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Phage therapy is now seen as a promising way to overcome the current global crisis in the spread of multidrug-resistant bacteria. However, phages are highly strain-specific, and in most cases one will have to isolate a new phage or search for a phage suitable for a therapeutic application in existing libraries. At an early stage of the isolation process, rapid screening techniques are needed to identify and type potential virulent phages. Here, we propose a simple PCR approach to differentiate between two families of virulent Staphylococcus phages (Herelleviridae and Rountreeviridae) and eleven genera of virulent Klebsiella phages (Przondovirus, Taipeivirus, Drulisvirus, Webervirus, Jiaodavirus, Sugarlandvirus, Slopekvirus, Jedunavirus, Marfavirus, Mydovirus and Yonseivirus). This assay includes a thorough search of a dataset comprising S. aureus (n = 269) and K. pneumoniae (n = 480) phage genomes available in the NCBI RefSeq/GenBank database for specific genes that are highly conserved at the taxonomic group level. The selected primers showed high sensitivity and specificity for both isolated DNA and crude phage lysates, which permits circumventing DNA purification protocols. Our approach can be extended and applied to any group of phages, given the large number of available genomes in the databases.

Bacteriophage therapy is considered one of the most promising therapeutic approaches against multi-drug resistant bacterial infections. Infections caused by Staphylococcus aureus are very efficiently controlled with therapeutic bacteriophage cocktails, containing a number of individual phages infecting a majority of known pathogenic S. aureus strains. We assessed the contribution of individual bacteriophages comprising a therapeutic bacteriophage cocktail against S. aureus in order to optimize its composition. Two lytic bacteriophages vB_SauM-515A1 (Myoviridae) and vB_SauP-436A (Podoviridae) were isolated from the commercial therapeutic cocktail produced by Microgen (Russia). Host ranges of the phages were established on the panel of 75 S. aureus strains. Phage vB_SauM-515A1 lysed 85.3% and vB_SauP-436A lysed 68.0% of the strains, however, vB_SauP-436A was active against four strains resistant to vB_SauM-515A1, as well as to the therapeutic cocktail per se. Suboptimal results of the therapeutic cocktail application were due to extremely low vB_SauP-436A1 content in this composition. Optimization of the phage titers led to an increase in overall cocktail efficiency. Thus, one of the effective ways to optimize the phage cocktails design was demonstrated and realized by using bacteriophages of different families and lytic spectra.

The ever-rising prevalence of multidrug-resistant bacteria necessitates the search for a therapeutic alternative to antibiotics. Using therapeutic products based on virulent bacteriophages might provide such an alternative. The aim of our study was to evaluate the efficacy of commercial phage products and natural bacteriophage monoisolates recovered from environmental sources against clinical strains of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. We compiled a collection of 147 strains that were subsequently genotypes using the MLST method. The efficacy of bacteriophages was evaluated in spot tests. The highest efficacy was demonstrated by "Staphylococcal bacteriophage" (86%, effective against S. aureus), "Purified polyvalent pyobacteriophage" (87.8%, effective against K. pneumoniae), and a group of phage products against P. aeruginosa, including "Pseudomonas aeruginosa bacteriophage" (87.5%), "Complex pyobacteriophage" (79.5–90%) and "Purified polyvalent pyobacteriophage" (90–92.5%). The efficacy of "Intesti bacteriophage", which targets E. faecium, was 4.2%. The efficacy of commercial phage products against S. aureus and K. pneumoniae was higher than the efficacy of individual phage monoisolates (60% for the S. aureus phage vB_SauP-436-3w and 5.9% for the K. pneumoniae phage vB_Kp_M_ Seu621). Thus, all tested commercial phage products were highly effective against P. aeruginosa, K. pneumoniae and S. aureus. There are no commercial phage products on the market against other ESKAPE pathogens, including Acinetobacter baumannii and Enterobacter cloacae. Besides, there are no effective phage products against E. faecium. This dictates the need for new effective bacteriophages against these species.

G-quadruplexes (G4s) are non-canonical DNA structures that could be considered as potential therapeutic targets for antimicrobial compounds, also known as G4-stabilizing ligands. While some of these ligands are shown

The Klebsiella pneumoniae bacterium is capable of causing the broad range of human nosocomial infections associated with antibiotic resistance and high mortality. Virulent bacteriophage therapy is one of the promising alternatives to antibiotic treatment of such infections. The study was aimed to isolate virulent bacteriophages effective against the relevant clinical K. pneumoniae strains, and to perform the molecular genetic characterization of these phages. Bacteriophages were isolated from the river water samples using the enrichment method. The whole-genome sequencing was performed on the MiSeq platform (Illumina). Three novel K. pneumoniae bacteriophages belonging to families Autographiviridae (vB_KpnP_NER40, GenBank MZ602146) and Myoviridae (vB_KpnM_VIK251, GenBank MZ602147; vB_KpnM_FRZ284, GenBank MZ602148) have been isolated and characterized. On the collection of 105 K. pneumoniae clinical strains, it has been found that bacteriophages vB_KpnP_NER40 and vB_KpnM_VIK251 have a narrow lytic spectrum (22% and 11%), which is limited to strains of the capsular types К2 and К20 respectively. In contrast, bacteriophage vB_KpnM_FRZ284 has a broad lytic spectrum (37%), causing the lysis of strains with different types of capsular polysaccharide. The phages are strictly virulent and have no genes encoding integrases, toxins or pathogenicity factors in their genomes. Genes of depolymerases, encoding the potential receptor binding proteins, have been found in the genomes of the capsular-specific bacteriophages vB_KpnP_NER40 and vB_KpnM_VIK251. The cocktail of three bacteriophages has lysed about 65% of the studied collection of K. рneumoniae strain and is potentially applicable for therapeutic purposes.

Pseudomonas aeruginosa — is one of the pathogens characterized by the critical number of multidrug-resistant (MDR) strains. Phage therapy is considered an alternative to antibiotics, especially in treatment of infections caused by MDR strains. The aim of this study was to isolate and characterize P. aeruginosa phages that could potentially be suitable for treating infectious diseases. To isolate the P. aeruginosa phages, enrichment cultures were used. The lytic activity spectrum was confirmed by spot testing on 40 P. aeruginosa strains. Whole-genome sequencing was performed using Illumina MiSeq instrument. Phylogenetic analysis was done using VICTOR tool. Isolated phages vB_PaeA-55-1w and vB_PaeM-198 from Autographiviridae and Myoviridae families, respectively, had a broad spectrum of lytic activity (about 50% each), including lysis of MDR strains. The genomes vB_PaeA-55-1w and vB_PaeM-198 comprise double-stranded DNA of 42.5 and 66.3 kbp in length, respectively. Open reading frames were annotated for both phages (52 for vB_PaeA-55-1w, and 95 for vB_PaeM-198), no integrases and toxins were detected. On a phylogenetic tree, vB_PaeA-55-1w phage was clustered with phages from the Phikmvvirus genus (Autographiviridae family), which are also used in phage therapy. vB_PaeM-198 phage was clustered with phages from the Pbunavirus genus (Myoviridae family). vB_PaeA-55-1w and vB_PaeM-198 phages could be considered as candidates for phage therapy and may be used to treat infections caused by MDR P. aeruginosa.

Phage therapy is a promising method of treating antibiotic-resistant infections. To obtain a safe therapeutic formulation, bacterial cell components, including endotoxins, must be removed from the phage lysate. This study was aimed at comparing the efficacy of purification methods for phage lysates intended for therapeutic use. Phages vB_KpnM_Seu621 (Myoviridae) and vB_KpnP_Dlv622 (Autographiviridae) were grown using the KP9068 strain of Klebsiella pneumoniae as a host. The obtained lysates were purified using phage precipitation with polyethylene glycol, CsCl density gradient ultracentrifugation, sucrose density gradient ultracentrifugation, precipitation with 100 kDa centrifugal filter units, and phage concentration on 0.22 µm cellulose filters in the presence of MgSO4. Endotoxin concentrations were determined by LAL testing. The obtained lysates contained 1.25 × 1012 ± 7.46 × 1010 and 2.25 × 1012 ± 1.34 × 1011 PFU/ml of vB_KpnM_Seu621 and vB_KpnP_Dlv622, respectively, and had endotoxin concentrations of 3,806,056 ± 429,410 and 189,456 ± 12,406 EU/ml, respectively. CsCl gradient ultracentrifugation was found to be the optimal conventional purification method in terms of reducing endotoxin concentrations and maintaining phage titers (303 ± 20 — 313 ± 35 EU/ml, 1.5–2.75 × 1012 ± 1.71 × 1011 PFU/ml). Sucrose gradient ultracentrifugation and filtration in the presence of MgSO4 were found to be the optimal non-traditional purification methods. A method for phage lysate purification should be selected for each phage preparation individually. Sucrose gradient ultracentrifugation and filtration in the presence of MgSO4 hold promise as purification methods that can produce phage preparations suitable for intravenous administration.

Mycobacterium tuberculosis complex (MTBC) species are classic examples of genetically monomorphic microorganisms due to their low genetic variability. Whole-genome sequencing made it possible to describe both the main species within the complex and M. tuberculosis lineages and sublineages. This differentiation is based on single nucleotide polymorphisms (SNPs) and large sequence polymorphisms in the so-called regions of difference (RDs). Although a number of studies have been performed to elucidate RD localizations, their distribution among MTBC species, and their role in the bacterial life cycle, there are some inconsistencies and ambiguities in the localization of RDs in different members of the complex. To address this issue, we conducted a thorough search for all possible deletions in the WGS data collection comprising 721 samples representing the full MTBC diversity. Discovered deletions were compared with a list of all previously described RDs. As with the SNP-based analysis, we confirmed the specificities of 79 regions at the species, lineage, or sublineage level, 17 of which are described for the first time. We also present RDscan (https://github.com/dbespiatykh/RDscan), an open-source workflow, which detects deletions from short-read sequencing data and correlates the results with high-specificity RDs, curated in this study. Testing of the workflow on a collection comprising ∼7,000 samples showed a high specificity of the found RDs. This study provides novel details that can contribute to a better understanding of the species differentiation within the MTBC and can help to determine how individual clusters evolve within various MTBC species. IMPORTANCE Reductive genome evolution is one of the most important and intriguing adaptation strategies of different living organisms to their environment. Mycobacterium offers several notorious examples of either naturally reduced (Mycobacterium leprae) or laboratory-reduced (Mycobacterium bovis BCG) genomes. Mycobacterium tuberculosis complex has its phylogeny unambiguously framed by large sequence polymorphisms that present unidirectional unique event changes. In the present study, we curated all known regions of difference and analyzed both Mycobacterium tuberculosis and animal-adapted MTBC species. For 79 loci, we have shown a relationship with phylogenetic units, which can serve as a marker for diagnosing or studying biological effects. Moreover, intersections were found for some loci, which may indicate the nonrandomness of these processes and the involvement of these regions in the adaptation of bacteria to external conditions.

There is growing concern about the emergence and spread of multidrug-resistant Neisseria gonorrhoeae. To effectively control antibiotic-resistant bacterial pathogens, it is necessary to develop new antimicrobials and to understand the resistance mechanisms to existing antibiotics. In this study, we discovered the unexpected onset of drug resistance in N. gonorrhoeae caused by amino acid substitutions in the periplasmic chaperone SurA and the β-barrel assembly machinery component BamA. Here, we investigated the i19.05 clinical isolate with mutations in corresponding genes along with reduced susceptibility to penicillin, tetracycline, and azithromycin. The mutant strain NG05 (surAmut bamAmut, and penAmut) was obtained using the pan-susceptible n01.08 clinical isolate as a recipient in the transformation procedure. Comparative proteomic analysis of NG05 and n01.08 strains revealed significantly increased levels of other chaperones, Skp and FkpA, and some transport proteins. Efflux pump inhibition experiments demonstrated that the reduction in sensitivity was achieved due to the activity of efflux pumps. We hypothesize that the described mutations in the surA and bamA genes cause the qualitative and quantitative changes of periplasmic chaperones, which in turn alters the function of synthesized cell envelope proteins.

Mycobacterium tuberculosis Beijing genotype associated with drug resistance is a growing public health problem worldwide. The aim of this study was the assessment of virulence for C57BL/6 mice after infection by clinical M. tuberculosis strains 267/47 and 120/26, which belong to the modern sublineages B0/W148 and Central Asia outbreak of the Beijing genotype, respectively. The sublineages were identified by the analysis of the strains’ whole-genomes. The strains 267/47 and 120/26 were characterized as agents of pre-extensively drug-resistant (pre-XDR) and multidrug-resistant (MDR) tuberculosis, respectively. Both clinical strains were slow-growing in 7H9 broth compared to the M. tuberculosis H37Rv strain. The survival rates of C57BL/6 mice infected by 267/47, 120/26, and H37Rv on the 150th day postinfection were 10%, 40%, and 70%, respectively. Mycobacterial load in the lungs, spleen, and liver was higher and histopathological changes were more expressed for mice infected by the 267/47 strain compared to those infected by the 120/26 and H37Rv strains. The cytokine response in the lungs of C57BL/6 mice after infection with the 267/47, 120/26, and H37Rv strains was different. Notably, proinflammatory cytokine genes Il-1α, Il-6, Il-7, and Il-17, as well as anti-inflammatory genes Il-6 and Il-13, were downregulated after an infection caused by the 267/47 strain compared to those after infection with the H37Rv strain.

Antibiotic resistance is a major public health concern in many countries worldwide. The rapid spread of multidrug-resistant (MDR) bacteria is the main driving force for the development of novel non-antibiotic antimicrobials as a therapeutic alternative. Here, we isolated and characterized three virulent bacteriophages that specifically infect and lyse MDR Klebsiella pneumoniae with K23 capsule type. The phages belonged to the Autographiviridae (vB_KpnP_Dlv622) and Myoviridae (vB_KpnM_Seu621, KpS8) families and contained highly similar receptor-binding proteins (RBPs) with polysaccharide depolymerase enzymatic activity. Based on phylogenetic analysis, a similar pattern was also noted for five other groups of depolymerases, specific against capsule types K1, K30/K69, K57, K63, and KN2. The resulting recombinant depolymerases Dep622 (phage vB_KpnP_Dlv622) and DepS8 (phage KpS8) demonstrated narrow specificity against K. pneumoniae with capsule type K23 and were able to protect Galleria mellonella larvae in a model infection with a K. pneumoniae multidrug-resistant strain. These findings expand our knowledge of the diversity of phage depolymerases and provide further evidence that bacteriophages and phage polysaccharide depolymerases represent a promising tool for antimicrobial therapy.

Whole genome sequencing of the Escherichia coli strain АВ1157 and its mutants AB1885 uvrB5, AB2463 recA13, and AB2494 lexA1, which have deficient DNA repair, recombination, and mutagenesis systems, was performed. It was found that the genomes of the AB2463 recA13 and AB2494 lexA1 strains differ from the genome of ancestral strain in several hundred mutations which arose most probably in the course of a single treatment of AB1157 with N-methyl-N-nitro-N-nitrosoguanidine. At the same time, the genome of the strain AB1885 obtained after treatment with nitrous acid contained ten times fewer differences from its parent strain. Mutations in the AB2463 recA13 and AB2494 lexA1 genomes were predominantly represented by GC to AT transitions distributed randomly along the genomes, and their locations did not coincide in these strains. The effect of spontaneous mutations on the differences between the strains studied that appeared during the period from their isolation to the sequence experiments seems to be insignificant. Earlier known genetic and phenotypic traits are annotated on the molecular level.

Recent advances in MS/MS technology have made it possible to use proteomic data to predict protein-coding sequences. This approach is called proteogenomics, and it allows to correctly translate start and stop sites and to reveal new open reading frames. Here, we focus on using proteogenomics to improve the annotation of Mycobacteriumtuberculosis strains. We also describe detail procedures of the extraction of proteins and their further preparation for LC-MS/MS analysis and outline the main steps of data analysis.

Recent advances in MS/MS technology have made it possible to use proteomic data to predict protein-coding sequences. This approach is called proteogenomics, and it allows to correctly translate start and stop sites and to reveal new open reading frames. Here, we focus on using proteogenomics to improve the annotation of Mycobacteriumtuberculosis strains. We also describe detail procedures of the extraction of proteins and their further preparation for LC-MS/MS analysis and outline the main steps of data analysis.

Mycobacterium tuberculosis is one of the most dangerous pathogens. Bacterial resistance to antituberculosis drugs grows each year, but searching for new drugs is a long process. Testing for available drugs to find active against mycobacteria may be a good alternative. In this work, antibiotics of the aureolic acid group were tested on a model organism Mycobacterium smegmatis. We presumed that antibiotics of this group may be potential G4 ligands. However, this was not confirmed in our analyses. We determined the antimicrobial activity of these drugs and revealed morphological changes in the cell structure upon treatment. Transcriptomic analysis documented increased expression of MSMEG_3743/soj and MSMEG_4228/ftsW, involved in cell division. Therefore, drugs may affect cell division, possibly disrupting the function of the Z-ring and the formation of a septum. Additionally, a decrease in the transcription level of several indispensable genes, such as nitrate reductase subunits (MSMEG_5137/narI and MSMEG_5139/narX) and MSMEG_3205/hisD was shown. We concluded that the mechanism of action of aureolic acid and its related compounds may be similar to that bedaquiline and disturb the NAD+/NADH balance in the cell. All of this allowed us to conclude that aureolic acid derivatives can be considered as potential antituberculosis drugs.

Beijing genotype Mycobacterium tuberculosis strains associate with increased virulence, resistance and/or higher transmission rates. This study describes a specific Beijing strain predominantly identified in the Panamanian province of Colon with one of the highest incidences of tuberculosis in the country. Retrospective mycobacterial interspersed repetitive unit/variable number of tandem repeats analysis of 42 isolates collected between January and August 2018 allowed to identify a cluster (Beijing A) with 17 (40.5%) Beijing isolates. Subsequent prospective strain-specific PCR-based surveillance from September 2019 to March 2020 confirmed the predominance of the Beijing A strain (44.1%) in this province. Whole-genome sequencing revealed higher-than-expected diversity within the cluster, suggesting long-term prevalence of this strain and low number of cases caused by recent transmission. The Beijing A strain belongs to the Asian African 3 (Bmyc13, L2.2.5) branch of the modern Beijing sublineage, with their closest isolates corresponding to cases from Vietnam, probably introduced in Panama between 2000 and 2012.

G-quadruplexes (G4) represent one class of non-canonical secondary nucleic acid structures that are currently regarded as promising and attractive targets for anti-cancer, anti-viral and antibacterial therapy. Herein, we probe a new i-clamp-inspired phenoxazine scaffold for designing G4-stabilizing ligands. The length of the protonated aminoalkyl tethers ('arms') of the phenoxazine-based ligand was optimized in silico. Two double-armed ligands differing in the relative orientation of their arms and one single-armed ligand were synthesized. The two-armed ligands significantly enhanced the thermal stability of the G-quadruplex structures (increasing the melting temperature by up to 20 °C) and displayed G4 selectivity over duplex DNA. The ligands look promising for biological studies and the phenoxazine scaffold could be a starting point for designing new G4-interacting compounds.

Mycobacterium tuberculosis Beijing B0/W148 is one of the most widely distributed clusters in the Russian Federation and in some countries of the former Soviet Union. Recent studies have improved our understanding of the reasons for the "success" of the cluster but this area remains incompletely studied. Here, we focused on the system omics analysis of the RUS_B0 strain belonging to the Beijing B0/W148 cluster. Completed genome sequence of RUS_B0 (CP020093.1) and a collection of WGS for 394 cluster strains were used to describe the main genetic features of the population. In turn, proteome and transcriptome studies allowed to confirm the genomic data and to identify a number of finds that have not previously been described. Our results demonstrated that expression of the whiB6 which contains cluster-specific polymorphism (a151c) increased almost 40 times in RUS_B0. Additionally, the level of ethA transcripts in RUS_B0 was increased by more than 7 times compared to the H37Rv. Start sites for 10 genes were corrected based on the combination of proteomic and transcriptomic data. Additionally, based on the omics approach, we identified 5 new genes. In summary, our analysis allowed us to summarize the available results and also to obtain fundamentally new data.

Tuberculosis, caused by Mycobacterium tuberculosis complex bacteria, remains one of the most pressing health problems. Despite the general trend towards reduction of the disease incidence rate, the situation remains extremely tense due to the distribution of the resistant forms. Most often, these strains emerge through the intra-host microevolution of the pathogen during treatment failure. In the present study, the focus was on three serial clinical isolates of Mycobacterium tuberculosis Beijing B0/W148 cluster from one patient with pulmonary tuberculosis, to evaluate their changes in metabolism during anti-tuberculosis therapy. Using whole genome sequencing (WGS), 9 polymorphisms were determined, which occurred in a stepwise or transient manner during treatment and were linked to the resistance (GyrA D94A, inhA t-8a) or virulence. The effect of the inhA t-8a mutation was confirmed on both proteomic and transcriptomic levels. Additionally, the amount of&nbsp, RpsL protein, which is a target of anti-tuberculosis drugs, was reduced. At the systemic level, profound changes in metabolism, linked to the evolution of the pathogen in the host and the effects of therapy, were documented. An overabundance of the FAS-II system proteins (HtdX, HtdY) and expression changes in the virulence factors have been observed at the RNA and protein levels.

Tuberculosis, caused by Mycobacterium tuberculosis complex bacteria, remains one of the most pressing health problems. Despite the general trend towards reduction of the disease incidence rate, the situation remains extremely tense due to the distribution of the resistant forms. Most often, these strains emerge through the intra-host microevolution of the pathogen during treatment failure. In the present study, the focus was on three serial clinical isolates of Mycobacterium tuberculosis Beijing B0/W148 cluster from one patient with pulmonary tuberculosis, to evaluate their changes in metabolism during anti-tuberculosis therapy. Using whole genome sequencing (WGS), 9 polymorphisms were determined, which occurred in a stepwise or transient manner during treatment and were linked to the resistance (GyrA D94A; inhA t-8a) or virulence. The effect of the inhA t-8a mutation was confirmed on both proteomic and transcriptomic levels. Additionally, the amount of RpsL protein, which is a target of anti-tuberculosis drugs, was reduced. At the systemic level, profound changes in metabolism, linked to the evolution of the pathogen in the host and the effects of therapy, were documented. An overabundance of the FAS-II system proteins (HtdX, HtdY) and expression changes in the virulence factors have been observed at the RNA and protein levels.

Comparative proteomic profiling of M. tuberculosis H37Rv strains cultured on two different nutrient media, Lowenstein-Jensen and Middlebrook 7H11, was performed using a label-free LC-MS/MS approach. It was shown that results obtained from two media possessed high convergence. The only difference was observed in the representation of fumarate reductase FrdB, its abundance was higher in the mycobacterial cells cultured on the Lowenstein-Jensen medium. The correlation analysis of biological repeats revealed the high convergence of the results obtained using the Middlebrook 7H11 medium. Thus, we can conclude that the use of the Middlebrook 7H11 medium is most appropriate in the scientific laboratory.

To date, a major attention was justly given to the global lineages of Mycobacterium tuberculosis. Here, we demonstrated an importance of the minor ones, on an example of intriguing and underestimated NEW-1 family that belongs to Euro-American lineage (lineage 4). Analysis of the global WGS/NGS datasets (5715 strains) identified 2235 strains of Lineage 4 and 66 strains of sublineage L4.5. This latter is marked with RD122 genomic deletion and includes NEW-1 family. Phylogenomic analysis confirmed a separate position of the NEW-1 family that we tentatively designate L4.5.1/Iran. We propose an evolution/migration scenario starting with origin of L4.5 1000–1300 ya in China, subsequent origin of the pre-NEW-1 intermediate genotype in Tibet, further migration to Xinjiang/Uyghur, and finally to Iran since 800 ya (origin of NEW-1), possibly, via expansion of the Mongol Yuan empire. Analysis of longitudinal phylogeographic datasets revealed a sharp increase in prevalence of NEW-1 strains in Iran and its eastwards neighbors in the last 20 years; most alarmingly, it is accompanied with significant association with multidrug resistance (MDR). Ongoing migration, especially, Afghan refugees flows to developed countries emphasize a risk of the wider spread of the epidemic MDR subtype within NEW-1 family that we coin as emerging resistant clone of M. tuberculosis in West Asia.

The physiology of Mycobacterium tuberculosis, the causative agent of tuberculosis, is being studied with intensity. However, despite the genomic and transcriptomic data available today, the pathogenic potential of these bacteria remains poorly understood. Therefore, proteomic approaches seem relevant in studying mycobacteria. This review covers the main stages in the proteomic analysis methods used to study mycobacteria. The main achievements in the area of M. tuberculosis proteomics are described in general. Special attention is paid to the proteomic features of the Beijing family, which is widespread in Russia. Considering that the proteome is a set of all the proteins in the cell, post-translational modifications of mycobacterium proteins are also described.

Mycobacterium tuberculosis Beijing B0/W148 is one of the most widely distributed clusters in the Russian Federation and in some countries of the former Soviet Union. Recent studies have improved our understanding of the reasons for the “success” of the cluster but this area remains incompletely studied. Here, we focused on the system omics analysis of the RUS_B0 strain belonging to the Beijing B0/W148 cluster. Completed genome sequence of RUS_B0 (CP030093.1) and a collection of WGS for 394 cluster strains were used to describe the main genetic features of the population. In turn, proteome and transcriptome studies allowed to confirm the genomic data and to identify a number of finds that have not previously been described. Our results demonstrated that expression of the whiB6 which contains cluster-specific polymorphism (a151c) increased almost 40 times in RUS_B0. Additionally, the level of ethA transcripts in RUS_B0 was increased by more than 7 times compared to the H37Rv. Start sites for 10 genes were corrected based on the combination of proteomic and transcriptomic data. Additionally, based on the omics approach, we identified 5 new genes. In summary, our analysis allowed us to summarize the available results and also to obtain fundamentally new data.

The Twort-like myoviruses (Kayvirus genus) of S. aureus are promising agents for bacteriophage therapy due to a broad host range and high killing activity against clinical isolates. This work improves the current understanding of the phage infection physiology by transcriptome analysis. The expression profiles of a typical member of the Kayvirus genus (vB_SauM-515A1) were obtained at three time-points post-infection using RNA sequencing. A total of 35 transcription units comprising 238 ORFs were established. The sequences for 58 early and 12 late promoters were identified in the phage genome. The early promoters represent the strong sigma-70 promoters consensus sequence and control the host-dependent expression of 26 transcription units (81% of genes). The late promoters exclusively controlled the expression of four transcription units, while the transcription of the other five units was directed by both types of promoters. The characteristic features of late promoters were long -10 box of TGTTATATTA consensus sequence and the absence of -35 boxes. The data obtained are also of general interest, demonstrating a strategy of the phage genome expression with a broad overlap of the early and late transcription phases without any middle transcription, which is unusual for the large phage genomes (&gt, 100 kbp).

The Central Asia Outbreak (CAO) clade is a growing public health problem for Central Asian countries. Members of the clade belong to the narrow branch of the Mycobacterium tuberculosis Beijing genotype and are characterized by multidrug resistance and increased transmissibility. The Rostov strain of M. tuberculosis isolated in Russia and attributed to the CAO clade based on PCR-assay and whole genome sequencing and the laboratory strain H37Rv were selected to evaluate the virulence on C57Bl/6 mice models by intravenous injection. All mice infected with the Rostov strain succumbed to death within a 48-day period, while more than half of the mice infected by the H37Rv strain survived within a 90-day period. Mice weight analysis revealed irreversible and severe depletion of animals infected with the Rostov strain compared to H37Rv. The histological investigation of lung and liver tissues of mice on the 30th day after injection of mycobacterial bacilli showed that the pattern of pathological changes generated by two strains were different. Moreover, bacterial load in the liver and lungs was higher for the Rostov strain infection. In conclusion, our data demonstrate that the drug-resistant Rostov strain exhibits a highly virulent phenotype which can be partly explained by the CAO-specific mutations.

Nowadays proteomics is one of the major instruments for editing and correcting annotation of genomic information. The correct genome annotation is necessary for omics studies of clinically relevant pathogens like Mycobacterium tuberculosis as well as for the progress in drug design and in silico biology. Here, we focused on the proteogenomic analysis of W-148 strain belonging to the Beijing B0/W148 cluster. This cluster, also known as a “successful” clone possesses unique pathogenic properties and has a unique genome organization. Taking into account high similarity of cluster strains at the genomic level we analyzed MS/MS dataset obtained for 63 clinical isolates of Beijing B0/W148. Based on H37Rv and W-148 annotations we identified 2546 proteins representing more than 60% of total proteome. A set of peptides (n = 404) specific for W-148 was found when compared with H37Rv. Start sites for 32 genes were corrected based on the combination of LC-MS/MS proteomic data with genomic six-frame translation. Additionally, we have shown the presence of peptides related to 10 genes earlier known as “pseudogenes”. Significance Mycobacterium tuberculosis is one of the most dangerous pathogens. Phylogenetically, it may be divided into major lineages and among them, lineage 2 (predominantly Beijing genotype) one of the most successful lineages with an increasing prevalence in the global population. At the same time, strains of the Beijing B0/W148 cluster, a “successful” clone of Mycobacterium tuberculosis possess even more interesting features. Only one complete genome of this cluster, W-148, present in the NCBI database (CP012090.1) and it demonstrates a number of significant differences from the well-known reference genome H37Rv. For the W-148 strain many genes are annotated as “pseudo” and no attempts were made to correct this. Thereby, in this study, we have conducted a proteomic analysis of the cluster strains and corrected current genome annotation. We hope that the data obtained will help to increase the quality of identifications in proteomic and transcriptomic analysis of M. tuberculosis Beijing B0/W148 cluster strain in subsequent studies.

Due to its rapid spread and association with the numerous outbreaks, the global spread of East Asian lineage of Mycobacterium tuberculosis strains presents a global concern. Although there were many attempts to describe its population structure, no consensus has been reached yet. To define unbiased classification that will facilitate future studies of this lineage, we analyzed the performance and congruence of eight different genotyping schemes based on phylogenetic analysis of 1,398 strains from 32 countries using whole-genome sequencing (WGS) data. We confirm that East Asian lineage comprises two major clades, designated proto-Beijing, which harbors unusual 43-signal spoligoprofile, and Beijing, with well-known spoligoprofile (deleted signals from 1 to 34). We show that different genotyping methods give high consistency results in description of ancient Beijing strains while the classification of modern Beijing strains is significantly divergent due to star-shaped phylogeny. Using WGS data we intersect different studies and for the first time provide balanced classification with well-defined major groups and their genetic markers. Our reconstructed phylogenetic tree can also be used for further analysis of epidemiologically important clusters and their ancestors as well as white spots of unclassified strains, which are prospective areas of research.

Steadily growing resistance of the tuberculosis causative agent towards a broad spectrum of antituberculosis drugs calls for rapid and reliable methods for identifying the genetic determinants responsible for this resistance. In this study, we present a biochip-based method for simultaneous identification of mutations within rpoB gene associated with rifampin resistance, mutations in katG, inhA, ahpC genes responsible for isoniazid resistance, mutations within the regions of gyrA and gyrB genes leading to fluoroquinolones resistance, and mutations in the rrs gene and the eis promoter region associated with the resistance to kanamycin, capreomycin and amikacin. The oligonucleotide microchip, as the core element of this assay, provides simultaneous identification of 99 mutations in the format “one sample—one PCR—one microchip”, and it makes it possible to complete analysis of multidrug-resistant and extensively drug-resistant tuberculosis within a single day. The tests on 63 Mycobacterium tuberculosis clinical isolates with different resistance profiles using the developed approach allows us to reveal the spectrum of drug-resistance associated mutations, and to estimate the significance of the inclusion of extra genetic loci in the determination of M. tuberculosis drug resistance.

The insertion sequence 6110 (IS6110) is the most studied transposable element in the Mycobacterium tuberculosis complex species. The element plays a significant role in genome plasticity of this important human pathogen, but still many causes and consequences of its transposition have not been fully studied. Here, we analyzed insertion sites for 902 Mycobacterium tuberculosis lineage 2 strains using whole-genome sequencing data. In total, 17,972 insertions were found, corresponding to 827 independent positions in the genome of the reference strain H37Rv. To trace the history of IS6110 expansion since proto-Beijing strains up to modern sublineages, we looked at the distribution of IS6110 across the genome-wide SNP-based phylogenetic tree. This analysis demonstrated a stepwise transposition of IS6110 that occurs by «copy-and-paste» mechanism. Additionally, we detected evolutionary-scale and sublineage-specific integration sites, which can be used for typing and for understanding the reasons for the success of the lineage. A significant part of such insertions affected the genes that are essential for the pathogen. Finally, we identified and confirmed deletions that occurred between differently oriented elements, which is uncommon for this family of insertion elements and appears to be another mechanism of genome variability.

Beijing B0/W148, a “successful” clone of Mycobacterium tuberculosis, is widespread in the Russian Federation and some countries of the former Soviet Union. Here, we used label-free gel-LC-MS/MS shotgun proteomics to discover features of Beijing B0/W148 strains that could explain their success. Qualitative and quantitative proteome analyses of Beijing B0/W148 strains allowed us to identify 1,868 proteins, including 266 that were differentially abundant compared with the control strain H37Rv. To predict the biological effects of the observed differences in protein abundances, we performed Gene Ontology analysis together with analysis of protein-DNA interactions using a gene regulatory network. Our results demonstrate that Beijing B0/W148 strains have increased levels of enzymes responsible for long-chain fatty acid biosynthesis, along with a coincident decrease in the abundance of proteins responsible for their degradation. Together with high levels of HsaA (Rv3570c) protein, involved in steroid degradation, these findings provide a possible explanation for the increased transmissibility of Beijing B0/W148 strains and their survival in host macrophages. Among other, we confirmed a very low level of the SseA (Rv3283) protein in Beijing B0/W148 characteristic for all «modern» Beijing strains, which could lead to increased DNA oxidative damage, accumulation of mutations and potentially facilitate the development of drug resistance.

Volume 4, no. 2, [e00182-16][1], 2016. Page 1: The byline and affiliation line should read as given above. [1]: /lookup/doi/10.1128/genomeA.00182-16

Mycobacterium bovis BCG (Bacille Calmette-Guérin) is a vaccine strain used for protection against tuberculosis. Here, we announce the complete genome sequence of M. bovis strain BCG-1 (Russia). Extensive use of this strain necessitates the study of its genome stability by comparative analysis.

A minisequencing method based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) was developed for rapid identification of single nucleotide polymorphisms at bla TEM gene codons 104, 164 and 238 associated with extended-spectrum activity on TEM-type beta-lactamases. The method was validated by testing the Escherichia coli and Klebsiella pneumoniae strains possessing the known bla TEM gene sequences.

Mycobacterium tuberculosis remains a leading cause of morbidity and mortality worldwide. This circumstance underscores the relevance of population studies of tuberculosis for transmission dynamics control. In this study, we describe a conversion of the spoligotyping of M. tuberculosis complex isolates on a platform of custom designed hydrogel microarrays (biochips). An algorithm of automated data processing and interpretation of hybridization results using online database was proposed. In total, the 445 samples were tested. Initially, 97 samples representing multiple species of M. tuberculosis complex and nontuberculous mycobacteria were used for protocol optimization and cut-off settings. The developed assay was further evaluated on the out-group of the 348 mycobacterial samples. Results showed high concordance with the conventional membrane-based spoligotyping method. Diagnostic sensitivity and diagnostic specificity of the spoligo–biochip assay were 99.1% and 100%, respectively. The analytical sensitivity was determined to be 500 genomic equivalents of mycobacterial DNA. The high sensitivity and specificity, ease of operation procedures, and the automatic processing of measured data make the developed assay a useful tool for the rapid and accurate genotyping of M. tuberculosis.

Tuberculosis caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis (MTB) strains is a growing problem in many countries. The availability of the complete nucleotide sequences of several MTB genomes allows to use the comparative genomics as a tool to study the relationships of strains and differences in their evolutionary history including acquisition of drug-resistance. In our work, we sequenced three genomes of Russian MTB strains of different phenotypes--drug susceptible, MDR and XDR. Of them, MDR and XDR strains were collected in Tomsk (Siberia, Russia) during the local TB outbreak in 1998-1999 and belonged to rare KQ and KY families in accordance with IS6110 typing, which are considered endemic for Russia. Based on phylogenetic analysis, our isolates belonged to different genetic families, Beijing, Ural and LAM, which made the direct comparison of their genomes impossible. For this reason we performed their comparison in the broader context of all M. tuberculosis genomes available in GenBank. The list of unique individual non-synonymous SNPs for each sequenced isolate was formed by comparison with all SNPs detected within the same phylogenetic group. For further functional analysis, all proteins with unique SNPs were ascribed to 20 different functional classes based on Clusters of Orthologous Groups (COG). We have confirmed drug resistant status of our isolates that harbored almost all known drug-resistance associated mutations. Unique SNPs of an XDR isolate CTRI-4(XDR), belonging to a Beijing family were compared in more detail with SNPs of additional 14 Russian XDR strains of the same family. Only type specific mutations in genes of repair, replication and recombination system (COG category L) were found common within this group. Probably the other unique SNPs discovered in CTRI-4(XDR) may have an important role in adaptation of this microorganism to its surrounding and in escape from antituberculosis drugs treatment.

Identification and typing of mycobacteria is very important for epidemiology, susceptibility testing and diagnostic purposes. This paper describes the development and validation of the alternative methods for species identification and typing of mycobacteria based on a matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-ToF MS). Altogether there were 383 clinical isolates analyzed which include 348 strains of Mycobacterium tuberculosis complex (MTBC) (342 strains of M. tuberculosis and 6 strains of M. bovis) and 35 strains of nontuberculous mycobacteria (NTM) represented by 16 different species. Direct bacterial profiling (DBP) by means of MALDI-ToF MS was carried out. Cluster analysis of DBP mass spectra divided them into two large separate groups corresponding to MTBC and NTM, and also demonstrated the possibility of isolate identification at the species level. Spoligotyping protocol based on mass spectrometry was developed and validated, it matched completely to classical spoligotyping data. Our results suggest that MALDI-ToF MS has potential as a rapid and reproducible platform for the identification and typing of Mycobacterium species.