scholarly journals Validez diagnóstica del GeneXpert para Mycobacterium tuberculosis y prueba de resistencia a rifampicina

2021 ◽  
Vol 4 (3) ◽  
pp. 176-180
Author(s):  
Ana Carolina Lacayo de Santana ◽  
Polyta Gabriela Rodríguez Cruz ◽  
Zayda Pérez Aguilar ◽  
Cecilia Vásquez Cornejo
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Lowenstein Jensen

Introducción. El diagnóstico temprano de tuberculosis permite el control de la enfermedad y su transmisibilidad. Objetivo. Describir la validez diagnóstica del GeneXpert MTB/RIF para Mycobacterium tuberculosis en muestra bronquial, utilizando como referencia el cultivo Löwenstein Jensen. Metodología. Estudio transversal analítico, mediante revisión de 942 registros de la Unidad de Broncoscopia durante el año 2014 al 2018, de las cuales 320 cumplieron criterios de inclusión. Estos datos fueron exportados a un formato compatible con Epi Info versión 7 y analizados con parámetros estadísticos de sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo, prueba de concordancia e índice Kappa a través de Epidat 4,2.  Resultado. De los 320 pacientes sometidos a fibrobroncoscopía diagnóstica para tuberculosis con GeneXpert MTB/RIF, los resultados negativos fueron 79 % (252) y positivo 21 % (68); el 1 % mostró resistencia a rifampicina. Se reportó una fuerte concordancia de GeneXpert MTB/RIF con el cultivo bacilo ácido alcohol resistente, que se determinó con un índice de kappa de 0,88 +/- (0,81-0,94) IC 95 %, una sensibilidad del 98 %, especificidad del 96 %, valor predictivo positivo 83 % (IC 95 %), valor predictivo negativo 99,6 % (CI 95 %).Conclusión. La prueba GeneXpert MTB/RIF tiene una capacidad altamente sensible y específica para el diagnóstico de tuberculosis en muestras obtenidas por fibrobroncoscopía.

Determination some Immunological Aspects in Pulmonary Tuberculosis Patients in Qadisiyah Province

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Syoof Khowman Alramahy ◽  
Akram Hadi Hamza
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Statistical Difference ◽  
Positive Culture ◽  
Control Group ◽  
Tuberculosis Patients ◽  
Significant Difference ◽  
Lowenstein Jensen ◽  
The Mean ◽  
Igg Level

This study was carried out to study of some immunological aspects among the pulmonary Tuberculosis patients infected with causative agent, Mycobacterium tuberculosis. A Total of 200 sputum samples were collected from patients attending the consultant Clinic for Chest and Respiratory disease center, Diwaniya. Control group (No=15) also included. According to acid fast stain of sputum, the patients were classified as positive (No=91,45.5%) and negative (No=109,54.5, Lowenstein Jensen medium used for the cultivation of samples, on which 70% of sputum samples where positive culture for this microorganism. The grown microorganism were identified as M. tuberculosis, based on positive A.F.B, Niacin producers ,negative for catlase at 68c. The mean IgG level was l184.053±76.684 mg/100 ml in tuberculosis group compared with 1016.533 ± 44.882 mg/100ml in control group, rendering the statistical difference significant. For IgA and IgM levels, they were at mean of 315.880±38.552 mg/100 ml and 119.527±8.464 mg/100 ml in control group compared with 396.358±38.776 mg/100 ml and 134.207±11.696 mg/100 ml in patients group respectively with significant difference

scholarly journals Characterization of Drug-Resistant Lipid-Dependent Differentially Detectable Mycobacterium tuberculosis

2021 ◽  
Vol 10 (15) ◽  
pp. 3249
Author(s):  
Annelies W. Mesman ◽  
Seung-Hun Baek ◽  
Chuan-Chin Huang ◽  
Young-Mi Kim ◽  
Sang-Nae Cho ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Culture Media ◽  
Multidrug Resistant ◽  
Culture Conditions ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Solid Culture ◽  
Lowenstein Jensen ◽  
Genetic Mechanisms ◽  
Lipid Resuscitation

An estimated 15–20% of patients who are treated for pulmonary tuberculosis (TB) are culture-negative at the time of diagnosis. Recent work has focused on the existence of differentially detectable Mycobacterium tuberculosis (Mtb) bacilli that do not grow under routine solid culture conditions without the addition of supplementary stimuli. We identified a cohort of TB patients in Lima, Peru, in whom acid-fast bacilli could be detected by sputum smear microscopy, but from whom Mtb could not be grown in standard solid culture media. When we attempted to re-grow Mtb from the frozen sputum samples of these patients, we found that 10 out of 15 could be grown in a glycerol-poor/lipid-rich medium. These fell into the following two groups: a subset that could be regrown in glycerol after “lipid-resuscitation”, and a group that displayed a heritable glycerol-sensitive phenotype that were unable to grow in the presence of this carbon source. Notably, all of the glycerol-sensitive strains were found to be multidrug resistant. Although whole-genome sequencing of the lipid-resuscitated strains identified 20 unique mutations compared to closely related strains, no single genetic lesion could be associated with this phenotype. In summary, we found that lipid-based media effectively fostered the growth of Mtb from a series of sputum smear-positive samples that were not culturable in glycerol-based Lowenstein–Jensen or 7H9 media, which is consistent with Mtb’s known preference for non-glycolytic sources during infection. Analysis of the recovered strains demonstrated that both genetic and non-genetic mechanisms contribute to the observed differential capturability, and suggested that this phenotype may be associated with drug resistance.

scholarly journals Multicenter Evaluation of the BACTEC MGIT 960 System for Recovery of Mycobacteria

1999 ◽  
Vol 37 (3) ◽  
pp. 748-752 ◽  
Author(s):  
Bruce A. Hanna ◽  
Adeleh Ebrahimzadeh ◽  
L. Bruce Elliott ◽  
Margie A. Morgan ◽  
Susan M. Novak ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Liquid Medium ◽  
Mycobacterium Avium ◽  
Culture Systems ◽  
Solid Media ◽  
Lowenstein Jensen ◽  
The Mean

We evaluated the BACTEC MGIT 960 system, which is a fully automated, noninvasive system for the growth and detection of mycobacteria with a capacity to incubate and continuously monitor 960 7-ml culture tubes. We studied 3,330 specimens, 2,210 respiratory and 1,120 nonrespiratory specimens, collected from 2,346 patients treated at six sites. Processed specimens were inoculated into the BACTEC MGIT 960 and BACTEC 460 TB systems, as well as onto Lowenstein-Jensen slants and Middlebrook 7H11/7H11 selective plates. From all culture systems, a total of 362 isolates of mycobacteria were recovered; these were recovered from 353 specimens collected from 247 patients. The greatest number of isolates of mycobacteria (289, or 80% of the 362 isolates) was recovered with the BACTEC MGIT 960, followed by the BACTEC 460 TB (271, or 75%) and solid media (250, or 69%). From all culture systems a total of 132 isolates of Mycobacterium tuberculosiscomplex were recovered. The greatest number of isolates of M. tuberculosis complex was recovered when liquid medium was combined with conventional solid media; the number recovered with BACTEC 460 TB plus solid media was 128 (97%), that recovered with BACTEC MGIT 960 plus solid media was 121 (92%), that recovered with BACTEC 460 TB was 119 (90%) and that recovered with all solid media combined was 105 (79%). The recovery with BACTEC MGIT 960 alone was 102 (77%). The mean times to detection (TTD) for M. tuberculosis complex were 14.4 days for BACTEC MGIT, 15.2 days for BACTEC 460 TB, and 24.1 days for solid media. The numbers of isolates of Mycobacterium avium complex (MAC) recovered were 172 (100%) for all systems, 147 (85%) for BACTEC MGIT 960, 123 (72%) for BACTEC 460 TB, and 106 (62%) for all solid media combined. The TTD for MAC in each system were 10.0 days for BACTEC MGIT 960, 10.4 days for BACTEC 460 TB, and 25.9 days for solid media. Breakthrough contamination rates (percentages of isolates) for each of the systems were 8.1% for BACTEC MGIT 960, 4.9% for BACTEC 460 TB, and 21.1% for all solid media combined.

scholarly journals Comparison of hypertonic saline-sodium hydroxide method with modified Petroff’s method for the decontamination and concentration of sputum samples

2013 ◽  
Vol 2 (3) ◽  
pp. 78-81 ◽  
Author(s):  
SK Chaudhary ◽  
B Mishra
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Sodium Hydroxide ◽  
Hypertonic Saline ◽  
P Value ◽  
Chi Square ◽  
Major Health ◽  
Medical College ◽  
Lowenstein Jensen ◽  
Novel Method ◽  
The Difference

INTRODUCTION: Tuberculosis is one of the major health problems particularly in developing countries. For definitive diagnosis of pulmonary tuberculosis identification of tubercle bacilli in sputum by microscopy and culture is essential. For decontamination and concentration of sputum, the commonly used method in the laboratory is Modified Petroff’s method but the Hypertonic saline–sodium hydroxide (HS-SH) method is known to be better for detection of Mycobacterium tuberculosis by culture. This study was aimed to compare a novel method for the improvement of decontamination and concentration of sputum samples. MATERIALS AND METHODS: A total of 50 confirmed smear positive sputum samples from pulmonary TB patients who visited at St. John’s Medical College and Hospital during 2009 to 2010, were processed for the decontamination process. Each sample was decontaminated by Modified Petroff’s and HS-SH method separately. Treated samples were cultured in Lowenstein-Jensen media in microbiology laboratory. RESULTS: The culture positive percents of Mycobacterium tuberculosis in the L-J medium treated with HS-SH and Modified Petroff’s method were 84.0% and 70.0%, respectively. A notable feature is that by HS-SH method more samples were positive by 4th week, statistically significant (Chi- square value-11.26 with p-value < 0.05) compare to Modified Petroff’s method. The difference for 3+ grades of L-J growths found slightly higher by Modified Petroff’s method but at lower grades of growths HS-SH method performed better. CONCLUSIONS: HS-SH method is better for the detection of Mycobacterium tuberculosis by culture when compared with the Modified Petroff’s method. DOI: http://dx.doi.org/10.3126/ijim.v2i3.8664   Int J Infect Microbiol 2013;2(3):78-81

scholarly journals Selective Inhibition of Mycobacterium tuberculosis by Para-Nitrobenzoic Acid (PNB) used in Lowenstein-Jensen Medium

2010 ◽  
Vol 5 (1) ◽  
pp. 25-28 ◽  
Author(s):  
S Nepali ◽  
P Ghimire ◽  
DK Khadka ◽  
S Acharya
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Fluorescence Microscopy ◽  
Selective Inhibition ◽  
Evaluation Study ◽  
Fluorescence Staining ◽  
Biochemical Tests ◽  
Nitrobenzoic Acid ◽  
National Tuberculosis ◽  
Lowenstein Jensen ◽  
Mycobacterial Growth

Background: Mycobacterial growth in media to which inhibitory substances are added has been used in species identification. Mycobacterium tuberculosis does not grow in Lowenstein-Jensen (LJ) medium containing para-nitrobenzoic acid (PNB); which can be a basis for its identification from other mycobacteria. Setting: National Tuberculosis Centre (NTC), Thimi, Bhaktapur, Nepal. Objectives: To evaluate usefulness of PNB containing LJ medium in identifying mycobacterial isolates. Methodology: This diagnostic evaluation study based at NTC was conducted from Sep 2006-Jun 2007. During the study period, a total of 857 sputum samples collected from patients attending NTC were analyzed using fluorescence microscopy. The smear positive samples were confirmed by Ziehl-Neelsen (ZN) staining. Smear positive samples were cultured on LJ media with and without PNB; followed by biochemical tests. Results: Out of total 857 sputum samples analyzed, 246 (28.7%) were positive for AFB on fluorescence staining and 214 (87%) of smear positive samples were also positive in culture. All the isolates which grow on LJ media without PNB did not grow on LJ media containing PNB. Conclusion: Mycobacterium tuberculosis can be identified and differentiated from non-tuberculous mycobacteria using PNB containing media, easily in labs where culture is being done. Keywords: PNB; AFB; LJ medium; Mycobacterium tuberculosis DOI: 10.3126/saarctb.v5i1.3080 SAARC J. Tuber. Lung Dis. HIV/AIDS 2008 Vol.5(1) 25-28

scholarly journals Wild-Type and Non-Wild-Type Mycobacterium tuberculosis MIC Distributions for the Novel Fluoroquinolone Antofloxacin Compared with Those for Ofloxacin, Levofloxacin, and Moxifloxacin

2016 ◽  
Vol 60 (9) ◽  
pp. 5232-5237 ◽  
Author(s):  
Xia Yu ◽  
Guirong Wang ◽  
Suting Chen ◽  
Guomei Wei ◽  
Yuanyuan Shang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Critical Concentration ◽  
Bacterial Species ◽  
Drug Susceptibility Testing ◽  
World Health ◽  
Wild Type ◽  
Resistance Mutations ◽  
Content Type ◽  
Lowenstein Jensen

ABSTRACTAntofloxacin (AFX) is a novel fluoroquinolone that has been approved in China for the treatment of infections caused by a variety of bacterial species. We investigated whether it could be repurposed for the treatment of tuberculosis by studying itsin vitroactivity. We determined the wild-type and non-wild-type MIC ranges for AFX as well as ofloxacin (OFX), levofloxacin (LFX), and moxifloxacin (MFX), using the microplate alamarBlue assay, of 126 clinicalMycobacterium tuberculosisstrains from Beijing, China, of which 48 were OFX resistant on the basis of drug susceptibility testing on Löwenstein-Jensen medium. The MIC distributions were correlated with mutations in the quinolone resistance-determining regions ofgyrA(Rv0006) andgyrB(Rv0005). Pharmacokinetic/pharmacodynamic (PK/PD) data for AFX were retrieved from the literature. AFX showed lower MIC levels than OFX but higher MIC levels than LFX and MFX on the basis of the tentative epidemiological cutoff values (ECOFFs) determined in this study. All strains with non-wild-type MICs for AFX harbored known resistance mutations that also resulted in non-wild-type MICs for LFX and MFX. Moreover, our data suggested that the current critical concentration of OFX for Löwenstein-Jensen medium that was recently revised by the World Health Organization might be too high, resulting in the misclassification of phenotypically non-wild-type strains with known resistance mutations as wild type. On the basis of our exploratory PK/PD calculations, the current dose of AFX is unlikely to be optimal for the treatment of tuberculosis, but higher doses could be effective.

scholarly journals Comparative study between using Lowenstein Jensen and Bio-FM media in identification of Mycobacterium tuberculosis

2013 ◽  
Vol 62 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Sherif Ahmed Essa ◽  
Sohair Abdel-Rahman Abdel-Samea ◽  
Yasser Mahmoud Ismaeil ◽  
Ahmad Abdelsadek Mohammad
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Comparative Study ◽  
Lowenstein Jensen
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