotic treatment among hospitalised patients with bloodstream infections. The trial will include 3626 patients across 60 hospitals and 6 countries. We will include patients with blood cultures confirming a pathogenic bacterium after hospital admission. Exclusion criteria will include patient factors (severe immunosuppression), infection site factors (endocarditis, osteomyelitis, undrained abscesses, infected prosthetic material) and pathogen factors (Staphylococcus aureus, Staphylococcus lugdunensis, Candida and contaminant organisms). We will leave the selection of specific antibiotics, doses and route of delivery to the discretion of treating physicians; no placebo control will be used given the diversity of pathogens and sources of bacteraemia. The intervention will be assignment of treatment duration to be 7 versus 14 days. We will minimise selection bias via central randomisation with variable block sizes, with concealed allocation until day 7 of adequate antibiotic treatment. The primary outcome is 90-day survival; we will test whether 7 days is non-inferior to 14 days of treatment, with a non-inferiority margin of 4% absolute mortality. Secondary outcomes include hospital and intensive care unit (ICU) mortality, relapse rates of bacteraemia, hospital and ICU length of stay, mechanical ventilation and vasopressor duration, antibiotic-free days, Clostridium difficile infection, antibiotic allergy and adverse events and colonisation/infection with antibiotic-resistant organisms.

ETHICS AND DISSEMINATION

The study has been approved by the ethics review board at each participating site. Sunnybrook Health Sciences Centre is the central ethics committee. We will disseminate study results via the Canadian Critical Care Trials Group and other collaborating networks to set the global paradigm for antibiotic treatment duration for non-staphylococcal Gram-positive, Gram-negative and anaerobic bacteraemia, among patients admitted to hospital.

TRIAL REGISTRATION NUMBER

The BALANCE (Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness) trial was registered at www.clinicaltrials.gov (registration number: NCT03005145).

Emerging erythromycin and clindamycin resistance in group A streptococci: Efficacy of linezolid and tedizolid in experimental necrotizing infection

OBJECTIVES

Clindamycin (CLI) and erythromycin (ERY) resistance is increasing among group A streptococci (GAS) causing invasive disease and alternative treatments are urgently required. In this study, the efficacy of the newer oxazolidinone tedizolid (TZD) was compared with the first drug in this class, linezolid (LNZ), in experimental murine myonecrosis caused by ERY-susceptible/CLI-susceptible (ERY^S/CLI^S) or ERY- resistant/CLI-resistant (ERY^R/CLI^R) GAS.

METHODS

Normal adult outbred Swiss Webster female mice (10 per group) were infected intramuscularly with ERY^S/CLI^S (ATCC 12384) or ERY^R/CLI^R (15-003) GAS. Treatments began 4 h post-infection and continued for 72 h. TZD and LNZ (10, 20 and 40 mg/kg) were given intraperitoneally every 12 h. Saline, penicillin (PEN), CLI and ERY were given every 6 h. Survival and infection severity signs and symptoms were followed for 12 days.

RESULTS

Both GAS strains were susceptible to LNZ, TZD and PEN; strain 15-003 was confirmed as constitutively resistant to ERY and CLI. Blood levels following a 40 mg/kg dose of LZD and TZD were 30.9 ± 4.0 μg/mL and 21.9 ± 5.3 μg/mL, respectively. Both TZD and LNZ were highly efficacious for the treatment of severe experimental myonecrosis caused by ERY^S/CLI^S and, importantly, ERY^R/CLI^R GAS.

CONCLUSION

In the current era of emerging macrolide/lincosamide resistance among GAS, these data support the use of TZD and LNZ as first-line antibiotics for the treatment of life-threatening GAS infections in humans.

Repetitive cellulitis caused by Streptococcus agalactiae isolates with different genotypic and phenotypic features in a patient having upper extremity with lymphedema after mastectomy and axillary lymph node dissection

•This is 3 episodes of repetitive cellulitis due to S. agalactiae (GBS) isolates.

•There was the possibility of GBS colonization in the genitourinary tracts.

•Blood-origin 3 isolates showed different genotypic and phenotypic features.

•These findings suggest the heterogeneity in strains endogenous to this patient.

•Our report supports the reinfection with endogenous GBS rather than recurrence.

Previously reported cases of recurrent cellulitis/erysipelas affecting chronically lymphedematous skin regions have been demonstrated to be due to Streptococcus agalactiae isolates with closely related genetic background which may be suggestive of relapse rather than reinfection. Herein, we report the occurrence of three episodes of repetitive cellulitis caused by S. agalactiae strains with different genotypic and phenotypic characteristics, including different antimicrobial susceptibility patterns (tetracycline, macrolide/lincosamide, and fluoroquinolone classes), in the left upper extremity of a patient with lymphedema, following left mastectomy and axillary lymph node dissection. The genotypic and phenotypic characteristics of the three isolates were confirmed based on the random amplified polymorphic DNA patterns, DNA profiles of virulence factors (bca–rib–bac–lmb–cylE), data on biofilm formation and cell invasion, antimicrobial susceptibility testing results, antimicrobial resistance (AMR) genotypes, and amino acid mutations associated with AMR. These results revealed that reinfection with S. agalactiae, rather than recurrence, occurred during the three episodes. In conclusion, microbiologic studies such as blood cultures or tissue cultures are certainly helpful in the management of recurrent infections or invasive infections such as bacteremia in order to better target antimicrobial therapy, regardless of the data previously presented.

Comparison of Nafcillin and Cefazolin for the Treatment of Methicillin-Susceptible Staphylococcus aureus Bacteremia

BACKGROUND

Traditionally, the antibiotic of choice for Methicillin-susceptible Staphylococcus aureus related blood stream infections (MSSA-BSI) are the antistaphylococcal penicillins. Cefazolin is considered an alternative agent, with recent evidence showing similar clinical efficacy. This study further evaluates the utility of nafcillin versus cefazolin in MSSA bacteremia including high disease burden sources of infection and its impact on treatment failure.

METHODS

This retrospective study included patients admitted to Methodist LeBonheur Healthcare adult hospitals from 2011 to 2016. Patients were included if they received at least 3 days of either nafcillin or cefazolin and had a positive blood culture for MSSA. The primary objective was to evaluate rates of treatment failure between groups. Secondary outcomes included clinical and microbiological cure, MSSA-BSI associated readmissions, identification of risk factors for treatment failure including disease burden, in-hospital and 90 day mortality.

RESULTS

A total of 277 patients were included (nafcillin n = 126; cefazolin n = 151). Treatment failure and microbiologic cure were similar between nafcillin and cefazolin (20.6% vs. 16.6%; 91.2% vs. 87.2%, respectively). Clinical cure was significantly higher in the cefazolin treatment arm (93.4 vs. 83.3%; P = 0.012). However, the total number of patients with high disease burden was greater in the nafcillin group (54.8% vs. 39.1%; P = 0.011). Higher rates of in-hospital mortality were observed in the nafcillin group (15.1% vs. 6%; P = 0.016).

CONCLUSIONS

Our study observed significantly higher rates of clinical cure and reduced in-hospital mortality in patients who received cefazolin. Further analysis is warranted to evaluate the effectiveness of these agents and identifying predictors of treatment failure.

Romo1-Derived Antimicrobial Peptide Is a New Antimicrobial Agent against Multidrug-Resistant Bacteria in a Murine Model of Sepsis

Abuse of antibiotics often leads to increase of multidrug-resistant (MDR) bacteria, which threatens the life of human beings. To overcome threat of antibiotic resistance, scientists are developing a novel class of antibiotics, antimicrobial peptides, that can eradicate MDR bacteria. Unfortunately, these antibiotics have mainly been developed to cure bacterial skin infections rather than others, such as life-threatening sepsis. Major pharmaceutical companies have tried to develop antiseptic drugs; however, they have not been successful. Here, we report that AMPR-11, the antimicrobial peptide (AMP) derived from mitochondrial nonselective channel Romo1, has antimicrobial activity against Gram-positive and Gram-negative bacteria comprising many clinically isolated MDR strains. Moreover, AMPR-11 increased the survival rate in a murine model of sepsis caused by MDR bacteria. We propose that AMPR-11 could be a novel antiseptic drug candidate with a broad antimicrobial spectrum to overcome MDR bacterial infection.

To overcome increasing bacterial resistance to conventional antibiotics, many antimicrobial peptides (AMPs) derived from host defense proteins have been developed. However, there are considerable obstacles to their application to systemic infections because of their low bioavailability. In the present study, we developed an AMP derived from Romo1 (AMPR-11) that exhibits a broad spectrum of antimicrobial activity. AMPR-11 showed remarkable efficacy against sepsis-causing bacteria, including multidrug-resistant strains, with low toxicity in a murine model of sepsis after intravenous administration. It seems that AMPR-11 disrupts bacterial membranes by interacting with cardiolipin and lipid A. From the results of this study, we suggest that AMPR-11 is a new class of agent for overcoming low efficacy in the intravenous application of AMPs and is a promising candidate to overcome multidrug resistance.

Calculated initial parenteral treatment of bacterial infections: Skin and soft tissue infections

This is the ninth chapter of the guideline "Calculated Parenteral Initial Therapy of Adult Bacterial Disorders - Update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter contains the first German S2k guidelines for bacterial skin and soft tissue infections. They encompass recommendations on diagnosis and treatment of the defined entities erysipelas (caused by beta-hämolytic streptococci), limited superficial cellulitis (S. aureus), severe cellulitis, abscess, complicated skin and soft tissue infections, infections of feet in diabetic patients ("diabetic foot"), necrotizing soft tissue infection and bite injuries.

Variation in Proportion of Blood Cultures Obtained for Children With Skin and Soft Tissue Infections

OBJECTIVES

To identify variation in the proportion of blood cultures obtained for pediatric skin and soft tissue infections (SSTIs) among children's hospitals.

METHODS

We conducted a retrospective cohort study using the Pediatric Health Information System database, which we queried for emergency department (ED)-only and hospital encounters between 2012 and 2017 for children aged 2 months to 18 years with diagnosis codes for SSTI. The primary outcome was proportion of SSTI encounters during which blood cultures were obtained. Encounters with and without blood cultures were compared for length of stay, costs, and 30-day ED revisit and readmission rates, adjusted for patient factors and hospital clustering. We also identified encounters with bacteremia using billing codes for septicemia and bacteremia.

RESULTS

We identified 239 954 ED-only and 49 291 hospital SSTI encounters among 38 hospitals. Median proportions of ED-only and hospital encounters with blood cultures were 3.2% (range: 1%- 11%) and 51.6% (range: 25%-81%), respectively. Adjusted ED-only encounters with versus without blood culture had higher costs ($1266 vs $460, P < .001), higher ED revisit rates (3.6% vs 2.9%, P < .001), and higher admission rates (2.0% vs 0.9%, P < .001). Hospital encounters with blood culture had longer length of stay (2.3 vs 2.0 days, P < .001), higher costs ($5254 vs $4425, P < .001), and higher readmission rates (0.8% vs 0.7%, P = .027). The overall proportion of encounters with bacteremia was 0.6% for ED-only encounters and 1.0% for hospital encounters.

CONCLUSIONS

Despite multiple studies in which low clinical value was demonstrated and current Infectious Diseases Society of America guidelines arguing against the practice, blood cultures were obtained frequently for children hospitalized with SSTIs, with substantial variation across institutions. Few bacteremic encounters were identified.

S2k guidelines for skin and soft tissue infections Excerpts from the S2k guidelines for "calculated initial parenteral treatment of bacterial infections in adults - update 2018"

These first German S2k guidelines for bacterial skin and soft tissue infections were developed as one chapter of the recommendations for "calculated initial parenteral treatment of bacterial infections" issued under the auspices of the Paul-Ehrlich Society, of which the main part is presented here. Well-calculated antibiotic therapies require precise diagnostic criteria. Erysipelas is defined as non-purulent infection considered to be caused by beta-hemolytic strepto-cocci. It is diagnosed clinically by its bright-red erythema and early fever or chills at disease onset. Penicillin is the treatment of choice. Limited soft tissue infection (cellulitis) is usually caused by Staphylococcus (S.) aureus, frequently originates from chronic wounds and presents with a more violaceous-red hue and only rarely with initial fever or chills. Treatment consists of first- or second--generation cephalosporins or flucloxacillin (IV). Severe cellulitis is a purulent, partially necrotic infection which extends through tissue boundaries to fascias and requires surgical management in addition to antibiotics. Moreover, it frequently fulfills the criteria for "complicated soft tissue infections", as previously defined by the Food and Drug Administration for use in clinical trials (they include comorbidities such as uncontrolled diabetes, peripheral artery disease, neutropenia). It requires antibiotics which besides S. aureus target anaerobic and/or gramnegative bacteria. The rare so-called necrotizing skin and soft tissue infections represent a distinct entity. They are characterized by rapid, life-threatening progression due to special bacterial toxins that cause ischemic necrosis and shock and need rapid and thorough debridement in addition to appropriate antibiotics. For cutaneous abscesses the first-line treatment is adequate drainage. Additional antibiotic therapy is required only under certain circumstances (e.g., involvement of the face, hands, or anogenital region, or if drainage is somehow complicated). The present guidelines also contain consensus-based recommendations for higher doses of antibiotics than those approved or usually given in clinical trials. The goal is to deliver rational antibiotic treatment that is both effective and well-tolerated and that exerts no unnecessary selection pressure in terms of multidrug resistance.

Utility of N-acetylcysteine in ischemic hepatitis in cirrhotics with acute variceal bleed: a randomized controlled trial

BACKGROUND AND AIMS

Ischemic hepatitis (IH) following acute variceal bleed (AVB) carries an ominous prognosis. N-Acetylcysteine (NAC), a potent anti-oxidant, may prevent IH by improving tissue oxygen delivery and improving hepatic hypoxia.

METHODS

Consecutive cirrhotics with AVB were prospectively randomized to receive either standard of care (SOC) plus NAC intravenously for 72 h(at 150 mg/kg/h for 1 h followed by 12.5 mg/kg/h for 4 h, followed by 6.25 mg/kg for 67 h) (Group A, n = 107) or SOC alone (Group B, n = 107).

RESULTS

Baseline characteristics were comparable. IH developed more frequently in Gr.B 25(23%) than A-15(14%); p = 0.08). Incidence of IH increased with severity of liver disease. Binary logistic regression analysis showed reduced incidence of IH in Gr.A than B [odds ratio (OR) 0.33, 0.11-0.93] patients after controlling for other significant factors. The incidence of acute kidney injury (AKI) was also reduced in Gr.A [OR 0.34, 0.15-0.75]. Development of IH was significantly associated with increased deaths due to liver failure at 6 weeks [subdistribution hazard ratio (SHR) 21.6, 7.4-62.8]. On multivariate competing risk analysis, significantly lower deaths due to liver failure (SHR 0.33, 0.11-0.97) were noted in Gr.A than B.

CONCLUSIONS

One in five patients with acute variceal bleed develops ischemic hepatitis which is associated with worse outcomes. NAC therapy averts deaths due to liver failure by preventing IH and reduces AKI and is, therefore, recommended for cirrhotics with acute variceal bleed.

TRIAL REGISTRATION

Clinicaltrials.gov no: NCT02015403.