Genotyping and drug susceptibility patterns of M. tuberculosis isolated from HIV seropositive patients in Tehran Iran

2021 ◽  
Vol 19 ◽  
Author(s):  
Seifu Gizaw Feyisa ◽  
Mehrnaz Rasoolinejad ◽  
Maliheh Hasan-nejad ◽  
Siroos Amini ◽  
Gholamreza Hamzelou ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Transmission Rate ◽  
Blot Hybridization ◽  
Drug Susceptibility ◽  
Variable Number ◽  
Drug Resistant ◽  
Recent Transmission ◽  
Tehran Province ◽  
Drug Resistant Strains ◽  
Hiv Seropositive

Aim: To investigate the prevalence and drug-resistance M. tuberculosis isolated from HIV seropositive individuals in Tehran, Iran. Background: Human immunodeficiency virus (HIV) is one of the most important risk factors for developing active tuberculosis (TB). Objective: To determine the rate of transmission and drug resistant M. tuberculosis (MTB) strains isolated from HIV seropositive patients in Tehran province, Iran. Methods: This study consecutively enrolled 217 TB/HIV coinfected patients from April 2018 to August 2019 at Emam Khomeini referral hospital and 5 other health centers in Tehran province. The isolates were genotyped using 15 loci Mycobacterial interspersed repetitive unit-variable number tandem repeats (MIRU-VNTR). Minimum inhibitory concentration (MIC) was determined for 6 drugs. In addition, mutations were assessed in rpoB, katG, inhA, and ahpC genes using Reverse Blot Hybridization Assay System. Results: A 20 (9.2%) patients were culture-positive for M. tuberculosis and typed by MIRU-VNTR, 13 (65%) strains formed 5 clusters, but 6 (30%) isolates had a unique pattern. The total Hunter–Gaston discrimination index (HGDI) for all 15 loci was 0.846, and the cluster size was 2 to 4 patients. The estimated proportion of recent transmission was 45%. The mutation was identified in 1 isolate, lost inhAW1 and mutation in MT1 loci, which was resistant to isoniazid (INH). Moreover, 1 (5%) and 3 (15%) isolates were resistant to INH and ethambutol (EMB), respectively, of which 1 was resistant to INH and EMB. Conclusion: The transmission rate of TB in HIV patients was relatively high; however, the prevalence of drug-resistant strains and TB infection in females was insignificant in this study (p < 0.05); none of the isolates was MDR strains.

scholarly journals Mycobaterial interspersed repetitive units-variable number of tandem repeats analysis and pattern of drug resistance in extended drug resistant (XDR) TB isolates from pulmonary tuberculosis patients in Bangladesh

2020 ◽  
Vol 46 (1) ◽  
pp. 22-28
Author(s):  
Shirin Tarafder ◽  
Md Bayzid Bin Monir
Keyword(s):  
Drug Resistance ◽  
Molecular Typing ◽  
Tandem Repeats ◽  
Variable Number ◽  
Drug Resistant ◽  
Gyra Gene ◽  
Drug Resistant Tuberculosis ◽  
Tree Analysis ◽  
Resistant Tuberculosis ◽  
Mdr Tb

Background: To investigate the spread of specific genotypes in a defined geographical area and to determine any relationship of these genotypes with drug resistance the most essential method is molecular typing. It allows a rapid and precise species differentiation. Objective: This study was intended to observe the genotypes of XDR mycobacterium tuberculosis by determining 24 loci MIRU-VNTR analysis. Methods: To gain an insight about molecular typing of MTB and drug resistance-associated mutations in XDR-TB isolates a total of 98 multi drug resistant tuberculosis (MDR-TB) isolates collected through Xpert MTB/RIF assay. They were subjected to 2nd line (Fluoroquinolones, kanamycin, capreomycin and amikacin) drug susceptibility testing through line probe assay (LPA) in a view to detect extensively drug resistant tuberculosis (XDR-TB). Genotyping was done for XDR-TB isolates using 24 loci Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats (MIRU-VNTR) using the online tool at http://www.MIRU-VNTRplus.org.. Out of 98 MDR-TB isolates 11(11.23%)  XDR-TB isolates were typed and analysed. Results: Twenty four loci MIRU-VNTR genotyping involving similarity searching and phylogenetic tree analysis revealed that six (54.60%) XDR-TB isolates belonged to Beijing strain, Other MTB strain also detected were Delhi/CAS two(18.20%), Haarlem two(18.20%) and New-1, one (9.10%) in number. Minimum spanning tree analysis showed two strain of Beijing family form a clonal complex. Beijing strains were more common among younger age group and within urban population. Beijing strains were also predominant in treatment failure patient. Only one new case of XDR-TB belongs to Delhi/CAS family. Second line mycobacterial drug resistance (MTBDRsl) detected by LPA showed the most prevalent mutations involved in Fluoroquinolones drug resistance (FQ) was Asp94Gly in gyrA gene (54.55%) in quinolone resistance determining region (QRDR) and for Injectable 2nd line Drug resistance (ISL) was A1401G, C1402T in 16S rrs gene (100%)..  All XDR-TB isolates showed resistance to Levofloxacin in 2nd line LPA but Moxifloxacin showed low level resistance to some cases. Conclusion: Molecular typing of XDR- TB isolates and pattern of drug resistance associated mutations in XDR-TB isolates in Bangladesh have not been reported previously. The result of this study highlights the need to reinforce the TB policy in Bangladesh with regard to control the spread and transmission as well as detection and treatment strategies regarding XDR-TB. Bangladesh Med Res Counc Bull 2020; 46(1): 22-28

scholarly journals Population structure of drug-resistant Mycobacterium tuberculosis in Central Asia

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Anna Engström ◽  
Uladzimir Antonenka ◽  
Abdylat Kadyrov ◽  
Gulmira Kalmambetova ◽  
Katharina Kranzer ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Population Structure ◽  
Central Asia ◽  
Tandem Repeats ◽  
Relative Size ◽  
Multidrug Resistant ◽  
Variable Number ◽  
Health Concern ◽  
Drug Resistant ◽  
Recent Emergence

Abstract Background Drug-resistant tuberculosis (TB) is a major public health concern threathing the success of TB control efforts, and this is particularily problematic in Central Asia. Here, we present the first analysis of the population structure of Mycobacterium tuberculosis complex isolates in the Central Asian republics Uzbekistan, Tajikistan, and Kyrgyzstan. Methods The study set consisted of 607 isolates with 235 from Uzbekistan, 206 from Tajikistan, and 166 from Kyrgyzstan. 24-loci MIRU-VNTR (Mycobacterial Interspersed Repetitive Units - Variable Number of Tandem Repeats) typing and spoligotyping were combined for genotyping. In addition, phenotypic drug suceptibility was performed. Results The population structure mainly comprises strains of the Beijing lineage (411/607). 349 of the 411 Beijing isolates formed clusters, compared to only 33 of the 196 isolates from other clades. Beijing 94–32 (n = 145) and 100–32 (n = 70) formed the largest clusters. Beijing isolates were more frequently multidrug-resistant, pre-extensively resistant (pre-XDR)- or XDR-TB than other genotypes. Conclusions Beijing clusters 94–32 and 100–32 are the dominant MTB genotypes in Central Asia. The relative size of 100–32 compared to previous studies in Kazakhstan and its unequal geographic distribution support the hypothesis of its more recent emergence in Central Asia. The data also demonstrate that clonal spread of resistant TB strains, particularly of the Beijing lineage, is a root of the so far uncontroled MDR-TB epidemic in Central Asia.

scholarly journals Comparison of routine field epidemiology and whole genome sequencing to identify tuberculosis transmission in a remote setting

2020 ◽  
Vol 148 ◽  
Author(s):  
J. L. Guthrie ◽  
L. Strudwick ◽  
B. Roberts ◽  
M. Allen ◽  
J. McFadzen ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Tandem Repeats ◽  
Variable Number ◽  
Yukon Territory ◽  
Contact Tracing ◽  
Whole Genome ◽  
Attitudes And Practices ◽  
Genomic Epidemiology ◽  
Recent Transmission

Abstract Yukon Territory (YT) is a remote region in northern Canada with ongoing spread of tuberculosis (TB). To explore the utility of whole genome sequencing (WGS) for TB surveillance and monitoring in a setting with detailed contact tracing and interview data, we used a mixed-methods approach. Our analysis included all culture-confirmed cases in YT (2005–2014) and incorporated data from 24-locus Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats (MIRU-VNTR) genotyping, WGS and contact tracing. We compared field-based (contact investigation (CI) data + MIRU-VNTR) and genomic-based (WGS + MIRU-VNTR + basic case data) investigations to identify the most likely source of each person's TB and assessed the knowledge, attitudes and practices of programme personnel around genotyping and genomics using online, multiple-choice surveys (n = 4) and an in-person group interview (n = 5). Field- and genomics-based approaches agreed for 26 of 32 (81%) cases on likely location of TB acquisition. There was less agreement in the identification of specific source cases (13/22 or 59% of cases). Single-locus MIRU-VNTR variants and limited genetic diversity complicated the analysis. Qualitative data indicated that participants viewed genomic epidemiology as a useful tool to streamline investigations, particularly in differentiating latent TB reactivation from the recent transmission. Based on this, genomic data could be used to enhance CIs, focus resources, target interventions and aid in TB programme evaluation.

scholarly journals Pulmonary Tuberculosis Outbreak in a High School, China

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
◽  
Yang Zhou ◽  
Bing Zhao ◽  
Tao Li ◽  
Qian Cheng ◽  
...  
Keyword(s):  
High School ◽  
Mycobacterium Tuberculosis ◽  
Tandem Repeats ◽  
Skin Testing ◽  
Drug Susceptibility ◽  
Variable Number ◽  
Hunan Province ◽  
Tuberculin Skin Testing ◽  
Nucleotide Polymorphisms ◽  
Symptom Screening

This study reports an outbreak of Tuberculosis (TB) in a high school in Hunan province, China during January 2017-April 2018. Contact investigation and TB screening were conducted through symptom screening, tuberculin skin testing, chest radiography and smear examination. Identification of positive isolates and drug susceptibility phenotype were assessed by standard method. Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR) and Whole Genome Sequencing (WGS) were performed to investigate the relationships among the positive isolates. A total of 90 students and one teacher were diagnosed active pulmonary TB among 2908 students and 188 staff, with an attack rate of 2.94%. Thirteen positive isolates were identified as drug susceptible Beijing family of Mycobacterium tuberculosis. Results of MIRU-VNTR typing and WGS revealed two clones of Mycobacterium tuberculosis circulating during outbreak. One hundred and twenty-nine Single Nucleotide Polymorphisms (SNPs) discriminated the isolates in two clusters; the maximum number of SNPs between any pair of isolates in each cluster was five or fewer. Our findings highlight the importance of early identification and isolation of the TB cases to prevent spread of TB. WGS provides better resolution than MIRU-VNTR to identify recent transmission in TB outbreak.

scholarly journals Morphologic characterization of Mycobacterium tuberculosis circulating strains in a Lisbon hospital.

2013 ◽  
Vol 19 (S4) ◽  
pp. 11-12
Author(s):  
C. Silva ◽  
E. Alverca ◽  
A.P. Alves de Matos ◽  
P.A. Carvalho ◽  
I. Portugal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mycobacterium Tuberculosis ◽  
Cell Envelope ◽  
Drug Susceptibility ◽  
Drug Resistant ◽  
Lowenstein Jensen ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Surface Figure

Tuberculosis (TB) is one of the major causes of mortality and morbidity worldwide accounting for 3.1 million deaths per year. This disease, caused by Mycobacterium tuberculosis (M. tuberculosis) made a deadly comeback, during the 1990’s, triggered mainly by the emergence of acquired immunodeficiency syndrome (AIDS). More recently, the emergence of multidrug resistant (MDR) and extensively drug resistant (XDR) M. tuberculosis strains, uncovered the most freighting face of this disease an incurable infection with the currently available therapeutic tools. Although Portugal is considered a medium incidence setting, annually are reported MDR and even XDR TB cases. The majority of these cases occur in the Lisbon area and the strains involved are genetically related being known as Lisboa family.In the present work a group of 283 M. tuberculosis isolates collected in a Lisbon hospital during a two years period (2008-2009) were studied. The morphology of colonies grown on Lowenstein-Jensen slants was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using previously described procedures. The aim of the study was the establishment of a link between mycobacteria drug susceptibility and structure. In the first part of the study approximately 20 isolates, with different drug susceptibility profiles ranging from pan-susceptible to XDR, were grown on Lowenstein-Jensen slants and their morphology was compared. Although all mycobacteria originated rough colonies their size differ with the drug susceptibility profile. The pan-susceptible strains generated larger colonies than drug resistant strains as shown in figure 1.These colonies were then processed for SEM analysis. The results obtained show that mycobacteria surface are distinct in susceptible and drug resistant strains as shown in figure 2.A and B. While drug susceptible mycobacteria have a homogenous surface (Figure 1A), drug resistant bacteria present a heterogeneous surface (Figure 2B) with small protrusions (Fig. 2B inset). In order to evaluate the existence of differences in the ultrastructure of circulating M. tuberculosis strains the colonies were processed and analysed by TEM. For this approach were selected only two isolates: the pan-susceptible R188/09 and the XDR HPV108/09.The results obtained by the analysis of at least 300 bacteria present in non consecutive sections show that mycobacteria cell width (0 350 nm) is similar for both bacteria (Table 1). Nevertheless, their cell length and cell envelope width are significantly different. The XDR strain is shorter (p=0.009) and has a ticker cell envelope (p=0.004) than the pan-susceptible strain. These results are in agreement with those published in the literature.Altogether our data clearly shows the existence of a link between mycobacteria ultrastructure and drug susceptibility. In order to better evaluate these differences a larger number of isolates must be studied. The use of other electron microscopy techniques, such as CEMOVIS, will avoid the formation of undesirable artefacts (e.g. mesosome) produced by dehydration and room temperature sectioning allowing a better characterization of mycobacteria ultrastructure.The authors acknowledge the funding by Fundação para a Ciência e Tecnologia (SFRH/BD/73579/2010, C2008-C2008_P2 and PEst-OE/CTM-UI0084/2011 grants.)

scholarly journals The contribution of microfluidics to the fight against tuberculosis

2021 ◽  
Vol 11 (1) ◽  
pp. 40-54
Author(s):  
Marina Cañadas-Ortega ◽  
Clara Gómez-Cruz ◽  
Juan José Vaquero ◽  
Arrate Muñoz-Barrutia
Keyword(s):  
Low Income ◽  
Drug Testing ◽  
Basic Research ◽  
Microfluidic Devices ◽  
Drug Susceptibility ◽  
Drug Resistant ◽  
Resistant Strains ◽  
Novel Approaches ◽  
On Chip ◽  
Drug Resistant Strains

Abstract The high mortality associated with tuberculosis brings forward the urgency of developing new therapies and strategies against the disease. With the advance of drug-resistant strains, traditional techniques have proven insufficient to manage the disease appropriately. Microfluidic devices have characteristics that can enhance treatment prescription and significantly advance our knowledge about the disease and its interaction within the human body. In addition, microfluidic systems provide advantages in terms of time and costs, which are particularly important in countries with low income and resources. This review will highlight how microdevices can help bridge the gaps in disease management, including their use for drug testing and development, drug susceptibility, basic research, and novel approaches to anti-TB vaccines and organ-on-chip studies.

scholarly journals Distribution and Clonality of drug-resistant tuberculosis in South Africa

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Halima Said ◽  
John Ratabane ◽  
Linda Erasmus ◽  
Yasmin Gardee ◽  
Shaheed Omar ◽  
...  
Keyword(s):  
South Africa ◽  
Tandem Repeats ◽  
Transmission Rate ◽  
Close Contact ◽  
Beijing Genotype ◽  
Drug Resistant ◽  
Western Cape ◽  
Eastern Cape ◽  
Drug Resistant Tuberculosis ◽  
Resistant Tuberculosis

Abstract Background Studies have shown that drug-resistant tuberculosis (DR-TB) in South Africa (SA) is clonal and is caused mostly by transmission. Identifying transmission chains is important in controlling DR-TB. This study reports on the sentinel molecular surveillance data of Rifampicin-Resistant (RR) TB in SA, aiming to describe the RR-TB strain population and the estimated transmission of RR-TB cases. Method RR-TB isolates collected between 2014 and 2018 from eight provinces were genotyped using combination of spoligotyping and 24-loci mycobacterial interspersed repetitive-units-variable-number tandem repeats (MIRU-VNTR) typing. Results Of the 3007 isolates genotyped, 301 clusters were identified. Cluster size ranged between 2 and 270 cases. Most of the clusters (247/301; 82.0%) were small in size (< 5 cases), 12.0% (37/301) were medium sized (5–10 cases), 3.3% (10/301) were large (11–25 cases) and 2.3% (7/301) were very large with 26–270 cases. The Beijing genotype was responsible for majority of RR-TB cases in Western and Eastern Cape, while the East-African-Indian-Somalian (EAI1_SOM) genotype accounted for a third of RR-TB cases in Mpumalanga. The overall proportion of RR-TB cases estimated to be due to transmission was 42%, with the highest transmission-rate in Western Cape (64%) and the lowest in Northern Cape (9%). Conclusion Large clusters contribute to the burden of RR-TB in specific geographic areas such as Western Cape, Eastern Cape and Mpumalanga, highlighting the need for community-wide interventions. Most of the clusters identified in the study were small, suggesting close contact transmission events, emphasizing the importance of contact investigations and infection control as the primary interventions in SA.

scholarly journals Predominant Mycobacterium tuberculosis Families and High Rates of Recent Transmission among New Cases Are Not Associated with Primary Multidrug Resistance in Lima, Peru

2015 ◽  
Vol 53 (6) ◽  
pp. 1854-1863 ◽  
Author(s):  
Francesca Barletta ◽  
Larissa Otero ◽  
Bouke C. de Jong ◽  
Tomotada Iwamoto ◽  
Kentaro Arikawa ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Multidrug Resistance ◽  
Variable Number Tandem Repeat ◽  
Drug Susceptibility ◽  
Variable Number ◽  
Content Type ◽  
Recent Transmission ◽  
Study Population ◽  
High Level ◽  
A Prospective Study

Sputum samples from new tuberculosis (TB) cases were collected over 2 years as part of a prospective study in the northeastern part of Lima, Peru. To measure the contribution of recent transmission to the high rates of multidrug resistance (MDR) in this area,Mycobacterium tuberculosiscomplex (MTBc) isolates were tested for drug susceptibility to first-line drugs and were genotyped by spoligotyping and 15-locus mycobacterial interspersed repetitive-unit (MIRU-15)-variable-number tandem repeat (VNTR) analysis. MDR was found in 6.8% of 844 isolates, of which 593 (70.3%) were identified as belonging to a known MTBc lineage, whereas 198 isolates (23.5%) could not be assigned to these lineages and 12 (1.4%) represented mixed infections. Lineage 4 accounted for 54.9% (n= 463) of the isolates, most of which belonged to the Haarlem family (n= 279). MIRU-15 analysis grouped 551/791 isolates (69.7%) in 102 clusters, with sizes ranging from 2 to 46 strains. The overall high clustering rate suggests a high level of recent transmission in this population, especially among younger patients (odds ratio [OR], 1.6;P= 0.01). Haarlem strains were more prone to cluster, compared to the other families taken together (OR, 2.0;P< 0.0001), while Beijing (OR, 0.6;P= 0.006) and LAM (OR, 0.7;P= 0.07) strains clustered less. Whereas streptomycin-resistant strains were more commonly found in clusters (OR, 1.8;P= 0.03), clustering rates did not differ between MDR and non-MDR strains (OR, 1.8;P= 0.1). Furthermore, only 16/51 MDR strains clustered with other MDR strains, suggesting that patients with primary MDR infections acquired the infections mostly from index cases outside the study population, such as retreated cases.

Reverse dot blot hybridization assay— An expeditious diagnostic tool for drug resistant TB

2022 ◽  
Vol 71 (12) ◽  
pp. 2851-2851
Author(s):  
Faeez Muhammad ◽  
Laiba Siddiqui ◽  
Rabbia Gul
Keyword(s):  
Blot Hybridization ◽  
Drug Susceptibility ◽  
Hybridization Assay ◽  
Drug Resistant ◽  
Dot Blot ◽  
Current Standard ◽  
Standard Drug ◽  
Dot Blot Hybridization ◽  
Reverse Dot Blot Hybridization ◽  
Reverse Dot Blot

Tuberculosis (TB) is one of the leading infectious diseases that is highly transmissible. It is reported to cause approximately 10 million infections and 1.4 million deaths globally in the year of 2019.¹ Prompt detection and treatment of TB are essential to intercept the proliferation of the disease. In the case of drug- resistant TB, failure to detect the resistance of anti TB drugs may give rise to extensively drug- resistant tuberculosis (XDR-TB). Thus, the rapid detection of drug resistance is vital;, however, the current standard drug susceptibility tests (DST) may take up to 12 weeks raising an alarming concern.² A study was done in China by Li Wan et al, on the accuracy of the reverse dot blot hybridization assay (RDBH) for rapidly detecting the resistance of four anti TB drugs (rifampicin (RIF), isoniazid (INH), streptomycin (SM) and ethambutol (EMB)) in mycobacterium tuberculosis (MTB) isolates.³ Continuous...

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