scholarly journals Re-decontamination of liquid mycobacterial cultures: Additional Mycobacterium tuberculosis yield in the era of Xpert MTB/RIF Ultra in Cape Town, South Africa

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Dawood Da Costa ◽  
Pieter Nel

A retrospective review of liquid mycobacterial cultures was performed at a laboratory in South Africa from 01 January 2018 to 31 December 2018 to assess the increased yield in detecting Mycobacterium tuberculosis complex following sample re-decontamination. Only 9 of 99 (9%) re-decontaminated samples were culture positive for M. tuberculosis complex. Xpert MTB/RIF Ultra, concurrently performed on 7 of the 9 samples, detected M. tuberculosis complex in all but 1 sample. Re-decontamination of non-sterile samples did not increase the M. tuberculosis complex yield enough to offset the financial costs and additional labour in a laboratory that utilises the Xpert MTB/RIF Ultra system as a first-line diagnostic modality.

2019 ◽  
Vol 3 (2) ◽  
pp. 35
Author(s):  
Titiek Sulistyowati ◽  
Deby Kusumaningrum ◽  
Eko Budi Koendhori ◽  
Ni Made Mertaniasih

Background: Tuberculosis continues one of the major challenges to global health. Mycobacterium tuberculosis complex can affect any organ other than the lung parenchyma, include central nervous system. The mortality rate of tuberculous meningitis (TBM) are high worldwide with up to half of survivors suffering irreversible sequelae. Diagnosis of TBM is difficult due to paucibacillary, various clinical manifestation, and invasive procedure to appropriate specimens. Objective: The objectiveis to study the positivity rate of microbiological laboratory diagnosis and its drug sensitivity patterns of TBM patients in Dr. Soetomo Hospital Surabaya during October 2015 until September 2016. Methods: Specimens were cerebrospinal fluids. Identification and drug anti TB sensitivity test were done by BACTEC MGIT 960 system in Clinical Microbiology Laboratory Dr. Soetomo Hospital Surabaya. Result: Most patients with TBM were women (54.29%). Based on age groups, most dominant was adult population (65.71%). Proportion percentage of positive M. tuberculosis complex among 180 specimens were 19.44%. First line anti TB drug sensitivity pattern of 35 isolates were 1 monoresistant, 1 poly-resistant, no multiple drug resistant (MDR), and 33 pan-susceptible. Conclusion: Positivity rate of Mycobacterium tuberculosis complex laboratory diagnosis from TBM suspect patients were low. There was no MDR TB in this study, but mono-resistant and poly-resistant. Microbiological diagnosis was important to give information of active disease and drug sensitivity pattern. Resistance to first line anti TB drugs is alarming to properly manage TBM patients.


2013 ◽  
Vol 5 (02) ◽  
pp. 083-089 ◽  
Author(s):  
Amresh Kumar Singh ◽  
Anand Kumar Maurya ◽  
Jyoti Umrao ◽  
Surya Kant ◽  
Ram Awadh Singh Kushwaha ◽  
...  

ABSTRACT Background: Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM) may or may not have same clinical presentations, but the treatment regimens are always different. Laboratory differentiation between MTBC and NTM by routine methods are time consuming and cumbersome to perform. We have evaluated the role of GenoType® Mycobacterium common mycobacteria/additional species (CM/AS) assay for differentiation between MTBC and different species of NTM in clinical isolates from tuberculosis (TB) cases. Materials and Methods: A total of 1080 clinical specimens were collected from January 2010 to June 2012. Diagnosis was performed by Ziehl-Neelsen staining followed by culture in BacT/ALERT 3D system (bioMerieux, France). A total of 219 culture positive clinical isolates (BacT/ALERT® MP cultures) were selected for differentiation by p-nitrobenzoic acid (PNB) sensitivity test as and BIO-LINE SD Ag MPT64 TB test considering as the gold standard test. Final identification and differentiation between MTBC and different species of NTM were further confirmed by GenoType® Mycobacterium CM/AS assay (Hain Lifescience, Nehren, Germany). Results: Out of 219 BacT/ALERT® MP culture positive isolates tested by PNB as 153 MTBC (69.9%) and by GenoType® Mycobacterium CM/AS assay as 159 (72.6%) MTBC and remaining 60 (27.4%) were considered as NTM species. The GenoType® Mycobacterium CM/AS assay was proved 99.3% sensitive and 98.3% specific for rapid differentiation of MTBC and NTM. The most common NTM species were; Mycobacterium fortuitum 20 (33.3%) among rapid growing mycobacteria and Mycobacterium intracellulare 11 (18.3%) among slow growing mycobacteria. Conclusion: The GenoType® Mycobacterium assay makes rapid and accurate identification of NTM species as compared with different phenotypic and molecular diagnostic tool and helps in management of infections caused by different mycobacteria.


2004 ◽  
Vol 10 (3) ◽  
pp. 329-335
Author(s):  
K. K. Abu Amero ◽  
M. A. Halablab

Wevaluated the COBAS AMPLICOR polymerase chain reaction [PCR] based test for the detection of Mycobacterium tuberculosis complex in 866 respiratory and non-respiratory samples. Acid-fast staining and culture on Lowenstein-Jensen medium were also performed on all samples. Of the 866 samples tested, 87 [10.0%] were PCR-positive compared to 94 [10.9%] culture positive. There were no false positive results but 7 PCR-negative, culture-positive samples were, considered false negatives after reviewing medical records of patients. A PCR inhibitory rate of 2.0% [17/866] was observed in respiratory samples only. Sensitivity, specificity, and positive and negative predictive values for this test were 92.5%, 100%, 100% and 99.1% respectively. This test is a valuable diagnostic tool for today’s mycobacteriology laboratory


Author(s):  
Nazlı Arslan ◽  
Müge Hacer Özkarataş ◽  
Nuran Esen ◽  
Aydan Özkütük

Objective: Tuberculosis retains its importance as the only infectious disease in the world that affects 10 million people and causes 1.5 million deaths per se. The major obstacle in the elimination and control of tuberculosis is the emergence and spread of resistant tuberculosis cases. It was aimed to determine the current Mycobacterium tuberculosis complex and its susceptibility to antituberculosis drugs at Dokuz Eylül University Hospital. Method: In our study, the results of all samples sent between January 2013 and November 2019 were examined retrospectively for the presence of M. tuberculosis complex and drug susceptibility results. The samples were cultured in Löwenstein Jensen media and BACTEC MGIT 960 system. Drug susceptibility testing was performed with the BACTEC MGIT 960 SIRE kit in accordance with the recommendations of the manufacturer. Results: In a total of 473 (2.2%) of 21620 specimens M. tuberculosis complex was reproduced. The samples were classified as pulmonary (n:300; 63.4%) and extrapulmonary (n:173; 36.6%), samples. When repeated samples of the same patient, were excluded, positive culture test results were determined in a total of 365 patients. Susceptibility to all primary antituberculosis drugs was shown in 275 of 321 (85.7%) patients, while total rates of resistance to streptomycin, isoniazid, rifampicin and ethambutol were found in respective number of patients as follows: (n:24 (7.5%), 22 (6.8%), (n:7; 2.2%) and (n:2; 0.6%). The rate of MDR was 0.6% in 2 patients. Conclusion: In our hospital, streptomycin is the first-line antituberculosis drug with the highest resistance rate. All susceptibility rates were seen lower than the data reported in Turkey Tuberculosis Control Report and other studies of Turkey. Implementing drug surveillance program plays an important role for maintaining these low rates and for the management of tuberculosis.


2017 ◽  
Vol 61 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Monika Krajewska-Wędzina ◽  
Anna Zabost ◽  
Ewa Augustynowicz-Kopeć ◽  
Marcin Weiner ◽  
Krzysztof Szulowski

Abstract Introduction: Tuberculosis is a highly infectious disease affecting humans and animals. It is caused by the Mycobacterium tuberculosis complex (MTBC) – Mycobacterium bovis and Mycobacterium caprae, which are aetiological factors of bovine tuberculosis (bTB). In Poland, the bTB eradication programme exists. Animals diagnosed with tuberculosis are in the majority of cases not treated, but removed from their herd and then sanitary slaughtered. Material and Methods: In total, 134 MTBC strains isolated from cattle in Poland were subjected to microbiological analysis. The resistance phenotype was tested for first-line antimycobacterial drugs used in tuberculosis treatment in humans: streptomycin, isoniazid, rifampicin, ethambutol, and pyrazinamide. The strains were isolated from tissues collected post mortem, so the test for drug resistance fulfilled only epidemiological criterion. Results: The analysis of drug-resistance of MTBC strains revealed that strains classified as M. bovis were susceptible to 4 antimycobacterial drugs: isoniazid, rifampicin, streptomycin, and ethambutol, and resistant to pyrazynamide. The strains classified as M. caprae were sensitive to all tested drugs. Conclusion: The results indicate that despite enormously dynamic changes in mycobacterial phenotype, Polish strains of MTBC isolated from cattle have not acquired environmental resistance. The strains classified as M. bovis are characterised by natural resistance to pyrazinamide, which is typical for this species.


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