Whole genome sequence data of Lactobacillus fermentum HFD1, the producer of antibacterial peptides

© 2020 The Author(s) Here we report the whole genome sequence of Lactobacillus fermentum HFD1 strain, the producer of antibacterial peptides. The genome consists of one circular chromosome with 2101878 bp in length and GC-content of 51.8%, and includes linear DNA with 5386 bp in length with 100% identity to bacteriophage phiX174. The analysis of the genome has revealed 2049 genes encoding for proteins including 867 proteins without known function and 70 genes encoding for RNAs (10 rRNAs, 59 tRNAs and 1 tmRNA). Putative genes responsible for the biosynthesis of 4 antimicrobial peptides were identified. The NCBI Bioproject has been deposited at NCBI under the accession number PRJNA615901 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA615901/) and consist of full annotated genome and raw sequence data

Characterization of gut contractility and microbiota in patients with severe chronic constipation

© 2020 Yarullina et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Chronic constipation (CC) is one of the most common gastrointestinal disorders worldwide. Its pathogenesis, however, remains largely unclear. The purpose of the present work was to gain an insight into the role of contractility and microbiota in the etiology of CC. To this end, we studied spontaneous and evoked contractile activity of descending colon segments from patients that have undergone surgery for refractory forms of CC. The juxta-mucosal microbiota of these colon samples were characterized with culture-based and 16S rRNA sequencing techniques. In patients with CC the spontaneous colonic motility remained unchanged compared to the control group without dysfunction of intestinal motility. Moreover, contractions induced by potassium chloride and carbachol were increased in both circular and longitudinal colonic muscle strips, thus indicating preservation of contractile apparatus and increased sensitivity to cholinergic nerve stimulation in the constipated intestine. In the test group, the gut microbiota composition was assessed as being typically human, with four dominant bacterial phyla, namely Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, as well as usual representation of the most prevalent gut bacterial genera. Yet, significant inter-individual differences were revealed. The phylogenetic diversity of gut microbiota was not affected by age, sex, or colonic anatomy (dolichocolon, megacolon). The abundance of butyrate-producing genera Roseburia, Coprococcus, and Faecalibacterium was low, whereas conventional probiotic genera Lactobacillus and Bifidobacteria were not decreased in the gut microbiomes of the constipated patients. As evidenced by our study, specific microbial biomarkers for constipation state are absent. The results point to a probable role played by the overall gut microbiota at the functional level. To our knowledge, this is the first comprehensive characterization of CC pathogenesis, finding lack of disruption of motor activity of colonic smooth muscle cells and insufficiency of particular members of gut microbiota usually implicated in CC

Bidirectional alterations in antibiotics susceptibility in Staphylococcus aureus—Pseudomonas aeruginosa dual-species biofilm

© 2020, The Author(s). In mixed infections, the bacterial susceptibility differs significantly compared to monocultures of bacteria, and generally the concentrations of antibiotics required for the treatment increases drastically. For S. aureus and P. aeruginosa dual species biofilms, it has been numerously reported that P. aeruginosa decreases S. aureus susceptibility to a broad range of antibiotics, including beta-lactams, glycopeptides, aminoglycosides, macrolides, while sensitizes to quinolones via secretion of various metabolites. Here we show that S. aureus also modulates the susceptibility of P. aeruginosa to antibiotics in mixed cultures. Thus, S. aureus—P. aeruginosa consortium was characterized by tenfold increase in susceptibility to ciprofloxacin and aminoglycosides compared to monocultures. The same effect could be also achieved by the addition of cell-free culture of S. aureus to P. aeruginosa biofilm. Moreover, similar increase in antibiotics efficacy could be observed following addition of S. aureus suspension to the P. aeruginosa mature biofilm, compared to P. aeruginosa monoculture, and vice versa. These findings open promising perspectives to increase the antimicrobial treatment efficacy of the wounds infected with nosocomial pathogens by the transplantation of the skin residential microflora

Identification of Antimicrobial Peptides from Novel Lactobacillus fermentum Strain

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Antimicrobial peptides (AMPs) are natural antagonistic tools of many bacteria and are considered as attractive antimicrobial agents for the treatment of bacteria with multidrug resistance. Lactic acid bacteria from the gastrointestinal tract of animals and human produce various AMPs inhibiting the growth of pathogens. Here we report the isolation and identification of novel Lactobacillus fermentum strain HF-D1 from the human gut producing AMPs which prevents the growth of P. aeruginosa and S. marcescens. The active fraction of peptides was obtained from the culture liquid by precipitation at 80% saturation of ammonium sulphate. For peptides identification, the precipitate was treated with guanidine hydrochloride to desorb from proteins, separated with ultrafiltration on spin columns with 10,000 MWCO, desalted with a reversed-phase chromatography and subjected to LC–MS/MS analysis. The in silico analysis of the identified 1111 peptides by using ADAM, CAMPR3 and AMPA prediction servers led to identification of the linear peptide with highly probable antimicrobial activity and further investigation of its antibacterial activity mechanism is promising. By using the dereplication algorithm, the peptide highly similar to non-ribosomal cyclic AMPs originally isolated from Staphylococcus epidermidis has been identified. This indicates that L. fermentum HF-D1 represents a novel strain producing antimicrobial peptides targeting P. aeruginosa and S. marcescens