scholarly journals Molecular Epidemiology of Mycobacterium tuberculosis strains isolated from pulmonary tuberculosis patients in south Ethiopia

2021 ◽  
Vol 15 (09) ◽  
pp. 1299-1307
Author(s):  
Yared Merid ◽  
Elena Hailu ◽  
Getnet Habtamu ◽  
Melaku Tilahun ◽  
Markos Abebe ◽  
...  

Introduction: Understanding the epidemiology of tuberculosis is limited by lack of genotyping data. We sought to characterize the drug susceptibility testing patterns and genetic diversity of M. tuberculosis isolates in southern Ethiopia. Methodology: A cross-sectional study was conducted among newly diagnosed sputum smear positive patients with tuberculosis visiting nine health facilities in southern Ethiopia from June 2015 to May 2016. Three consecutive sputum samples (spot-morning-spot) per patient were examined using acid-fast bacilli smear microscopy with all smear positive specimens having acid-fast bacilli cultures performed. M. tuberculosis isolates had drug susceptibility testing performed using indirect proportion method and were genotyped with RD9 deletion analysis and spoligotyping. Mapping of strain was made using geographic information system. Results: Among 250 newly diagnosed patients with tuberculosis, 4% were HIV co-infected. All 230 isolates tested were M. tuberculosis strains belonging to three lineages: Euro-American, 187 (81%), East-African-Indian, 31 (14%), and Lineage 7 (Ethiopian lineage), 8 (4%); categorized into 63 different spoligotype patterns, of which 85% fell into 28 clusters. M. tuberculosis strains were clustered by geographic localities. The dominant spoligotypes were SIT149 (21%) and SIT53 (19%). Drug susceptibility testing found that 14% of isolates tested were resistant to > 1 first line anti- tuberculosis drugs and 11% to INH. SIT 149 was dominant among drug resistant isolates. Conclusions: The study revealed several clusters and drug resistant strains of M. tuberculosis in the study area, suggesting recent transmission including of drug resistant tuberculosis. Wider monitoring of drug susceptibility testing and geospatial analysis of transmission trends is required to control tuberculosis in southern Ethiopia.

2020 ◽  
Author(s):  
Yared Merid ◽  
Elena Hailu ◽  
Getnet Habtamu ◽  
Melaku Tilahun ◽  
Markos Abebe ◽  
...  

Abstract Background Understanding the epidemiology of tuberculosis (TB) is limited by lack of genotyping data. We sought to characterize the drug susceptibility testing (DST) patterns and genetic diversity of M. tuberculosis (Mtb) isolates in Southern Ethiopia. Methodology A cross-sectional study was conducted among newly diagnosed sputum smear positive patients with TB visiting nine health facilities in southern Ethiopia from June 2015 to May 2016. Three consecutive sputum samples (spot-morning-spot) per patient were examined using acid-fast bacilli (AFB) smear microscopy with all smear positive specimens having AFB cultures performed. Mtb isolates had DST performed using indirect proportion method and were genotyped with RD9 deletion typing and spoligotyping. Spoligotyping International Types (SIT) and sub-lineages (clades) were assigned according to the SITVITWEB data base. Results Among 250 newly diagnosed patients with TB, 154 (52%) were male and 143 (57%) from rural areas. The prevalence of HIV co-infection was 4%. Of the 250 AFB positive sputum samples, 230 (92%) were culture positive. All 230 isolates were M. tuberculosis strains belonging to three lineages: Euro-American, 187 (81%); East-African-Indian, 31 (14%); and Lineage 7 (Ethiopian lineage), 8 (4%). The 230 isolates could be categorized into 65 different spoligotype patterns, of which 84% fell into 29 clusters. The dominant spoligotypes were SIT149 (21%), SIT53 (19%) and new strains (16%). Mtb strains were clustered by districts. DST revealed that 14% of Mtb isolates were resistant to > 1 first line anti-TB drugs including 11% to isoniazid. SIT 149 was the most prevalent genotype among drug resistant isolates (20%). Conclusion The study revealed several clusters including lineage 7 strains circulating in southern Ethiopia. SIT 149 (T3-ETH) was the most dominant circulating strain in the study area including among drug-resistant cases.


Author(s):  
Rajani Ranganath ◽  
Hemant Deepak Shewade ◽  
Abdul K Bahadur ◽  
Venkatesh Naik ◽  
Sharath Burugina Nagaraja ◽  
...  

Abstract Background India implements universal drug susceptibility testing (UDST) using rapid genotypic tests (cartridge-based nucleic acid amplification test CBNAAT - and line probe assay - LPA). to bridge the gap of diagnosis of multidrug/rifampicin-resistant TB. There is limited evidence assessing the implementation of UDST in India. We assessed the implementation among people with pulmonary TB notified from public facilities in October 2019 from Raichur (Karnataka), India. Methods A cohort study involving secondary data in routine programme settings was conducted. All people with TB underwent a rapid genotypic DST for rifampicin resistance followed by first line-LPA (FL-LPA) if sensitive and second line-LPA (SL-LPA) if resistant. Results Of 217 people, 15.7% (n=34) did not undergo rapid genotypic DST. Of 135 who were rifampicin-sensitive detected on CBNAAT, 68.1% (n=92) underwent FL-LPA, and out of the six rifampicin-resistant cases, 66.7% (n=4) underwent SL-LPA. Overall, 65.4% (142/217) completed the UDST algorithm. Children (aged <15 y) and people with bacteriological non-confirmation on microscopy were less likely to undergo rapid genotypic DST. Of 183 patients who underwent both rapid genotypic DST and sputum smear microscopy, 150 were bacteriologically confirmed and, of them, 9 (6%) were ‘rapid DST-negative’. Conclusion We found gaps at various steps. There were a significant number of ‘rapid DST-negative, smear-positive’ patients.


2018 ◽  
Vol 146 (7) ◽  
pp. 824-831 ◽  
Author(s):  
O. Popovici ◽  
Ph. Monk ◽  
D. Chemtob ◽  
D. Chiotan ◽  
P.J. Freidlin ◽  
...  

AbstractExtensively drug-resistant (XDR) tuberculosis (TB) poses a threat to public health due to its complicated, expensive and often unsuccessful treatment. A cluster of three XDR TB cases was detected among foreign medical students of a Romanian university. The contact investigations included tuberculin skin testing or interferon gamma release assay, chest X-ray, sputum smear microscopy, culture, drug susceptibility testing, genotyping and whole-genome sequencing (WGS), and were addressed to students, personnel of the university, family members or other close contacts of the cases. These investigations increased the total number of cases to seven. All confirmed cases shared a very similar WGS profile. Two more cases were epidemiologically linked, but no laboratory confirmation exists. Despite all the efforts done, the source of the outbreak was not identified, but the transmission was controlled. The investigation was conducted by a team including epidemiologists and microbiologists from five countries (Finland, Israel, Romania, Sweden and the UK) and from the European Centre for Disease Prevention and Control. Our report shows how countries can collaborate to control the spread of XDR TB by exchanging information about cases and their contacts to enable identification of additional cases and transmission and to perform the source investigation.


2020 ◽  
Vol 10 (7) ◽  
pp. 2605 ◽  
Author(s):  
Christian Lienhardt ◽  
Mario C. Raviglione

The World Health Organization (WHO) End Tuberculosis (TB) Strategy has set ambitious targets to reduce 2015 TB incidence and deaths by 80% and 90%, respectively, by the year 2030. Given the current rate of TB incidence decline (about 2% per year annually), reaching these targets will require new transformational tools and innovative ways to deliver them. In addition to improved tests for early and rapid detection of TB and universal drug-susceptibility testing, as well as novel vaccines for improved prevention, better, safer, shorter and more efficacious treatments for all forms of TB are needed. Only a handful of new drugs are currently in phase II or III clinical trials, and a few combination regimens are being tested, mainly for drug-resistant TB. In this article, capitalising on an increasingly rich medicine pipeline and taking advantage of new methodological designs with great potential, the main areas where progress is needed for a transformational improvement of treatment of all forms of TB are described.


2019 ◽  
Vol 147 ◽  
Author(s):  
R. S. Salvato ◽  
S. Schiefelbein ◽  
R. B. Barcellos ◽  
B. M. Praetzel ◽  
I. S. Anusca ◽  
...  

AbstractTuberculosis (TB) is the leading cause of death among infectious diseases worldwide. Among the estimated cases of drug-resistant TB, approximately 60% occur in the BRICS countries (Brazil, Russia, India, China and South Africa). Among Brazilian states, primary and acquired multidrug-resistant TB (MDR-TB) rates were the highest in Rio Grande do Sul (RS). This study aimed to perform molecular characterisation of MDR-TB in the State of RS, a high-burden Brazilian state. We performed molecular characterisation of MDR-TB cases in RS, defined by drug susceptibility testing, using 131Mycobacterium tuberculosis (M.tb)DNA samples from the Central Laboratory. We carried out MIRU-VNTR 24loci, spoligotyping, sequencing of thekatG,inhA andrpoB genes and RDRiosublineage identification. The most frequent families found were LAM (65.6%) and Haarlem (22.1%). RDRiodeletion was observed in 42 (32%) of theM.tbisolates. Among MDR-TB cases, eight (6.1%) did not present mutations in the studied genes. In 116 (88.5%)M.tbisolates, we found mutations associated with rifampicin (RIF) resistance inrpoB gene, and in 112 isolates (85.5%), we observed mutations related to isoniazid resistance inkatG andinhA genes. An insertion of 12 nucleotides (CCAGAACAACCC) at the 516 codon in therpoB gene, possibly responsible for a decreased interaction of RIF and RNA polymerase, was found in 19/131 of the isolates, belonging mostly to LAM and Haarlem families. These results enable a better understanding of the dynamics of transmission and evolution of MDR-TB in the region.


2013 ◽  
Vol 57 (6) ◽  
pp. 2522-2525 ◽  
Author(s):  
Imran Ahmed ◽  
Kauser Jabeen ◽  
Raunaq Inayat ◽  
Rumina Hasan

ABSTRACTPakistan is a high-burden country for tuberculosis (TB). The emergence and increasing incidence of extensively drug-resistant (XDR) TB has been reported in Pakistan. Similarly, the prevalence of multidrug-resistant TB infections with fluoroquinolone resistance (pre-XDR) is also increasing. To treat these infections, local drug susceptibility patterns of alternate antituberculosis agents, including levofloxacin (LVX), linezolid (LZD), and amoxicillin-clavulanate (AMC), is urgently needed. The aim of this study was to determine the susceptibility frequencies of drug-resistant (DR)Mycobacterium tuberculosisagainst LVX, LZD, and AMC. All susceptibilities were determined on Middlebrook 7H10 agar. A critical concentration was used for LVX (1 μg/ml), whereas MICs were determined for LZD and AMC.M. tuberculosisH37Rv was used as a control strain. A total of 102M. tuberculosisisolates (XDR,n= 59; pre-XDR,n= 43) were tested. Resistance to LVX was observed in 91.2% (93/102). Using an MIC value of 0.5 μg/ml as a cutoff, resistance to LZD (MIC ≥ 1 μg/ml) was noted in 5.9% (6/102). Although the sensitivity breakpoints are not established for AMC, the MIC values were high (>16 μg/ml) in 97.1% (99/102). Our results demonstrate that LZD may be effective for the treatment of XDR and pre-XDR cases from Pakistan. High resistance rates against LVX in our study suggest the use of this drug with caution for DR-TB cases from this area. Drug susceptibility testing against LVX and AMC may be helpful in complicated and difficult-to-manage cases.


2016 ◽  
Vol 42 (4) ◽  
pp. 286-289 ◽  
Author(s):  
Ana Julia Reis ◽  
Simone Maria Martini de David ◽  
Luciana de Souza Nunes ◽  
Andreia Rosane de Moura Valim ◽  
Lia Gonçalves Possuelo

ABSTRACT We conducted a cross-sectional, retrospective study, characterized by classical and molecular epidemiology, involving M. tuberculosis isolates from a regional prison in southern Brazil. Between January of 2011 and August of 2014, 379 prisoners underwent sputum smear microscopy and culture; 53 (13.9%) were diagnosed with active tuberculosis. Of those, 8 (22.9%) presented with isoniazid-resistant tuberculosis. Strain genotyping was carried out by 15-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat analysis; 68.6% of the patients were distributed into five clusters, and 87.5% of the resistant cases were in the same cluster. The frequency of drug-resistant tuberculosis cases and the rate of recent transmission were high. Our data suggest the need to implement an effective tuberculosis control program within the prison system.


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