MDR-TB Antibody Response (Western Blot) to Fractions of Isoniazid and Rifampicin Resistant Antigens of Mycobacterium tuberculosis Alireza Hadizadeh Tasbiti 1 • Shamsi Yari 1 • Mostafa Ghanei 1,2 • Mohammad Ali Shokrgozar 3 • Ahmadreza Bahrmand 1 Received: 26 April 2015 / Accepted: 8 July 2015 Ó Springer Science+Business Media New York 2015 Abstract Drug-resistant TB poses a major threat to control of TB worldwide. Despite progress in the detection of Multidrug-resistant TB (MDR-TB) cases, a major diagnostic gap remains: 55 % of reported TB patients estimated to have MDR-TB were not detected in 2013. MDR-TB antigens were conjugated to CNBr-activated Sepharose 4B. Specific polyclonal antibodies against MDR-TB Ags were prepared in rabbits using two boosted injections of the MDR-TB antigen. The antibodies were purified and treated with susceptible TB to remove any non-specific and cross-reactive antibodies. In the present study, comparative analysis of electrophoretic pattern of different antigens of INH/RIF-resistant TB were studied for identifying protein profiles. A RIF-resistant TB antigen was shown here to have different protein profiles from INH-resistant TB isolate. The results of Western blotting analysis showed that in the RIF- and INH-resistant anti- genic fractions some bands of 14.4 and 45 kDa as immunogenic were common. Moreover, four bands of RIF- resistant TB antigen fractions (16, 19, 21, and 45 KDa) and one band of INH-resistant TB (about 26 KDa) were detected as diagnostic antigens. This study suggests that the Western blot is an accurate test to survey INH- and RIF- resistant TB antigens of M. tuberculosis infection. These findings indicate that MDR-TB diagnosis (based on Ag detection) could be useful in the identification of disease stages that precede symptomatic and microbiologically positive TB, such as subclinical and incipient TB. Keywords MDR-TB Á INH- and RIF-resistant TB Á MDR-TB antibody response Á DR-TB detection Introduction Tuberculosis (TB) remains one of the world’s deadliest communicable diseases. In 2013, an estimated 9.0 million people developed TB and 1.5 million died from the disease, 360,000 of whom were HIV-positive [1]. Despite this enormous global burden, case detection rates are low, posing major hurdles for TB control. Con- ventional TB diagnosis continues to rely on smear micro- scopy, culture, and chest radiography. These tests have known limitations [2]. The main obstacles to controlling TB worldwide are multidrug resistance, the absence of concise diagnostic methods, and variations in the protective effects of the BCG vaccination [3]. As part of the post- 2015 global TB strategy’s, the early diagnosis of TB is emphasized, and inclusion of drug susceptibility testing (DST) is now targeted as a universal standard for patient care, including for both new and previously treated patients. Detection of TB without investigation for drug resistance can lead to ineffective treatment, further devel- opment, and spread of drug-resistant strains and additional suffering and costs for patients [1]. Conventional tests for detection of drug resistance are slow, tedious, and difficult to perform in field conditions [2]. On the other hand, the most TB serological tests rely on detection of the humoral antibody immune response to M. tuberculosis, while WHO recently announced its first negative policy in TB, against & Ahmadreza Bahrmand tbchemistry@gmail.com; padideh79@yahoo.com 1 Tuberculosis Department, Pasteur Institute of Iran, Tehran, Iran 2 Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran 3 National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran 123 Curr Microbiol DOI 10.1007/s00284-015-0891-x