• Volume 62 , Number 1
  • Page: 132–3

Dr. Mukherjee, et al. respond to Dr. Deo

Ashok Mukherjee; Amar K. Sharma; Radhey S. Misra; H. K. Kar; Rama Mukherjee; Gurusaran P. Talwar

To the Editor:

In response to Dr. Deo's letter claiming that ICRC and Mycobacterium w "may not be very different," the following points are offered for consideration.

1) ICRC was isolated by Bapat, et al . (1) from leproma nodules and grown in a "conditioned" medium. This organism belongs to the M. avium-intracellulare complex and grows in T/900R mice with evidence of dissemination in the liver and sciatic nerve with production of foot drop (2).

2) Mycobacterium w has its origin in a collection of atypical mycobacteria grown from sputum specimens and made available in 1974 to Dr. G. P. Talwar by Dr. S. P. Tripathy who was Director of the Tuberculosis Research Center in Madras at that time. This organism, probably a commensal of the upper respiratory tract, is a fast grower and is nonpathogenic to mice, rats and guinea pigs. Its growth and metabolic properties (4, 6) are similar to organisms belonging to Runyon's Group 4.

3) The results of DNA hybridization studies on the two organisms reported by Grossinsky, et al . (3) show that at a low stringency the percentage of binding of M. leprae DNA is 10.5 for ICRC and Mycobacterium w , 10.8 for M. avium and 10.3 for M. phlei . More importantly, at a high stringency Mycobacterium w has a distinctly higher binding, i.e., 3.9% as compared to 2.9% for ICRC. In the same article the authors have made the statement that Mycobacterium w shows the highest degree of homology with M. leprae among the three candidate vaccines.

4) With reference to the RFLP patterns studied by the same workers, the restriction enzymes selected and the regions probed are rather conserved. Restriction and probing of other regions are likely to bring out dissimilarities between the two organisms.

The data from the source, growth characteristics, animal pathogenicity and DNA analysis stated above make it clear that the two organisms are quite different. The therapeutic efficacy obtained with Mycobacterium w used in conjunction with multidrug therapy (MDT) has been clearly and unequivocally demonstrated in a number of studies (5, 7, 8) . The only logical way by which the comparative merits of these two different organisms for immunoprophylaxis or immunotherapy can be gauged is with a comparative trial on a standard protocol by an independent party.

We look forward to the results from the ongoing comparative vaccine immunoprophylaxis trial in progress in Avadi, Tamil Nadu, India, where Mycobacterium w , ICRC (contributed by Dr. C. V. Bapat), and killed M. leprae plus BCG are under a coded comparative trial.

We hope that the data presented above clarifies any doubt about the identity of Mycobacterium w .


- Ashok Mukherjee, M.D.
Syed A. Zaheer, M.B.B.S., D.V.D., Ph.D.
Amar K. Sharma, M.D.
Radhey S. Misra, M.D., D.D.
H. K. Kar, M. D.
Rama Mukherjee, Ph.D.
Gurusaran P. Talwar, D.Sc, F.I.C.A., F.A.Sc, F.N.A.

Institute of Pathology-ICMR
Departments of Dermatology
Safdarjang and R.M.L. Hospitals and the National Institute of Immunology
New Delhi, India



1. BAPAT, C. V. and MODAK, M. S. Growth of ICRC bacilli in footpad of mice. Lepr. India 50(1978)144-155.

2. BAPAT, C. V., RANADIVE, K. J. and KHANOLKAR, V. R. Growth characteristics of an acid-fast mycobactcrium isolated from human lepromatous leprosy. Int. J. Lepr. 29(1961)329-342.

3. GROSSINSKY, C. M., JACOB, W. R., CLARK-CURTISS, J. E. and BLOOM, B. R. Genetic relationship among Mycobacterium leprae , Mycobacterium tuberculosis and candidate leprosy vaccine strains determined by DNA hybridization: identification of an M. leprae -specific repetitive sequence. Infect. Immun. 57(1989)1535-1541.

4. KATOCH, V. M. A report on the biochemical analysis of Mycobacterium w . Lepr. India 53(1981)385-389.

5. MUKHERJEE, A., ZAHEER, S. A., SHARMA, A. K., MISRA, R. S., KAR, H. K., MUKHERJEE, R. and TALWAR, G. P. Histopathological monitoring of an immunotherapeutic trial with Mycobacterium w . Int. J. Lepr. 60(1992)28-35.

6. SAXENA, V. K., SINGH, U. S. and SINGH, A. K. Bacteriological study of a rapidly growing strain of Mycobacterium. Lepr. India 50(1978)588-596.

7. TALWAR, G. P., ZAHEER, S. A., MUKHERJEE, R., WALIA, R., MISRA, R. S., SHARMA, A. K., KAR, H. K., MUKHERJEE, A., PARIDA, S. K., SURESH, N. R., NAIR, S. K. and PANDEY, R. M. Immunotherapeutic effects of an anti-leprosy vaccine based on a saprophytic cultivable mycobacterium, Mycobacterium w , in multibacillary leprosy patients. Vaccine 8(1990)121-129.

8. TALWAR, G. P., ZAHEER, S. A., SURESH, N. R., PARIDA, S. K, MUKHERJEE, R., SINGH, I. G., SHARMA,A. K., KAR, H. K., MISRA, R. S. and MUKHERJEE, A. Immunotherapeutic trials with a candidate antileprosy vaccine based on Mycobacterium w . Trop. Med. Parasitol. 41(1990)369-370.

9. ZAHEER, S. A., MUKHERJEE, R., BEENA, R., MISRA, R. S., SHARMA, A. K., KAR, H. K., KAUR, M., NAIR, S., MUKHERJEE, A. and TALWAR, G. P. Combined multidrug and Mycobacterium w in vaccine therapy in patients with multibacillary leprosy. J. Infect. Dis. 167(1993)401-410.

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