Topical Administration of Lactiplantibacillus plantarum Accelerates the Healing of Chronic Diabetic Foot Ulcers through Modifications of Infection, Angiogenesis, Macrophage Phenotype and Neutrophil Response.

This work aimed to evaluate the adjuvant treatment to surgical debridement using topical applications of Lactiplantibacillus plantarum ATCC 10241 cultures in complicated diabetic foot ulcers as compared to diabetic foot ulcers receiving surgical wound debridement. A randomised controlled trial was performed involving 22 outpatients with complicated diabetic foot ulcers that either received surgical debridement (SuDe, n = 12) or surgical debridement plus topical applications of L. plantarum cultures (SuDe + Lp, n = 10) every week during a 12 week treatment period. Compared to patients receiving SuDe, patients treated with SuDe + Lp exhibited significantly increased fibroplasia and angiogenesis, as determined by Masson's trichrome staining and the study of CD34 cells, α-smooth muscle actin to semi-quantify vascular area, number of vessels and endothelial cells. In addition, a promotion of the polarisation of macrophages from M1 (CD68) to M2 (CD163) phenotype was observed in SuDe + Lp patients with remarkable differences in the tissue localisation. Bacterial counts were significantly diminished in the SuDe + Lp group compared to the SuDe group. Ex vivo assays, using polymorphonuclears isolated from peripheral blood of patients with diabetes and healthy individuals and challenged with Staphylococcus aureus demonstrated that the addition of L. plantarum supernatants significantly improved the phagocytosis of these cells. L. plantarum-secreted components increased the neutrophils bactericidal activity and regulated the netosis induced by S. aureus. At day 49, the average wound area reduction with SuDe + Lp was 73.5% compared with 45.8% for SuDe (p < 0.05). More patients progressed to closure with SuDe + Lp compared with SuDe treatment, indicating the ability of L. plantarum to accelerate the healing. At day 60, 60% of patients treated with SuDe + Lp achieved 100% of wound area reduction compared with 40% for SuDe. We propose that SuDe + Lp could be an effective adjuvant to surgical debridement when SuDe is not satisfactory for patients with complicated diabetic foot ulcers. The treatment is cheap and easy to apply and the product is easy to obtain.

FTIR spectroscopy of chronic venous leg ulcer exudates: an approach to spectral healing marker identification.

Chronic venous leg ulcer (CVLU) arises as a chronic venous insufficiency complication and is a major cause of morbidity throughout the world. Our hypothesis is that the CVLU exudate composition is a biochemical representation of the wound clinical state. Then, Fourier Transform Infrared (FTIR) spectroscopy could be a useful and less-invasive technique to study the clinical state of the ulcer. For this, the aim of this work was to perform a spectral characterization of the exudate from CVLU using FTIR spectroscopy to identify potential healing markers. 45 exudate samples from CVLU, 95% of the strains isolated from CVLU in planktonic and biofilm phenotypes and other related biological samples such as human plasma, serum, urine, blood cells, urea, creatinine, glucose and albumin were studied by FTIR spectroscopy. According to the vibration frequency of biomolecules' (lipids, proteins, nucleic acids and carbohydrates) characteristic bonds in the infrared region, different spectral windows were selected and spectral areas of each window were measured. Besides, Savitzky-Golay second derivatives were obtained for all spectra and peaks from each standardized window were detected. FTIR spectroscopy allowed identification of sample types (exudate, plasma, serum, urine) as each one presents a unique relative composition and ratios range. Also, this technique could be useful to identify bacteria in the phenotypic-ulcer state and allows differentiation of whether bacteria are in the biofilm or planktonic form which is unlikely by conventional methods. In this work we found some spectral markers (areas, peaks) that allow identification of several parameters in the exudate such as (a) total cellularity, (b) inflammatory cell load, (c) bacterial load, (d) fibrin amount, and (e) inflammatory proteins. Because the measured areas or founded peaks are concentration-dependent this method could also serve to measure them. Therefore, FTIR spectroscopy could be useful to evaluate patient evolution as all these exudate parameters represent critical negative markers for wound healing.

Compounds from Lactobacillus plantarum culture supernatants with potential pro-healing and anti-pathogenic properties in skin chronic wounds.

CONTEXT: It is necessary to advance the field of alternative treatments for chronic wounds that are financially accessible to the least economically developed countries. Previously we demonstrated that topical applications of Lactobacillus plantarum culture supernatants (LAPS) on human-infected chronic wounds reduce the pathogenic bioburden, the amount of necrotic tissue, and the wound area, as well as promote debridement, granulation tissue, and wound healing. OBJECTIVE: To study LAPS chemically and biologically and to find potential molecules responsible for its pro-healing and anti-pathogenic properties in chronic wounds. MATERIALS AND METHODS: (1) Chemical analysis: extracts were subjected to a column chromatography and the fractions obtained were studied by GCMS. (2) Quantification: dl-lactic acid (commercial kit), phenolic compounds (Folin-Ciocalteu), H2O2 (micro-titration), and cations (flame photometry). (3) Biological analysis: autoinducers type 2 (AI-2) (Vibrio harveyi BB170 bioassay), DNAase activity (Agar DNAase), and Pseudomonas aeruginosa biofilm inhibition (crystal violet technique). RESULTS: According to its biological activity, the most significant molecules found by GCMS were the following: antimicrobials (mevalonolactone, 5-methyl-hydantoine, benzoic acid, etc.); surfactants (di-palmitin, distearin, and 1,5-monolinolein); anesthetics (barbituric acid derivatives), and AI-2 precursors (4,5-dihydroxy-2,3-pentanedione and 2-methyl-2,3,3,4-tetrahydroxytetrahydrofurane). Concentrations measured (µg/mL): DL-lactic acid (11.71 ± 1.53) and H2O2 (36 ± 2.0); phenolic compounds (485.2 ± 15.20); sodium (370 ± 17); potassium 920 ± 24); calcium (20 ± 4); and magnesium (15 ± 3). DNAase from LAPS had activity on genomic DNA from PMNs and P. aeruginosa. DISCUSSION AND CONCLUSION: The molecules and biological activities found in LAPS could explain the observed effects in human chronic wounds.

Inhibition of quorum sensing in Pseudomonas aeruginosa by sesquiterpene lactones.

Six sesquiterpene lactones (SLs) of the goyazensolide and isogoyazensolide-type isolated from the Argentine herb Centratherum punctatum were evaluated on their ability to inhibit virulence factors of Pseudomonas aeruginosa ATCC 27853. Although compounds were not able to completely inhibit bacterial growth at 200µg/ml, the SLs do altered biofilm formation, elastase activity, and production of N-acyl-homoserinelactones (AHLs) which are known quorum sensing autoinducers at lower concentration. Compounds 2, 3, and 5 displayed significant inhibitory effects on P. aeruginosa biofilm formation at 0.5µg/ml being compound 3 (1.32µM) the most potent (42%). Compounds 2, 3, 4, 5 and 6, inhibited 39, 44, 42, 32 and 35% the production of AHLs at 100µg/ml and inhibited by more than 50% the elastase activity at 0.5µg/ml. Our results clearly indicated that sesquiterpene lactones are good candidates for the development of new antimicrobial agents acting not as bactericidal but as antipathogenic agents.

Antipathogenic properties of Lactobacillus plantarum on Pseudomonas aeruginosa: the potential use of its supernatants in the treatment of infected chronic wounds.

Pathogenic bacteria delay wound healing through several different mechanisms such as persistent production of inflammatory mediators or maintenance of necrotic neutrophils, which release cytolytic enzymes and free oxygen radicals. One of the most frequent pathogens isolated from infections in chronic wounds is Pseudomonas aeruginosa. This bacterium is extremely refractory to therapy and to host immune attack when it forms biofilms. Therefore, antibiotics and antiseptics are becoming useless in the treatment of these infections. In previous works, we demonstrated that Lactobacillus plantarum has an important antipathogenic capacity on P. aeruginosa. The aim of the present work was to elucidate the mechanism involved in the control of growth of P. aeruginosa on different surfaces by L. plantarum. For this purpose, we investigated the effects of L. plantarum supernatants on pathogenic properties of P. aeruginosa, such as adhesion, viability, virulence factors, biofilm formation, and quorum sensing signal expression. L. plantarum supernatants were able to inhibit pathogenic properties of P. aeruginosa by a quorum quenching mechanism. The antipathogenic properties mentioned above, together with the immunomodulatory, tissue repair, and angiogenesis properties in the supernatants of L. plantarum, make them an attractive option in infected chronic wound treatment.

In vivo and in vitro antibacterial activity of acanthospermal B, a sesquiterpene lactone isolated from Acanthospermum hispidum.

Acanthospermal B (AcB), the major sesquiterpene lactone (SL) of Acanthospermum hispidum, an herb widely spread in Argentina, is a selective antibacterial agent against Enterococcus faecalis and Staphylococcus aureus, but inactive on Gram-negative and Lactobacillus. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main microorganisms involved in human chronic infection. A balb\c mouse skin infection model was developed to reproduce the lesions caused by acute and chronic infections produced by MRSA. After determination of the maximum concentration of AcB unable to produce tissular injury after intradermal injection, the anti-MRSA effect of AcB was evaluated on skin, liver and spleen tissues of infected mice. AcB, at doses of 2.5 mg/kg, produced a ten times decrease of MRSA growth in skin infection. In addition, the same dose prevented the dissemination to liver and/or spleen. AcB also displayed a bacteriostatic effect, in vitro, on MRSA cultures at 50 µg/mL that seems to be caused by partial denaturation of total bacterial DNA and/or inhibition of the PCR reaction in not denaturized DNA. Finally, total MRSA cell wall lysis occurred at a concentration of 100 µg/mL of AcB after 2 h of exposure.

Bacteriotherapy with Lactobacillus plantarum in burns.

Bacterial colonisation and infection remain the major causes of delayed healing and graft rejection following burns. Topical treatment is necessary to reduce the incidence of burn wound infection. Silver sulphadiazine (SD-Ag) is an often used microbicidal agent. However, this treatment produces adverse reactions and side-effects. On the basis of experimental data and clinical application of lactobacilli as probiotics, we performed this exploratory study to establish the effectiveness of bacteriotherapy with topical application of the innocuous bacteria Lactobacillus plantarum cultured in De Man, Rogosa and Sharpe medium to provide an alternative method for burn treatment using SD-Ag as a reference. These innocuous bacteria would compete with other bacteria that are wound pathogens and would modify the wound environment and promote tissue repair. Eighty burned patients from the Plastic Surgery and Burns Unit were grouped into infected (delayed) second- and third-degree and non infected (early) third-degree burns and treated with L. plantarum or SD-Ag. The proportion of patients with delayed second-degree burns was 0.71 for L. plantarum and 0.73 for SD-Ag (relative rate: -2.72%) with respect to the decrease in bacterial load (<10(5) bacteria/g of tissue), promotion of granulating tissue wound bed and healing. In early third-degree burns, the values were 0.75 for L. plantarum and 0.84 for SD-Ag (relative rate: -1.07%) in preventing wound infection and promotion of granulation tissue, 0.90 in graft taking for both treatments (relative rate: 0%) and 0.75 for L. plantarum and 0.77 for SD-Ag (relative rate: -2.60%) in healing. In delayed third-degree burns, values were 0.83 for L. plantarum and 0.71 for SD-Ag (relative rate: +16.90%) with respect to the decrease in the bacterial load (<10(5) bacteria/g of tissue) and providing a granulating tissue wound bed, 0.90 in graft taking for both treatments (relative rate: 0%) and 0.75 for L. plantarum and 0.64 for SD-Ag (relative rate: + 17.19%) in healing. Although the number of patients (between 12 and 15 per group) did not enable the application of a power statistical test, these results suggest that the L. plantarum treatment should be studied in greater depth and could be used as a valid alternative for the topical treatment of burns.

Combined autoimmune models of arthritis reveal shared and independent qualitative (binary) and quantitative trait loci.

Collagen-induced arthritis (CIA) and proteoglycan-induced arthritis (PGIA) are murine models for rheumatoid arthritis both in terms of their pathology and genetics. Using the F(2) hybrids of the CIA-susceptible, but PGIA-resistant DBA/1 mice, and the CIA-resistant, but PGIA-susceptible BALB/c mice, our goals were to 1) identify both model-specific and shared loci that confer disease susceptibility, 2) determine whether any pathophysiological parameters could be used as markers that distinguish between nonarthritic and arthritic mice, and 3) analyze whether any immune subtraits showed colocalization with arthritis-related loci. To identify chromosomal loci, we performed a genome scan on 939 F(2) hybrid mice. For pathophysiological analyses, we measured pro- and anti-inflammatory cytokines (IL-1, IL-6, TNF-alpha, IFN-gamma, IL-4, IL-10, IL-12), Ag-specific T cell proliferation and IL-2 production, serum IgG1 and IgG2 levels of both auto- and heteroantibodies, and soluble CD44. In addition to multiple CIA- and PGIA-related loci identified in previous studies, we have identified nine new CIA- and eight new PGIA-linked loci. Comprehensive statistical analysis demonstrated that IL-2 production, T cell proliferation, and IFN-gamma levels differed significantly between arthritic and nonarthritic animals in both CIA and PGIA populations. High levels of TNF-alpha, IFN-gamma, IL-2, and Ab production were detected in F(2) hybrids with CIA, whereas T cell proliferation, IL-2 and IFN-gamma production, and a shift to IgG2a isotype were more characteristic of PGIA. Quantitative trait loci analysis demonstrated colocalization of numerous immune subtraits with arthritis-related traits. Quantitative trait loci on chromosomes 5, 10, 17, 18, and X were found to control arthritis in both models.

Th1 and Th2 cytokines regulate proteoglycan-specific autoantibody isotypes and arthritis.

BALB/c mice immunized with human cartilage proteoglycan (PG) develop arthritis accompanied by the production of autoantibodies to mouse cartilage PG. To determine whether the autoantibody isotype contributes to the onset and severity of arthritis, PG-specific serum IgG1 (Th2, IL-4-cytokine-supporting) and IgG2a (Th1, IFN-gamma-controlling) concentrations were monitored during immunization with PG in IL-4-deficient and IFN-gamma-deficient mice. Paradoxically, despite elevated IFN-gamma, the PG-specific IgG1 isotype was significantly higher than the PG-specific IgG2a response, and the PG-specific IgG1 isotype was independent of IL-4. In contrast, the serum concentration of PG-specific IgG2a isotype was six times higher in IL-4-deficient mice than in wild-type controls. Moreover, the high concentration of PG-specific IgG2a isotype in IL-4-deficient mice corresponded to an increased severity of arthritis. The concentration of PG-specific IgG2a isotype was lower in IFN-gamma-deficient mice than in wild-type mice, and the incidence and severity of arthritis also were significantly lower. Concentrations of PG-specific IgG2a isotype autoantibody correlated with the onset and severity of arthritis, suggesting a pathological role of this isotype, probably locally in the joint.