Interleukin-8 production by polymorphonuclear leukocytes from patients with chronic infected leg ulcers treated with Lactobacillus plantarum.

Bacterial infection impairs the healing process, promoting the chronicity of inflammation and wounds. Because antibiotics fail to eradicate bacteria, especially in biofilm form, new therapeutic modalities may be required. In the present study, the effectiveness of bacteriotherapy with Lactobacillus plantarum on infected chronic venous ulcers was investigated and its effects on interleukin (IL)-8 production by cells from the ulcer bed and neutrophils isolated from peripheral blood that were previously challenged in vitro with Pseudomonas aeruginosa and L. plantarum were studied. Topical application of L. plantarum culture to lesions (25-60 cm(2)) of 14 diabetic and 20 non-diabetic patients induced debridement, granulation tissue formation and total healing after 30 days in 43% diabetics and in 50% non-diabetics. No significant differences between the groups were observed. The cells from ulcer beds collected after treatment with L. plantarum for 10 days showed a decrease in the percentage of polymorphonuclear, apoptotic and necrotic cells and an enhancement of IL-8 production. IL-8 production by isolated neutrophils from these patients was compared with that in diabetics without ulcers, as well as normal subjects under basal conditions, and after infection of polymorphonuclear cells with P. aeruginosa preincubated either with or without L. plantarum. The basal values in diabetic and ulcer patients were higher than normal (p <0.001) and were increased by P. aeruginosa infection in normal, diabetics (p <0.001) and non-diabetics with ulcers (p <0.01). Preincubation with L. plantarum decreased IL-8 production in patients with ulcers non-diabetic and diabetic (p <0.001). Lactobacillus plantarum treatment reduced wound bacterial load, neutrophils, apoptotic and necrotic cells, modified IL-8 production and induced wound healing.

Differences between Pseudomonas aeruginosa in a clinical sample and in a colony isolated from it: comparison of virulence capacity and susceptibility of biofilm to inhibitors.

We study the differences between Pseudomonas aeruginosa from an infected wound (clinical strain) and a colony isolated from it. We assessed the in vitro inhibition of these P. aeruginosa biofilms by DNase and filtrate of Lactobacillus plantarum cultures (acid=AF and neutralize=NF) with crystal violet technique. Inhibition by AF was greatest than DNase for clinical and isolated strain (p<0.001) and greatest than NF for clinical (p<0.05) and isolated strain (p<0.001). Using a burn model in mice, we compared the infection producing by clinical and isolated strains in planktonic and biofilm form. Deaths were quantified and the infection was assessed by determining CFU/g of tissue in the lesion, spleen and liver. The infections with planktonic bacteria tended to become systemic and more deadly than biofilm infections. All infected wounds required the same healing period (30 days). These findings were independent of the origin of the bacteria (clinical or colony isolated strain).

Recovery from experimental malnutrition with soymilk: immunological and genetic aspects.

Experimental malnutrition models have been useful to study the effects of malnutrition at early ages. Substantial evidence exists that malnutrition in critical stages of development could result in chromosomal damages. The effect of nutritional rehabilitation with soymilk as a complement of a restricted diet, on plasma and muscle proteins, chromosomal integrity, and unspecific and mucosa immune responses, was studied. Adult male and female Wistar rats (5 weeks old) were assigned to different nutritional conditions: (a) 14 days on protein restricted diet (corn flour and water), followed by 14 days in which water was replaced by soymilk, as nutritional rehabilitation; (b) the same conditions above but periods of 28 days of a protein restricted diet, and 28 days of nutritional rehabilitation and (c) age-matched malnourished (protein restricted diet without nutritional rehabilitation) and normally nourished controls. After both nutritional rehabilitation periods, the weights reached were significantly higher (p < 0.001) than the malnourished control values, but lower than the normal control ones. Plasma protein concentrations were similar in all groups. Muscle proteins that were diminished during the restricted diet, reached normal control values after both rehabilitation periods. The protein restricted diet, produced numeric and structural chromosomal abnormalities. Nutritional rehabilitation was only partially able to revert these abnormalities. The phagocytic activity and gut mucosa IgA-secreting cells were significantly reduced (p < 0.001) during the restricted diet; both nutritional rehabilitation periods induced a significant increase of both, phagocytic activity and IgA secreting cells. These values were similar to controls. Our results show that the supplementation of a protein-restricted diet with soymilk improved tissue protein content, as well as unspecific and gut mucosa immune responses, even though it was not able to reinstate fully normal body weight and a normal chromosome karyotype.

Interference of Lactobacillus plantarum with Pseudomonas aeruginosa in vitro and in infected burns: the potential use of probiotics in wound treatment.

This study evaluated the ability of the probiotic organism Lactobacillus plantarum to inhibit the pathogenic activity of Pseudomonas aeruginosa, both in vitro and in vivo, and investigated the mechanisms involved in such protection. L. plantarum whole cultures, culture filtrates (acid filtrate and neutralised acid filtrate) and isolated, washed cells were tested in vitro for their effects on the production of the P. aeruginosa quorum-sensing signal molecules, acyl-homoserine-lactones (AHLs), and two virulence factors controlled by these signal molecules, elastase and biofilm. All were inhibited by L. plantarum cultures and filtrates, but not by isolated, washed cells. The acid L. plantarum growth medium itself had some inhibitory activity, but the greatest activity was exerted by the whole culture. To test the in-vivo activity of L. plantarum, a burned-mouse model was used in which burns infected with P. aeruginosa were treated with L. plantarum at 3, 4, 5, 7 and 9 days post-infection. Samples from skin, liver and spleen taken after 5, 10 and 15 days demonstrated inhibition of P. aeruginosa colonisation by L. plantarum. There was also an improvement in tissue repair, enhanced phagocytosis of P. aeruginosa by tissue phagocytes, and a decrease in apoptosis at 10 days. These results indicate that L. plantarum and/or its by-products are potential therapeutic agents for the local treatment of P. aeruginosa burn infections.