, 2004). Here, we

present a newly devised PCR-RFLP method to differentiate M.tb from other members of the MTC on the basis of the −6T/C narK2 promoter SNP. Because none of these PCR-RFLP methods can fully differentiate the MTC members, a combination of different PCR-RFLP assays can improve the confidence of diagnosis. Previously, the −215T/C SNP upstream of narGHJI was correlated with differential nitrate reduction in MTC (Stermann et al., 2004); M. tb having the −215T genotype could reduce nitrate, whereas other members having the −215C genotype could not reduce nitrate. However, an extension of this analysis to more strains refuted this hypothesis on the basis of high nitrate reductase activity in M. canetti (−215C genotype) and some other ancestral strains of the M. tb−215C genotype (Goh et al., 2005). Interestingly, the nitrate reductase activity of MTC strains correlates better with the −6T/C SNP present in the narK2X promoter. Y-27632 in vivo Both M. tb and M. canetti have the −6T genotype and both can reduce nitrate, whereas M. africanum, M. microti, M. bovis and BCG have the −6C genotype and all lack nitrate reductase activity. Because the −6C genotype results

in completely abolishing narK2X promoter activity, it is likely that all these species lack functional narK2X genes and this promoter defect is one of the key factors contributing to the lack of inducible nitrate reductase activity in them. The plasmid pNarG-GM1 was a generous gift provided by Dr C.D. Sohaskey. We sincerely acknowledge Dr H.K. Prasad, India, for providing genomic

DNA of clinical isolates of the MTC. This work was financially supported by a grant to J.S.T. ABT-199 in vitro from the Department of Biotechnology, Government of India. S.C. is grateful to CSIR for a research associateship. We acknowledge the facilities of the Biotechnology Information Systems (BTIS), Department of Biotechnology, and Government of India. “
“Methanococcus maripaludis has two surface appendages, namely flagella and pili. Flagella have been shown to be required for swimming, but no specific role has been assigned as yet to pili. In this report, wild-type M. maripaludis cells are compared with mutants lacking either pili or flagella or both surface appendages isothipendyl in their ability to attach to a variety of surfaces including nickel, gold and molybdenum grids as well as glass, silicon and mica. Wild-type cells attached to varying degrees to all surfaces tested, except mica, via their flagella as observed by scanning electron microscopy. Large cables of flagella were found to leave the cell and to be unwound on the surface. In addition, such cables were often found to connect cells. In contrast, cells lacking either flagella or pili or both surface appendages were unable to attach efficiently to any surfaces. This indicates a second role for flagella in addition to swimming in M. maripaludis, as well as a first role for pili in this organism, namely in surface attachment.