Antimicrobial activity and antibiotic susceptibility were tested for 23 Lactobacillus and three Bifidobacterium strains isolated from different ecological niches. Agar-well diffusion method was used to test the antagonistic effect (against Staphylococcus aureus, Escherichia coli, Bacillus cereus and Candida albicans) of acid and neutralized (pH 5.5) lyophilized concentrated supernatants (cell-free supernatant; CFS) and whey (cell-free whey fractions; CFW) from de Man–Rogosa–Sharpe/trypticase-phytone-yeast broth and skim milk. Acid CFS and CFW showed high acidification rate-dependent bacterial inhibition; five strains were active against C. albicans. Neutralized CFS/CFW assays showed six strains active against S. aureus (L. acidophilus L-1, L. brevis 1, L. fermentum 1, B. animalis subsp. lactis L-3), E. coli (L. bulgaricus 6) or B. cereus (L. plantarum 24-4В). Inhibition of two pathogens with neutralized CFS (L. bulgaricus 6, L. helveticus 3, L. plantarum 24-2L, L. fermentum 1)/CFW (L. plantarum 24-5D, L. plantarum 24-4В) was detected. Some strains maintained activity after pH neutralization, indicating presence of active substances. The antibiotics minimum inhibitory concentrations (MICs) were determined by the Epsilometer test method. All strains were susceptible to ampicillin, gentamicin, erythromycin and tetracycline. Four lactobacilli were resistant to one antibiotic (L. rhamnosus Lio 1 to streptomycin) or two antibiotics (L. acidophilus L-1 and L. brevis 1 to kanamycin and clindamycin; L. casei L-4 to clindamycin and chloramphenicol). Vancomycin MICs > 256 μg/mL indicated intrinsic resistance for all heterofermentative lactobacilli. The antimicrobially active strains do not cause concerns about antibiotic resistance transfer and could be used as natural biopreservatives in food and therapeutic formulations.

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Pemphigus is a life-threatening skin disease which is associated with IgG autoantibodies against desmoglein (Dsg)1 and Dsg3, leading to blisters of the skin and/or mucous membranes. Considering the central role of autoreactive Dsg-specific T cells in pemphigus pathogenesis we aimed at evaluating three methods that allow a specific monitoring of the autoreactive T cell response in patients with pemphigus including i) cytokine-secretion by ELISpot assay ii) 3 H-thymidine incorporation and iii) flow-cytometric HLA-DRB1*04:02-Dsg3-peptide dextramer staining. Our cohort consists of a total of 37 pemphigus patients at different disease states (active, chronic, remittent) and 24 age-and sex-matched healthy controls (HC). By ELISpot assay, we observed predominantly Th2 type autoreactive Dsgspecific T cell responses in both, pemphigus vulgaris and foliaceus as significantly elevated numbers of Dsg1-and Dsg3-specific IL-5 + T cells were observed compared to HC (p<0.001). Moreover, Dsg3-specific Th2 cell numbers correlated with anti-Dsg3 serum IgG (r¼0.472; p¼0.036). Using 3 H-thymidine incorporation, we consistently detected Dsg3-specific proliferative T cell responses in PV patients which were augmented by repeated Dsg3-stimulation. However, T cell recognition of distinct previously described epitopes of Dsg3 was only marginally detected (stimulation index > 2.5) owing to the low precursor frequency. Still, using HLA-DRB1*04:02-Dsg3-peptide dextramers we could identify peripheral T cell subsets specific for the Dsg3 epitopes Dsg3(190-204) and Dsg3(253-267). Thus, monitoring of autoreactive T cells holds major promise as a readout parameter in therapeutic approaches aimed at down-regulating pathogenic T cells in pemphigus.