Recently, more and more scientific works have been devoted to non-tuberculous mycobacteria, both by domestic and foreign researchers. One of the main reasons for this is the increase in patients with immunosuppression of various origins, improvement of the quality of laboratory and instrumental diagnostics of mycobacteriosis. This article focuses on the representatives of the M. fortuitum group, as the main pathogens among the group of fast-growing mycobacteria. The data on the modern classification based on the use of molecular genetic studies are indicated. The M. fortuitum group includes: Mycobacterium fortuitum, M. peregrinum, M. senegalense, M. porcinum, M. houstonense, M. neworleansense, M. boenickei, M. conceptionense, M. septicum, M. alvei. According to the new data, mycobacteria were divided into 5 clades (Abscessus-Chelonae, Fortuitum-Vaccae, Terrae, Triviale, Tuberculosis-Simiae), and based on molecular genetic studies, new genera in the Mycobacteriaceae family were isolated: Mycolicibacter spp., Mycolicibacillus spp., Mycolicibacillus spp., Mycobacteroides spp., Mycolicibacterium spp. In accordance with the new classification, representatives of the Mycobacterium fortuitum group belong to the genus Mycolicibacterium. The main epidemiological features of the main sources of the spread of mycobacteria, factors and ways of their transmission are indicated. Due to their wide distribution in the environment, representatives of the M. fortuitum group are capable of causing diseases of the pulmonary and extrapulmonary localization. The distinctive features of pathogenicity factors, due to which the course of the disease is determined, are noted. The article also indicates the main difficulties and features of determining the sensitivity to antimicrobial chemotherapy drugs, provides data on the main features of antibiotic resistance of M.fortuitum group. In preparing the review, literature sources obtained from international and domestic databases were used: Scopus, Web of Science, Springer, RSCI.

Over the last years, an increasing attention in modern medical microbiology has been paid to examining Actinomycetaceae, Corynebacteriaceae, Mycobacteriaceae, Nocardiaceae, Gordoniaceae sps. Members of the Mycobacteriaceae family are increasingly examined in research and real-life practice, whereas bacteria belonging to families such as Nocardiaceae and Gordoniaceae remain poorly investigated despite novel methods emerging in practical microbiology that allow to more accurately identify microorganisms. According to the current classification, the genus Nocardia includes over 80 species, most of which rarely result in human disease development. Most often, members of the genus Nocardia cause lesions in bronchopulmonary system, which, however, may also cause development of pathological processes in other anatomical sites. Likewise, members of the genus Gordonia may also trigger infectious lesions in human, which were previously often incorrectly identified as other actinomycetes or mycobacteria. Owing to use of 16S rRNA sequencing, it substantially improved identification of these bacteria. Currently, an increasing number of microorganisms with potential clinical significance has been recorded. In addition, similar to nocardiosis, diverse primary and secondary immunodeficiencies play a primary role in gordonii-associated development of pathological processes. However, an additional risk factor may be represented by pathological conditions associated with ingestion of foreign bodies colonized by such microorganisms. Most often, members the genus Nocardia cause lesions in the bronchopulmonary system able, however, affect other anatomical areas. Half of all cases of pulmonary nocardiosis are accompanied by pathological processes of extrapulmonary localization, whereas as low as 20% of patients manifest with extrapulmonary form of the disease usually occurring when the pathogen spreads hematogenously or via other routes also highlighted by primary pulmonary lesion. Moreover, members of the genus Gordonia may result in similar infectious lesions. Currently, the number of aerobic actinomycetes of potential clinical significance is increasing that may be due to their role in diverse pathological processes of various etiologies, which have been more often reported in scientific publications. Few reports regarding infections caused by the genus Gordonia ara available which may be due to a paucity of microorganisms isolated from clinical material or false identification as mycobacteria or Nocardia. Similar to nocardiosis, diverse immunodeficiencies play a primary role in the development of pathological processes associated with Gordonia. However, an additional risk factor may be linked to pathological conditions associated with the ingestion of foreign bodies colonized by these microorganisms. Available publications allows to underline etiological significance of Gordonia in development of cholecystitis, granulomatous skin lesions, eyelid abscess of other soft tissues, granulomatous mastitis, brain abscess and meningitis, as well as external otitis, bronchitis, endocarditis and mediastinitis. In addition, all these microorganisms can cause bacteremia associated with use of a central venous catheter. Owing to emergence of new detection methods as well as elevated rate of immunocompromised patients, and subsequently increased amount of new cases caused by members of the Nocardiaceae and Gordoniaceae families, an interest they rise will grow progressively.

More and more publications appear in the modern literature on the increase in the prevalence of non-tuberculous mycobacteria (NTMs), in particular, representatives of M. chelonae / Mycobacterium abscessus complex (MABSc). The paper presents data on the current classification of M. chelonae / Mycobacterium abscessus complex and its main representatives. The main data on the possible sources and ways of infection of MABSc patients in hospital are presented. The main features of cultivation on various nutrient media and their possible identification using modern methods are also indicated. The main risk factors for the development of mycobacteriosis in patients and the possible clinical picture are described. The prevalence of MABSc representatives in the structure of non-tuberculous mycobacteria isolated from clinical material from 483 patients from the Samara region was assessed for examination for tuberculosis, and the prevalence from 933 patients with cystic fibrosis (CF) from 55 regions of the Russian Federation from 2016 to 2019 was estimated. In total, as a result of the study, 316 NTM strains (65.4%) were isolated and identified in the first group of patients. M.abscessus was isolated and identified 10 strains and 5 strains - M.chelonae, which amounted to 3.2% and 1.6%, respectively, of all NTMs. In general, MABSc representatives were isolated in 3.1% of the examined patients. As a result of a screening study of patients with CF, 14194 microorganism strains from 933 patients were isolated and identified. Altogether M. abscessus was isolated and confirmed from 14 patients of different ages. Thus, the prevalence of MABSc among the examined patients with CF in the Russian Federation was 1.5%.

Objectives to analyze the quality and quantity of the intestinal microflora of relatively healthy people and/or of those who did not visit a doctor in the last 3 months, before and 1 month after taking a meta-prebiotic complex containing dietary fiber (inulin) and oligosaccharides (oligofructose). Material and methods. We examined the individuals who considered themselves healthy and/or did not consult a doctor during the past 3 months. To detect the presence of dyspeptic complaints, the clinical data were collected. 114 people with different suboptimal status and non-specific dyspeptic complaints were chosen for the study and underwent the clinical examination for the degree of gut microbiota imbalance before taking the meta-prebiotic complex. 78 people followed the course of the meta-prebiotic and were examined after 1 month after the start. Results. We have obtained new data on intestinal biocenosis at various suboptimal status in relatively healthy people: the total number of bacteria is insufficient. When using a meta-prebiotic complex containing inulin and oligofructose, the composition of the intestinal microflora was improved due to the decreased cases of detection of opportunistic enterobacteria and other gram-negative microorganisms. Conclusion. The significance of studying the intestinal microbiotic complex in patients with the increased suboptimal health status is proved, and the earlier active screening of this category of patients is recommended.