The Effect of Mesenchymal Stem Cells on Wound Infection.

Wound infection often requires a long period of care and an onerous treatment process. Also, the rich environment makes the wound an ideal niche for microbial growth. Stable structures, like biofilm, and drug-resistant strains cause a delay in the healing process, which has become one of the important challenges in wound treatment. Many studies have focused on alternative methods to deal the wound infections. One of the novel and highly potential ways is mesenchymal stromal cells (MSCs). MSCs are mesoderm-derived pluripotent adult stem cells with the capacity for self-renewal, multidirectional differentiation, and immunological control. Also, MSCs have anti-inflammatory and antiapoptotic effects. MScs, as pluripotent stromal cells, differentiate into many mature cells. Also, MSCs produce antimicrobial compounds, such as antimicrobial peptides (AMP), as well as secrete immune modulators, which are two basic features considered in wound healing. Despite the advantages, preserving the structure and activity of MSCs is considered one of the most important points in the treatment. MSCs' antimicrobial effects on microorganisms involved in wound infection have been confirmed in various studies. In this review, we aimed to discuss the antimicrobial and therapeutic applications of MSCs in the infected wound healing processes.

Biocontrol treatment: Application of Bdellovibrio bacteriovorus HD100 against burn wound infection caused by Pseudomonas aeroginosa in mice.

Owing to the high level of resistance to various antibiotics in bacteria causing burn wound infections, the alternative therapeutics is highly demanded. Bdellovibrio and like organisms (BALOs) seem to be a superb choice. In the present study, Bdellovibrio bacteriovorus HD100 was selected for treating burn wound infection caused by Pseudomonas aeruginosa strain PAO1 in a mouse model. In this experiment, two treatments, meropenem as antibiotic and B. bacteriovorus, were employed. Histopathology indicated an accelerated healing rate in both treatments in comparison with the control. Moreover, quantitative reverse transcription PCR (qRT-PCR) was applied to investigate the expression of tnf-α (tumor necrosis factor alpha), pdgf (platelet-derived growth factor), tgf-ß1 (transforming growth factor beta1), ifn-γ (interferon gamma), vegf (vascular endothelial group factor), and col1 (collagen type 1). The results demonstrated that treating burn wound areas with Bdellovibrio not only decrease the inflammatory phase period, but also may improve the characteristics of proliferative phases of wound healing. In addition, a significant difference was explored between the two treatment groups in the regulation of all genes, except for pdgf revealed a significant up regulation in both treatment groups. The results disclose that Bdellovibrio attenuates P. aeruginosa in burn wounds infections and improves the wound healing process.

Partitioning of Recombinant Pseudomonas putida POS-F84 Proline Dehydrogenase in Aqueous Two-Phase Systems: Optimization Using Response Surface Methodology.

Empirical modeling the partition behavior and recovery of a recombinant Pseudomonas putida POS-F84 proline dehydrogenase (ProDH) in aqueous two-phase systems (ATPS) was carried out by response surface methodology (RSM). Polyethylene glycol 1000 (PEG-1000) concentration, sodium carbonate concentration, and pH, which were the most important factors, were chosen for modeling the partition feature of enzyme. The adequacy of the models was investigated by means of variance analysis. Also, to confirm the efficiency of the ATPS in partition and purification of recombinant ProDH, purity and enzymatic activity was studied. After numerical optimization, an optimal ATPS composed of 14.33% PEG-1000 and 11.79% sodium carbonate at pH 7.48 was achieved. Yield, purification factor, and recovery were 81.41%, 60.82, and 270.82%, respectively. Purified recombinant ProDH was found as a single protein band into the upper PEG-rich phase and the specific activity was calculated to be 46.23 ± 2.1 U/mg. Collectively, our data showed that the RSM could be an appropriate and powerful tool to define the best ATPS system for recovery and purification of P. putida ProDH.

Antibacterial Activity of Euphorbia hebecarpa Alcoholic Extracts Against Six Human Pathogenic Bacteria in Planktonic and Biofilm Forms.

BACKGROUND: Biofilm formation is a primary cause of considerable bacterial destruction. OBJECTIVES: In an effort to combat these industrial and medical bacterial biofilm problems, our study aims to determine the antimicrobial effect of Euphorbia hebecarpa. MATERIALS AND METHODS: The inhibition efficiency of alcoholic extracts on the planktonic form of six pathogenic bacteria was evaluated using a disk diffusion technique. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values were determined by means of a macrobroth dilution method. The effects of the extracts on biofilms were calculated using a microtiter plate method. RESULTS: The results of the disk diffusion assay (MBC and MIC) confirmed that E. hebecarpa ethanolic extracts were more efficient than methanolic extracts in the inhibition of planktonic forms of bacteria. Also, the inhibitory effect of the extracts in a broth medium was greater than in a solid medium. Extracts of E. hebecarpa were found to inhibit biofilm formation better than demolish of biofilm and preventing metabolic activity of bacteria in biofilm structures. The greatest inhibitory effects of E. hebecarpa extracts were observed for the biofilm formation of B. cereus (92.81%). In addition, the greatest demolition was observed for the S. aureus biofilm (74.49%), and the metabolic activity decrement of this bacteria was highest (78.21%) of all the tested bacteria. CONCLUSIONS: The results of this study suggest that E. hebecarpa extracts can be used to inhibit the planktonic and biofilm forms of these selected bacteria.

The inhibitory effect of Thymus vulgaris extracts on the planktonic form and biofilm structures of six human pathogenic bacteria.

OBJECTIVE: Microorganisms are responsible for many problems in industry and medicine because of biofilm formation. Therefore, this study was aimed to examine the effect of Thymus vulgaris (T. vulgaris) extracts on the planktonic form and biofilm structures of six pathogenic bacteria. MATERIALS AND METHODS: Antimicrobial activities of the plant extracts against the planktonic form of the bacteria were determined using the disc diffusion method. MIC and MBC values were evaluated using macrobroth dilution technique. Anti-biofilm effects were assessed by microtiter plate method. RESULTS: According to disc diffusion test (MIC and MBC), the ability of Thymus vulgaris (T. vulgaris ) extracts for inhibition of bacteria in planktonic form was confirmed. In dealing with biofilm structures, the inhibitory effect of the extracts was directly correlated to their concentration. Except for the inhibition of biofilm formation, efficacy of each extract was independent from type of solvent. CONCLUSION: According to the potential of Thymus vulgaris (T. vulgaris) extracts to inhibit the test bacteria in planktonic and biofilm form, it can be suggested that Thymus vulgaris (T. vulgaris) extracts can be applied as antimicrobial agents against the pathogenic bacteria particularly in biofilm forms.

The Effects of Allium sativum Extracts on Biofilm Formation and Activities of Six Pathogenic Bacteria.

BACKGROUND: Garlic is considered a rich source of many compounds, which shows antimicrobial effects. The ability of microorganisms to adhere to both biotic and abiotic surfaces and to form biofilm is responsible for a number of diseases of chronic nature, demonstrating extremely high resistance to antibiotics. Bacterial biofilms are complex communities of sessile microorganisms, embedded in an extracellular matrix and irreversibly attached to various surfaces. OBJECTIVES: The present study evaluated the antimicrobial activity of Allium sativum extract against the biofilms of six pathogenic bacteria and their free-living forms. The clinical isolates in this study had not been studied in any other studies, especially in regard to biofilm disruption and inhibition of biofilm cell metabolic activity. MATERIALS AND METHODS: Antimicrobial activities of A. sativum L. extracts (methanol and ethanol extracts) against planktonic forms of bacteria were determined using the disc diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values were evaluated by a macrobroth dilution technique. The anti-biofilm effects were assessed by microtiter plate method. RESULTS: The results showed that the A. sativum L. extract discs did not have any zone of inhibition for the tested bacteria. However, The MIC values of A. sativum L. extracts (0.078 - 2.5 mg/mL) confirmed the high ability of these extracts for inhibition of planktonic bacteria. A. sativum L. extracts were efficient to inhibit biofilm structures and the concentration of each extract had a direct relation with the inhibitory effect. CONCLUSIONS: Finally, it can be suggested that the extracts of this plant be applied as antimicrobial agents against these pathogens, particularly in biofilm forms.