Modern and Ancestral Genotypes of Mycobacterium tuberculosis from Andhra Pradesh, India

Abstract

Traditionally, the distribution of the Mycobacterium tuberculosis genotypes in India has been characterized by widespread prevalence of ancestral lineages (TbD1+ strains and variants) in the south and the modern forms (TbD1− CAS and variants) predominating in the north of India. The pattern was, however, not clearly known in the south-central region such as Hyderabad and the rest of the state of Andhra Pradesh where the prevalence of both tuberculosis (TB) and human immunodeficiency virus (HIV) infection is one of the highest in the country; this area has been the hotspot of TB vaccine trials. Spoligotyping of 101 clinical isolates obtained from Hyderabad and rural Andhra Pradesh confirmed the occurrence of major genogroups such as the ancestral (or the TbD1+ type or the East African Indian (EAI) type), the Central Asian (CAS) or Delhi type and the Beijing lineage in Andhra Pradesh. Sixty five different spoligotype patterns were observed for the isolates included in this study; these were further analyzed based on specific genetic signatures/mutations. It was found that the major genogroups, CAS and “ancestral,” were almost equally prevalent in our collection but followed a north-south compartmentalization as was also reported previously. However, we observed a significant presence of MANU lineage in south Andhra Pradesh, which was earlier reported to be overwhelmingly present in Mumbai. This study portrays genotypic diversity of M. tuberculosis from the Indian state of Andhra Pradesh and provides a much needed snapshot of the strain diversity that will be helpful in devising effective TB control programs in this part of the world.

Spoligotype patterns of Mycobacterium tuberculosis isolated from extra pulmonary tuberculosis patients in Puducherry, India

“…This supports the concept of clear demarcation between the strains prevalent in North and South India. This common finding is slightly different from the experience of Thomas et al [9] from Andhra Pradesh, who reported a higher prevalence rate of 40% for CAS type. This could be perhaps due to the presence of Non-Resident Indians (NRI) from Hyderabad who work in Middle East countries and migrant population from North Indian states who come and work in Hyderabad, which is the commercial capital of Andhra Pradesh state.…”

“…It was also pointed out from earlier studies that Beijing strains were absent in rural areas of Andhra Pradesh and rural TB units of Mumbai, though it was prevalent at a rate 6.8% in urban population of Andhra Pradesh, 10.4% among treatment failure cases and 3.4% from new cases of urban Mumbai. [9,10] As far as Manu strains are concerned, studies conducted in North India by various researchers have reported varying prevalence of these strains at a frequency of 1.2%, [7] 0.55% [11] and even 0% [5] in particular areas. Central India [8] has not recorded these strains.…”

“…Central India [8] has not recorded these strains. Chittoor district of South Andhra Pradesh in South India [9] reported 6.93% of Manu [12] Delhi P 105 22 3.8 8 12.4 Kulkarni et al(2005) [13] Mumbai P 216 30 17 10 Guitterz et al (2006) [14] India @ P 91 26 10 Singh et al (2007) [11] Delhi [7] Varanasi and Uttar Pradesh P 83 32.5 9.6 10.8 1. 2 Sharma et al (2008) [5] Kanpur [4] in 2013 on EPTB specimens reported 6.4% of Manu strains, all of which are pansensitive.…”

“…This is borne out of the reports from different geographical areas of India. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Spoligotyping is a hybridization assay which targets the deoxyribonucleic acid (DNA) Indian Journal of Medical Microbiology vol. 33, No.…”

Mixed Infections and Rifampin Heteroresistance among Mycobacterium tuberculosis Clinical Isolates

“…Compared with Beijing strains, EAI strains showed not only less virulence but also a 100-fold lower replication level in lung infections (33). It is noteworthy that the Manu and EAI lineages are believed to be closely related or even derived from a latest common ancestor (34). Although a small number of resistant strains might not be detected by molecular methods because of the overgrowth of sensitive strains in drug-free medium, a majority of resistant strains in cases of mixed infections can be detected in drug selection medium.…”