Introduction Osteoarthritis (OA) is a common polyetiological disease of the musculoskeletal system, leading to disability. The condition can prevent a person from work, affect mental health, increasing mortality and affecting health care resources around the world as a current and future disease burden. OA had been considered an aseptic disease in the past and now the microbiological factor is viewed as one of the significant etiological aspects of the condition.The objective was to summarize the literature data on the role of microorganisms in the etiology and pathogenesis of osteoarthritis, including concomitant HIV infection.Material and methods The original literature search (2010 to 2023) was conducted on key resources including Scientific Electronic Library (www.elibrary.ru) and the National Library of Medicine (www.pubmed.org). Literature searches included both Russian and English studies reporting the effect of microbiological factors on the development of arthropathy.Results and discussion New, more advanced microbiological diagnostic methods have been used. There has been evidence of a variety of microorganisms including pathogenic and opportunistic pathogens in the absence of clinical and radiological signs of arthritis. This changes ideas about the etiology and pathogenesis of degenerative processes in the articular cartilage and necessitates a revision of treatment protocols for some joint diseases. Multicenter comprehensive studies of the microbiome of joint formations, blood and intestines are needed.Conclusions The presence of pathogenic microflora in the joint structures is evident in a significant number of observations. There is evidence of a local infectious process in the local cellular elements of osteochondral tissue in patients with previously diagnosed aseptic osteoarthritis. Intestinal microbiomes and the urogenital tract are most common sources of infection. A local influence of the immunodeficiency virus on the development of osteonecrotic processes in joint formations can be suggested in HIV patients.

Background The incidence of nontuberculous mycobacterial (NTM) diseases is increasing globally, with risk factors remaining poorly understood. COVID-19 may alter respiratory tract conditions affecting NTM colonization and infection patterns. Objective To evaluate species diversity of NTM isolated from patients with NTM-associated diseases with and without a history of COVID-19. Methods We analyzed 464 clinical NTM isolates from Russian patients stratified by COVID-19 status (COVID-19+, n=271; COVID-19−, n=193). Diagnosis verification followed ATS/ERS/ESCMID/IDSA Clinical Practice Guidelines. Species identification employed MALDI-TOF mass spectrometry and molecular techniques. Statistical analyses used chi-square and Fisher’s exact tests with 95% confidence intervals. Results Slowly growing species predominated in both groups (97.9% vs 98.2%, p>0.05). COVID-19 was associated with a significant 28% reduction in Mycobacterium avium complex (MAC) prevalence (94.8% vs 66.8%, p<0.05), primarily due to decreased M. avium isolation (80.3% vs 52.0%, p<0.05). Conversely, rare NTM species showed increased prevalence in COVID-19+ patients: M. kansasii complex (0% vs 8.1%, p<0.05), M. terrae complex (0% vs 3.3%, p<0.05), M. simiae complex (0.5% vs 7.0%, p<0.05), and unclassifiable species (2.6% vs 12.9%, p<0.05). Conclusions COVID-19 significantly alters the NTM species spectrum in patients with NTM-associated diseases, with reduced MAC prevalence and increased detection of rare NTM species. These findings highlight the importance of species-level identification and may require adaptation of diagnostic and therapeutic approaches in post-COVID patients.