Mycobacterium Simiae Research Articles

Microbial rrn copy number is associated with soil C: N ratio and pH under long-term fertilization

Soil microbial life-history strategies, as indicated by rRNA operon (rrn) copy numbers, strongly influence agro-ecosystem functioning. Long-term N fertilization causes strong and lasting changes in soil properties, yet its impact on microbial strategies remains largely unexplored. Using long-term field experiments across three agro-ecosystems, we consistently found that N fertilization strongly decreased soil C: N ratio and pH, further increasing the community-level rrn copy number, including both average rrn copy number and total 16S rRNA copy number. Soil C: N stoichiometry balanced by N supplement favored the growth of N-dependent copiotrophic species containing high rrn copy numbers (an average of 2.5) and increased their network connections, predominantly contributing to community-level rrn copy number increase. Decreased soil pH caused by N fertilization also favored the growth of some species whose abundances negatively correlated with pH, partially contributing to the community-level rrn copy number increase. By examining the genomes of two dominant species, we found that microorganisms with a higher rrn copy number (6), e.g., Streptomyces scabiei, possessed more genes related to C and N transport and metabolism. In contrast, the Mycobacterium simiae with a lower rrn copy number (1) has more genes associated with secondary metabolite biosynthesis and lipid transport and metabolism. Our finding challenges the concept of microbial life-strategy regulation solely by nutrient availability, highlighting the important contributions of soil stoichiometric balance and pH to microbial strategies in agro-ecosystems under long-term N inputs.

Granulomatous pneumonia caused by Mycobacterium simiae and necroulcerative enteritis caused by Entamoeba spp in a panther chameleon (Furcifer pardalis)

Granulomatous pneumonia caused by Mycobacterium simiae and necroulcerative enteritis caused by Entamoeba spp in a panther chameleon (Furcifer pardalis)

Absence of Tuberculosis-Causing Mycobacteria from Slaughtered Livestock Tissues and Environmental Samples, Gauteng Province, South Africa.

Mycobacterium tuberculosis complex (MTBC) is a group of bacteria responsible for causing tuberculosis in animals and humans. In South Africa (S.A), slaughterhouses are registered by the government and closely inspected and audited for hygienic slaughter practices. Meat inspection to detect lesions has been used for passive surveillance, monitoring, and diagnosis of the disease status. Information on the current status of bovine tuberculosis (bTB) in livestock in the country is limited. Hence, we investigated the occurrence of Mycobacterium spp. in the tissues of slaughtered livestock and environmental samples in abattoirs in Gauteng province of South Africa (S.A). The cross-sectional study employing random sampling from cattle, pigs, and sheep (with the collection of liver, lung, spleen, and different lymph nodes) irrespective of lesions was carried out in 19 red meat abattoirs. Five hundred animals were sampled, comprising cattle (n = 369), pigs (n = 90), and sheep (n = 41). Additionally, 19 environmental samples were collected from feedlots, or where animals drink water while awaiting slaughter, to identify mycobacterial species using culture, acid-fast bacteria staining, and polymerase chain reaction (PCR). The Chi-square and Fisher's Exact tests were used to detect statistically significant differences in the frequency of detection of Mycobacterium spp. according to the variables investigated (types of tissues, livestock, abattoirs, etc.). The PCR assays detected no MTBC complex species DNA in the bacterial isolates from cattle (n = 32). Sequence analysis (16S rDNA) of the isolates from eight cattle confirmed only two species, namely Mycobacterium colombiense (99.81% identity) and Mycobacterium simiae (99.42% identity). The remaining isolates were identified as members of the Actinomadura species. From the environmental samples, bacterial isolation was made from three samples, and two could only be identified up to the genus level (Mycobacterium species) while the remaining isolate was identified as Mycobacterium senuense (99.22% identity). The study revealed the absence of bovine tuberculosis-causing pathogens in red meat abattoirs of the Gauteng province. Although non-tuberculous Mycobacteria have been implicated as potentially causing tuberculosis-like diseases in livestock, their occurrence in the current study was found to be low, but the potential to cause disease cannot be ignored.

Genomic diversity and clinical relevance of Mycobacterium simiae.

Mycobacterium simiae is a slow-growing non-tuberculous mycobacterium that can cause non-tuberculous mycobacterium (NTM) pulmonary disease and extrapulmonary infections. Until now, detailed genomic and clinical characteristics, as well as possible transmission routes of this rare pathogen remain largely unknown. We conducted whole genome sequencing of available M. simiae isolates collected at a tertiary care centre in Central Germany from 2006 to 2020 and set them into context with publicly available M. simiae complex sequences through phylogenetic analysis. Resistance, virulence and stress genes, as well as known Mycobacteriaceae plasmid sequences were detected in whole genome raw reads. Clinical data and course were retrieved and correlated with genomic data. We included 33 M. simiae sensu stricto isolates from seven patients. M. simiae showed low clinical relevance with only two patients fulfilling American Thoracic Society (ATS) criteria in our cohort and three receiving NTM-effective therapy. The bacterial populations were highly stable over time periods of up to 14 years, and no instances of mixed or re-infections with other strains of M. simiae were observed. Clustering with <12 single nucleotide polymorphisms distance was evident among isolates from different patients; however, proof for human-to-human transmission could not be established from epidemiological data. Overall, the available sequence data for M. simiae complex was significantly extended and new insights into its pathogenomic traits were obtained. We demonstrate high longitudinal genomic stability within single patients. Although we cannot exclude human-to-human transmission, we consider it unlikely in the light of available epidemiological data.

Beyond the Needle: Unmasking Atypical Mycobacteria in Postvaccination Abscesses in Children.

Atypical or nontuberculous mycobacteria (NTM) are an environmental organism responsible for opportunistic infection. Rapid-growing NTM are more commonly associated with hospital-acquired infections. Many of the organisms responsible for diseases in immunocompromised patients and hospital-acquired infections originate from tap water, such as Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium gordonae, Mycobacterium simiae, Mycobacterium mucogenicum, Mycobacterium fortuitum, Mycobacterium chelonae, and Mycobacterium abscessus. NTM is a rare organism responsible for the injection abscess. Considering low incidents, not much clinical data are available for this condition. Here, we discuss such cases which can be helpful to spread awareness and provide data for future policy makers. This was a retrospective study. Data on patients with injection abscess were collected from the last 6 years. Detailed history and clinical examination findings were analyzed. Children with injection abscess were operated and their further management and outcome were studied. A total of 13 cases with confirmed culture of NTM were treated over 6 years. The age ranged from 2½ months to 5¾ years with male:female ratio of 7:6. All patients hailed from the same geographical area. All children were healthy with no history of any long-term or chronic illness, without additional symptoms and had received Bacillus Calmette-Guérin vaccination at birth. The total duration of illness varied from 1 to 5 months, with a mean of 3 months. All patients had a history of intramuscular age-appropriate vaccination as per the national immunization schedule. All patients were followed up to 6 months after intervention and none of our patients developed relapse. Patient who does not respond with optimum treatment should have a high suspicion of such opportunistic infection, which is crucial to their management. Hospital-acquired NTM infections often result from contaminated instruments or fluids. Adherence to strict aseptic precautions, hand hygiene and environmental precautions are the key to preventing these infections. In case of skin and soft tissue infections / abscesses, surgical intervention plays a significant role for managing the patient.

Examining Miliary Disease Etiology in a Coccidioides-Endemic Center: A Retrospective Cohort Study.

Background: A miliary pattern on chest imaging is often attributed to tuberculosis (TB) infection. However, a myriad of conditions can cause a miliary pattern, many of which are imminently life-threatening. Research Question: The primary aim of our study is to elucidate the potential causes of miliary chest imaging patterns to improve workup and empiric therapy selection. The secondary aims are to discern the predictors of miliary disease etiology and to determine whether appropriate empiric antimicrobial therapies were given. Study Design and Methods: In this retrospective cohort study, we searched a radiology database for patients with chest imaging studies described by the word "miliary". Subjects were excluded if they were under 18 years of age and if there were insufficient objective data to support a miliary disease etiology. A radiologist independently reviewed all imaging studies, and studies that did not appear to have a true miliary pattern were excluded. The collected data include patient demographics, immunocompromising risk factors, conditions associated with miliary disease, β-D-glucan levels, serum eosinophil count, and empiric therapies received. Results: From our 41-patient cohort, 22 patients (53.7%) were clinically diagnosed with coccidioidomycosis, 8 (19.5%) with TB, 7 (17.1%) with metastatic solid cancer, 1 (2.4%) with lymphoma, 1 (2.4%) with other (Mycobacterium simiae), and 3 (7.3%) with unknown diseases (the sum equals 42 patients because one individual was diagnosed with both coccidioidomycosis and TB). All six patients with greater than 500 eosinophils/μL were diagnosed with coccidioidomycosis. Of the 22 patients diagnosed with coccidioidomycosis, 20 (90.91%) were empirically treated with an antifungal regimen. Of the eight patients with TB, six were empirically treated for TB. Interpretation: Based on our data from a Coccidioides-endemic region with close proximity to tuberculosis-endemic areas, the leading cause of miliary disease is coccidioidomycosis, although TB and cancer are also common etiologies. Serum eosinophilia and elevated β-D-glucan levels were strongly predictive of coccidioidomycosis in our patient cohort with a miliary chest imaging pattern.

Non-Tuberculous Mycobacteria Infections based on 16S rRNA detections in patients with Suspected Chronic Tuberculosis at a Tertiary Referral Hospital in Indonesia

This study identified non-tuberculous mycobacteria (NTM) isolates from the clinical respiratory specimen of patients suspected of chronic tuberculosis at a tertiary referral hospital in Indonesia. In this study, 20 clinical non-tuberculous mycobacteria (NTM) isolates were obtained from respiratory samples examined in the tuberculosis section of the Clinical Microbiology laboratory at Dr Soetomo General Hospital. The isolates were identified using TB Ag MPT 64 (SD Bioline) and targeting 16S rRNA genes sequence for analysis at the species level. Data on clinical features were collected and chest radiographs were evaluated. The highest bacterium found in the isolates was Mycobacterium kansasii (12 strains, 60%.), followed by Mycobacterium gordonae (2 strains, 5%), Mycobacterium parascofulaceum (2 strains, 5%), Mycobacterium avium (1 strain, 2.5%), Mycobacterium simiae (1 strain, 2.5%). Mycobacterium abcessus (1 strain, 2.5%), and Mycobacterium paraterrae (1 strain, 2.5%). Males dominated patients with Mycobacterium kansasii. Clinical symptoms include cough, dyspneu, hemoptysis, chest pain, and sweats. Half of the patients had a history of previous tuberculosis and other comorbid diabetes mellitus. Non-tuberculous mycobacteria (NTM) species identified were dominated by Mycobacterium kansasii. The predominance of non-tuberculous mycobacteria (NTM) species from clinical respiratory can be a reference to determine prudent treatment for patients in high-burden TB countries.

Antimicrobial Susceptibility Distributions of Clinical Isolates of Nontuberculous Mycobacteria in Israel.

There is a scarcity of data regarding the antimicrobial susceptibility testing profiles of nontuberculous mycobacterial (NTM) in Israel and other Middle Eastern countries. We aimed to describe the antimicrobial susceptibility profiles of NTM in Israel. A total of 410 clinical isolates of NTM, identified to the species level using matrix-assisted laser desorption ionization-time of flight mass spectrometry or hsp65 gene sequencing, were included. Minimum inhibitory concentrations for slowly growing mycobacteria (SGM) and rapidly growing mycobacteria (RGM) for 12 and 11 drugs were determined using the Sensititre SLOMYCOI and RAPMYCOI broth microdilution plates, respectively. Mycobacterium avium complex (MAC) was the most frequently isolated species (n = 148; 36%), followed by Mycobacterium simiae (n = 93; 23%), Mycobacterium abscessus group (n = 62; 15%), Mycobacterium kansasii (n = 27; 7%), and Mycobacterium fortuitum (n = 22; 5%) accounting together for 86% of isolates. The most active agents against SGM were amikacin (98%/85%/100%) and clarithromycin (97%/99%/100%), followed by moxifloxacin (25%/10%/100%) and linezolid (3%/6%/100%) for MAC, M. simiae, and M. kansasii, respectively. For RGM, the most active agents were amikacin (98%/100%/88%) followed by linezolid (48%/80%/100%) and clarithromycin (39%/28%/94%) for M. abscessus group, M. fortuitum, and M. chelonae, respectively. These findings can assist in guiding the treatment of NTM infections.

Molecular epidemiology of nontuberculous mycobacteria isolated from tuberculosis-suspected patients

It is a growing problem around the world to deal with nontuberculous mycobacteria infection (NTM), but its clinical significance is still largely unknown. This study aims to investigate the epidemiology of NTM infections from various clinical samples and determine their clinical significance. From December 2020 to December 2021, 6125 clinical samples were collected. In addition to phenotypic detection, genotypic detection through multilocus sequence typing (hsp65, rpoB, and 16S rDNA genes) and sequencing was also conducted. Records of patients were consulted for clinical information, such as symptoms and radiological findings. Of the 6,125 patients, 351 (5.7%) were positive for acid-fast bacteria (AFB). Out of 351 AFB, 289 (82.3%) and 62 (17.7%) subjects were identified as M. tuberculosis complex (MTC) and NTM strains, respectively. Isolates of Mycobacterium simiae and M. fortuitum were the most frequent, followed by isolates of M. kansasii and M. marinum. We also isolated M. chelonae, M. canariasense, and M. jacuzzii, which are rarely reported. Symptoms (P = 0.048), radiographic findings (P = 0.013), and gender (P = 0.039) were associated with NTM isolates. M. Fortuitum, M. simiae, and M. kansasii presented with bronchiectasis, infiltration, and cavitary lesions most frequently, while cough was the most common symptom. In conclusion, Mycobacterium simiae and M. fortuitum were presented in seventeen and twelve NTM isolates from the collected samples. There is evidence that NTM infections in endemic settings may contribute to the dissemination of various diseases and the control of tuberculosis. In spite of this, further research is needed to evaluate the clinical significance of NTM isolates.

2185. Pulmonary Non-Tuberculosis Mycobacteria (NTM) Infections in Adult Patients at a Tertiary Care Hospital in Saudi Arabia

Abstract Background Burden of Non-tuberculous Mycobacteria (NTM) disease is increasing in both developed and developing countries. Local data is needed to guide our understanding of the epidemiology and outcome of NTM management in our population. The main objectives of the study are to describe management of patients with NTM infection and determine treatment outcomes in adult patients. Also, to explore the epidemiology of mycobacterial species associated with pulmonary NTM. Methods A 10-year (2010-2020), retrospective cohort study was conducted at a tertiary care hospital in Saudi Arabia. All patients with positive NTM culture were screened. Adult patients (≥ 18 years old) diagnosed with pulmonary NTM disease and received treatment for ≥ two months were included. Clinical data was collected from the patient’s chart using standardised form. The primary end points were overall cure rate (clinical, microbiological, and radiological cure), recurrence, relapse, and re-infection rate. The secondary end points were mortality and hospital admission rate for NTM infection. The Chi-square test was used to compare parameters. Univariate then multivariable logistic regression were used to model the effect of the outcome. Screening of patients with positive Non-tuberculous Mycobacteria culture for eligibility Results Forty-five patients met the study inclusion criteria. 60% were male with a median age of 53. The most common comorbidities were malignancy and bronchiectasis. NTM species were Mycobacterium simiae (35%), Mycobacterium avium Complex (27%), and Mycobacterium abscessus (18%). Overall cure rate was 95%, with 85%, 85% and 74% of microbiological, clinical, and radiological rate achieved, respectively. Greater number of patients were treated before the recent pulmonary NTM guideline. Regimens were based on general treatment for NTM infection with clarithromycin, ethambutol, and rifampicin utilized the most. 69% of regimens were adjusted after speciation. The median duration of treatment was 36 weeks. Relapse, recurrence and reinfection rate was 20%, 9%, and 2%, respectively. NTM related hospital admission rate was 34%. Baseline characteristics of Patients with Pulmonary Non-tuberculous Mycobacteria (n=45) Primary and secondary outcomes Clinical Presentation, diagnosis and treatment of Patients with pulmonary Non-tuberculous Mycobacteria (n=45) This table is showing the clinical course of all patients included in the study with subgroup analysis per each specie of Non-tuberculous Mycobacteria Conclusion Pulmonary NTM disease in our patients was mainly due to three species in 80%. High overall cure rate and low recurrence rate were achieved. The findings of this study will serve as a guide for the management of pulmonary NTM disease in Saudi population. Disclosures All Authors: No reported disclosures.

Nghiên cứu tỷ lệ phân bố các loài Nontuberculous mycobacteria phân lập được tại bệnh viện 74 Trung ương bằng phương pháp giải trình tự gen hsp65

In recent years, the burden of nontuberculous mycobacteria pulmonary disease has increased worldwide. Nontuberculous mycobacteria - NTM infection is often misdiagnosed with Mycobacterium tuberculosis - MTB because of their similar clinical manifestations and preclinical manifestations. For MTB, the National Tuberculosis Program and the Ministry of Health (Vietnam) have a standard treatment regimen, while for NTM, an individualized treatment regimen based on infectious NTM species. Therefore, accurate identification of the causative NTM species can help clinicians choosing an effective treatment regimen. Among 122 suspected NTM samples collected at National Hospital 74, we successfully identified 115 strains belonging to NTM. Analytical DNA sequences, building phylogenetic trees were analyzed by Bioedit, ClustalX2, and MEGA-X software; comparing and identifying reference species from gene bank were used BLAST-NCBI. Slow-growing mycobacteria accounted for 61.7%, consists of Mycobacterium avium complex (37.4%), Mycobacterium lentiflavum (7.0%), Mycobacterium simiae (7.0%), Mycobacterium gordonae complex (5.2%) and other species less than 2.0%. The detection rate of rapid-growing mycobacteria was 38.3% including Mycobacterium abscessus complex (31.3%), and Mycobacterium fortuitum (7.0%). The most prevalent NTM species belonged to Mycobacterium avium complex and Mycobacterium abscessus complex (68.7%). The proportion of NTM infection in patients 50 years and older is 2.3 times higher than in patients under 50 years. This proportion is 5 times higher in females while there is no significant difference in males.

Mycobacterium simiae Isolates Subtypes and Molecular Drug Susceptibility in Iran

Background: Despite the clinical and epidemiological importance of Mycobacterium simiae worldwide, including in Iran, there is no clear and effective treatment regimen for M. simiae and its different subtypes. Objectives: Concerning the superiority of molecular approaches, this study aims to identify the common M. simiae subtypes submitted to the National Reference Tuberculosis (TB) Laboratory of Iran and study the presence of drug resistance by molecular detection methods. Methods: We included sputum samples with M. simiae confirmation submitted to the National Reference TB Laboratory of Iran from May 2014 to May 2016. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used for drug susceptibility testing (DST). Results: Among 7200 TB suspected patients, a total of 60 M. simiae cases belonging to subtype I were identified. All the included clinical isolates met the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) diagnostic criteria and were considered the disease’s causative pathogen. Males (58.33%), elderly (68.54%), and patients with a history of TB (51.42%) were shown to be more prone to infection with the disease. All clinical isolates of M. simiae were resistant to rifampin (RIF) and isoniazid (INH). Amikacin/kanamycin (AMK/KAN) and ciprofloxacin (CIP) susceptibility was found to be 91.66% and 88.33%, respectively. Conclusions: Subtype I was exclusively identified among M. simiae patients in Iran. Molecular detection of drug resistance suggests that amikacin/kanamycin and ciprofloxacin could be used to treat patients infected with M. simiae subtype I.

Presence and habitats of bacterial fish pathogen relatives in a marine salmon post-smolt RAS

Recycling aquaculture system (RAS) requires well-functioning microbial communities to support fish welfare and to minimize the risk of spreading diseases. In this study of a marine post-smolt RAS we searched for groups of bacteria containing known salmon pathogens in a 16S RAS library that covered samples from four different sites over a year. In the first of the four production cycles included, there was a severe outbreak of fish skin ulcers associated with over 50 % loss of the fish population. To study the presence of potentially pathogenic bacteria from various habitats in the RAS, we used a refined 16 S rRNA gene library approach. The short library sequences of 250 bp were aligned towards 16 S sequences of recognized fish pathogenic bacteria 750-1500 bp long. The latter sequences were widely defined and gathered from GenBank into a fish pathogens database (FPD) prior to the alignment. Pathogen-relatives detected were Moritella viscosa, Psychrobacter immobilis and Aeromonas salmonicida, all with 100 % similarity; Tenacibaculum dicentrarchi, Pseudoalteromonas piscicida, Mycobacterium simiae, Aliivibrio wodanis and Fransicella philomiragia that had 97-99 % similarity and Shewanell puterfaciens, Flavobacterium johnsoniae, Piscirickettsia salmonis, and Bacillus mycoides that had 90-95 % sequences similarity. The pathogen-relatives habituated differently in the RAS as their relative abundances changed between the sites and over time in response to changing operational conditions. The biofilter biofilm was a unique site due to its remarkable low abundance of the pathogen-relatives, whereas three pathogen-relatives with high similarity to classical salmon winter ulcers strains were highly present in the fish skin ulcers. All pathogen-relatives identified were also detected in the production water, three of them at high relative abundance. Thus, we recommend the fish skin and the production water as the best sampling sites for pathogens early warning and specific screening approaches.

Drug susceptibility profiling and genetic determinants of drug resistance in Mycobacterium simiae isolates obtained from regional tuberculosis reference laboratories of Iran.

BackgroundAmong Non-tuberculous mycobacteria (NTM) which generally cause opportunistic infections, especially in immunocompromised hosts, Mycobacterium simiae (M. simiae) is one of the most important NTM, associated with pulmonary disease. The main concern about M. simiae infections is the extreme resistance of this NTM to antibiotics. There are limited studies about drug susceptibility testing (DST) and the causes of drug resistance in M. simiae. Hence, the current study aimed to identify the M. simiae isolates and to assess the drug resistance of the isolates using phenotypic and molecular methods.Materials and methodsIn this study, 50 clinical pulmonary isolates suspected of NTM were collected from regional tuberculosis reference laboratories in Iran. The isolates were identified as M. simiae by using standard biochemical tests and molecular methods. DST was performed for identified M. simiae isolates and additional 35 M. simiae isolates from the department archive, against eight drugs. The mutations in gyrA, gyrB, and rrl genes in clarithromycin and moxifloxacin resistant isolates were investigated by polymerase chain reaction (PCR) followed by sequencing.ResultsOut of 50 suspected NTM isolates, 25 isolates were detected as M. simiae species based on the biochemical tests, and 18 isolates were verified based on the rpoB gene sequence analysis to achieve a total of 53 isolates when the archive isolates were included. DST results showed that all 53 isolates were resistant to isoniazid, rifampin, and clofazimine. The rate of resistance to ethambutol and linezolid were 34 (64%), and 40 (76%) respectively. The highest susceptibility rate was demonstrated for amikacin 53 (100%) and clarithromycin 45(85%), followed by moxifloxacin 35(66%). Sequence analysis showed mutations in positions 2058 and 2059 of the rrl gene, as well non-synonymous mutation at codons 389, 444, and 571 of the gyrB gene. Sequence analysis showed no mutation in the gyrA gene. drug-resistant isolates with mutations showed higher MICs compared to non-mutant resistant isolates.ConclusionsThis study revealed amikacin, clarithromycin, and moxifloxacin as the most effective antibiotics. However, since M. simiae exhibited a high level of antibiotic resistance in vitro, therefore, species identification and determining the antibiotic susceptibility pattern of the isolates are essential before treatment.

Global prevalence of non-tuberculous mycobacteria in adults with non-cystic fibrosis bronchiectasis 2006–2021: a systematic review and meta-analysis

ObjectiveTo accurately estimate the global prevalence of non-tuberculous mycobacteria (NTM) in adults with non-cystic fibrosis (non-CF) bronchiectasis and to determine the proportion of NTM species and subspecies in clinical patients...

Quinoxaline-based efflux pump inhibitors restore drug susceptibility in drug-resistant nontuberculous mycobacteria.

Nontuberculous mycobacteria (NTM) comprise several ubiquitous, environmentally localized bacteria that may be responsible for serious human diseases. NTM-associated pulmonary infections largely affect individuals with underlying respiratory disease or chronic disease and immunosuppressed patients. Mycobacterium simiae and M. abscessus are two NTMs responsible for lung disease in immunocompetent and immunocompromised individuals. In this study, two NTM strains were isolated from two patients admitted to an Italian hospital and were identified as M. simiae and M. abscessus. The two NTMs were tested for drug susceptibility against different antibiotics. To restore drug susceptibility, a new series of 2-aryl-3-phenoxymethyl-quinoxaline derivatives (QXs) was designed, synthesized, and investigated as efflux pump inhibitors (EPIs) against two clinical isolates of the above-cited NTMs, evaluating how EPIs can influence the drug minimal inhibitory concentration values and, therefore, the activity. The different\ resistance levels tracked in the clinical strains were reduced by EPIs, and in several cases, the susceptibility was completely restored. QXs also resulted as potential chemical probes to be used in drug susceptibility tests to identify the resistance origin when detected.

Characterization of Non-tuberculous Mycobacteria by Line Probe Assay Isolated from Pulmonary Tuberculosis Suspected Patients at Rajasthan

Non-tuberculous Mycobacteria (NTM) are emerging as an important opportunistic pathogen. Since clinical presentation of NTM infection is similar to tuberculosis (TB), patients present as suspected TB or drug resistant TB. Presently in the National Tuberculosis Elimination Programme (NTEP ) NTM are not being speciated, but there is an urgent need to characterize the NTM so that appropriate treatment can be given as many species are multi-drug resistant. The purpose of the present study was to use Line Probe Assay (LPA) i.e. GenoType Mycobacterium CM/AS assay to characterize NTM for rapid early reporting and to know the pattern of NTM at Rajasthan. Sputum samples from 5000 TB and Multi Drug Resistant TB (MDRTB) suspect patients were processed and cultured on Mycobacterium Growth Indicator Tube (MGIT). Culture isolates found positive for mycobacteria in Ziehl Neelsen (ZN) staining and negative by MPT64 antigen test were then subjected for GenoType Mycobacterium CM/AS Among sputum samples from 5000 patients 1520 (30.4%) patient samples were positive for mycobacteria, among these 1488 (97.9%) were Mycobacterium tuberculosis (MTB) and 32 (2.1%) were NTM, among them 56.2% were Mycobacterium intracellulare, 21.8% Mycobacterium abscessus, 9.3% Mycobacterium fortuitum, 1% Mycobacterium simiae and 9.3% isolates showed invalid results. Incidence of NTM was very low (2.1%) among them M. intracellulare and M. abscessus were the most commonly isolated species, GenoType Mycobacterium CM/AS assay was found to be easy, rapid and reliable test giving valid results in 91% cases in 3-5 days of getting growth.

The Value of Sputum Polymerase Chain Reaction for Detection of Nontuberculous Mycobacteria in Cystic Fibrosis Patients with Negative Nontuberculous Mycobacteria Sputum Culture.

Background: Cystic Fibrosis (CF) is a life-threatening autosomal recessive disease. The purpose of this study was to evaluate the value of Polymerase Chain Reaction (PCR) in CF patients with Nontuberculous Mycobacteria (NTM) negative sputum culture. Methods: This is a descriptive cross-sectional study. The population included all children with CF, aged between 5 - 18 years old, with an NTM negative sputum culture. The patient's sputum samples were sent for smear and culture of NTM, RFLP PCR, and PCR sequence. Results: In total, 57 CF patients with negative NTM sputum culture were enrolled. Nine patients (15.78%) had positive sputum PCR for NTM. Among these strains, Mycobacterium simiae was the most common one with 5 cases (8.77% of total positive cases). Conclusion: PCR can be used as an alternative diagnostic method for NTM in CF patients with negative NTM sputum culture, always under clinical suspicion of the disease.

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 40nm. 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, and64µg/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.

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.