Isolation, identification and retrospective study of foot-and-mouth disease virus from affected Mithun (Bos frontalis) in north-eastern India.

Foot-and-mouth disease (FMD) is a contagious disease of cloven-hoofed animals that causes substantial and perpetual economic loss. Apart from the contagious nature of the disease, the FMD virus can establish in a "carrier state" among all cloven-hoofed animals. The Mithun (Bos frontalis), popularly called the "Cattle of Mountain," is found in the geographically isolated, hilly region of north-east India: Arunachal Pradesh, Nagaland, Manipur and Mizoram. Despite the geographical inaccessibility, infection by FMD virus has emerged as the single most devastating disease among Mithun after the eradication of rinderpest from this region. Samples from outbreaks of FMD in Mithun were analysed by sandwich ELISA, multiplex RT-PCR (MRT-PCR) and liquid-phase blocking enzyme-linked immunosorbent assay and isolated in the BHK-21 cell line. The results indicate the presence of FMDV serotype "O." The sequencing and molecular phylogenies have revealed close relationships in the lineage of type "O" isolates from Bangladesh. The findings will provide useful information for further research and development of a sustainable programme for the progressive control of FMD in the Mithun population.

Isolation and characterization of Shiga toxigenic Escherichia coli of animal and bird origin by multiplex polymerase chain reaction.

AIM: The purpose of this study was to determine the virulence genes and serotype of Shiga toxin producing Escherichia coli (STEC) strains isolated from animals and birds. MATERIALS AND METHODS: A total of 226 different samples viz., fecal, intestinal content, rectal swab and heart blood were collected from different clinically affected/healthy animals and birds and were streaked on McConkeys' lactose agar and eosin methylene blue agar for isolation of E. coli, confirmed by staining characteristics and biochemical tests. By polymerase chain reaction (PCR) all the E. coli isolates were screened for certain virulence genes, viz., Shiga toxin 1 (stx1), stx2 and eae and enterohemolytic (Ehly) phenotype was observed in washed sheep blood agar plate. All the isolated E. coli strains were forwarded to the National Salmonella and Escherichia Centre, Central Research Institute, Kasauli (Himachal Pradesh) for serotyping. RESULTS: Out of 226 samples 138 yielded E. coli. All the isolates were screened for molecular detection of different virulent genes, viz. stx1, stx2 and eae, based on which 36 (26.08%) were identified as STEC. Among those STEC isolates, 15 (41.67%), 14 (38.89%), 1 (2.78%) exhibited eae, stx2, stx1 alone, respectively, whereas 4 (11.11%) and 2 (5.56%) carried both stx1 and stx2, stx2 and eae, respectively. Among the STEC isolates 22 were belonged to 15 different sero-groups, viz., O2, O20, O22, O25, O43, O60, O69, O90, O91, O95, O106, O118, O130, O162 and O170 and others were untypable. Ehly phenotype was observed in 10 (27.78%) the STEC isolates. CONCLUSION: The present study concluded that STEC could be isolated from both clinically affected as well as healthy animals and birds. Regular monitoring of more samples from animal and bird origin is important to identify natural reservoir of STEC to prevent zoonotic infection.

Mode of uptake of insoluble solid substrates by microorganisms. II: Uptake of solid n-alkanes by yeast and bacterial species.

Using two species of yeast and one of bacterium, evidence has ben obtained which indicates that the microbial uptake of solid alkane powders occurs primarily through a substrate solubilization mechanism. EDTA, a strong inhibitor of hydrocarbon solubilization by the cells, inhibited the growth of these organisms on alkane powder; the inhibition could be removed vai a supply of artificially solubilized alkane. One of the yeast strians, which was a mutant incapable of growing on solid alkane powder and liquid alkane, could grow very well on artifically solubilized alkanes. It was demonstrated that the solid alkane solubilization rate during microbial growth could satisfactorily account for the maximal alkane uptake rate actully observed during growth. The specificity of solubilization for the solid alkane used as the growth substrate was demonstrated.