Photoelimination Potential of Chitosan NanoparticlesIndocyanine Green Complex Against the Biological Activities of Acinetobacter baumannii Strains: A Preliminary In Vitro Study in Burn Wound Infections

Abstract

Introduction: Acinetobacter baumannii strains are important agents causing serious nosocomial infections including soft-tissue and skin infections in patients with burn wounds which have become resistant to several classes of antibiotics. Antimicrobial photodynamic therapy (aPDT) as an alternative antimicrobial procedure is suggested for the treatment of these kinds of infections. The aim of the current study is to evaluate the antibacterial and anti-biofilm efficiency of aPDT by the utilization of an improved form of indocyanine green (ICG) which is encapsulated in chitosan nanoparticles (NCs@ICG). Methods: NCs@ICG were synthesized and confirmed by the scanning electron microscope (SEM). aPDT was performed using NCs@ICG with an 810 nm wavelength of the diode laser at the fluency of 31.2 J/cm2 on 50 A. baumannii strains isolated from burn wounds. The antibacterial and antibiofilm potential of NCs@ICG-aPDT was determined via the colony forming unit (CFU)/mL and crystal violet assays, respectively. In addition, microbial biofilm degradation was evaluated by the SEM. Results: According to the results, NCs@ICG-aPDT showed a significant reduction of 93.2% on the CFU/ mL of planktonic A. baumannii strains compared to the control group (untreated group; P < 0.05). In addition, the biofilm formation of A. baumannii strains was significantly reduced by 55.3% when the bacteria were exposed to NCs@ICG-aPDT (P < 0.05). In contrast, NCs@ICG, ICG, and the diode laser alone were not able to inhibit the CFU/mL and biofilm of A. baumannii strains (P > 0.05). Based on the results of SEM images, NCs@ICG-aPDT disrupted the biofilm structure of A. baumannii strains more than other groups. Conclusion: NCs@ICG-aPDT demonstrates a promising treatment candidate for exploitation in wound infections against both planktonic and biofilm forms of A. baumannii strains

Antibiotics Combinations and Chitosan Nanoparticles for Combating Multidrug Resistance Acinetobacter baumannii

“…The difference in the antimicrobial activities against MDR A. baumannii were dependent on the different concentrations of the tested CNPs. Our results are in line with other two previous studies conducted by Cobrado et al 70 and Pourhajibagher et al 71 Interestingly, Pourhajibagher et al proved that CNPs produced significant reduction of 93.2% on the viable count of planktonic and of 55.3% on the biofilm formation of A. baumannii strains as compared to the control group. 71 Furthermore, the activities of CNPs (5 mg/mL) when combined with CT, TGC or MEM, CT+MEM and TGC+MEM were evaluated via measuring the MDF as previously reported.…”

Approaches for Mitigating Microbial Biofilm-Related Drug Resistance: A Focus on Micro- and Nanotechnologies

“…55.3% compared to the ICG irradiated group with ca. 46.2%, which was also evident in the disrupted biofilm architecture viewed through SEM [ 219 ]. A closer observation of the effects exerted by chloroaluminium phthalocyanine (ClAlPc) encapsulated in CHNPs towards the biofilms of S. mutans ATCC 25175 at an irradiation dose of 100 J cm −2 through SEM revealed that the cells were irregularly shaped and arranged in shorter chains [ 220 ].…”

Gram-Negative Bacteria Holding Together in a Biofilm: The Acinetobacter baumannii Way

“…Chitosan nanoparticles have some advantages, such as being nontoxic, low immunogenic and biodegradable. In this regard, Pourhajibagher et al observed that, using a diode laser as a light source in a wavelength of 810 nm exposure, the PS indocyanine green encapsulated in chitosan NPs caused significant disruption to preformed biofilms by A. baumannii isolates from burn wounds, as also confirmed by SEM analysis [ 158 ]. In another study, Fekrirad et al found that chitosan at 1/2× MIC enhanced the antibiofilm efficacy of erythrosine-mediated-PDI against A. baumannii preformed biofilm causing a marked decrease in the number of viable biofilm cells (>3 log10 colony forming units, CFU/mL) [ 188 ].…”