High rates of nontuberculous mycobacteria isolation from patients with presumptive tuberculosis in Iran

Nontuberculous mycobacteria (NTM) can cause disease which can be indistinguishable from tuberculosis (TB), posing a diagnostic and therapeutic challenge, particularly in low- and middle-income settings. We aimed to investigate the mycobacterial agents associated with presumptive clinical pulmonary TB in Iran. A total of 410 mycobacterial isolates, obtained between March 2014 and January 2016, from 7600 clinical samples taken from consecutive cases of presumptive diagnosis of TB were identified. Phenotypic and molecular tests were used to identify the isolated organisms to the species level. Single-locus and multilocus sequence analysis based on 16S rRNA, rpoB, hsp65 and ITS locus were used to confirm the results. Of 410 consecutive strains isolated from suspected TB subjects, 62 isolates (15.1%) were identified as NTM. Patients with positive NTM cultures met American Thoracic Society diagnostic criteria for NTM disease. Mycobacterium simiae was the most frequently encountered (38.7%), followed by Mycobacterium fortuitum (19.3%), M. kansasii (17.7%) and M. avium complex (8.0%). Isolation of NTM, including M. simiae, from suspected TB cases is a serious public health problem and merits further attention by health authorities, physicians and microbiologists.

Clinical, Radiological, and Microbiological Characteristics of Mycobacterium simiae Infection in 97 Patients

Mycobacterium simiae is a rare species of slow-growing nontuberculous mycobacteria (NTM). From 2002 to 2017, we conducted a retrospective study that included all patients with NTM-positive respiratory samples detected in two university hospitals of the French overseas department of Reunion Island. We recorded the prevalence of M. simiae in this cohort, as well as the clinical, radiological, and microbiological features of patients with at least 1 sample positive for M. simiae In our cohort, 97 patients (15.1%) were positive for M. simiae Twenty-one patients (21.6%) met the American Thoracic Society (ATS) criteria for infection. M. simiae infection was associated with bronchiectasis, micronodular lesions, and weight loss. Antibiotic susceptibility testing was performed for 60 patients, and the isolates were found to have low susceptibility to antibiotics, except for amikacin, fluoroquinolones, and clarithromycin. Treatment failed for 4 of the 8 patients treated for M. simiae infection. Here, we describe a specific cluster corresponding to a large cohort of patients with M. simiae, a rare nontuberculous mycobacterium associated with low pathogenicity and poor susceptibility to antibiotics.

Green synthesis of selenium nanoparticles using Rosmarinus officinalis and investigated their antimicrobial activity

The interest of many has been attracted by plant-mediated synthesizing procedures for nanoparticles since they provide certain qualities including being cost-effective, quick, and compatible with the environment. In this regard, this work introduces the production of selenium-nanoparticles (Se-NPs) in a biological manner utilizing aqueous extracts of Rosmarinus officinalis (R. officinalis). Production of Se-NPs was confirmed using UV-visible (UV-Vis) spectrophotometry. Also, dynamic light scattering (DLS) analysis was used for determination particle size distribution, while we distinguished the identification of crystalline construction of nanoparticles through the means of X-ray diffraction (XRD) pattern, DLS, and transmission electron microscopy (TEM) examination indicated that Se-NPs are often spherical with a size about 20 to 40 nm. The minimum inhibitory concentration (MIC) of the synthesized Se-NPs by R. officinalis extract against Mycobacterium tuberculosis (M. tuberculosis), Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) was 256, 16, 32, 128, and 64 µg/mL, respectively. The synthesized Se-NPs had no significant effect on Mycobacterium simiae (M. simiae) and had exhibited a strong antimicrobial functionality towards the gram-positive and gram-negative bacteria and can stand as a potent antibacterial agent.

Mycobacterium simiae pulmonary disease in Iran: systematic review and meta-analysis

Mycobacterium simiae is one of the most common nontuberculous mycobacteria (NTM) microorganisms causing lung disease in many countries in the world. A reliable estimate of the extent of M. simiae pulmonary disease has not been well investigated in Iran. We systematically searched multiple databases to identify relative studies. Studies were excluded if they did not use the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) diagnostic criteria for NTM diseases. Data were extracted independently and in duplicate. We assessed pooled estimate by using a random model effect, and sources of heterogeneity were assessed by using Cochran's Q and the I 2 statistic. The potential for publication bias was explored by using Begg's and Egger's tests. All analyses were conducted with Stata 14.0 (StataCorp, College Station, TX, USA). Of 172 articles identified, seven met the inclusion criteria. Of 355 patients who were culture positive for NTM, 82 had M. simiae pulmonary disease according to the ATS/IDSA diagnostic criteria. The pooled frequency of M. simiae pulmonary disease among patients with NTM was 25.0% (95% confidence interval, 16.8-33.2). No evidence of publication bias was observed among the included studies (p >0.05 for Begg's and Egger's tests). Clinical isolates of M. simiae are increasingly being recognized as a cause of pulmonary disease in Iran and need further attention by health authorities.

Genomic insights into Mycobacterium simiae human colonization

Mycobacterium simiae (Karassova V, Weissfeiler J, Kraszanay E, Acta Microbiol Acad Sci Hung 12:275-82, 1965) is a slow-growing nontuberculous Mycobacterium species found in environmental niches, and recently evidenced as an opportunistic Human pathogen. We report here the genome of a clinical isolate of M. simiae (MsiGto) obtained from a patient in Guanajuato, Mexico. With a size of 6,684,413 bp, the genomic sequence of strain MsiGto is the largest of the three M. simiae genomes reported to date. Gene prediction revealed 6409 CDSs in total, including 6354 protein-coding genes and 52 RNA genes. Comparative genomic analysis identified shared features between strain MsiGto and the other two reported M. simiae genomes, as well as unique genes. Our data reveals that M. simiae MsiGto harbors virulence-related genes, such as arcD, ESAT-6, and those belonging to the antigen 85 complex and mce clusters, which may explain its successful transition to the human host. We expect the genome information of strain MsiGto will provide a better understanding of infective mechanisms and virulence of this emergent pathogen.

Nontuberculous mycobacteria in cystic fibrosis patients on the Island of Gran Canaria. A population study

OBJECTIVE

To determine the prevalence of nontuberculous mycobacteria (NTM) colonization and disease in cystic fibrosis (CF) patients.

PATIENTS AND METHODS

All the CF patients followed-up from 2002 to 2012 with three acid-fast bacilli (AFB) cultures were included. The American Thoracic Society (ATS) criteria for NTM lung disease were applied.

RESULTS

Forty-four of the 53 patients being followed-up were included. The mean time of follow-up was 7.0 years. A total of 18 patients (40.9%) were NTM positive. The NTN mean annual prevalence was 14.1%. The risk of Mycobacterium abscessus complex was higher in the group of 10-14 years-old (p < 0.001). Ten patients (22.7% of the entire cohort) met the ATS microbiological criteria. The mean annual prevalence of NTM disease was 10.4%. Seven patients (four with Mycobacterium simiae and three with M. abscessus complex) with multiple positive cultures, positive AFB smears and clinical worsening were treated. Three patients with M. simiae and none of those with M. abscessus were cured.

CONCLUSIONS

Overall NTM prevalence of colonization and disease were high in our CF patients. Patients <15 years old had a higher risk of M. abscessus complex colonization. Multiple positive cultures or positive AFB smears were associated with disease.

Burden of non-tuberculous mycobacterial diseases in Saudi Arabian children: The first nationwide experience

BACKGROUND

Non-tuberculous mycobacteria (NTM) causing pulmonary and extra-pulmonary diseases are increasing worldwide. A large paucity of data related to pediatric NTM diseases exists globally and particularly in Saudi Arabia.

METHODS

The first nationwide exploratory study on existence of NTM diseases among Saudi Arabian children (0-14 years old) has been carried out during 2016-2017. Suspected NTM isolates with clinical and demographical data were enrolled from regional reference laboratories. Species level identification of isolates was carried out by commercial line probe assays and gene sequencing.

RESULTS

In 12 months, 52 culture positive cases with 44(84.6%) confirmed disease incidences were identified. Demographically, Saudi nationals (86.5%) were dominated and 77.3% cases have different comorbid conditions. Lymphadenitis (40.4%) followed by 26.9% of pulmonary cases with 42.8% of confirmed clinical relevance were mainly reported. Species identification showed Mycobacterium simiae (31.8%), M. abscessus (23.1%) and nine other species including rarely encountering M. riyadhense. Ascites caused by M. monacense, pulmonary disease caused by M. riyadhense and M. monacense were rarest clinical events and reported for the first time globally in a pediatric cohort.

CONCLUSIONS

Diverse NTM diseases even in immunocompetent children are an upcoming challenge in Saudi Arabia. Lack of awareness on NTM disease must be addressed with immediate development of management plans.

Disseminated Mycobacterium Simiae with Pelvic Malakoplakia in an AIDS Patient

Malakoplakia in an acquired immunodeficiency syndrome (AIDS) patient with disseminated Mycobacterium simiae infection presented with a large pelvic mass that caused organ dysfunction from mimicking a tumor. Malakoplakia is a rare, chronic granulomatous abnormal host response toward infectious agents, presenting as a tumor-like lesion. This is the first report of pelvic malakoplakia after disseminated M. simiae infection in an AIDS patient.

Granulomatous interstitial nephritis in the setting of disseminated Mycobacterium simiae: a rare presentation of immune reconstitution inflammatory syndrome

Disseminated Mycobacterium simiae is a rare opportunistic infection reported most commonly in advanced human immunodeficiency virus (HIV) infection. Treatment can be further complicated by the occurrence of severe immune reconstitution inflammatory syndrome (IRIS). We present the first case of disseminated multi-drug-resistant M. simiae in the setting of advanced HIV, complicated by IRIS in the form of granulomatous interstitial nephritis causing acute renal failure. This case highlights the importance of recognizing rare complications of IRIS, as delays in therapy can be life threatening.

Non-tuberculous mycobacteria profiles and their anti-mycobacterial resistance at a major medical center in Lebanon

INTRODUCTION

Infection with non-tuberculosis mycobacteria (NTM) has been on the rise globally causing a wide spectrum of respiratory and extrapulmonary infections in humans. Studies on these pathogens from the Middle-East including Lebanon are scarce.

METHODOLOGY

This retrospective study addresses the approach used for investigation, speciation and antimicrobial resistance (AMR) profiles of recovered NTM isolates from respiratory sources at a major tertiary care center in Lebanon during two periods (2003-2007 and 2013-2017). Processing of specimens, culture and differentiation of recovered NTM isolates from Mycobacterium tuberculosis were done in-house according to standard procedures. Upon request, speciation and AMR testing were performed using molecular and broth dilution methods, respectively, at Mayo Medical Laboratories (Rochester, Minnesota, USA).

RESULTS

Among 108 NTM analyzed isolates, 8 species were revealed during the two periods: M. simiae (51% vs 61%), M. avium complex (MAC) (6 % vs 12%) M. fortuitum (12% vs 5%), M. gordonae (6% vs 5%), M. abscessus (6% vs 7%), M. immunogenum (12% vs 0%), M. szulgai (4% vs 0%) and M. peregrinum (0% vs 2%). M. simiae isolates showed high susceptibility (93%-96%) to amikacin and clarithromycin, but high resistance to rifampin, ethambutol, ciprofloxacin, rifabutin, linezolid, trimethoprim/sulfamethoxazole and moxifloxacin. MAC isolates were only susceptible to clarithromycin (86%). M. abscessus isolates were uniformly susceptible to amikacin (100%).

CONCLUSION

The revelaed different NTM species, with predominance of M.simiae and various AMR profiles provide a current epidemiologic database and help guiding the selection of appropriate empirical therapy once the clinical relevance is established.

Molecular drug susceptibility testing against the first-line (rifampin and isoniazid) and second-line (ciprofloxacin-amikacin and kanamycin) treatment in different subtypes of Mycobacterium simiae

OBJECTIVE BACKGROUND

Mycobacterium simiae has been identified as the most prevalent slow growing mycobacteria that has been isolated among Iranian patients. Due to an importance of molecular approaches in the treatment of nontuberculosis mycobacteria, this study aimed to evaluate molecular drug susceptibility testing against the first-line (rifampin and isoniazid) and second-line (ciprofloxacin-amikacin and kanamycin) treatment in different subtypes of M. simiae.

METHODS

The study involved all patients presenting to our referral tuberculosis center from March 2014 to August 2016, with confirmation of M. Simiae. For all sputum samples, after digestion and decontamination, followed by DNA extraction, polymerase chain reaction-restriction fragment length polymorphism was performed using the hsp65 gene. Furthermore, susceptibility to rifampin, isoniazid, ciprofloxacin, amikacin, and kanamycin were evaluated using rpoB, inhA, katG, gyrA, and rrs genes, respectively.

RESULTS

In total, 60 cases (58.33% men and 41.66% women) of M. simiae infections were identified and all were confirmed as subtype I. All the patients were resistant to the first line-tuberculosis drugs, while 88.33% and 91.66% of cases were susceptible to ciprofloxacin and both amikacin and kanamycin, respectively.

CONCLUSION

Regarding the given result, first-line tuberculosis drugs should be excluded from the treatment regimen of M. simiae patients. In addition, subtype I seems to be the most or even the only isolated M. simiae subtype among all Iranian patients. While both amikacin and kanamycin drugs showed better efficacy in the treatment M. simiae, the most susceptible antibiotic is still indeterminate.

Necrotizing Cervical Lymphadenitis Caused by Mycobacterium simiae in an HIV-Positive Patient: Imaging with (18)F-FDG PET/CT

Mycobacterium simiae (M. simiae) is an opportunistic pathogen rarely associated with human disease, although in recent years M. simiae has been detected with increasing frequency in human immunodeficiency virus (HIV)-infected patients, usually causing disseminated infection with fever, diarrhea and weight loss. We report the case of an HIV-positive man, who was referred for an (18)F-FDG PET/CT to evaluate a solitary pulmonary nodule. The PET/CT showed incidental large necrotic cervical lymph nodes, compatible with necrotizing cervical lymphadenitis. Biopsy and culture of one of the affected lymph nodes were positive for M. simiae. We present the first report of (18)F-FDG PET/CT imaging of an infectious process caused by M. simiae in humans.

Mycobacterium simiae pulmonary infection: a case series and literature review

Incidence of Mycobacterium simiae pulmonary infection is increasing and diagnosis and treatment are challenging. We surveyed the clinical features, risk factors, diagnosis, and management in 20 patients from northeastern Iran diagnosed by line probe assay and confirmed by sequencing the ITS (16S-23S) rRNA region and carried out a literature review using the keywords "pulmonary infection" and "Mycobacterium simiae." The mean age of patients was 55.1 years, with 80% female and 90% diagnosed by sputum. Clinical symptoms included severe cough (90%), sputum production (70%), haemoptysis (50%), and chest pain (35%). Comorbidities included a history of tuberculosis (60%), smoking (40%), or chronic obstructive pulmonary disease (20%). Patients were treated with levofloxacin, clarithromycin, and co-trimoxazole. Except for two patients, the clinical symptoms improved. Mycobacterium simiae pulmonary infection is increasing in people with underlying diseases. Although choosing the most appropriate treatment remains a challenge, combining successful treatments could be useful in treating these patients.

Occurrence and risk factors of nontuberculous mycobacteria in tuberculosis-suspected patients in the north of Iran

Background and Objectives:

Some Nontuberculous Mycobacteria (NTM) can occasionally infect the human population and cause infections having symptoms similar to tuberculosis (TB). This study tried to provide updated data about the frequency and diversity of NTM species.

Materials and Methods:

Suspicious samples of Mycobacterium tuberculosis (MTB) with both positive results in Ziehl-Neelsen (ZN) staining and Löwenstein-Jensen medium culturing were evaluated during January 2016 and December 2018 in Gorgan, Iran. After determination of MTB isolates by the growth rate, pigmentation status, the niacin test, and the insertion sequence 6110 (IS6110) PCR assay, other unknown isolates (presumably NTM) were detected by the 16S rDNA sequencing method and drawing the phylogenetic tree. Based on the patients’ demographic information, their risk factors were also assessed.

Results:

Among 226 culture-positive samples, obtained from 2994 individuals with suspected symptoms of TB, the analyses found 12 (5.3%) NTM and three Mycobacterium caprae isolates. Mycobacterium simiae (6/12) was the most prevalent NTM species. The average nucleotide similarity value was 98.2% ± 3.7. In comparison to patients with MTB (211 confirmed cases), other mycobacterium infections were more common in patients over 65 years old (Odd ratio (95% convenience interval): 2.96 (0.69 – 12.59), P = 0.14).

Conclusion:

Although the NTM species has a small portion in TB suspected patients, their prevalence has increased, mainly in elderly patients. Moreover, M. simiae was the most prevalent NTM species in our region. Therefore, identification of common species in each region is recommended and clinicians should pay more attention to them in each region.

A case of multidrug-resistant Mycobacterium simiae in an elderly woman

Mycobacterium simiae is an emerging and spreading pathogen in Iran and little data about its drug susceptibility test (DST) and no standard treatment regimen are available. We report a case of multidrug-resistant M. simiae respiratory infection in a 65-year-old woman with a history of previous Mycobacterium tuberculosis infection. The patient was treated with clarithromycin, levofloxacin, and cotrimoxazole for one year and eventually died while still suffering from respiratory problems. For DST, broth microdilution method was used according to the Clinical and Laboratory Standards Institute guidelines as well as molecular DST in clinical isolate. Mycobacterium simiae was resistant to streptomycin, moxifloxacin, clarithromycin, and cotrimoxazole antibiotics and was sensitive to clofazimine and amikacin antibiotics. Inappropriate use of antibiotics without determining the pattern of antibiotic resistance increases the likelihood of resistance and, for resistant specimens, the need to review the treatment protocol and replace antibiotics. Effectiveness based on antibiotic resistance pattern is essential.

Drug susceptibility testing of Mycobacterium simiae: An emerging pathogen in Iran

INTRODUCTION

Mycobacterium simiaeis an emerging pathogen in Iran and little is known about drug susceptibility patterns of this pathogen.

MATERIALS AND METHODS

Twenty-five clinical isolates of M. simiaefrom 80 patients with confirmed NTM pulmonary disease were included in this study. For drug susceptibility testing (DST), proportional and broth microdilution methods were used according to the clinical and laboratory standards institute (CLSI) guideline.

RESULTS

All clinical isolates of M. simiaewere resistant to isoniazid, rifampicin, ethambutol, streptomycin, amikacin, kanamycin, ciprofloxacin, and clarithromycin. They also were highly resistant to ofloxacin (80%). Susceptibility to ofloxacin was only noted in the 5 isolates.

CONCLUSIONS

Clinical isolates of M. simiae were multidrug-resistant, and had different drug susceptibility patterns than previously published studies. DST results can assist in selecting more appropriate treatment regimens. Newer drugs with proven clinical efficacy correlating with in vitrosusceptibility should be substituted with first-and second-line anti-TB drug testing.

Reactivation of Mycobacterium simiae after the recovery of COVID-19 infection

There are limited studies on the coinfection of coronavirus disease 2019 (COVID-19) with nontuberculous mycobacteria. Here, we briefly describe the reactivation of Mycobacterium simiae infection in a patient who had recovered from COVID-19 in October 2020, Iran. During the pandemic of COVID-19, other infectious agents should not be ignored.

The first diagnostic test for specific detection of Mycobacterium simiae using an electrochemical label-free DNA nanobiosensor

Mycobacterium simiae has been reported to be the most prevalent species of Nontuberculous mycobacteria (NTM) in many countries. As both phenotypic and molecular detection of M. simiae and other NTMs have limitations, finding an accurate, fast, and low-cost diagnostic method is critical for the management of infections. Here, we report the development of a new type of label-free electrochemical biosensor using a gold electrode decorated with l-cysteine/PAMAM dendrimer for specific targeting of M. simiae ITS sequence. DNA hybridization was monitored by measuring changes in the free guanine electrical signal with changing ssDNA target concentrations by differential pulse voltammetry (DPV) method. Response surface methodology (RSM) was applied for the optimization of variables affecting biosensor response. Under optimal conditions, the biosensor revealed a wide linear range from 10^-14 M to 10^-6 M and a detection limit of 1.40 fM. The fabricated biosensor showed an excellent selectivity to M. simiae in the presence of other similar pathogenic bacteria. Moreover, experimental results confirmed that this biosensor exhibited great precision and high reproducibility, hence provides a low-cost, label-free, and faster detection analysis, representing a novel strategy in detecting other NTMs.

[Mycobacterial pulmonary infection due to Mycobacterium simiae]

INTRODUCTION

Mycobacterium simiae pulmonary infections remain exceptional in France.

CASE REPORT

We report a case of M. simiae lung infection and a 10-year follow-up in a non-immunocompromised host.

CONCLUSION

This case emphasizes the difficulties of choosing the appropriate drugs and their side effects in the absence of any existing gold standard.

[Mycobacterium simiae pneumonia: a case report]

We report a case of Mycobacterium simiae pneumonia in an immunocompetent women aged 55 years, after a stay in Thailand. The diagnosis was based on culture isolation of non-tuberculous mycobacteria from bronchoalveolar lavage. The culture isolate was identified as M. simiae by biochemical and molecular methods. The patient was treated. Her condition remained stable for 5 years. During the sixth years, a relapse occurred, and a new treatment was prescribed. This is a rare case in view of the absence of any predisposing factor. M. simiae should be considered a possible causative agent of pulmonary disease, even in immunocompetent patients.

Nontuberculous Mycobacterial Infection and Pulmonary Disease in Northern Israel: A Focus on Mycobacterium simiae

BACKGROUND

The prevalence of nontuberculous mycobacteria (NTM) pulmonary disease is rising globally. Previously, we described a high prevalence of Mycobacterium simiae isolation in Israel.

RESEARCH QUESTION

What is the prevalence of NTM pulmonary disease and M simiae pulmonary disease in Northern Israel? Which factors are associated with mortality among people with NTM?

STUDY DESIGN AND METHODS

We retrospectively recorded all samples from Clalit Health Services-Haifa District reference mycobacteria laboratory for growth of NTM between January 2010 and March 2021. We manually reviewed a random sample of corresponding patients' electronic medical files and extracted demographic, clinical, and radiologic data, and data on the course of the disease. Univariate and multivariate analyses were performed to assess factors associated with features of NTM pulmonary disease and mortality.

RESULTS

A total of 2,968 clinical isolates from 1,501 people yielded NTM species. The relative abundance of M simiae, Mycobacterium avium complex (MAC), and other species increased over the study period. Among the 550 patients' files reviewed, clinical presentation, fulfilment of established criteria for NTM pulmonary disease, and mortality rates were not significantly different between patients with M simiae, MAC, and Mycobacterium kansasii/Mycobacterium szulgai, with 27.7%, 35.3%, and 27.8% of people fulfilling criteria for NTM pulmonary disease. Factors associated with mortality included age, male sex, and immunosuppression. Compared with MAC isolation, M simiae was associated with elevated mortality (hazard ratio, 1.84; 95% CI, 1.05-3.23). The extrapolated national annual incidence rate of NTM pulmonary disease was 1.7 to 2.0 per 100,000 population.

INTERPRETATION

Infection with M simiae is prevalent in Israel, and although considered minimally pathogenic, demonstrated similar clinical and radiologic features to MAC pulmonary disease.

Disseminated Mycobacterium simiae Infection in a Patient with Complete IL-12p40 Deficiency

Mendelian susceptibility to mycobacterial disease (MSMD) is a rare group of genetic disorders characterized by infections with weakly virulent environmental mycobacteria (EM) or Mycobacterium bovis bacillus Calmette-Guérin (BCG). Herein, we described the case of a 4.5-year-old boy with protein-losing enteropathy, lymphoproliferation, and candidiasis, who was found to have disseminated Mycobacterium simiae infection. A homozygous mutation in the IL12B gene, c.527_528delCT (p.S176Cfs*12) was identified, responsible for the complete IL-12p40 deficiency. He was resistant to anti-mycobacterial treatment and finally died due to sepsis-related complications.

Treatment management of M. simiae infection complicated by severe immune reconstitution syndrome in two patients living with HIV

Nontuberculosis mycobacterium are increasingly being identified as sources of disseminated infections in immunocompromised patients. These infections can be challenging to identify and treat due complexities of diagnosis and inherent resistance to many medications. We present two cases of patients with human immunodeficiency virus who had Mycobacterium simiae infections, complicated by immune reconstruction inflammatory syndrome (IRIS). We also present a review of the English literature surrounding the disease, including reported resistance patterns to antimicrobial therapy, which can be highly variable.