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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
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
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
Editorial for the Special Issue “Antimicrobial Resistance and Genetic Elements in Bacteria”
Full text linkThroughout human history, bacterial infections have been an omnipresent threat, which have, on occasion, resulted in devastating pandemics affecting humanity [...
Cholera in Ethiopia in the 1990 s: epidemiologic patterns, clonal analysis, and antimicrobial resistance
No full textIn 1993, after 6 years of absence, cholera re-emerged in the Horn of Africa. Following its introduction to Djibouti, the disease spread to the central and southern areas of Ethiopia reaching Somalia in 1994. Cholera outbreaks persisted in Ethiopia with a recrudescence of cases in 1998. Twenty-two Vibrio cholerae O1 strains, selected to represent the 1998 history of cholera in Ethiopia, were characterized by random amplified polymorphic DNA patterns, BglI ribotyping and antimicrobial susceptibility. All isolates showed a unique amplified DNA pattern and a prevalent ribotype B8a. All strains were multidrug-resistant and harboured an IncC plasmid which conferred resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and trimethoprim. These findings indicate that a group of closely related V. cholerae O1 strains was responsible for the cholera epidemic in Ethiopia in 1998
Clonal relationship among Vibrio cholerae O1 El Tor strains isolated in Somalia
No full textOne hundred and three Vibrio cholerae O1 strains, selected to represent the cholera outbreaks which occurred in
Somalia in 1998–1999, were characterized by random amplified polymorphic DNA patterns, ribotyping, and
antimicrobial susceptibility. All strains showed a unique amplified DNA pattern and 2 closely related ribotypes (B5a
and B8a), among which B5a was the more frequently identified. Ninety-one strains were resistant to ampicillin,
chloramphenicol, spectinomycin, streptomycin, sulfamethoxazole, and trimethoprim, conferred, except for spectinomycin,
by a conjugative plasmid IncC. These findings indicated that the group of strains active in Somalia in the late
1990s had a clonal origin
Identification of pigmented Serratia marcescens symbiotically associated with Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae)
Full text linkTo characterize red pigment-producing bacteria (RPPB) regularly released during oviposition by red palm weevil (RPW), RPPB were recovered from eggs deposited in apples supplied as substrate for oviposition. The presence of RPPB was also detected from gut, the reproductive apparatus of dissected adult and virgin insects and from pupal cases collected within infested palms. RPPB were also identified all along the tissue of these palms. Analysis of the 16S rDNA, gyrB, rpoB, recA, and groEL sequences assigned RPPB to the species Serratia marcescens. RPPB exhibited an antimicrobial activity assessed by the agar well diffusion method against a number of gram-positive and gram-negative bacteria. In this study, we first report the identification of a red pigment-producing S. marcescens as extracellular symbiont of RPW. Route of transmission, detection within different organs, and a wide spread along the infested palm tissue, suggested S. marcescens is present as extracellular symbiont in different developmental stages of the RPW. Additionally, the antimicrobial activity exhibited versus Bacillus spp., Paenibacillus spp., and Lysinibacillus spp., reported as insect pathogens and potential candidates for biocontrol agents, could ascribe for S. marcescens a potential protective role
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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