21 Recent studies have demonstrated that antibiotic resistance in pathogenic bacteria could be 22 reverted to the drug sensitive phenotype by the treatment with the newly introduced iodine 23 containing nanomolecular complex, FS-1. Antibiotic resistance reversion has been verified as a 24 promising therapeutic approach to combat multidrug resistant infections. The mechanisms of 25 action, however, remain unclear. A collection strain, Escherichia coli ATCC showing 26 an extended spectrum of resistance to beta-lactam and aminoglycoside antibiotics was used in 27 this study as a model organism. The FS-1 treated culture and the negative control variant were 28 sequenced by PacBio RS II System following the SMRTbell 20-kb library preparation protocol.29 Total RNA samples of these strains were sequenced by Ion Torrent. It was shown that the 30 treatment with FS-1 caused a profound gene expression alternation switching the bacterial 31 metabolism to anaerobic respiration, increased anabolism, oxidative/acidic stress response and an 32 inhibition of many nutrient uptake systems. All this leads to an increase in the susceptibility to 33 antibiotics even when FS-1 is removed from the medium. The later fact implies an involvement 34 of epigenetic mechanisms in gene regulation and antibiotic resistance reversion. This hypothesis 35 was investigated by base-call kinetic analysis in PacBio reads and DNA methylation profiling in 36 the sequenced genomes. Several DNA motifs of adenosine and cytosine methylation were 37 identified. While the numbers of methylated sites in chromosomes and plasmids of both 38 genomes, NC and FS, were similar, the distribution of the methylated sites was different. It may 39 explain the observed long lasting effect of the treatment of E. coli with FS-1 on antibiotic 40 susceptibility of this model microorganism.41 Author summary 42 The emergence of multidrug resistant bacteria is a great concern, since the misuse of antibiotics 43 have caused a strong selective pressure for these resistant bacteria and various treatment options 44 are becoming ineffective. Drug induced reversion of antibiotic resistant is considering a 45 promising approach to address this problem. This study was set out to investigate genetic 46 mechanisms of action of a new iodine-containing nano-micelle drug FS-1 that induces antibiotic 47 resistance reversion in bacteria. Escherichia coli ATCC BAA-196 was used as a model of 48 multidrug resistant microorganisms. With this purpose in mind, we have sequenced the genomic 49 DNA and total RNA samples of E. coli cultivated on medium containing FS-1, served as an 50 experimental (FS) variant, and bacteria cultivated on normal medium, served as negative control 51 (NC). RNA sequencing showed a differential gene expression in the FS-1 treated strain that may 52 explain the observed increase in susceptibility to gentamicin and ampicillin. Application of the 53 3 rd generation sequencing technology, SMRT PacBio, allowed an unambiguous whole genome 54 assembly of NC and FS variants, a...

News of the National Academy of Sciences of the Republic of Kazakhstan. Series of biology and medicine.

Staphylococcus aureus ATCC BAA-39 is the reference organism for a multidrug-resistant Staphylococcus aureus (MRSA) strain that was used to study drug-induced resistance reversion by an iodine-containing nanomolecular complex, FS-1. PacBio sequencing was performed on both the experimental and control strains, followed by genome assembly, variant calling, and DNA modification profiling.

Onosma roots are widely used in traditional medicine to treat various diseases throughout the world. In this study, for the first time, we investigated the component composition and biological activity of various extracts from the roots of Onosma gmelinii collected in the highlands of the Kakpakty Mountains of the Almaty region (Republic of Kazakhstan). Extracts were obtained by three different methods: percolation extraction, ultrasound-assisted extraction, and supercritical carbon dioxide extraction. The component composition of the extracts was determined by gas chromatography/mass spectrometry (GC/MS), naphthoquinones by thin-layer chromatography (TLC), and spectrophotometric method. In this study, the presence of shikonin and its derivatives in the extracts was confirmed. The concentration of naphthoquinones during CO2 extraction was about 40%, during ultrasonic extraction about 3%, and during percolation extraction about 1.3%. The GC-MS method identified 69 chemical compounds in the ultrasonic extract, 46 compounds in the CO2 extract, and 51 compounds in the percolation extract. The extracts were tested on a panel of bacteria and viruses: two Gram-negative bacteria (Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027); nine Gram-positive bacteria (Staphylococcus aureus ATCC 6538-P, Staphylococcus aureus ATCC BAA-39, Staphylococcus epidermidis ATCC 51625, Staphylococcus epidermidis ATCC 12228, Streptococcus pyogenes ATCC 19615, Streptococcus pneumoniae ATCC BAA-660, Enterococcus hirae ATCC 10541, Enterococcus faecalis ATCC 51575, Enterococcus faecium ATCC 700221); and two fungal species (Candida albicans ATCC 10231, Candida albicans ATCC 2091); five subtypes of influenza virus A (A/FPV/Weybridge/78 (H7N7), A/Swine/Iowa/15/30 (H1N1), A/black-headed gull/Atyrau/743/04 (H13N6), A/FPV/Rostock/1934 (H7N1), A/Almaty/8/98 (H3N2)). The root extracts of Onosma gmelinii showed antibacterial activity in different degrees against all tested Gram-positive bacterial strains, while no inhibitory effect on Gram-negative bacteria was observed. The results indicated that the ultrasonic extract effectively inhibits the growth of the majority of tested Gram-positive bacteria (MBC from 18.3 to 293.0 µg/mL). CO2 extract had the greatest bactericidal activity (MBC from 0.1 to 24.4 µg/mL). Percolation extract insignificantly inhibited bacterial growth (MBC from 2343.8 to 4687.5 µg/mL). CO2 extract and ultrasonic extract significantly reduced the activity of C. albicans. The results of the antiviral action showed that the ultrasonic extract has the greatest effectiveness against different subtypes of the influenza virus A, while other extracts did not show significant activity.

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