Necrotising fasciitis caused by P aeruginosa in a male patient with chronic lymphocytic leukaemia

Monomicrobial Necrotizing Fasciitis and Sepsis Caused by Pseudomonas aeruginosa and Pseudomonas fluorescens: A Series of Ten Cases

Monomicrobial necrotizing fasciitis caused by Pseudomonas species is a rare infection. The purpose of this study was to elucidate the specific characteristics and clinical outcomes of necrotizing fasciitis caused by Pseudomonas aeruginosa and Pseudomonas fluorescens. Ten patients with monomicrobial necrotizing fasciitis caused by Pseudomonas species were retrospectively reviewed over an 8-year period. Differences in mortality, patient characteristics, clinical presentations, laboratory data, and clinical outcomes were compared between the death and the survival groups. Two patients died with the mortality rate of 20%. Pseudomonas aeruginosa accounted for 9 patients and Pseudomonas fluorescens for one patient. The most common comorbidity is type 2 diabetes mellitus in 5 patients. We found the death patients had lower albumin level and higher counts of band forms of leukocytes than those of the survival patients. Monomicrobial necrotizing fasciitis caused by Pseudomonas species needs emergent surgical intervention and aggressive intensive care due to high mortality rate. We reported the first case of monomicrobial necrotizing fasciitis with Pseudomonas fluorescens. Severe hypoalbuminemia and increased counts of banded leukocytes in initial laboratory presentations can be considered as poor prognostic factors.

Skin manifestations of Pseudomonas aeruginosa infections

PURPOSE OF REVIEW

Pseudomonas aeruginosa is an opportunistic pathogen with considerable morbidity and mortality, particularly in vulnerable hosts. Skin manifestations are common, either representing local inoculation or secondary skin seeding following bloodstream infections. As patients with various predisposing conditions are expanding, we sought to review the most recent published evidence regarding epidemiology, risk factors and diagnosis of skin manifestations of P. aeruginosa.

RECENT FINDINGS

New data exist on epidemiology and diagnosis of skin infections; systemic infections are impacted by multidrug-resistance issues and host immune status.

SUMMARY

Green nail syndrome, toe web infection, hot tub folliculitis, hot hand-foot infection and external otitis are the most common infections originating from the skin per se. Local treatments are the cornerstone and prognosis is favorable in immunocompetent hosts. Ecthyma gangrenosum and P. aeruginosa subcutaneous nodules are usually associated with bloodstream infections and occur primarily in immunocompromised hosts. Necrotizing skin and soft tissue infections occur in diabetic, alcoholic and immunocompromised patients; management requires a multidisciplinary team with surgical approach. Burn wound infections may also be challenging, requiring a specialized team. In all the four latter types of P. aeruginosa skin infections portending significant morbidity and mortality, systemic antibiotics are an integral part of the treatment.

Ceftolozane-Tazobactam Treatment of Hypervirulent Multidrug Resistant Pseudomonas aeruginosa Infections in Neutropenic Patients

The effectiveness of ceftolozane/tazobactam for the treatment of infections in neutropenic patients caused by hypervirulent multidrug-resistant (MDR) Pseudomonas aeruginosa has not been previously reported. We identified seven cases of MDR P. aeruginosa infection in neutropenic patients over a four-month period within the same hematology ward. Four cases were associated with rapid progression despite piperacillin-tazobactam or meropenem therapy, and three patients developed sepsis or extensive skin/soft tissue necrosis. In three of the four cases, patients were empirically switched from meropenem to ceftolozane/avibactam before carbapenem susceptibility test results were available, and all four patients underwent extensive surgical debridement or amputation of affected tissues and survived. Further investigation revealed a common bathroom source of MDR P. aeruginosa clonal subtypes ST175 and ST235 that harbored genes for type III secretion system expression and elaboration of ExoU or ExoS exotoxin. We conclude that ceftolozane/tazobactam plus early source control was critical for control of rapidly progressing skin and soft infection in these neutropenic patients caused by highly virulent ST175 and ST235 clones of MDR P. aeruginosa.

Skin and Soft Tissue Infections in Non-Human Immunodeficiency Virus Immunocompromised Hosts

Skin and soft tissue infections among the non-human immunodeficiency virus infected immunosuppressed population are a serious and growing concern. Many pathogens can cause cutaneous infections in these patients owing to the highly varied and profound immune deficits. Although patients can be infected by typical organisms, the diversity and antimicrobial-resistant nature of the organisms causing these infections result in significant morbidity and mortality. The diagnostic approach to these infections in immunocompromised hosts can differ dramatically depending on the potential causative organisms. An understanding of new immunosuppressive treatments and evolving antimicrobial resistance patterns are required to optimally manage these difficult cases.

[Necrotizing Soft Tissue Infection Caused by Serratia marcescens in a Patient Treated with Tocilizumab]

We report herein on a case of community-acquired necrotizing soft tissue infection caused by Serratia marcescens. The patient had been treated with prednisolone, tocilizumab and tacrolimus for rheumatoid arthritis. Since Gram staining of the tissue revealed Gram negative rod bacteria, ceftriaxone and clindamycin were administered as empiric therapy. Tissue culture revealed S. marcescens. Ceftriaxone was continued according to the antibiotic sensitivity. She underwent debridement of necrotic tissue and continued ceftriaxone for 17 days. She recovered and was discharged after skin grafting.

Necrotising fasciitis due to an infected sebaceous cyst

The current case presents a patient who was admitted to our hospital with the diagnosis of cellulitis of the right groin. In the following days, the patient's condition deteriorated and developed a septic shock. Exploration in the operating room showed a necrotising fasciitis of the adductor muscles, with an infected sebaceous cyst in the inguinal crest as port d'entrée. After extensive surgical debridement, antibiotic therapy, haemodynamic and respiratory support, the patient recovered. Necrotising fasciitis is a rare but very lethal condition, which necessitates aggressive surgical therapy and antibiotic support. The current case report is the first report to show a necrotising fasciitis due to an infected sebaceous cyst.