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

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.

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.

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.

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.