1,721,009 research outputs found
Relativistic generalizations of gravity-induced localization models
No full textAbstractNonunitary versions of Newtonian gravity leading to wavefunction localization admit natural special-relativistic generalizations. They include the first consistent relativistic localization models. At variance with the unified model of localization and gravity, the purely localizing version requires negative energy fields, which however are less harmful than usual and can be used to build ultraviolet-finite theories
Molecular epidemiology and origin of cholera reemergence in Italy and Albania in the 1990s
No full textIn 1994 a cholera epidemic occurred in Italy and Albania after more than a decade of case absence. To investigate genotypic characteristics and
the origin of the epidemic strains, 110 Vibrio cholerae O1 El Tor isolates from Italy and Albania were studied by randomly amplified polymorphic
DNA analysis (RAPD), BglI ribotyping, and pulsed-field gel electrophoresis (PFGE) of genomic DNA. The Italian and Albanian strains were all
ribotype 6 and their RAPD and PFGE patterns were identical as well. These findings indicated that the 1994 isolates belonged to the same clone
and that the clone was part of the larger global spread of epidemic ribotype 6 strains, which started in southern Asia in 1990
SXT-related integrating conjugative element and IncC plasmids in Vibrio cholerae O1 strains in Eastern Africa
No full textObjectives: The objective of this study was to investigate the extent of resistance patterns and associated
mobile genetic elements in epidemic V. cholerae O1 El Tor strains isolated from Eastern Africa in
the late 1990s.
Methods: Self-transmissible genetic elements and associated clusters of genes encoding resistance
were detected by conjugation experiments. Detection of SXT-related integrating conjugative elements
(ICEs) and associated antibiotic resistance genes was performed by PCR to amplify the SXT elementintegrase
gene (int), right SXT element-chromosome junction (attP-prfC) and genes conferring resistance
to chloramphenicol (floR), sulfamethoxazole (sulII), streptomycin (strA) and trimethoprim (dfrA1).
Genomic relatedness was established by random amplified polymorphic DNA patterns.
Results: Of 224 strains analysed, 200 isolates exhibited resistance to four or more antimicrobials. An
IncC plasmid, encoding resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and
trimethoprim, conferred multidrug resistance to 113 strains isolated from Somalia and Ethiopia, whereas
an SXT-related ICE, encoding resistance to chloramphenicol, streptomycin, sulfamethoxazole and
trimethoprim, conferred multidrug resistance to 74 strains isolated from Sudan, Kenya and Tanzania.
Conclusions: This study has shown the spread of SXT-related ICEs among V. cholerae O1 African isolates.
It has also highlighted the role of two distinct genetic elements in conferring multiple resistance to
the two distinct groups of V. cholerae O1 strains that, in the late 1990s, spread through Eastern Africa, a
critical geographic region for the persistence and transmission of cholera to the entire continent
Zonal-meridional decomposition and the Hamiltonian description of planetary fluid dynamics
No full textThe basic properties of planetary flows are studied within the framework of the noncanonical Hamiltonian approach formulated by Morrison. A zonal-symmetric decomposition is applied in Order to characterize the contributions of the different dynamical terms. Steady states and the Lorenz energy and angular momentum cycles are also written within the Lie-Poisson bracket formalism. (C) 2011 Elsevier B.V. All rights reserved
Susceptibility to rifaximin of Vibrio cholerae strains from different geographical areas
No full textFour hundred and eight clinical strains of Vibrio cholerae isolated from different geographical areas and with different antimicrobial resistance patterns were tested for susceptibility to rifaximin, a non-absorbable antibiotic active in vitro against Gram-negative bacteria. The MICs ranged from 0.5 to 4 mg/l for all strains. These values and the pharmacokinetic properties suggest rifaximin as an attractive antimicrobial agent for choler
Composite IS1-tetracycline resistance elements in aerobactin-encoding FIme plasmids from Salmonella wien.
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