HNOXPred: a web tool for the prediction of gas-sensing H-NOX proteins from amino acid sequence.

SUMMARY: HNOXPred is a webserver for the prediction of gas-sensing heme-nitric oxide/oxygen (H-NOX) proteins from amino acid sequence. H-NOX proteins are gas-sensing hemoproteins found in diverse organisms ranging from bacteria to eukaryotes. Recently, gas-sensing complex multi-functional proteins containing only the conserved amino acids at the heme centers of H-NOX proteins, have been identified through a motif-based approach. Based on experimental data and H-NOX candidates reported in the literature, HNOXPred is created to automate and facilitate the identification of similar H-NOX centers across systems. The server features HNOXSCORES scaled from 0 to 1 that consider in its calculation, the physicochemical properties of amino acids constituting the heme center in H-NOX in addition to the conserved amino acids within the center. From user input amino acid sequence, the server returns positive hits and their calculated HNOXSCORES ordered from high to low confidence which are accompanied by interpretation guides and recommendations. The utility of this server is demonstrated using the human proteome as an example. AVAILABILITY AND IMPLEMENTATION: The HNOXPred server is available at https://www.hnoxpred.com. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Detection of antibiotic resistance in probiotics of dietary supplements.

BACKGROUND: Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. FINDINGS: Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. CONCLUSIONS: This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.