Aim of the study. World’s scientists are focused on creating new technologies and antimicrobial products. Application of nanotechnologies has high importance to reach this goal by developing new materials that would inhibit growth of pathogenic microorganisms and stop infections before it occurs. The aim of our work was to evaluate intluence of graphene oxide and metal nanostructures composites on antibiotic resistant Acinetobacter baumannii strains.
Material and methods. We studied 79 strains of Acinetobacter baumannii isolated from various clinical materials in microbiology laboratory by using standard methods.
Results. A. baumannii strains, that we tested, had acquired resistance mechanisms for the most of antibiotics we tested. 22.8% (n=18) of strains were resistant to all the antibiotics we tested. After one hour of incubation graphene oxide and metal nanostructures composites showed better performance on strains that were susceptible, than resistant to ceftazidime, and ciprofloxacin (100%, n=6 respectively 37.0%, n = 27, p = 0.004), doxacycline (57.6%, n=19, respectively 30.4%, n=14, p=0.015), carbapenems (imipenem and meropenem) (77.8%, n=7 respectively 37.1% n = 26, p = 0.025), gentamicin (69.2%, n=9 respectively 36.4%, n=24, p=0.03), tigecycline (53.3%, n=16 respectively 34.7%, n=17, p=0.082). After two hours of incubation graphene oxide and metal nanostructures composites effect on strains that were resistant and susceptible to antibiotics became similar. Strains, that were resistant to doxacycline were effected more than susceptible ones (93.5%, n=43, respectively 51.5%, n=17, p<0.001).
Conclusions. Graphene oxide and metal nanostructures composites has shown very significant effect on Acinetobacter baumannii strains that are susceptible to beta-lactams (ceftazidime, carbapenems) and ciprofloxacin after a short exposition, while it took longer incubation time (2 hrs.) to effect resistant strains. Some of eftected A. baumannii strains showed recovery after 2 hours of incubation. Plausible cause is not optimal composition of graphene oxide and metal nanostructures composites and requires further studies to achieve longterm bactericidal effect. These nanostructures works well on aminoglycoside (gentamicin, amikacin) and tygecycline susceptible strains as well as resistant after 2 hours of exposition.
