Reconstituting the genus Mycobacterium

The definition of a genus has wide-ranging implications both in terms of binomial species names and also evolutionary relationships. In recent years, the definition of the genus Mycobacterium has been debated due to the proposed split of this genus into five new genera ( Mycolicibacterium , Mycolicibacter , Mycolicibacillus , Mycobacteroides and an emended Mycobacterium ). Since this group of species contains many important obligate and opportunistic pathogens, it is important that any renaming of species does not cause confusion in clinical treatment as outlined by the nomen periculosum rule (56a) of the Prokaryotic Code. In this study, we evaluated the proposed and original genus boundaries for the mycobacteria, to determine if the split into five genera was warranted. By combining multiple approaches for defining genus boundaries (16S rRNA gene similarity, amino acid identity index, average nucleotide identity, alignment fraction and percentage of conserved proteins) we show that the original genus Mycobacterium is strongly supported over the proposed five-way split. Thus, we propose that the original genus label be reapplied to all species within this group, with the proposed five genera potentially used as sub-genus complex names.

Hematology Profile of Tuberculosis Lymphadenitis Patients at Siti Rahmah Hospital, Padang, Indonesia

Tuberculosis (TB) is a progressive granulomatous infectious disease caused by Gram-positive acid-resistant bacilli classified in the genus Mycobacterium. Tuberculosis in humans is caused by Mycobacterium tuberculosis (MTB) and it mainly infects the lungs, although it can also infect intestines, meninges, bones, lymph nodes, skin that cause extra-pulmonary TB. Tuberculous lymphadenitis is an inflammatory process in lymph nodes as a result of MTB activity. The inflammatory process caused by MTB activity is often associated with anemia as the most common complication. Anemia in TB is caused by an inflammatory process associated with bone marrow suppression due to pro-inflammatory cytokines, thus inhibiting the proliferation and differentiation of erythroid progenitor cells. This chronic TB infection also affects iron hemostasis, thus further affecting the hematological profile of TB patients. This study aimed to determine the hematology profile of TB lymphadenitis patients in the Siti Rahmah Hospital, Padang, Indonesia. This was a descriptive study, with a population of patients diagnosed with TB lymphadenitis based on the results of a fine needle biopsy in the Colli region. The samples of this study consisted of 24 patients who have tested the hematology profile. Tuberculosis lymphadenitis patients in females were higher than males, the mean age was 26.75±19.53 years old dominated by an adult (54%). The mean of 3 hemoglobin levels was 11.8±1.522 g/dL, with 62.5% anemia patients. The mean leukocyte count was 10400±3018.926/mm , 3 with 54.2% of patients had normal levels of leukocyte. The mean of thrombocyte count was 334750±74440.668/mm , with 83.3% in normal levels and the mean of Erythrocyte Sedimentation Rate (ESR) was 35.25±31.489 mm/h, with 54.2% patients in high ESR. Hematology profile in TB lymphadenitis patient was anemia, normal levels of leukocytes, thrombocyte, and increased levels of ESR.

Analysis of interaction mechanisms between main objects of tuberculosis-target therapy and corresponding selective inhibitors

Aim. Search for new inhibitors of the mitotic apparatus of mycobacterium and a number of enzymatic targets. Methods. 3D models of key targets reconstruction and geometry optimization and analysis of biologically active conformations of inhibitors were performed according to a previously developed technique. Results. A revision of mycobacterial inhibitors, which exhibit antimicrobial action against representatives of the genus Mycobacterium, was carried out, which made it possible to create an appropriate reference library of compounds. The complete spatial structure of a number of the main targets of targeted therapy for tuberculosis was reconstructed and verified, and the features of their interaction with selective inhibitors were established. Chemogenomic profiling was performed, which made it possible to draw conclusions regarding the uniqueness of the studied sites and the potential toxicity of compounds related to these sites for humans. Conclusions. A well-developed search algorithm for known inhibitors of proteins with M. tuberculosis allows further study of the features of their interaction with the corresponding homologues of M. bovis and the development of new, more selective compounds using molecular dynamics and docking methods. Keywords: tuberculosis, in silico, anti-tuberculosis drugs.

The Synergetic Effect of Sitafloxacin-Arbekacin Combination in the Mycobacteroides abscessus Complex

Background Mycobacteroides abscessus (M. abscessus) is the most commonly isolated rapidly growing mycobacteria (RGM) and is one of the most antibiotic-resistant RGM with rapid progression, therefore, treatment of M. abscessus is still challenging. The genus mycobacterium has long been known to have both rough and smooth colony phenotypes. Rough morphotypes generally are more virulent than smooth morphotypes. Recently, the efficacy of sitafloxacin, new fluoroquinolone (FQ), containing regimens against M. abscessus complex have been reported. We here presented a new combination treatment with sitafloxacin that targeted rough morphotypes of M. abscessus, causing aggressive infections. Results Thirty-four clinical strains of M. abscessus were isolated from various clinical samples at the Juntendo university hospital from 2011 to 2020. The susceptibility to a combination of sitafloxacin and antimicrobial agents was compared to that of the antimicrobial agents alone. Ten isolates (90.9%) of M. abscessus subsp. abscessus were susceptible to both sitafloxacin and arbekacin when the combination is administered; while, 11 isolates (50.0%) of M. abscessus subsp. massiliense were susceptible. Synergistic effects against M. abscessus complex were shown in 8 strains (23.5%) treated with sitafloxacin-amikacin combination, 9 (26.5%) and 19 (55.9%) of sitafloxacin-imipenem combination, and sitafloxacin-arbekacin combination, respectively. Sitafloxacin-arbekacin combination also exhibited synergistic effects against 10 strains (45.5%) of M. abscessus subsp. massiliense and 8 stains (72.7%) of M. abscessus subsp. abscessus, a highly resistant subspecies of M. abscessus. The sitafloxacin-arbekacin combination revealed more synergistic effects in rough morphotypes of M. abscessus complex (p = 0.008). Conclusion We demonstrated the synergistic effect of the sitafloxacin-arbekacin combination against M. abscessus complex. Further, this combination regimen might be more effective against M. abscessus subsp. abscessus or rough morphotypes of M. abscessus complex.

BIOLOGICAL PROPERTY OF THE ECOLOGICAL CULTURES MYCOBACTERIUM VACCAE

Prokaryotes of the genus Mycobacterium occupy an important evolutionary and historical place in the system of microorganisms of prokaryotic and eukaryotic organization in the Earth's biosphere. These are the most ancient microorganisms that have passed a long historical path of mutual adaptation with the evolving biosphere over billions of years. Antiquity of origin is very important in the process of developing a stable and at the same time adaptive genomic apparatus, which provides genetic information support for the very diverse physiological needs of a carrier of a given genotype in the constantly changing conditions of the environment of existence and creating competitive advantages over similar carriers of gene programs in the limited space of a specific ecosystem. A significant species diversity of prokaryotes of the genus Mycobacterium is a consequence of the wide divergence of the ancestral ancestor species of the sapronous type in the process of soil formation from lithotrophic forms to the highest degree of bioparasitism in the form of highly specialized infectious pathogens with pronounced pathogenicity, invasiveness and the potential ability to take root in an internal macroorganism and an extremely effective antagonist the immune system of supervision over the genetic homeostasis of a macroorganism with a paradigm of tolerance to its genetically own and categorical intolerance to carriers of geneticaly foreign information. Only a small number of mycobacterial species have adapted to the internal environment of eukaryotic macroorganisms as a result of the suppression of the protective mechanisms of the lymphoid system by pathogenic factors. The path of symbiotic relationships, mutually beneficial interpopulation, turned out to be much more effective. As a result, a dynamic microbial organ arose - the microbiota of the large intestine, inhabited by indigenous and transient microbionts, among which Mycobacterium vaccae occupy an important place. Ecological strains "K", "N", "Gk", "Gn" of Mycobacterium vaccae were isolated and identified by conventional bacteriological methods. Examined their basic properties. The strains possessed morpho-tinctorial, cultural and biochemical properties characteristic of the species, were apathogenic for laboratory animals when administered parenterally, caused short-term sensitization to mycobacterial antigens and induced antitilogenesis. In broiler chickens on fattening with oral feeding of live culture, they stimulated metabolism, increased weight gain and increased the protective properties of the nonspecific link of the immune reactivity of the macroorganism. Strains of atypical mycobacteria were isolated on the territory of one poultry farm and had similar biocharacteristics; they are suitable for use as probiotics to increase nonspecific resistance, stimulate the physiological functions of the macroorganism, increase weight gain and improve feed payment.

Reconstituting the genus Mycobacterium

The definition of a genus has wide ranging implications both in terms of binomial species names and also evolutionary relationships. In recent years, the definition of the genus Mycobacterium has been debated due to the proposed split of this genus into five new genera (Mycolicibacterium, Mycolicibacter, Mycolicibacillus, Mycobacteroides and an emended Mycobacterium). Since this group of species contains many important obligate and opportunistic pathogens, it is important that any renaming of species is does not cause confusion in clinical treatment as outlined by the nomen periculosum rule (56a) of the Prokaryotic Code.In this study, we evaluated the proposed and original genus boundaries for the mycobacteria, to determine if the split into five genera was warranted. By combining multiple approaches for defining genus boundaries (16S rRNA gene similarity, amino acid identity index, average nucleotide identity, alignment fraction and percentage of conserved proteins) we show that the original genus Mycobacterium is strongly supported over the proposed five-way split. Thus, we propose that the original genus label be reapplied to all species within this group, with the proposed five genera used as sub-genus complex names.

No ntuberculous Mycobacteria

There has been a sharp increase in the number of diseases associated with potentially pathogenic microorganisms of the genus Mycobacterium, which differ from Mycobacterium tuberculosis. These bacteria are known as atypical mycobacteria or nontuberculosis mycobacteria (NTM), and the diseases they cause are called mycobacteriosis. NTMs include more than 20 species of acid-resistant microorganisms that are widespread in the environment and that are not members of the M. tuberculosis complex. However, the role of certain types of NTMs in the pathogenesis of human diseases is rather ambiguous. The aim of the paper was to analyse the current rise in the incidence of NTM diseases, as well as the main areas of research on early diagnosis of mycobacteriosis and the detection and testing of drug susceptibility of these microorganisms. The paper summarises current views on NTM species differences, their prevalence and pathogenicity for humans and animals. The authors analysed the main efforts aimed at diagnosis and treatment of NTM diseases. The paper cites the results of the study of NTM susceptibility/resistance to anti-tuberculosis drugs. The diagnosis of mycobacteriosis remains extremely difficult, mainly because of the similarity of the clinico-radiological evidence with that of tuberculosis. Detection of NTM multiple and extensive drug resistance to the majority of anti-tuberculosis drugs complicates the treatment of the NTM disease. Further study of various aspects of NTM diseases is especially important given the increase in the incidence and prevalence of mycobacteriosis all over the world, challenging differential diagnosis, and detection of NTM extensive drug resistance.

Prophage BPs Alters Mycobacterial Gene Expression and Antibiotic Resistance

Diseases caused by mycobacteria such as Mycobacterium tuberculosis are the leading cause of death worldwide. With the emergence of strains that are resistant to first-line anti-tuberculosis drugs and naturally drug-resistant pathogens such as M. abscessus, there is a need to increase our understanding of mycobacterial fitness and virulence and identify new targets for drugs. The majority of the pathogenic species of the bacterial genus Mycobacterium, including M. tuberculosis, carry integrated viral genomes (prophages) that are hypothesized to contribute to virulence. Though we know many of the ways in which phage genes directly contribute to pathogenesis, e.g., the CTX prophage encodes the toxin in Vibrio cholera, we know little about the impact of phages that encode no obvious toxin or virulence gene. Using an RNAseq approach, our lab recently showed for the first time that the presence of a prophage alters the expression of 7.4% of genes in the pathogenic mycobacterial species, M. chelonae. The presence of prophage BPs increased the expression of genes in the whiB7 regulon, including whiB7, eis2, and tap, and decreased the expression of a padR-family transcription factor. BP lysogens were more resistant to aminoglycosides (kanamycin and amikacin) and tetracycline than wild-type strains of M. chelonae. In order to determine how the BP prophage drives changes in bacterial gene expression and phenotype, we will test the effects of individual BP genes expressed during lysogeny, such as the immunity repressor, on bacterial gene expression and antibiotic resistance phenotypes.

Looking beyond Typical Treatments for Atypical Mycobacteria

The genus Mycobacterium comprises not only the deadliest of bacterial pathogens, Mycobacterium tuberculosis, but several other pathogenic species, including M. avium and M. abscessus. The incidence of infections caused by atypical or nontuberculous mycobacteria (NTM) has been steadily increasing, and is associated with a panoply of diseases, including pulmonary, soft-tissue, or disseminated infections. The treatment for NTM disease is particularly challenging, due to its long duration, to variability in bacterial susceptibility profiles, and to the lack of evidence-based guidelines. Treatment usually consists of a combination of at least three drugs taken from months to years, often leading to severe secondary effects and a high chance of relapse. Therefore, new treatment approaches are clearly needed. In this review, we identify the main limitations of current treatments and discuss different alternatives that have been put forward in recent years, with an emphasis on less conventional therapeutics, such as antimicrobial peptides, bacteriophages, iron chelators, or host-directed therapies. We also review new forms of the use of old drugs, including the repurposing of non-antibacterial molecules and the incorporation of antimicrobials into ionic liquids. We aim to stimulate advancements in testing these therapies in relevant models, in order to provide clinicians and patients with useful new tools with which to treat these devastating diseases.