Emergence of multi-drug resistant organisms (MDROs) causing Fournier's gangrene

Abstract

Background: Fournier's gangrene is an uncommon but often devastating infection. There are few contemporary data on the risk factors and evolving microbiologic trends including drug-resistant organisms implicated in these life-threatening infections.

Methods: A retrospective study of Fournier's gangrene from 2006 to 2015 at a large academic hospital was conducted. Cases were identified using ICD codes (ICD-9: 608.83, V13.89; ICD-10: N49.3, Z87.438), and a review of medical, radiographic, and pathology records was performed to confirm each case. Data collected included socio-demographics, medical conditions, bacterial pathogens and their resistance patterns, treatments, and outcome. Descriptive and univariate statistics were performed.

Results: A total of 59 cases were evaluated with an overall incidence of 31.8 cases per 100,000 admissions which remained stable over the study period. Mean age was 56 years (range 18-91), 71% were male, and 44% white. Risk factors included overweight/obesity (61%), diabetes (44%, with a mean A1c of 9.6%), immunocompromised state (34%), and illicit use (20%). A causative organism was identified in all except 2 cases; 12 patients (21%) had a multidrug-resistant organism (MDRO) with MRSA being the most common pathogen (n = 8, 14% of all cases), followed by ESBL E. coli (n = 3) and MDRO Acinetobacter (n = 1). MRSA was the sole pathogen isolated in five (63%) of the eight cases involving this organism. Among those with an aerobic Gram-negative rod (GNR) isolated, 32% were fluoroquinolone-resistant. Overall, 30% of cases had a poor outcome (15% died and an additional 15% had loss of an organ/body part). Those with an MDRO were more likely to experience a poor outcome (42% vs. 28%), although this was not statistically significant (p = 0.48); of note, most (83%) MDRO cases were initially treated with an antibiotic that the organism was susceptible.

Conclusions: This report highlights the emergence of MDROs as an important cause of Fournier's gangrene including MRSA and drug-resistant GNRs. Antibiotics should be chosen with broad-spectrum, anti-MDRO activity given the high morbidity and mortality associated with these infections.

Keywords: Epidemiology; Fournier's gangrene; MDRO; MRSA; Multi-drug resistant organisms; Necrotizing fasciitis; Outcome; Risk factors; Treatment.