Genomic diversity and transmission dynamics of <i>M. tuberculosis</i> in Africa: a systematic review and meta-analysis

Mekonnen, Daniel; Derbie, Awoke; Abeje, Andargachew; Shumet, Abebe; Kassahun, Yonas; Nibret, Endalkachew; Munshea, Abaineh; Bobosha, Kidist; Wassie, Liya; Biadglegne, Fantahun; Aseffa, Abraham; Sack, Ulrich

doi:10.5588/ijtld.19.0127

Cited by 10 publications

(11 citation statements)

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“…Our results demonstrated that majority of the 107 M. tuberculosis strains belonged to lineage 4-the most widespread lineage and among the more virulent globally [67]. The predominant clades identified in this lineage were LAM (29%), T (21.5%) and Haarlem (19.6%), which were reported in Algeria and in Northern African countries as large common clades [68]. The most prevalent sub-lineage LAM 9 (SIT 42, 13.1%) is predominant in North Africa as well as in a number European countries such as Spain, Italy and Belgium, sharing a close cluster with Northern Africa countries [69].…”

Section: Plos Neglected Tropical Diseasesmentioning

confidence: 57%

Broad diversity of Mycobacterium tuberculosis complex strains isolated from humans and cattle in Northern Algeria suggests a zoonotic transmission cycle

et al. 2020

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Mycobacterium tuberculosis complex (MTBC) comprises closely related species responsible for human and animal tuberculosis (TB). Efficient species determination is useful for epidemiological purposes, especially for the elucidation of the zoonotic contribution. In Algeria, data on MTBC genotypes are largely unknown. In this study, we aimed to investigate the occurrence and diversity of MTBC genotypes causing human and bovine TB in Northern Algeria. During a two-year sampling period (2017–2019) in two regions of Northern Algeria, we observed an overall prevalence of 6.5% of tuberculosis (TB) among slaughtered cattle, which is higher than previous Algerian data yet comparable to neighboring countries. A total of 296 Mycobacterium tuberculosis complex (MTBC) isolates were genotyped by spoligotyping: 181 from tissues with TB-like lesions collected from 181 cattle carcasses and 115 from TB patients. In human isolates, we identified 107 M. tuberculosis, seven M. bovis and one “M. pinnipedii-like”, while for bovine samples, 174 isolates were identified as M. bovis, three as M. caprae, three as “M. pinnipedii-like” and one as “M. microti-like”. The majority of isolates (89.2%) belonged to 72 different known Shared International Types (SIT) or M. bovis spoligotypes (SB), while we also identified seven new SB profiles (SB2695 to SB2701). Twenty-eight of the SB profiles were new to Algeria. Our data suggest zoonotic transmission in Sétif, where significantly more TB was observed among cattle (20%) compared to the slaughterhouses from the three other regions (5.4%–7.3%) (p < 0.0001), with the isolation of the same M. bovis genotypes from TB patients. The present study showed a high genetic diversity of MTBC isolated from human and cattle in Northern Algeria. Even though relatively small in terms of numbers, our data suggest the zoonotic transmission of TB from cattle to humans, suggesting the need for stronger eradication strategies for bovine TB.

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Section: Plos Neglected Tropical Diseasesmentioning

confidence: 57%

Broad diversity of Mycobacterium tuberculosis complex strains isolated from humans and cattle in Northern Algeria suggests a zoonotic transmission cycle

et al. 2020

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“…This is particularly true for M . tb , where the interaction of genotypic variation among different strains with human genetic polymorphism play a prominent role in the epidemiology of TB diseases [ 4 – 7 ] . The overall epidemiology of MTBC species is influenced by the environment, with its frequency and distribution being dependent on social, economic, and ecological causes [ 4 , 8 ] .…”

Section: Introductionmentioning

confidence: 99%

Epidemiology of Mycobacterium tuberculosis lineages and strain clustering within urban and peri-urban settings in Ethiopia

et al. 2021

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Background Previous work has shown differential predominance of certain Mycobacterium tuberculosis (M. tb) lineages and sub-lineages among different human populations in diverse geographic regions of Ethiopia. Nevertheless, how strain diversity is evolving under the ongoing rapid socio-economic and environmental changes is poorly understood. The present study investigated factors associated with M. tb lineage predominance and rate of strain clustering within urban and peri-urban settings in Ethiopia. Methods Pulmonary Tuberculosis (PTB) and Cervical tuberculous lymphadenitis (TBLN) patients who visited selected health facilities were recruited in the years of 2016 and 2017. A total of 258 M. tb isolates identified from 163 sputa and 95 fine-needle aspirates (FNA) were characterized by spoligotyping and compared with international M.tb spoligotyping patterns registered at the SITVIT2 databases. The molecular data were linked with clinical and demographic data of the patients for further statistical analysis. Results From a total of 258 M. tb isolates, 84 distinct spoligotype patterns that included 58 known Shared International Type (SIT) patterns and 26 new or orphan patterns were identified. The majority of strains belonged to two major M. tb lineages, L3 (35.7%) and L4 (61.6%). The observed high percentage of isolates with shared patterns (n = 200/258) suggested a substantial rate of overall clustering (77.5%). After adjusting for the effect of geographical variations, clustering rate was significantly lower among individuals co-infected with HIV and other concomitant chronic disease. Compared to L4, the adjusted odds ratio and 95% confidence interval (AOR; 95% CI) indicated that infections with L3 M. tb strains were more likely to be associated with TBLN [3.47 (1.45, 8.29)] and TB-HIV co-infection [2.84 (1.61, 5.55)]. Conclusion Despite the observed difference in strain diversity and geographical distribution of M. tb lineages, compared to earlier studies in Ethiopia, the overall rate of strain clustering suggests higher transmission and warrant more detailed investigations into the molecular epidemiology of TB and related factors.

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“…The observation of a shift from predominant pulmonary TB to predominant LN-associated TB in certain geographic regions like Ethiopia, is provocative. The link between Mtb lineages and type of TB (PTB Vs EPTB) is unclear [76,77] and some association between Mycobacterium africanum (MAF) and EPTB [78][79][80] have been reported. In general, LD formation profiling among Mtb and MAF isolates disaggregated by types of TB (EPTB Vs PTB) might narrow the existing knowledge gap.…”

Section: Ld-positive Mtb In Pulmonary and Extra Pulmonary Tbmentioning

confidence: 99%

Lipid droplets and the transcriptome of Mycobacterium tuberculosis from direct sputa: a literature review

et al. 2021

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Mycobacterium tuberculosis (Mtb), the main etiology of tuberculosis (TB), is predominantly an intracellular pathogen that has caused infection, disease and death in humans for centuries. Lipid droplets (LDs) are dynamic intracellular organelles that are found across the evolutionary tree of life. This review is an evaluation of the current state of knowledge regarding Mtb-LD formation and associated Mtb transcriptome directly from sputa.Based on the LD content, Mtb in sputum may be classified into three groups: LD positive, LD negative and LD borderline. However, the clinical and evolutionary importance of each state is not well elaborated. Mounting evidence supports the view that the presence of LD positive Mtb bacilli in sputum is a biomarker of slow growth, low energy state, towards lipid degradation, and drug tolerance. In Mtb, LD may serve as a source of chemical energy, scavenger of toxic compounds, prevent destruction of Mtb through autophagy, delay trafficking of lysosomes towards the phagosome, and contribute to Mtb persistence. It is suggest that LD is a key player in the induction of a spectrum of phenotypic and metabolic states of Mtb in the macrophage, granuloma and extracellular sputum microenvironment. Tuberculosis patients with high proportion of LD positive Mtb in pretreatment sputum was associated with higher rate of poor treatment outcome, indicating that LD may have a clinical application in predicting treatment outcome.The propensity for LD formation among Mtb lineages is largely unknown. The role of LD on Mtb transmission and disease phenotype (pulmonary TB vs extra-pulmonary TB) is not well understood. Thus, further studies are needed to understand the relationships between LD positivity and Mtb lineage, Mtb transmission and clinical types.

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Genomic diversity and transmission dynamics of M. tuberculosis in Africa: a systematic review and meta-analysis

Cited by 10 publications

References 0 publications

Broad diversity of Mycobacterium tuberculosis complex strains isolated from humans and cattle in Northern Algeria suggests a zoonotic transmission cycle

Broad diversity of Mycobacterium tuberculosis complex strains isolated from humans and cattle in Northern Algeria suggests a zoonotic transmission cycle

Epidemiology of Mycobacterium tuberculosis lineages and strain clustering within urban and peri-urban settings in Ethiopia

Lipid droplets and the transcriptome of Mycobacterium tuberculosis from direct sputa: a literature review

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