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allied
academies
September 20-21, 2017 | Philadelphia, USA
Global summit on
TUBERCULOSIS AND LUNG DISEASE
Int J Respir Med 2017 Volume 2 Issue 2
Northeast India is the easternmost region of India and comprises of Seven Sister
States—Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland
and Tripura—and the Himalayan state of Sikkim. Though there are many studies
characterizing M. tuberculosis isolates from different parts of India, studies highlighting
genotypic diversity among isolates from north east India are rare. The present study
aimed to obtain an initial insight into the predominant spoligotypes prevalent in north
east region. Sputum samples from presumptive MDR patients were received from the
north east states for Drug suseptitibility testing (DST). All specimens were screened
for presence of AFB by Ziehl-Neelsen (ZN) staining. The samples were processed by
N-acetyl-L cysteine - Sodium hydroxide (NALC-NaOH) method. Drug susceptibility
testing (DST) was performed by either Line Probe Assay (Hains, MTBDR plus for RIF and
INH) or by MGIT960 liquid culture system (Becton Dickinson, Sparks, MD) after routine
mycobacterial identification. (RIF; 1 µg/ml, INH; 0.1 µg/ml). 148 isolates randomly
selected from existing stocks were subjected to spoligotyping as per standard protocol
and spoligo patterns obtained were compared to those within the SITVIT2 database.
The age of the patients varied from 10-77 years with mean age of 31 years. 99 (67.0%)
patients were male and 49 (33%) were female with a male female ratio of 2: 1. 28
(19%) isolates were sensitive to both the drugs whereas 107 (72.3%) isolates were
MDR. 8(5.4%) isolates were INH resistant and 2 (1.3%) were mono RIF resistant.
Spoligotyping yielded 31 different patterns, 23 of these were unique (1 isolate only)
whereas 8 patterns containing 125 isolates were clustered (2 or more isolates) with
a clustering rate of 84.45%. SIT 1 predominated in this study with 104/148 (70.2%)
isolates. Apart from SIT 1 there were no major clusters. The predominant family in this
study was found to be Beijing (73.64% of total strains). Other families corresponded
to Central Asian (CAS) and East African Indian (EAI). The Harlem family, the poorly
defined T family and “Manu” were present as minor families. Among 107 MDR
strains, 85 belonged to SIT1. Of these mutation data was available for 67 isolates. For
rifampicin, commonest mutation was at codon S531L of rpoB gene (58/67; 86.5%)
followed by H526Y (2/67; 3.0%) and D516V (2/67; 3.0%). In 5 isolates (7.5%), resistance
was determined by absence of wild type probes alone. For INH high level resistance
corresponding to mutation in codon 315 of Kat G gene occurred in 97.0% (65/67) of
samples whereas low level resistance in -15 promoter region was present in two strain.
According to previous available data EAI and CAS were found to be predominant in
India. High percentage of Beijing genotype in north east India is significantly higher
than the rest of India. Considering the fact that this genotype is the major cause of
outbreaks involving drug resistant variants worldwide, our findings are major cause of
concern for health authorities.
e:
arojyoti@gmail.comPredominance of
Mycobacterium tuberculosis
Beijing genotype among presumptive multidrug
resistance patients from North East India
Arora J
National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India