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Toxigenic Vibrio cholerae, rarely isolated from the aquatic environment between cholera epidemics, can be detected in what is now understood to be a dormant stage, i.e., viable but nonculturable when standard bacteriological methods are used. In the research reported here, biofilms have proved to be a source of culturable V. cholerae, even in nonepidemic(More)
Vibrio cholerae persists in aquatic environments predominantly in a nonculturable state. In this study coccoid, nonculturable V. cholerae O1 in biofilms maintained for 495 days in Mathbaria, Bangladesh, pond water became culturable upon animal passage. Culturability, biofilm formation, and the wbe, ctxA, and rstR2 genes were monitored by culture, direct(More)
Forty-two episodes of Vibrio parahaemolyticus infections were detected in Beira, Mozambique, from January to May 2004. The majority of the isolates (81%) belonged to the pandemic serovars (O3:K6 and O4:K68) of V. parahaemolyticus. The pandemic serovars were positive by group-specific PCR (GS-PCR) and a PCR specific for open reading frame ORF8 (ORF8-PCR),(More)
The treatment regimen for diarrhea depends greatly on correct diagnosis of its etiology. Recent diarrhea outbreaks in Bangladesh showed Vibrio cholerae to be the predominant cause, although more than 40% of the suspected cases failed to show cholera etiology by conventional culture methods (CMs). In the present study, suspected cholera stools collected from(More)
New variants of Vibrio cholerae O1 have appeared in different time-frames in various endemic regions, especially in Asia and Africa. Sixty-nine strains of V. cholerae O1 isolated in Zambia between 1996 and 2004 were investigated by various genotypic techniques to determine the lineage of virulence signatures and clonality. All strains were positive for(More)
Seasonal plankton blooms correlate with occurrence of cholera in Bangladesh, although the mechanism of how dormant Vibrio cholerae, enduring interepidemic period in biofilms and plankton, initiates seasonal cholera is not fully understood. In this study, laboratory microcosms prepared with estuarine Mathbaria water (MW) samples supported active growth of(More)
The genetic characteristics of Vibrio parahaemolyticus strains isolated in 2004 and 2005 in Mozambique were assessed in this study to determine whether the pandemic clone of V. parahaemolyticus O3 : K6 and O4 : K68 serotypes has spread to Mozambique. Fifty-eight V. parahaemolyticus strains isolated from hospitalized diarrhoea patients in Beira, Mozambique,(More)
Little is known about the physical and socioeconomic postpartum consequences of women who experience obstetric complications and require emergency obstetric care (EmOC), particularly in resource-poor countries such as Bangladesh where historically there has been a strong cultural preference for births at home. Recent increases in the use of skilled birth(More)
Vibrio cholerae O1 strains that are hybrids between the classical and El Tor biotypes were isolated during two consecutive years (2004-2005) from diarrheal patients in Mozambique. Similar variants isolated in Bangladesh and recently isolated El Tor strains were analyzed for genetic diversity. Pulsed-field gel electrophoresis (PFGE) analysis using the(More)
Evaluation of the Hessian matrix of a scalar function is a subproblem in many numerical optimization algorithms. For large-scale problems often the Hessian matrix is sparse and structured, and it is preferable to exploit such information when available. Using symmetry in the second derivative values of the components it is possible to detect the sparsity(More)