scholarly journals Detection of Mycobacterium tuberculosis growth by direct microscopic observation has a lower cost, higher sensitivity and higher diagnostic value than liquid and solid media cultures

2014 ◽  
Vol 32 (3) ◽  
pp. 315
Author(s):  
B Grigoriu ◽  
S Olaru-Peter ◽  
C Grigoriu ◽  
LV Boiculese ◽  
AC Gradinaru ◽  
...  
2005 ◽  
Vol 33 (2) ◽  
pp. 260-265 ◽  
Author(s):  
L Saglam ◽  
M Akgun ◽  
E Aktas

We investigated the diagnostic value of induced sputum (IS) and bronchial lavage (BL) specimens in patients with suspected pulmonary tuberculosis who had negative spontaneous sputum specimens or who were unable to produce sputum spontaneously. IS specimens and BL specimens obtained using flexible fibreoptic bronchoscopy from 55 patients were evaluated for the presence of acid-fast bacilli (AFB) and cultured for Mycobacterium tuberculosis. Positive results were found with IS smear in 23 patients, BL smear in 26 patients, and IS or BL culture in 42 patients. Culture of BL specimens had a higher sensitivity than IS or BL smears or culture of IS specimens. The highest sensitivity rate was obtained with a positive BL or IS culture (86%). For early diagnosis (a positive IS or BL smear), the sensitivity was 57%. IS has a higher sensitivity rate than spontaneous sputum for the detection of tuberculosis, and fibreoptic bronchoscopy is useful for the early diagnosis of tuberculosis when AFB are not detected in spontaneous or induced sputum specimens.


2020 ◽  
Vol 65 (1) ◽  
pp. e01948-20
Author(s):  
Dalin Rifat ◽  
Si-Yang Li ◽  
Thomas Ioerger ◽  
Keshav Shah ◽  
Jean-Philippe Lanoix ◽  
...  

ABSTRACTThe nitroimidazole prodrugs delamanid and pretomanid comprise one of only two new antimicrobial classes approved to treat tuberculosis (TB) in 50 years. Prior in vitro studies suggest a relatively low barrier to nitroimidazole resistance in Mycobacterium tuberculosis, but clinical evidence is limited to date. We selected pretomanid-resistant M. tuberculosis mutants in two mouse models of TB using a range of pretomanid doses. The frequency of spontaneous resistance was approximately 10−5 CFU. Whole-genome sequencing of 161 resistant isolates from 47 mice revealed 99 unique mutations, of which 91% occurred in 1 of 5 genes previously associated with nitroimidazole activation and resistance, namely, fbiC (56%), fbiA (15%), ddn (12%), fgd (4%), and fbiB (4%). Nearly all mutations were unique to a single mouse and not previously identified. The remaining 9% of resistant mutants harbored mutations in Rv2983 (fbiD), a gene not previously associated with nitroimidazole resistance but recently shown to be a guanylyltransferase necessary for cofactor F420 synthesis. Most mutants exhibited high-level resistance to pretomanid and delamanid, although Rv2983 and fbiB mutants exhibited high-level pretomanid resistance but relatively small changes in delamanid susceptibility. Complementing an Rv2983 mutant with wild-type Rv2983 restored susceptibility to pretomanid and delamanid. By quantifying intracellular F420 and its precursor Fo in overexpressing and loss-of-function mutants, we provide further evidence that Rv2983 is necessary for F420 biosynthesis. Finally, Rv2983 mutants and other F420H2-deficient mutants displayed hypersusceptibility to some antibiotics and to concentrations of malachite green found in solid media used to isolate and propagate mycobacteria from clinical samples.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Liang-Yuan Li ◽  
Tian-Sheng Yan ◽  
Jing Yang ◽  
Yu-Qi Li ◽  
Lin-Xi Fu ◽  
...  

Abstract Background Subjects with chronic respiratory symptoms and preserved pulmonary function (PPF) may have small airway dysfunction (SAD). As the most common means to detect SAD, spirometry needs good cooperation and its reliability is controversial. Impulse oscillometry (IOS) may complete the deficiency of spirometry and have higher sensitivity. We aimed to explore the diagnostic value of IOS to detect SAD in symptomatic subjects with PPF. Methods The evaluation of symptoms, spirometry and IOS results in 209 subjects with chronic respiratory symptoms and PPF were assessed. ROC curves of IOS to detect SAD were analyzed. Results 209 subjects with chronic respiratory symptoms and PPF were included. Subjects who reported sputum had higher R5–R20 and Fres than those who didn’t. Subjects with dyspnea had higher R5, R5–R20 and AX than those without. CAT and mMRC scores correlated better with IOS parameters than with spirometry. R5, R5–R20, AX and Fres in subjects with SAD (n = 42) significantly increased compared to those without. Cutoff values for IOS parameters to detect SAD were 0.30 kPa/L s for R5, 0.015 kPa/L s for R5–R20, 0.30 kPa/L for AX and 11.23 Hz for Fres. Fres has the largest AUC (0.665, P = 0.001) among these parameters. Compared with spirometry, prevalence of SAD was higher when measured with IOS. R5 could detect the most SAD subjects with a prevalence of 60.77% and a sensitivity of 81% (AUC = 0.659, P = 0.002). Conclusion IOS is more sensitive to detect SAD than spirometry in subjects with chronic respiratory symptoms and PPF, and it correlates better with symptoms. IOS could be an additional method for SAD detection in the early stage of diseases.


Elkawnie ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Mashuri Masri ◽  
Cut Muthiadin ◽  
Masita Masita ◽  
Tri Cahyanto ◽  
Lianah Lianah ◽  
...  

Abstract: Tuberculosis (TB) is a contagious infectious disease caused by Mycobacterium tuberculosis. 10 million people suffer from TB Every year. Although TB is a preventable and treatable disease, 1.5 million people die every year due to TB. Alternative treatments continue to be pursued, and treatment with the latest TB drugs that are continuously being encouraged. Black cumin (Nigella sativa) seed contains essential oils with active compounds such as thymohydroquinone, Oleoresins, flavonoids, alkaloids, saponins, tannins, and terpenoids that act as antibacterial drugs. This study aims to determine the sensitivity of  N. sativa seed extract in inhibiting the growth of  M. tuberculosis strain H37RV and MDR-TB (Multidrug Resistance-TB). This research using Microscopic-Observation and Drug-Susceptibility Assay (MODS) method. Extraction of N. sativa was carried out by the maceration method using 70% methanol as a solvent. The results showed that the M. tuberculosis strain H37RV and MDR-TB were sensitive to N. sativa extract at concentrations of 5 and 10% but resistant to N. sativa extract at concentrations of 1 and 3%.Abstrak: Tuberkulosis (TB) adalah penyakit menular yang disebabkan oleh Bakteri Mycobacterium tuberculosis. Penyakit ini menimbulkan dampak kematian yang cukup mengkhawatirkan.  Penyakit tersebut dapat dicegah dan diobati. Salah satu sumber pengobatannya menggunakan biji jintan hitam (Nigella sativa) yang mengandung minyak atsiri dengan senyawa aktif seperti timohidrokuinon, oleoresin, flavonoid, alkaloid, saponin, tanin, dan terpenoid yang berfungsi sebagai obat antibakteri. Penelitian ini bertujuan untuk mengetahui sensitivitas ekstrak biji N. sativa dalam menghambat pertumbuhan M. tuberculosis strain H37RV and MDR-TB (Multidrug-Resistance-TB). Penelitian ini menggunakan metode Microscopic-Observation and Drug-Susceptibility Assay (MODS). Ekstraksi N. sativa dilakukan dengan metode maserasi menggunakan pelarut metanol 70%. Hasil yang diperoleh menunjukkan bahwa bakteri M. tuberculosis strain H37RV dan TB-MDR, kedua  strain tsb sensitif terhadap ekstrak N. sativa konsentrasi 5 dan 10%,  tetapi resisten terhadap  ekstrak N. sativa konsentrasi 1 dan 3%.


1999 ◽  
Vol 37 (3) ◽  
pp. 748-752 ◽  
Author(s):  
Bruce A. Hanna ◽  
Adeleh Ebrahimzadeh ◽  
L. Bruce Elliott ◽  
Margie A. Morgan ◽  
Susan M. Novak ◽  
...  

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.


Blood ◽  
1979 ◽  
Vol 53 (5) ◽  
pp. 1023-1027 ◽  
Author(s):  
AA Fauser ◽  
HA Messner

Abstract Pluripotent hemopoietic progenitors in human bone marrow can be identified by their ability to give rise in culture to colonies that contain more than one lineage of hemopoietic differentiation. Growth of these mixed colonies is supported by media conditioned by leukocytes in the presence of phytohemagglutinin (PHA-LCM) and erythropoietin. They can be readily recognized by direct microscopic observation because of their composition of colorless cells and cells with a red appearance typical for hemoglobin. Seventy-three individual mixed colonies from 6 individuals were prepared by cytocentrifugation for further cytological examination. In addition to neutrophilic granulocytes and erythroblasts, megakaryocytes were present in 16 of the 73 colonies, as identified by positive reaction for acid phosphatase. Macrophages were found in 24 and eosinophils in 6 of the 73 colonies.


2020 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Enid Owusu ◽  
Mercy Jemima Newman

(1) Background: Present methods for drug susceptibility tests (DST) rely on culture methods that are sophisticated and relatively faster, or a slow and cheaper option. These methods frustrate disease control; therefore, there is a need for methods that incorporate key functions of microscopy and culture, with reduced cost burden and sophistry. Thus, the purpose of this study was to identify which, among the most commonly used (in Ghana) methods, can conveniently be used at health centers located in rural areas for effective DST determination of Mycobacterium tuberculosis (MTB). (2) Methods: Mycobacterium tuberculosis isolates were tested for their susceptibility to streptomycin, isoniazid, rifampicin, ethambutol (SIRE), and pyrazinamide by microscopic observation drug susceptibility (MODS) and BACTEC MGIT 960 methods. Evaluations were based on shorter turnaround periods, rapidity, ease of use, cost, etc. A comparative analysis was statistically expressed as kappa values. (3) Results: Endpoints for drug susceptibilities by MODS averaged 13 days (7–32), whilst that for BACTEC MGIT 960 was 10 days with a further 12 days to detect resistance. Therefore, a turnaround period of 22 days was needed for DST by BACTEC MGIT 960, compared to 13 days for MODS. There were differences in correlation levels between the two methods, as determined by their kappa values. (4) Conclusion: The MODS assay was found to be less costly, more user-friendly, and still able to be conveniently used at health centers located in rural areas known to be endemic for TB, particularly in Ghana.


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