Unusual "flesh-eating" strains of Escherichia coli

Necrotizing Skin and Soft Tissue Infection after Gluteal Augmentation in a Perioperatively Asymptomatic COVID-19 Patient-Complications of the Post-Lockdown Era? A Case Report

Introduction: Aesthetic surgery procedures are generally done in a relatively healthy population and carry a rather low risk compared to other surgical specialties. The incidence of complications in aesthetic surgery varies greatly depending on the type, wound cleanliness regarding the anatomical site, complexity of the surgery, patient's age, and comorbidities but is generally considered low. The overall incidence of surgical site infections (SSIs) in all aesthetic surgical procedures is around 1% in most of the literature while cases of necrotizing soft tissue infections are mostly found as individual reports. In contrast, treating COVID-19 patients is still challenging with many diverse outcomes. Surgical stress and general anesthesia are known mediators of cellular immunity impairment while studies regarding COVID-19 infection unquestionably have shown the deterioration of adaptive immunity by SARS-CoV-2. Adding COVID-19 to the modern surgical equation raises the question of immunocompetence in surgical patients. The main question of the modern post-lockdown world is: what could be expected in the postoperative period of perioperatively asymptomatic COVID-19 patients after aesthetic surgery? Case report: Here, we present a purulent, complicated, necrotizing skin and soft tissue infection (NSTI) after gluteal augmentation most likely triggered by SARS-CoV-2-induced immunosuppression followed by progressive COVID-19 pneumonia in an otherwise healthy, young patient. To the best of our knowledge, this is the first report of such adverse events in aesthetic surgery related to COVID-19. Conclusion: Aesthetic surgery in patients during the incubation period of COVID-19 or in asymptomatic patients could pose a significant risk for surgical complications, including severe systemic infections and implant loss as well as severe pulmonary and other COVID-19-associated complications.

Severe Skin and Soft-Tissue Infections

Skin and soft-tissue infections (SSTIs) are a common reason for hospital admission. Severe SSTIs, particularly necrotizing infections, often require intensive care. Source control (often with surgical debridement) and broad-spectrum antimicrobials are paramount for minimizing significant morbidity and mortality. Rapid diagnostic tests may help in selection and de-escalation of antimicrobials for SSTIs. Besides early source control and early effective antimicrobial therapy, other patient-level factors such as comorbidities and immune status play a role in clinical outcomes. Intravenous immunoglobulin continues to be studied for severe SSTI, though recruitment in trials continues to be an issue. Severe SSTIs are complex to manage, due in part to regional variation in predominant pathogens and antimicrobial resistance patterns, as well as variations in host immune responses. This review includes descriptions of source control, antimicrobial therapies, intravenous immunoglobulin, and hyperbaric oxygen therapy, as well as host factors in severe SSTIs.

Necrotizing fasciitis caused by mono-bacterial gram-negative infection with E. coli - the deadliest of them all: A case series and review of the literature

Introduction

Unlike other skin and soft tissue infections, necrotizing fasciitis (NF) is a very rare but potentially fatal condition. Common organisms causing NF are poly-microbial (type I) infection with mixed organisms and mono-bacterial gram-positive infection with mainly streptococci (type II). Mono-bacterial gram-negative NF is a rare form of NF that is not included in the current classification.

Case series

We report four cases of mono-bacterial gram-negative NF caused by E. coli. All patients presented in septic shock and showed landscape-like skin necrosis and pain out of proportion. Radical debridement and escalation of antibiotic treatment was performed in all patients. Short-term survival was 50%. Two patients died of multiorgan failure. Two patients survived short term: One patient was amputated through the knee but died six months later of metastatic prostate cancer. One patient was covered with split thickness skin grafts and died three months later of catheter-associated sepsis with endocarditis.

Discussion

Recent findings suggest adding a type III fasciitis, which is caused by mono-bacterial gram-negative organisms. As patients are getting older with even more comorbidities, mono-bacterial gram-negative NF will be an increasing problem for physicians treating soft tissue and skin infections.

In oncologic diseases, liver cirrhosis, renal diseases or otherwise immunocompromised patients, mono-bacterial gram-negative NF with E. coli is underestimated. Therefore, in these patients, antibiotic treatment should cover Gram-negative organisms including E. coli. However even with adjusted antibiotic treatment and radical debridement, the short-term survival and long-term outcome are poor.

Necrotizing fasciitis in haematological patients: a different scenario

To describe and compare the characteristics of necrotizing fasciitis (NF) in patients with and without haematological malignancy. All adult patients diagnosed with NF and treated at our hospital were included (January 2010-March 2019). Diagnosis was based on intraoperative findings or consistent clinical/radiological characteristics, and patients were classified as group A (with haematological malignancy) or group B (without haematological malignancy). Student's t (quantitative), Fisher's exact (qualitative), and Kaplan-Meyer tests were used for the statistical analysis. The study included 29 patients: 8 in group A and 21 in group B. All haematological patients had severe neutropenia (0.2 [0.02-0.5] ×10⁹ cells/L; p < 0.001) and positive blood cultures (100% vs. 61.9%; p = 0.04) at diagnosis. Gram-negative bacilli NF was more common in group A (87.5% vs. 9.5%; p = 0.001), predominantly due to Escherichia coli (50% vs. 9.5%; p = 0.056). Surgical treatment was less common in haematological patients (5 [62.5%] vs. 21 [100%]; p = 0.015). Overall, 9 (31%) patients died: 4 (50%) in group A and 5 (23.8%) in group B (p = 0.17). The univariate analysis showed that mortality tended to be higher (OR 3.2; 95%CI 0.57-17.7; p = 0.17) and to occur earlier (2.2 ± 2.6 vs. 14.2 ± 19.9 days; p = 0.13) in haematological patients. The LRINEC index > 6 did not predict mortality in either group. In our study, NF in patients with haematological malignancies was mainly due to Gram-negative bacilli, associated to high and early mortality rates. In our experience, the LRINEC scale was not useful for predicting mortality.

E. coli Monomicrobial Necrotizing Fasciitis in an Iron-Overloaded Adolescent

Escherichia coli is an extremely unusual cause of monomicrobial necrotizing fasciitis of the extremities in children. We report a transfusion-dependent adolescent boy with iron-overload secondary to congenital dyserythropoietic anemia who developed severe E. coli monomicrobial necrotizing fasciitis of the leg following a minor trauma. Combined surgical, antimicrobial and supportive care resulted in a good outcome.

T6SS and ExoA of flesh-eating Aeromonas hydrophila in peritonitis and necrotizing fasciitis during mono- and polymicrobial infections

An earlier report described a human case of necrotizing fasciitis (NF) caused by mixed infection with 4 Aeromonas hydrophila strains (NF1-NF4). While the NF2, NF3, and NF4 strains were clonal and possessed exotoxin A (ExoA), the NF1 strain was determined to be phylogenetically distinct, harboring a unique type 6 secretion system (T6SS) effector (TseC). During NF1 and NF2 mixed infection, only NF1 disseminated, while NF2 was rapidly killed by a contact-dependent mechanism and macrophage phagocytosis, as was demonstrated by using in vitro models. To confirm these findings, we developed 2 NF1 mutants (NF1ΔtseC and NF1ΔvasK); vasK encodes an essential T6SS structural component. NF1 VasK and TseC were proven to be involved in contact-dependent killing of NF2 in vitro, as well as in its elimination at the intramuscular injection site in vivo during mixed infection, with overall reduced mouse mortality. ExoA was shown to have an important role in NF by both NF1-exoA (with cis exoA) and NF2 during monomicrobial infection. However, the contribution of ExoA was more important for NF2 than NF1 in the murine peritonitis model. The NF2∆exoA mutant did not significantly alter animal mortality or NF1 dissemination during mixed infection in the NF model, suggesting that the ExoA activity was significant at the injection site. Immunization of mice to ExoA protected animals from NF2 monomicrobial challenge, but not from polymicrobial infection because of NF2 clearance. This study clarified the roles of T6SS and ExoA in pathogenesis caused by A. hydrophila NF strains in both mouse peritonitis and NF models in monomicrobial and polymicrobial infections.

Treatment of severe skin and soft tissue infections: a review

PURPOSE OF REVIEW

To review the salient features of the management of severe skin and soft tissue infections (SSTIs), including toxic shock syndrome, myonecrosis/gas gangrene, and necrotizing fasciitis.

RECENT FINDINGS

For severe SSTIs, intensive care, source control, and broad-spectrum antimicrobials are required for the initial phase of illness. There is an increasing focus on the utility of rapid diagnostic tests to help in selection and de-escalation of antimicrobials for SSTIs. In addition, clinical prediction scores have shown promise in helping predict patients who do not require antimicrobials directed against methicillin-resistant Staphylococcus aureus. Immune status has been shown to be important in clinical outcomes of some, but not all types of SSTIs. The debate for benefits of intravenous immunoglobulin continues to be waged in the recent literature.

SUMMARY

Severe SSTIs are common and their management complex due to regional variation in predominant pathogens and antimicrobial resistance patterns, as well variations in host immune responses. Unique aspects of care for severe SSTIs are discussed including the role of surgical consultation and source control. The unique features of SSTIs in immunocompromised hosts are also described.

Atypical Presentation of Escherichia coli Monomicrobial Necrotizing Fasciitis in a Renal Transplant Patient: A Case Report

Skin and soft tissue infections (SSTIs) are one of most frequent infectious causes for referral to the emergency department and one of the most frequent infectious causes of hospital admissions. Escherichia coli, the most commonly occurring gram-negative pathogen involved in these infections, contributes to about 7% of all SSTIs cases where gram-positive organisms reign dominant. Patients are more susceptible to these gram-negative SSTIs if they are neutropenic, have hematologic malignancies, have undergone solid organ or hematopoietic transplantation, or have cirrhotic liver disease. Due to their immunocompromised state, the prognosis is very poor and not well understood. We report a case of an atypical presentation of an E coli monomicrobial necrotizing fasciitis in a renal transplant patient. Our findings support improved mortality with rapid aggressive interventions, such as amputation, in immunocompromised patients.

Are there any reasons to change our behavior in necrotizing fasciitis with the advent of new antibiotics?

PURPOSE OF REVIEW

The treatment of necrotizing fasciitis requires a multifaceted approach, consisting of surgical source control with immediate surgical debridement along with life support, clinical monitoring, and antimicrobial therapy. Many drugs are now available for the treatment of this life-threatening infectious disease, and the purpose of this review is to provide the reader with an updated overview of the newest therapeutic options.

RECENT FINDINGS

Because most necrotizing soft tissue infections are polymicrobial, broad-spectrum coverage is advisable. Acceptable monotherapy regimens include piperacillin-tazobactam or a carbapenem. However, drugs such as ceftolozane-tazobactam, ceftazidime-avibactam in association with an antianaerobic agent (metronidazole or clindamycin) are currently available as valuable alternatives. The new cephalosporins active against methicillin-resistant Staphylococcus aureus (MRSA), ceftaroline, and ceftobiprole share similar antibacterial activity against Gram-positive cocci, and they might be considered as an alternative to nonbetalactam anti-MRSA agents for necrotizing fasciitis management. Two new long-acting lypoglycopeptides - oritavancin and dalbavancin - share the indications for acute bacterial skin and skin structure infections and had similar activity against Gram-positive cocci including MRSA and streptococci.

SUMMARY

Carbapenem-sparing agents are particularly suitable for antimicrobial stewardship strategy. The new long-acting lypoglycopeptides are very effective in treating necrotizing fasciitis and are uttermost attractive for patients requiring short hospital stays and early discharge.

Diagnosis and management of skin and soft tissue infections in the intensive care unit: a review

PURPOSE

To review the salient features of the diagnosis and management of the most common skin and soft tissue infections (SSTI). This review focuses on severe SSTIs that require care in an intensive care unit (ICU), including toxic shock syndrome, myonecrosis/gas gangrene, and necrotizing fasciitis.

METHODS

Guidelines, expert opinion, and local institutional policies were reviewed.

RESULTS

Severe SSTIs are common and their management complex due to regional variation in predominant pathogens and antimicrobial resistance patterns, as well as variations in host immune responses. Unique aspects of care for SSTIs in the ICU are discussed, including the role of prosthetic devices, risk factors for bacteremia, and the need for surgical consultation. SSTI mimetics, the role of dermatologic consultation, and the unique features of SSTIs in immunocompromised hosts are also described.

CONCLUSIONS

We provide recommendations for clinicians regarding optimal SSTI management in the ICU setting.

A Fatal Case of Necrotizing Fasciitis Caused by a Highly Virulent Escherichia coli Strain

Necrotizing fasciitis is a serious disease characterized by the necrosis of the subcutaneous tissues and fascia. E. coli as the etiologic agent of necrotizing fasciitis is a rare occurrence. A 66-year-old woman underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy. She rapidly developed necrotizing fasciitis which led to her death 68 hours following surgery. An E. coli strain was isolated from blood and fascia cultures. DNA microarray revealed the presence of 20 virulence genes.

Sequential necrotizing fasciitis caused by the monomicrobial pathogens Streptococcus equisimilis and extended-spectrum beta-lactamase-producing Escherichia coli

Necrotizing fasciitis is a rapidly progressing bacterial infection of the superficial fascia and subcutaneous tissue that is associated with a high mortality rate and is caused by a single species of bacteria or polymicrobial organisms. Escherichia coli is rarely isolated from patients with monomicrobial disease. Further, there are few reports of extended-spectrum beta-lactamase (ESBL)-producing E. coli associated with necrotizing fasciitis. We report here our treatment of an 85-year-old man who was admitted because of necrotizing fasciitis of his right thigh. Streptococcus equisimilis was detected as a monomicrobial pathogen, and the infection was cured by amputation of the patient's right leg and the administration of antibiotics. However, 5 days after discontinuing antibiotic therapy, he developed necrotizing fasciitis on his right upper limb and died. ESBL-producing E. coli was the only bacterial species isolated from blood and skin cultures. This case demonstrates that ESBL-producing E. coli can cause monomicrobial necrotizing fasciitis, particularly during hospitalization and that a different bacterial species can cause disease shortly after a previous episode.

Draft Genome Sequence of a Necrotoxigenic Escherichia coli Isolate

Here, we present the draft genome sequence of a necrotoxigenic Escherichia coli strain isolated from a patient following a very rapidly evolving, lethal necrotizing fasciitis.

Fatal necrotizing fasciitis due to necrotic toxin-producing Escherichia coli strain

We report a fatal case of necrotizing soft tissues infection caused by an Escherichia coli strain belonging to phylogenetic group C and harbouring numerous virulence factors reported to be part of a pathogenicity island (PAI) such as PAI II_J96 and conserved virulence plasmidic region.

Catastrophic hemophagocytic lymphohistiocytosis in a young man with nephrotic syndrome

BACKGROUND

In its early stage, necrotizing fasciitis mimics a milder cutaneous infection, such as cellulitis, and is an uncommon but potentially fatal complication of nephrotic syndrome. It may trigger an uncontrolled and catastrophic immune response, such as hemophagocytic lymphohistiocytosis (HLH).

CASE REPORT

A 19-y-old man presented with steroid-resistant nephrotic syndrome and rapidly progressing Escherichia coli monomicrobial necrotizing fasciitis with bacteremia. The conditions developed one day after steroid therapy, leading to multiple organ dysfunction syndrome. A provisional diagnosis of HLH was promptly made, based upon the patient's fever, unremitting shock, marked pancytopenia, hyperferritinemia, hypofibrinogenemia, and the typical histiocytic hemophagocytosis in pleural effusion. Despite aggressive medical treatment and organ support, the patient died 8 days after transfer to our intensive care unit. Final bone marrow examination confirmed the diagnosis of HLH.

CONCLUSIONS

Although nephrotic syndrome associated with E. coli infection is common, this is the first reported case of E. coli monomicrobial necrotizing fasciitis with bacteremia resulting in HLH in a patient with nephrotic syndrome.

Monomicrobial necrotizing fasciitis in a single center: the emergence of Gram-negative bacteria as a common pathogen

BACKGROUND

Necrotizing fasciitis (NF) is a life-threatening soft tissue infection. It is usually caused by Streptococcus pyogenes and other Gram-positive bacteria. Several reports, however, emphasize the importance of Gram-negative rods in this infection.

METHODS

We retrospectively studied all cases of monomicrobial necrotizing fasciitis hospitalized in our center during the years 2002-2012. We compared clinical characteristics and outcomes of patients with Gram-negative versus Gram-positive infection.

RESULTS

Forty-five cases were reviewed, 19 caused by Gram-negative organisms, 10 of them Escherichia coli, and 26 caused by Gram-positive organisms, 10 of them S. pyogenes. Compared to Gram-positive infections, patients with Gram-negative infections were more likely to have a baseline malignancy (9/19, 47.4%) or to have undergone recent surgery (4/19, 42.3%). The 30-day mortality was higher among Gram-negative infected patients (8/19, 42.1% vs. 8/26, 30.8%). Creatine phosphokinase (CPK) was elevated in a minority of patients with Gram-negative necrotizing fasciitis, and its absolute value was lower than in Gram-positive necrotizing fasciitis.

CONCLUSIONS

In our center, 42% of monomicrobial necrotizing fasciitis cases were found to be caused by Gram-negative organisms, mostly E. coli. These infections usually appeared in immunocompromised or postoperative patients, often presented with normal CPK levels, and were associated with high mortality rates.