Differential Immune Responses and Underlying Mechanisms of Metabolic Reprogramming in Smooth and Rough Variants of Mycobacterium peregrinum Infections.

Mycobacterium peregrinum (Mpgm) is a rapidly growing mycobacteria that is classified as a nontuberculous mycobacterium (NTM) and is commonly found in environmental sources such as soil, water, and animals. Mpgm is considered an opportunistic pathogen that causes infection in immunocompromised individuals or those with underlying medical conditions. Although there have been clinical reports on Mpgm, reports of the immune response and metabolic reprogramming have not been published. Thus, we studied standard Mpgm-ATCC and two clinical strains (Mpgm-S and Mpgm-R) using macrophages and mouse bone marrow-derived cells. Mpgm has two types of colony morphologies: smooth and rough. We grew all strains on the 7H10 agar medium to visually validate the morphology. Cytokine levels were measured via ELISA and real-time PCR. The changes in mitochondrial function and glycolysis in Mpgm-infected macrophages were measured using an extracellular flux analyzer. Mpgm-S-infected macrophages showed elevated levels of inflammatory cytokines, including interleukin (IL)-6, IL-12p40, and tumor necrosis factor (TNF)-α, compared to Mpgm-ATCC- and Mpgm-R-infected macrophages. Additionally, our findings revealed metabolic changes in Mpgm-ATCC and two clinical strains (Mpgm-S and Mpgm-R) during infection; significant changes were observed in the mitochondrial respiration, extracellular acidification, and the oxygen consumption of BMDMs upon Mpgm-S infection. In summary, within the strains examined, Mpgm-S displayed greater virulence, triggered a heightened immune response, and induced more profound shifts in bioenergetic metabolism than Mpgm-ATCC and Mpgm-R. This study is the first to document distinct immune responses and metabolic reorganization following Mpgm infection. These findings lay a crucial foundation for further investigations into the pathogenesis of Mpgm.

Effect of COVID-19 pandemic on incidence of mycobacterial diseases among suspected tuberculosis pulmonary patients in Tehran, Iran.

Background: Recent pandemic of coronavirus SARS-CoV-2 (COVID-19) caused limitations in the country's strategies to fight against mycobacterial infections. The aim of this study was to compare the suspected tuberculosis (TB) pulmonary patients before and during the COVID-19 pandemic (January 2018-December 2021) who were referred to the National Reference TB Laboratory (NRL TB), Tehran, Iran. The mycobacterial isolated strains were identified and compared with previous data. Methods: A total of 16,899 clinical samples collected from 7041 suspected pulmonary TB patients were received from 2018 to 2021. Primary isolation of Mycobacterium isolates was done on Löwenstein-Jensen medium. Then, the DNA was extracted from acid-fast bacillus culture-positive samples and identification was performed by IS6110, Hsp65, and 16S-23S rRNA genes using polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism, and nested PCR methods. Results: A total of 11679 specimens (69.1%) from 4866 suspected TB patients were collected in 2018-2019 and 5220 specimens (30.8%; from 2175 patients) in 2020-2021. Out of 11679 specimens, 2046 samples that belong to 852 patients were infected with Mycobacterium tuberculosis, and the remaining were non-TB Mycobacterium (NTM) species (n = 244) isolated from 102 patients. The cultures for 12894 specimens were either negative (76.3%) or contaminated (845/16899; 5%). A comparison of the total number of patients who were referred for diagnosis and treatment (954/666 patients, P > 0.05) showed a 30.1% reduction during the COVID-19 pandemic. Although, with these low number of patients, the significant increases of NTM species (P < 0.05) among suspected TB pulmonary patients were observed. Besides, new species of NTM, for example, Mycobacterium peregrinum and Mycobacterium montefiorense, were detected. For the past 20 years, these two species were not reported from pulmonary patients in Iran. Conclusions: During the pandemic of COVID-19, the TB diagnosis network became irregular, as a consequence, many patients could not reach the treatment center, and this could increase the circulation of mycobacterial diseases (TB and NTM). The study shows the emergence of new opportunistic NTM species also.

Disseminated Mycobacterium peregrinum and Mycobacterium avium infection in a patient with AIDS: A case report and review of literature.

Disseminated nontuberculous mycobacterial infections are frequently recognized in patients living with human immunodeficiency virus/acquired immunodeficiency syndrome (AIDS) and Mycobacterium avium-intracellulare complex (MAIC) is the most common species. Mycobacterium peregrinum is a rapidly growing mycobacterium that accounts for 1-2% of community-acquired and healthcare-associated infections. It mainly causes skin and soft tissue infection. Disseminated infection by M. peregrinum has never been reported in patients with AIDS. We describe a case of disseminated co-infection of M. peregrinum and M. avium in a 33-year-old male with newly diagnosed AIDS, and review the literature regarding M. peregrinum infection. The patient's bone marrow culture grew M. peregrinum and his blood culture grew M. avium. The diagnosis of disseminated co-infection of M. peregrinum and M. avium was confirmed. Disseminated infection due to M. peregrinum is rare and diagnosis can be challenging. Due to limited case numbers, there is no treatment guideline for M. peregrinum nowadays. Further study is warranted for better understanding M. peregrinum related infections.

Gene Sequencing and Phylogenetic Analysis: Powerful Tools for an Improved Diagnosis of Fish Mycobacteriosis Caused by Mycobacterium fortuitum Group Members.

The Mycobacterium fortuitum group (MFG) consists of about 15 species of fast-growing nontuberculous mycobacteria (NTM). These globally distributed microorganisms can cause diseases in humans and animals, especially fish. The increase in the number of species belonging to MFG and the diagnostic techniques panel do not allow to clarify their real clinical significance. In this study, biomolecular techniques were adopted for species determination of 130 isolates derived from fish initially identified through biochemical tests as NTM belonging to MFG. Specifically, gene sequencing and phylogenetic analysis were used based on a fragment of the gene encoding the 65 KDa heat shock protein (hsp65). The analyzes made it possible to confirm that all the isolates belong to MFG, allowing to identify the strains at species level. Phylogenetic analysis substantially confirmed what was obtained by gene sequencing, except for six strains; this is probably due to the sequences present in NCBI database. Although the methodology used cannot represent a univocal identification system, this study has allowed us to evaluate its effectiveness as regards the species of MFG. Future studies will be necessary to apply these methods with other gene fragments and to clarify the real pathogenic significance of the individual species of this group of microorganisms.

Odontogenic cutaneous sinus tracts due to infection with nontuberculous mycobacteria: a report of three cases.

BACKGROUND: Soft tissue or skin infections due to nontuberculous mycobacteria (NTM) have been reported frequently and are mostly associated with trauma or cosmetic interventions like plastic surgery. However, infection with NTM as a result of a dental procedure have rarely been described and the lack of clinical suspicion and a clear clinical manifestation makes diagnosis challenging. CASE PRESENTATION: We report on three patients with a facial cutaneous sinus tract of dental origin, due to an infection with respectively Mycobacterium fortuitum, M. abscessus and M. peregrinum. The infection source was the dental unit waterlines (DUWLs), which were colonized with NTM. CONCLUSIONS: Water of the DUWL can pose a health risk. This report emphasizes the need for quality control and certification of water flowing through DUWLs, including the absence of NTM. Our report also shows the need for a rapid recognition of NTM infections and accurate laboratory diagnosis in order to avoid long-term ineffective antibiotic treatment.

Mycobacterium peregrinum Skin Infection: Case Report.

BACKGROUND: Mycobacterium peregrinum is a rapidly growing mycobacterium (RGM) that rarely causes skin infections. The correct identification of the specific RGM infecting the skin will enhance therapeutic success. OBJECTIVE: To highlight the importance of rapid and precise identification of the Mycobacterium involved in skin infections in order to enhance therapeutic success. METHODS: We describe an RGM skin infection in an immunocompetent patient. RESULTS: Classic methods (biochemical tests and culture) of RGM identification are time-consuming, and the histopathological features are not specific. Some molecular methods are reliable but expensive. The PRAhsp-65 is a simple procedure that is helpful in identifying the specific agent of an RGM. CONCLUSION: Although skin infections caused by M peregrinum are rare, they represent a substantial clinical challenge. Specific and more effective treatment options depend on the development of precise and rapid methods for identifying mycobacterial species.

Mycobacterium peregrinum skin infection: case report

BACKGROUND: Mycobacterium peregrinum is a rapidly growing mycobacterium (RGM) that rarely causes skin infections. The correct identification of the specific RGM infecting the skin will enhance therapeutic success. OBJECTIVE: To highlight the importance of rapid and precise identification of the Mycobacterium involved in skin infections in order to enhance therapeutic success. METHODS: We describe an RGM skin infection in an immunocompetent patient. RESULTS: Classic methods (biochemical tests and culture) of RGM identification are time-consuming, and the histopathological features are not specific. Some molecular methods are reliable but expensive. The PRAhsp-65 is a simple procedure that is helpful in identifying the specific agent of an RGM. CONCLUSION: Although skin infections caused by M peregrinum are rare, they represent a substantial clinical challenge. Specific and more effective treatment options depend on the development of precise and rapid methods for identifying mycobacterial species.

A Case of Mycobacterial Skin Disease Caused by Mycobacterium peregrinum, and a Review of Cutaneous Infection.

An 83-year-old Japanese man presented with a 2-month history of symptomatic nodules on the left hand. He was not in an immunocompromised condition and reported no causal events. A biopsy specimen demonstrated granulomatous tissue with mixed cell infiltration consisting of neutrophils, histiocytes, lymphocytes, and multinuclear giant cells. No bacillus was detected by PAS, acid-fast stain, immunofluorescent stain or polymerase chain reaction analysis. The isolate was found to be a rapidly growing mycobacterium after 4 weeks of incubation at 25°C on an Ogawa egg slant. Mycobacterium peregrinum was isolated by DNA-DNA hybridization analysis, 16S rRNA gene sequence, and by its production of 3-day arylsulfatase. The patient received 200 mg oral minocycline for 28 weeks. The lesion disappeared after 10 weeks of this treatment.