Pathogens and their resistance behavior in necrotizing fasciitis

Necrotizing fasciitis (NF) is a rare but life-threatening condition in which extensive soft tissue destruction can occur very quickly if left untreated. Therefore, timely broad-spectrum antibiotic administration is of prognostic importance in addition to radical surgical debridement.

This study evaluates the cases of NF in our hospital during the last ten years retrospectively with respect to the pathogens involved and their antimicrobial resistance. This approach aims to provide guidance regarding the most targeted initial antibiotic therapy.

We performed a retrospective microbiological study evaluating pathogen detection and resistance patterns including susceptibility testing of 42 patients with NF.

Type 1 NF (polymicrobial infection) occurred in 45% of the patients; 31% presented type 2 NF (monomicrobial infection). The most common pathogens detected were E. coli, staphylococci such as Staphylococcus aureus and Staphylococcus epidermidis, Proteus mirabilis, enterococci, and streptococci such as Streptococcus pyogenes. Twelve percent presented an additional fungus infection (type 4). Ten percent showed no cultivation. Two percent (one patient) presented cocci without specification.

Most pathogens were sensitive to antibiotics recommended by guidelines. This confirms the targeting accuracy of the guidelines. Further studies are necessary to identify risk factors associated with multidrug resistant infections requiring early vancomycin/meropenem administration.