Chronic wounds represent an increasing problem worldwide. Graphene oxide (GO) has been reported to exhibit strong antibacterial activity toward both Gram-positive and Gram-negative bacteria. The aim of this work was to investigate the in vitro antimicrobial and antibiofilm efficacy of GO against wound pathogens. Staphylococcus aureus PECHA 10, Pseudomonas aeruginosa PECHA 4, and Candida albicans X3 clinical isolates were incubated with 50 mg/liter of GO for 2 and 24 h to evaluate the antimicrobial effect. Optical and atomic force microscopy images were performed to visualize the effect of GO on microbial cells. Moreover, the antibiofilm effect of GO was tested on biofilms, both in formation and mature. Compared to the respective time controls, GO significantly reduced the S. aureus growth both at 2 and 24 h in a time-dependent way, and it displayed a bacteriostatic effect in respect to the GO t = 0; an immediate (after 2 h) slowdown of bacterial growth was detected for P. aeruginosa , whereas a tardive effect (after 24 h) was recorded for C. albicans . Atomic force microscopy images showed the complete wrapping of S. aureus and C. albicans with GO sheets, which explains its antimicrobial activity. Moreover, significant inhibition of biofilm formation and a reduction of mature biofilm were recorded for each detected microorganism. The antibacterial and antibiofilm properties of GO against chronic wound microorganisms make it an interesting candidate to incorporate into wound bandages to treat and/or prevent microbial infections.

Background: Helicobacter pylori treatment failure may be due to resistance to macrolides and 5‐nitroimidazoles.Aim: To test whether a preliminary in vitro susceptibility test of H. pylori to tinidazole and clarithromycin and a consequent specific regimen could improve the eradication rate.Methods: A total of 109 consecutive H. pylori‐positive patients with dyspeptic symptoms were included. At endoscopy, biopsy from the antrum was obtained for H. pylori culture and antimicrobial susceptibility testing. Fifty‐six patients were treated with omeprazole, tinidazole and clarithromycin for 10 days (group OTC) and 53 patients received therapy on the basis of the susceptibility test (group SUSC). Treatment success was evaluated by the ¹³C‐urea breath test 1 month after the end of therapy.Results: Eight patients dropped out. Overall primary resistance to clarithromycin, tinidazole and both antibiotics was 13%, 33% and 4%, respectively. In group OTC, H. pylori was eradicated in 81% and 75% of patients by per protocol and intention‐to‐treat analysis, respectively. Per protocol and intention‐to‐treat eradication rates for group SUSC were 98% and 91% (P < 0.05 vs. group OTC).Conclusions: These data show that in H. pylori infection, antibiotic therapy based on the results of culture and susceptibility testing gives, in comparison to standard therapy, a significant improvement in eradication rate.