Mycobacterium Tuberculosis: A Continous Challenge for Physicians

The Open Microbiology Journal

Background: Tuberculosis is one of the most important infectious diseases that has claimed its victims throughout much of known human history. With Koch's discovery of the tubercle bacillus as the etiologic agent of the disease, his sanitary and hygienic measures, which were based on his discovery and the development of a vaccine against tuberculosis by Albert Calmette and Camille Guérin in 1921, an attenuated Mycobacterium bovis strain, bacilli Calmette-Guérin (BCG), and the discovery of the first antibiotic against tuberculosis, streptomycin by Selman Waksman in 1943, soon led to the opinion that appropriate control measures had become available for tuberculosis and it had been assumed that the disease could ultimately be eradicated. The emergence of resistant strains of this bacteria and widespread distribution of the disease in the world, and the emergence of the AIDS epidemic destroyed any possibility of global control of tuberculosis in the foreseeable future. Objectives: ...

IP innovative publication pvt. ltd, 2019

Introduction: Tuberculosis continues to be the leading cause of morbidity and mortality in developing nations. Off late infections due to mycobacterial species other than tubercle bacilli are being reported frequently. Nontuberculous mycobacteria are being increasingly recognized and isolated as pathogens from immunocompetent host too. They are found in both pulmonary and extrapulmonary form of disease. The prevalence of infections due to NTM is known to vary with place, host and climatic factors. Aim: the present study is a retrospective cross-sectional observational study for a period of two years from Jan.2013- Dec.2014, at Princess Era Hospital,a teaching hospital of Deccan college of medical sciences at Hyderabad. Data from microbiology lab records was retrieved and analysed. Materials and Methods: about 232 specimens from 229 patients with clinical symptoms of tuberculosis were analysed for laboratory diagnosis of nontuberculosis mycobacterial infection in mycobacteriology section of microbiology laboratory. Seventy nine samples were obtained from 78 patients with pulmonary form of disease and 153 samples were from 151 patients with extrapulmonary form of disease. Study was approved by ethical committee of the college and patient consent was obtained prior to sample collection. All the specimens received in the laboratory were processed by direct microscopy for acid fast bacilli using Ziehl Neelsen stain. Culture was performed on conventional LJ media and Middle Brook 7H12 media in MGIT 320 automated system. Identification of culture positive isolates was achieved by standard biochemical test and rapid immunochromatography test for detection of mycobacterial tuberculosis protein 64 antigen [MPT64]. Results: Direct microscopy was positive in 20.52%. and 4.25% of which were later identified as NTM. Culture yielded positive result in 22.27% of the subjects. NTM were isolated in 3.49% of the total subjects studied. Mycobacterium tuberculosis was the most common isolate as 84.31%, both in pulmonary and extrapulmonary form of disease as 76.92% and 92%. NTM were isolated in 15.68% of culture positive samples. Majority of the NTM’s were from pulmonary specimens as 75% and rest from extrapulmonary specimens as 25%. In subjects above 50 years of age, NTM was more prevalent in men. The most common predisposing risk factor was chronic obstructive lung disease with bronchiectasis in majority and cavitary lesion in one. And pleural effusion in rest as 25%. In the present study only rapid growers were isolated and M. chelonae was the predominant species 87.5% followed by M.fortuitum in 12.5%. Sputum yielded maximum NTM’s as 50%, BAL as 25% followed by pleural fluid and pleural biopsy as 12.5% each. MPT64 antigen test and Para Nitro Benzoic acid resistance at 500ug/ml concentration were found to be very useful presumptive test for identification of NTM. Samples in duplicate where ever feasible were obtained and processed for NTM; and all yielded the same microbe confirming the etiological role. Conclusion: NTM infection in symptomatic subjects was seen in significant proportion of the culture positives. Therefore, laboratories performing mycobacterial culture should be equipped with facilities for identification and drug susceptibility test for NTM in order to provide proper diagnosis and targeted therapy. Failure to do so may increase the chances of them being misinterpreted and reported as MDR-TB.

PloS one, 2012

Nontuberculous mycobacterial (NTM) infections cause morbidity worldwide. They are difficult to diagnose in resource-limited regions, and most patients receive empiric treatment for tuberculosis (TB). Our objective here is to evaluate the potential impact of NTM diseases among patients treated presumptively for tuberculosis in Mali. We re-evaluated sputum specimens among patients newly diagnosed with TB (naïve) and those previously treated for TB disease (chronic cases). Sputum microscopy, culture and Mycobacterium tuberculosis drug susceptibility testing were performed. Identification of strains was performed using molecular probes or sequencing of secA1 and/or 16S rRNA genes. Of 142 patients enrolled, 61 (43%) were clinically classified as chronic cases and 17 (12%) were infected with NTM. Eleven of the 142 (8%) patients had NTM disease alone (8 M. avium, 2 M. simiae and 1 M. palustre). All these 11 were from the chronic TB group, comprising 11/61 (18%) of that group and all were i...

Early diagnosis of tuberculosis (TB) and initiating optimal treatment would not only enable a cure of an individual patient but will also curb the transmission of infection and disease to others in the community. Of the several distinct components of TB control programmes, case-finding remains the cornerstone for effective control. However, there are no definite guidelines available as on date as how to use optimally the number of diagnostic tests ranging from simple AFB microscopy to complex molecular biological techniques which have become available over a period; to establish or rule out diagnosis of tuberculosis in a given patient. Therefore, there is need for description and evaluation of the existing important techniques available for the diagnosis of TB and drug susceptibility testing and their advantages and limitations which will help in the development of appropriate TB diagnostic guidelines for the implementation of TB control strategies.

International Journal of Mycobacteriology

The genus Mycobacterium comprises a diverse group of species which includes the most pathogenic Mycobacterium tuberculosis complex (MTBC) and Mycobacterium leprae. Apart from these two groups, the remaining species of Mycobacterium are collectively referred to as nontuberculous mycobacteria (NTM). [1] The species belonging to NTM form a large and distinct group that is ubiquitous, prevailing in both natural environments and human dwellings, including hospital setups. [2] Their pathogenic potential had long been underestimated. Moreover, the diagnosis and treatment of NTM diseases create a dilemma for physicians as their clinical features often overlap with that of MTBC. NTM diseases are difficult to treat as most of them are resistant to first-line anti-tubercular drugs. They are often misdiagnosed as tuberculosis (TB) or drug-resistant TB (DR-TB) based on acid-fast bacilli (AFB) finding in TB endemic settings. [3] The American Thoracic Society (ATS) and Infectious Diseases Background: Nontuberculous mycobacteria (NTM) are on the rise worldwide. The diagnosis and treatment of NTM disease create a dilemma for physicians as their clinical features often overlap with that of tuberculosis (TB). The present study aims to report a series of NTM infections presenting as suspected TB. Methods: It was a prospective observational study starting from December 2018 to January 2022. A total of 1850 suspected TB patients (pulmonary = 522 and extrapulmonary = 1328) were included in this study. Clinical features, radiological findings, microbiological diagnosis, treatment, and outcome were recorded. Clinical specimens were processed for Ziehl-Neelsen staining, GeneXpert MTB/Rif assay by cartridge-based nucleic acid amplification test, and culture. The culture-positive isolates were categorized as Mycobacterium tuberculosis complex or NTM depending on the detection of MPT64 antigen by immunochromatographic test. The NTM isolates were speciated by line probe assay using GenoType® Mycobacterium common mycobacteria kit. The criteria of the American Thoracic Society/ Infectious Diseases Society of America were applied to confirm NTM disease. Results: Of 1850 suspected TB patients, NTM disease was diagnosed in 20 patients (pulmonary = 9, nonpulmonary = 11). Eight NTM cases presented as suspected drug-resistant-TB with a history of antitubercular therapy. Among pulmonary NTM cases, Mycobacterium scrofulaceum (n = 7) was the most common species followed by Mycobacterium kansasii (n = 1) and Mycobacterium intracellulare (n = 1). In nonpulmonary cases, Mycobacterium abscessus (n = 8) was involved in majority of cases followed by Mycobacterium fortuitum (n = 3). Cavitary lung disease and laparoscopic port site infections were most frequent pulmonary and non-pulmonary manifestations respectively. Conclusion: Hence, there is an urgent need for better diagnostic and drug susceptibility testing facility along with standardized treatment protocol for NTM disease.

European Respiratory Journal, 2010

The objective of this research is to analyze the seismic effect of the building of geometrical plan configurations and compare the analysis on various parameters i.e. axial forces, displacement, base shear, bending moment, shear force, support reaction etc. For this analysis response spectrum method has been selected and it is analyzed by using STAAD Pro software. In this analysis a regular square shape building in plan is analyzed and the same is compared with H-shape plan building. Also, all the data being used for this analysis are same i.e. size of column, beam, height of floors, etc. The results of this analysis have been compared using graphs and by graphical representation of displacement of both the buildings, axial forces, stress distribution through the height of the building etc. This analysis has been carried out to observe the effect on the stability of the building under seismic analysis and to make an ease in the selection of the shape of the building in the seismic zone.

PENANGKARAN PENELITIAN LEMBAGA PENELITIAN DAN PENGABDIAN PADA MASYARAKAT (LP2M) UIN LAUDDIN Malino 11-08-2014 s/d 07-09-2014

2006

Las Entidades No Lucrativas son aquellas con fines sociales y que reciben fondos de patrocinadores quienes no esperan recibir beneficios proporcionales a los recursos otorgados.