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

Fatal Necrotizing Fasciitis Mediated by Escherichia coli After Parotidectomy and Neck Dissection: A Case Report and Review of the Literature

Necrotizing soft tissue infection (NSTI) is a rare, but life-threatening, complication of head and neck surgery. We present a 70-year-old male with a history of immunosuppression who presented with polymicrobial NSTI following parotidectomy and neck dissection for cutaneous squamous cell carcinoma. The objective of this report was to promote awareness for NSTI following parotidectomy and selective neck dissection and highlight the management measures that can optimize survival outcomes. We performed a database search that identified 1,025 citations, of which 5 articles described classified as craniocervical necrotizing fasciitis following major head and neck surgery. Consent was obtained from the patient for inclusion in the research study and Institutional Review Board approval was waived. Our literature review yielded 6 cases of craniocervical necrotizing fasciitis following major head and neck surgery. This NSTI, however-unlike the others previously reported-was predominantly mediated by Escherichia coli, a bacterium associated with elevated mortality rates. Despite immediate awake fiberoptic intubation, repeated surgical debridement, and empirical antibiotic therapy, he deteriorated rapidly and was withdrawn from life-support on postoperative day seven. Prophylactic antibiotics, airway management, prompt diagnosis, and surgical debridement are critical for limiting mortality in NSTI of the head and neck.

Silver nanoparticles enhance the efficacy of aminoglycosides against antibiotic-resistant bacteria

As the threat of antimicrobial-resistant bacteria compromises the safety and efficacy of modern healthcare practices, the search for effective treatments is more urgent than ever. For centuries, silver (Ag) has been known to have antibacterial properties and, over the past two decades, Ag-based nanoparticles have gained traction as potential antimicrobials. The antibacterial efficacy of Ag varies with structure, size, and concentration. In the present study, we examined Ag nanoparticles (AgNPs) for their antimicrobial activity and safety. We compared different commercially-available AgNPs against gram-negative Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and gram-positive Staphylococcus aureus methicillin-resistant and susceptible strains. The most effective formula of AgNPs tested had single-digit (μg/mL) minimum inhibitory concentrations against gram-negative multidrug-resistant clinical bacterial isolates with novel and emerging mechanisms of resistance. The mode of killing was assessed in E. coli and was found to be bactericidal, which is consistent with previous studies using other AgNP formulations. We evaluated cytotoxicity by measuring physiological readouts using the Caenorhabditis elegans model and found that motility was affected, but not the lifespan. Furthermore, we found that at their antibacterial concentrations, AgNPs were non-cytotoxic to any of the mammalian cell lines tested, including macrophages, stem cells, and epithelial cells. More interestingly, our experiments revealed synergy with clinically relevant antibiotics. We found that a non-toxic and non-effective concentration of AgNPs reduced the minimum inhibitory concentrations of aminoglycoside by approximately 22-fold. Because both aminoglycosides and Ag are known to target the bacterial ribosome, we tested whether Ag could also target eukaryotic ribosomes. We measured the rate of mistranslation at bactericidal concentration and found no effect, indicating that AgNPs are not proteotoxic to the host at the tested concentrations. Collectively, our results suggest that AgNPs could have a promising clinical application as a potential stand-alone therapy or antibiotic adjuvants.