First Report of Vannellidae Amoebae (Vannella Spp.) Isolated From Biofilm Source

Background: Members of the Vannellidae family are free-living amoebae (FLA) distributed mainly in water and soil sources. The present study reports the first isolation of this genus in the biofilm source from hospital environment in Tehran, Iran.Methods: Biofilm samples were collected from hospital environment. Cultivation was performed in non-nutrient agar covered with a heat-killed Escherichia coli. Cloning of the suspected amoe­bae was done. PCR amplification and Homology analysis using the Basic Local Alignment Search Tool (BLASTn) was performed to search for the most similar reference sequences.Results: Microscopic examination showed numerous fan-shaped amoebae and peculiar cysts differ­ent to the usual shape of typical FLA. Sequence analysis of the PCR- product revealed that the suspected amoebae are highly homologous with Vannella spp. gene (99% identity and 100% query coverage) available in the gene bank database.Conclusion: Although Vannella spp. is not proved to be pathogenic itself, but they are capable of har­boring pathogenic intracellular organisms such as Microsporidian parasites. Thus, identifica­tion of such amoebae can be of clinical importance, as they could lead to transmission of other pathogens to human

Optimization of fluoride-containing bioactive glasses as a novel scolicidal agent adjunct to hydatid surgery

We have presented a novel scolicidal agent made from fluoride-containing bioactive glass (FBG). The samples were characterized by XRD and the ion release behavior of the samples was evaluated at 37°C. The scolicidal activity, cellular response and antibacterial activity and biocompatibility of the different concentrations of the FBG (ranging from 0.5 to 2mgml-1) were evaluated in vitro and in vivo. The results showed an easy diffusion of the fluoride through the glass matrix in an F concentration-dependent manner. The FBG showed an intensive scolicidal property, so that toxicity effect begun from 5min and the samples with 20, 10, 5 and 0 fluoride showed 98±2, 93±5.8, 76.2±6 and 5.8±1.7 scolicidal activity, respectively, after 8h exposing time. Our data revealed that scolicidal activity of the FBG increased with the increase of F ratio and concentrations of the bioactive glass. On the other hand, all the synthesized FBG samples found to be cyto-biocompatible when tested in vitro (MTT and LDH assays) and in vivo (no significant infiltration of inflammatory cells compared with control, p>0.05), and antibacterial against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The results demonstrated that the synthesized FBG might have a potential application in prevention of post-surgery infections, especially hydatidosis. © 2015 Elsevier B.V

Comparison of the antibacterial effects of a short cationic peptide and 1 silver bioactive glass against extensively drug-resistant bacteria, Pseudomonas aeruginosa and Acinetobacter baumannii, isolated from burn patients

Abstract: We have already established that a short cationic peptide (CM11) has high antimicrobial activity against a number of bacterial pathogens. Considering the untreatable problem of burn infections caused by Pseudomonas aeruginosa and Acinetobacter baumannii, this study evaluated and compared antibacterial effects of the CM11 peptide and 1 silver-doped bioactive glass (AgBG) against extensively drug-resistant strains of these bacteria which were isolated from burn patients. Accordingly, the bacteria were isolated from burn patients and their antibiotic resistance patterns and mechanisms were fully determined. The isolated bacterial from patients were resistant to almost all commonly used antibiotics and silver treatment. The isolates acquired their resistance through inactivation of their porin, the overexpression of efflux pump, and beta-lactamase. CM11 peptide and 1 AgBG had minimum inhibitory concentration (MIC) of � 16 μg ml�1 and � 4 mg ml�1 for clinical isolates, respectively. The minimum bactericidal concentration (MBC) of peptide and 1 AgBG for resistant bacteria was � 32 μg ml�1 and � 4 mg ml�1, respectively. Among the clinical isolates, two P. aeruginosa isolates and one A. baumannii isolate were resistant to 1 AgBG disk. The CM11 peptide also showed high biocompatibility in vivo and no cytotoxicity against fibroblasts and adipose-derived mesenchymal stem cells in concentrations � 64 μg ml�1 and � 32 μg ml�1, respectively, while the safe concentration of 1 AgBG for these cells was � 16 μg ml�1. In conclusion, these findings indicated that the 1 silver is not safe and effective for treatment of such infections. The data suggest that CM11 peptide therapy is a reliable and safe strategy that can be used for the treatment of burn infections caused by antimicrobial-resistant isolates. The next stage of the study will be a multicenter clinical trial. © 2018, Springer-Verlag GmbH Austria, part of Springer Nature