scholarly journals Molecular Epidemiology of Mycobacterium tuberculosis To Describe the Transmission Dynamics Among Inuit Residing in Iqaluit Nunavut Using Whole-Genome Sequencing

Author(s):  
Gonzalo G Alvarez ◽  
Alice A Zwerling ◽  
Carla Duncan ◽  
Christopher Pease ◽  
Deborah Van Dyk ◽  
...  

Abstract Background In the last decade, tuberculosis (TB) incidence among Inuit in the Canadian Arctic has been rising. Our aim was to better understand the transmission dynamics of TB in this remote region of Canada using whole-genome sequencing. Methods Isolates from patients who had culture-positive pulmonary TB in Iqaluit, Nunavut, between 2009 and 2015 underwent whole-genome sequencing (WGS). The number of transmission events between cases within clusters was calculated using a threshold of a ≤3 single nucleotide polymorphism (SNP) difference between isolates and then combined with detailed epidemiological data using a reproducible novel algorithm. Social network analysis of epidemiological data was used to support the WGS data analysis. Results During the study period, 140 Mycobacterium tuberculosis isolates from 135 cases were sequenced. Four clusters were identified, all from Euro-American lineage. One cluster represented 62% of all cases that were sequenced over the entire study period. In this cluster, 2 large chains of transmission were associated with 3 superspreading events in a homeless shelter. One of the superspreading events was linked to a nonsanctioned gambling house that resulted in further transmission. Shelter to nonshelter transmission was also confirmed. An algorithm developed for the determination of transmission events demonstrated very good reproducibility (κ score .98, 95% confidence interval, .97–1.0). Conclusions Our study suggests that socioeconomic factors, namely residing in a homeless shelter and spending time in a gambling house, combined with the superspreading event effect may have been significant factors explaining the rise in cases in this predominantly Inuit Arctic community.

2019 ◽  
Vol 147 ◽  
Author(s):  
J. L. Guthrie ◽  
L. Strudwick ◽  
B. Roberts ◽  
M. Allen ◽  
J. McFadzen ◽  
...  

AbstractFew studies have used genomic epidemiology to understand tuberculosis (TB) transmission in rural and remote settings – regions often unique in history, geography and demographics. To improve our understanding of TB transmission dynamics in Yukon Territory (YT), a circumpolar Canadian territory, we conducted a retrospective analysis in which we combined epidemiological data collected through routine contact investigations with clinical and laboratory results. Mycobacterium tuberculosis isolates from all culture-confirmed TB cases in YT (2005–2014) were genotyped using 24-locus Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats (MIRU-VNTR) and compared to each other and to those from the neighbouring province of British Columbia (BC). Whole genome sequencing (WGS) of genotypically clustered isolates revealed three sustained transmission networks within YT, two of which also involved BC isolates. While each network had distinct characteristics, all had at least one individual acting as the probable source of three or more culture-positive cases. Overall, WGS revealed that TB transmission dynamics in YT are distinct from patterns of spread in other, more remote Northern Canadian regions, and that the combination of WGS and epidemiological data can provide actionable information to local public health teams.


2021 ◽  
Vol 15 (2) ◽  
pp. 1
Author(s):  
Yustinus Maladan ◽  
Tri Wahyuni ◽  
Hana Krismawati

In the antibiotic era, Tuberculosis (TB) drugs resistance especially Rifampicin (RIF) is highly reported around the world. Resistance of RIF is caused by the mutation of genes that associated with RIF receptor. The aims of this study are detecting the Single Nucleotide Polymorphism of Rifampicin resistant genes using Whole Genome Sequencing (WGS) and analysing the profile of protein changing caused by SNP. Twenty Mycobacterium tuberculosis culture samples were passed on WGS procedure and 19 samples were adequate to further bioinformatics analysis. Single Nucleotide Polymorphisms Analysis was done using TBprofiler. Based on TBProfiler, seventeen samples were resistant to rifampicin. The mutations that cause the resistance are S450L, D435Y, H445Y, 430P, Q432K. Other Single Nucleotide Polymorphisms H835R, V534M and R224C were also found. The H835R mutants are present together with the S450L, V534M with S450L mutants, and R224C with Q432K mutants. Native protein for RNA Polymerase Subunit β used was the result of separation from the crystal structure of Mycobacterium tuberculosis H37Rv RNA polymerase (PDB: 5UHB). Binding affinity RIF to RNA Polymerase Subunit β calculated using AutoDock vina. Construction of mutant 3D structures using FoldX5. From the analysis, it was found that seventeen samples were resistant to rifampicin and two samples did not contain SNP which could cause resistance to rifampicin.


Author(s):  
Emmanuel Lecorche ◽  
Côme Daniau ◽  
Kevin La ◽  
Faiza Mougari ◽  
Hanaa Benmansour ◽  
...  

Abstract Background Post-surgical infections due to Mycobacterium chimaera appeared as a novel nosocomial threat in 2015, with a worldwide outbreak due to contaminated heater-cooler units used in open chest surgery. We report the results of investigations conducted in France including whole genome sequencing comparison of patient and HCU isolates. Methods We sought M. chimaera infection cases from 2010 onwards through national epidemiological investigations in healthcare facilities performing cardiopulmonary bypass together with a survey on good practices and systematic heater-cooler unit microbial analyses. Clinical and HCU isolates were subjected to whole genome sequencing analyzed with regards to the reference outbreak strain Zuerich-1. Results Only two clinical cases were shown to be related to the outbreak, although 23% (41/175) heater-cooler units were declared positive for M. avium complex. Specific measures to prevent infection were applied in 89% (50/56) healthcare facilities although only 14% (8/56) of them followed the manufacturer maintenance recommendations. Whole genome sequencing comparison showed that the clinical isolates and 72% (26/36) of heater-cooler unit isolates belonged to the epidemic cluster. Within clinical isolates, 5 to 9 non-synonymous single nucleotide polymorphisms were observed, among which an in vivo mutation in a putative efflux pump gene observed in a clinical isolate obtained for one patient under antimicrobial treatment. Conclusions Cases of post-surgical M. chimaera infections were declared to be rare in France, although heater-cooler units were contaminated as in other countries. Genomic analyses confirmed the connection to the outbreak and identified specific single nucleotide polymorphisms, including one suggesting fitness evolution in vivo.


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