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

Abstract

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.

Evaluation of the discriminatory power of spoligotyping and 19-locus mycobacterial interspersed repetitive unit-variable number of tandem repeat analysis (MIRU-VNTR) of Mycobacterium bovis strains isolated from cattle in Algeria

“…Those new spoligotypes received the ID numbers SB2520 (n = 1), SB2521 (n = 5), SB2522 (n = 1), and SB2523 (n = 1). Two of the four new spoligotypes, SB2520 and SB2521, have been described recently in Algerian cattle and human samples respectively [ 22 ].…”

“…caprae in Africa. In Algeria two isolates of spoligotypes SB1451 and SB0835 were described before [ 22 , 23 ], pointing to a rare occurrence of M . caprae in this country.…”

Knowledge and practice of bovine tuberculosis among occupational workers in abattoirs in Abuja

“…In cattle the respondent in this study believed that signs were emaciation and respiratory distress with lesions seen in pulmonary organ and extra pulmonary organ. Damene et al, (2020) reported small circumscribed tubercles with yellow content in the left tracheobronchial lymph node; white-yellowish foci in the medial mediastinal lymph node; yellow necrosis in the liver; grey to white-yellowish tubercle in the uterus; gray-reddish tubercle and Large caseous mass in the lungs. Samuel et al, (2014) reported calcified and necrotic granulomas in the lungs of a bull carcass.…”

“…Tuberculosis (TB) a chronic bacterial disease of animals and man is characterized by progressive development of specific granulomatous lesions of tubercles in affected tissue (Shitaye et al, 2006). This disease, is wide spread in nature, infectious and a leading cause of death due to a single infectious agent (Mycobacterium) among humans in the world; Mycobacterium tuberculosis is the most common cause of human tuberculosis; however, an unknown proportion of cases are due to Mycobacterium bovis (Damene et al, 2020;Mujeeb-ur-Rahman et al, 2020). Bovine tuberculosis (bTB) is a chronic contagious zoonotic disease of both domestic and wild animals including humans, primarily caused by M. bovis (Jemal et al, 2016).…”

Molecular epidemiology of bovine tuberculosis in Northern Ghana identifies several uncharacterized bovine spoligotypes and suggests possible zoonotic transmission

“…The close relationship between the communities and cattle offers potential zoonotic transmission between cattle and humans and humans to cattle in areas where human M. tuberculosis prevalence is very high. Other people at risk of zoonotic transmission are abattoir staff who work with minimal or no understanding of the mode of transmission of zoonotic TB [64,[66][67][68]. Analysis of the spoligotypes identified one (1) M. tuberculosis (Lineage (L) 4 Cameroon sub-lineage and one (1) M. africanum (L6) in cattle samples with the M. africanum (L6) sharing spoligotype profile with human isolates SIT181/ SB0147.…”