Browsing by Author "Siya Ram"

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Enterococci in river Ganga surface waters: Propensity of species distribution, dissemination of antimicrobial-resistance and virulence-markers among species along landscape
(2009) Pushpa Lata; Siya Ram; Madhoolika Agrawal; Rishi Shanker
Background. Surface waters quality has declined in developing countries due to rapid industrialization and population growth. The microbiological quality of river Ganga, a life-sustaining surface water resource for large population of northern India, is adversely affected by several point and non-point sources of pollution. Further, untreated surface waters are consumed for drinking and various household tasks in India making the public vulnerable to water-borne diseases and outbreaks. Enterococci, the 'indicator' of water quality, correlates best with the incidence of gastrointestinal diseases as well as prevalence of other pathogenic microorganisms. Therefore, this study aims to determine the distribution of species diversity, dissemination of antimicrobial-resistance and virulence-markers in enterococci with respect to rural-urban landscape along river Ganga in northern India. Results. Enterococci density (χ2: 1900, df: 1; p < 0.0001) increased from up-to-down gradient sites in the landscape. Species diversity exhibit significant (χ2: 100.4, df: 20; p < 0.0001) and progressive distribution of E. faecalis, E. faecium, E. durans and E. hirae down the gradient. Statistically discernible (p: 0.0156 - < 0.0001) background pool of resistance and virulence was observed among different Enterococcus spp. recovered from five sites in the up-to-down gradient landscape. A significant correlation was observed in the distribution of multiple-antimicrobial- resistance (viz., erythromycin-rifampicin-gentamicin-methicillin and vancomycin-gentamicin-streptomycin; rs: 0.9747; p: 0.0083) and multiple-virulence-markers (viz., gelE+esp+; r s: 0.9747; p: 0.0083; gelE+efaA+; r s: 0.8944; p: 0.0417) among different Enterococcus spp. Conclusion. Our observations show prevalence of multiple-antimicrobial-resistance as well as multiple-virulence traits among different Enterococcus spp. The observed high background pool of resistance and virulence in enterococci in river waters of populous countries has the potential to disseminate more alarming antimicrobial-resistant pathogenic bacteria of same or other lineage in the environment. Therefore, the presence of elevated levels of virulent enterococci with emerging vancomycin resistance in surface waters poses serious health risk in developing countries like India. © 2009 Lata et al; licensee BioMed Central Ltd.
On the absolute hausdorff summability of a fourier series
(1972) S.N. Lal; Siya Ram
In this paper a theorem on the absolute Hausdorff sum- inability of a series associated with a Fourier series has been established. This theorem unifies and extends various known results. © 1972 Pacific Journal of Mathematics.
Real time PCR for the rapid detection of vanA gene in surface waters and aquatic macrophyte by molecular beacon probe
(2009) Pushpa Lata; Siya Ram; Madhoolika Agrawal; Rishi Shanker
Enterococci serve as an "indicator" of fecal contamination for recreational water quality. The vancomycin-resistant-enterococci (VRE) are emerging environmental contaminants in the surface waters. The aim of this study was to develop a rapid and specific molecular beacon probe (MBP)-based real-time PCR assay for detection of vanA gene in surface waters and aquatic macrophyte. The limit of detection (LOD) of the MBP assay was 1 CFU/mL of VRE [r ) 0.943; PCR efficiency ) 99.7%] in 2-fold dilution format within 2.5 h and demonstrated high specificity for environmental enterococci isolates exhibiting VanA phenotype (n ) 25). VRE were detected from downstream surface waters of the rivers impacted by point sources of pollution andrecreationalactivities. TheprobedetectedvanA geneinroot-mat associated microbiota of E. crassipes (Mart.) Solms. an aquatic nuisance weed, at eutrophic sites of the surface waters(ANOVA p < 0.001).Inaddition,theassayenableddetection of otherwise nondetectable vanA gene concentration in the upstream sites of two Indian rivers (Student's t test p < 0.001). The MBP assay developed can be used for sensitive and rapid detection of VRE in surface waters and identification of nonpoint sources of pollution for implementation of preventive measures to protect human health. © 2009 American Chemical Society.
The absolutes ummabilityo f fourier series of a function of wiener’s class by nörlund means
(1977) S.N. Lal; Siya Ram
In this paper we prove that under suitable restrictions on pn and the integral modulus of continuity of a function f of Wiener's class the Fourier series of f is summable |N, pn|. © 1977 American Mathematical Society.