The aim of this study was to investigate the morphologic and ultrastructural features of biofilms of slow and fast-growing mycobacteria in different stress conditions, presence and absence of oleic acid albumin dextrose catalase (OADC) enrichment and at different temperatures: 30, 37 and 42 °C. Four hundred mycobacterial isolates were taken. The biomass of each biofilm was quantified using a modified microtiter plate assay method. Isolates were divided into those that formed fully established biofilms, moderately attached biofilms and weakly adherent biofilms by comparison with a known biofilm-forming strain. The large quantity of biofilm was produced by Mycobacterium smegmatis at temperature 37 and 42 °C as compared to 30 °C. Mycobacterium fortuitum and M. avium developed large amount of biofilm at 30 °C as compared to 37 and 42 °C. Mycobacterium tuberculosis developed strong biofilm at 37 °C and no biofilm at 30 and 42 °C in Sauton's media. The selected non-tuberculous mycobacteria and H37Rv developed strong biofilm in the presence of OADC enrichment in Sauton's medium. Microscopic examination of biofilms by scanning electron microscopy revealed that poorly adherent biofilm formers failed to colonize the entire surface of the microtiter well. While moderately adherent biofilm formers grew in uniform monolayers but failed to develop a mature three-dimensional structure. SEM analysis of an isolate representative of the group formed fully established biofilms with a textured, multi-layered, three-dimensional structure.

M ycobacterium avium subspecies paratuberculosis (MAP) infects wide variety of animals and is endemic in the domestic livestock population of the country (Singh et al., 2010a). MAP has also been associated with Inflammatory Bowel disease (Crohn's disease) in human beings (Singh et al., 2008). Live cultivable MAP bacilli have been reported from milk based food items (ice creams, cheese, condensed milk,

A systematic ultrastructure of peripheral nerves across the spectrum of leprosy was studied with an aim to better understanding the pathogenesis of nerve involvement in leprosy using light and electron microscope. The pathogenesis of nerve destruction varies in leprosy considerably along the spectrum. The study has begun to shed new light on some aspects of the infection of Mycobacterium leprae (M. lepare) and phenomenon has opened new avenue of research and possible mechanism of pathogenesis in TT/BT/BL/LL leprosy. In tuberculoid type (TT) and borderline tuberculoid (BT) leprosy, the degenerative changes of Schwann cells (SCs) and presence of perineural and perivascular cuffing by mononuclear cells. The endoneurial blood vessel (EBV) showed thickening of basement membrane with hypertrophy of EC leading to narrowing or complete occlusion of lumen and causing ischemia. However, borderline lepromatous (BL) and lepromatous leprosy (LL) foamy macrophages and vacuolated SC contain numerous small dense materials, irregular in shape and size was prominent and, considered to be degenerated and fragmented M. Leprae. The dense materials were also found in the cytoplasm of vascular EC. It was revealed that besides SC, the EC of EBV frequently harbor M. leprae in LL. The lumen of the EBV was wide open with enlarged nucleus. In the present study, the ultrastructural characteristics suggest that hypersensitivity mechanisms are possibly responsible for nerve damage in TT/BT leprosy. However, the study indicates that the mechanisms of nerve damage in BL/LL are basically different wherein hypersensitivity appears to play a very limited role.

In the present study, Indirect Fluorescent antibody test (iFAT) has been used as the "screening test" for the detection of MAP bacilli in the milk samples of lactating domestic livestock. A total of 372 milk samples from lactating animals were screened by iFAT and results were compared with microscopy of milk samples and milk ELISA test. Comparative analysis of the results of three tests showed that iFAT had fairly good sensitivity (84.7%) and specificity (90.4%), with respect to ZN staining (microscopy) with kappa value of 0.735 and "good" strength of agreement. Similar comparison with milk ELISA test revealed, sensitivity (73.3%) and specificity of (72.6%) with kappa value of 0.443 and strength of agreement was moderate. Lower or higher difference in sensitivity and specificity of iFAT with respect to ZN staining and milk ELISA may be due to the difference in detection "target" of the test i.e., antigen or antibody. It was concluded that iFAT was a reliable and sensitive diagnostic test for the detection of MAP in milk and can also be used for the "mass screening" of the milk samples.

In the present article we observed the quantification and morphological, ultrastructural features of biofilms of fast growing clinical isolates M. smegmatis in presence of first line antibacterial drug streptomycin, isoniazid rifampicin, ethambutol and pyrazinamide. Biofilm of M. smegmatis was found to be unaffected at concentration of drugs that inhibited growth of planktonic bacilli .Thus, the biofilm growth modus appears to be a strategy for replicating bacilli to evade the trap of antibacterials. Planktonic and biofilm cells had similar intrinsic antibiotic susceptibility. Electron microscopy revealed that control (no drug) biofilms consisted primarily of bacterial clusters and fibrillar elements. The extracellular polymeric substance (EPS) material was less abundant in antibiotic-treated than in control biofilms beacause in the presence of high antibiotic concentrations at MIC level. The study is explored that the effect of drug on biofilm is time dependent means if the drugs were added at initial phase of biofilm, significant inhibitory effect were observed.Int J Appl Sci Biotechnol, Vol 3(4): 635-641