Previously, we isolated lactic acid bacteria from the slime of the garden snail Helix aspersa Müller and selected Weissella viridescens UCO-SMC3 because of its ability to inhibit in vitro the growth of the skin-associated pathogen Cutibacterium acnes. The present study aimed to characterize the antimicrobial and immunomodulatory properties of W. viridescens UCO-SMC3 and to demonstrate its beneficial effect in the treatment of acne vulgaris. Our in vitro studies showed that the UCO-SMC3 strain resists adverse gastrointestinal conditions, inhibits the growth of clinical isolates of C. acnes, and reduces the adhesion of the pathogen to keratinocytes. Furthermore, in vivo studies in a mice model of C. acnes infection demonstrated that W. viridescens UCO-SMC3 beneficially modulates the immune response against the skin pathogen. Both the oral and topical administration of the UCO-SCM3 strain was capable of reducing the replication of C. acnes in skin lesions and beneficially modulating the inflammatory response. Of note, orally administered W. viridescens UCO-SMC3 induced more remarkable changes in the immune response to C. acnes than the topical treatment. However, the topical administration of W. viridescens UCO-SMC3 was more efficient than the oral treatment to reduce pathogen bacterial loads in the skin, and effects probably related to its ability to inhibit and antagonize the adhesion of C. acnes. Furthermore, a pilot study in acne volunteers demonstrated the capacity of a facial cream containing the UCO-SMC3 strain to reduce acne lesions. The results presented here encourage further mechanistic and clinical investigations to characterize W. viridescens UCO-SMC3 as a probiotic for acne vulgaris treatment.

Indoxyl sulfate (IS) is involved in the progression of chronic kidney disease (CKD) and in its cardiovascular complications. One of the approaches proposed to decrease IS is the administration of synbiotics. This work aimed to search for a probiotic strain capable to decrease serum IS levels and mix it with two prebiotics (inulin and fructooligosaccharide (FOS)) to produce a putative synbiotic and test it in a rat CKD model. Two groups of Sprague-Dawley rats were nephrectomized. One group (Lac) received the mixture for 16 weeks in drinking water and the other no (Nef). A control group (C) included sham-nephrectomized rats. Serum creatinine and IS concentrations were measured using high-performance liquid chromatography with diode array detector (HPLC-DAD). Optical microscopy and two-photon excitation microscopy was used to study kidney and heart samples. The Lac group, which received the synbiotic, reduced IS by 0.8% while the Nef group increased it by 38.8%. Histological analysis of kidneys showed that the Lac group increased fibrotic areas by 12% and the Nef group did it by 25%. The synbiotic did not reduce cardiac fibrosis. Therefore, the putative synbiotic showed that function reducing IS and the progression of CKD in a rat model, but no heart protection was observed.

Gamma-aminobutyric acid (GABA) is a bioactive amino acid with anti-inflammatory and neurotransmitter properties, yet limited information exists regarding its production by Lactiplantibacillus paraplantarum. We evaluated factors that influence GABA synthesis by L. paraplantarum HK-1 and assessed its production in vitro and under simulated gastrointestinal conditions. GABA production was analyzed using HPLC with pre-column derivatization, gene expression was assessed through RT-qPCR, and probiotic characteristics were evaluated using standard microbiological methods. L. paraplantarum HK-1 demonstrated dose-dependent GABA production with monosodium glutamate (MSG) supplementation, achieving maximum levels at 500 mM MSG (161.1 µg/mL), which was significantly higher than those in other treatments (p < 0.01). A strong positive correlation was observed between MSG concentration and GABA production (r = 0.908, p = 0.002). Gene expression analysis revealed a 61.6-fold higher gadB expression at 500 mM MSG compared to 250 mM, though statistical significance with GABA production was not achieved (r = 0.741, p = 0.259). The strain exhibited appropriate probiotic characteristics including γ-hemolytic activity, bile salt tolerance, and acid resistance. Under simulated gastrointestinal conditions, maximum GABA production occurred in the distal colon (148.3 ± 19.0 µg/mL with probiotic vs. 7.2 ± 6.2 µg/mL control), with overall production significantly higher in probiotic-treated groups (p < 0.001). Overall, L. paraplantarum HK-1 produced GABA throughout gastrointestinal phases and showed traits consistent with probiotic use. These results position HK-1 as a promising GABA-producing candidate for functional food applications, pending in vivo validation.

Knowledge of Feline Leukemia Virus (FeLV) sequence variation has mainly been developed using Sanger sequencing methods. However, advances in next generation sequencing methods and their broad use in laboratories has been changing our understanding of viral genetics. FeLV sequencing has specific complications with the presence of both exogenous (exFeLV) and endogenous (enFeLV) virus with frequent recombination between them, limiting sequencing approaches. Here we report an FeLV-A and FeLV-B amplicon-based comparison between Sanger, Illumina, and Oxford Nanopore sequencing methods in Chilean domestic cats. We analysed the hypervariable envelope gene, where a higher number of variants as well as recombination with endogenous strains occurs. We detected multiple variants and viral quasispecies infecting the cats. We compared these three methods to evaluate the advantages and disadvantages between them. Although the Sanger method is highly reliable, it showed a high fail rate (many amplicons did not produce useable sequence) and the sequences obtained showed artificial sequence clustering when compared with the NGS methods. Illumina sequencing showed a lower error rate but could not discriminate between exogenous and endogenous viruses. Finally, Oxford Nanopore (MinION) sequencing could successfully detect low-abundance sequences and discriminate between FeLV-A and FeLV-B sequences, although its higher error-rate requires caution in interpretation of the results. Our results indicate advantages and disadvantages for each method, with the purpose of sequencing needing to be considered in the choice of method. Results of large viral phylogenetic trees combing sequences derived from mixed sequencing methods, such as those combining historical and contemporary sequencing need to be considered with some caution as artificial clustering by sequencing method may occur.