Molecular epidemiology of multidrug-resistant Shigella dysenteriae type 1 causing dysentery outbreaks in Central African Republic, 2003-2004.

Shigella dysenteriae type 1 (Sd1) represents a particular threat in developing countries because of the severity of the infection and its epidemic potential. Antimicrobial susceptibility testing and molecular subtyping by pulsed-field gel electrophoresis (PFGE) and plasmid profiling (PP) of Sd1 isolates collected during two dysentery outbreaks (2013 and 445 cases of bloody diarrhoea) in Central African Republic (CAR) during the period 2003-2004 were reported. Eleven Sd1 comparison strains (CS) acquired by travellers or residents of Africa (n=10) or Asia (n=1) between 1993 and 2003 were also analysed. The 19 Sd1 isolates recovered from CAR outbreaks were multidrug resistant, although susceptible to quinolones and fluoroquinolones. Molecular subtyping by PFGE was more discriminatory than PP. The PFGE using XbaI and NotI restriction enzymes indicated that the two outbreaks were due to two different clones and also revealed a genetic diversity among the CS recovered from outbreak or sporadic cases between 1993 and 2003. This study was the result of a fruitful collaboration between field physicians and microbiologists. The data collected will serve as the basis for establishing long-term monitoring of Sd1 in CAR

The genus Serratia revisited by genomics

The genus Serratia has been studied for over a century and includes clinically-important and diverse environmental members. Despite this, there is a paucity of genomic information across the genus and a robust whole genome-based phylogenetic framework is lacking. Here, we have assembled and analysed a representative set of 664 genomes from across the genus, including 215 historic isolates originally used in defining the genus. Phylogenomic analysis of the genus reveals a clearly-defined population structure which displays deep divisions and aligns with ecological niche, as well as striking congruence between historical biochemical phenotyping data and contemporary genomics data. We highlight the genomic, phenotypic and plasmid diversity of Serratia, and provide evidence of different patterns of gene flow across the genus. Our work provides a framework for understanding the emergence of clinical and other lineages of Serratia

Determinación del origen clonal de los aislamientos colombianos de vibriocholerae 01

IP 2104-04-039-96Incluye anexos.Elizabeth Castañeda ... [et al.]. -- En: Encuentro Nacional deInvestigacion en Enfermedades Infecciosas (1;1998 jun : 11-13). -- [s.l. : s.n.]. -- p. -- 28 cm. -- Molecular epidemiology of cholera in Cololombia /;Elizabeth Castañeda ... [et al.]. -- En: American Societyformicrobiology(98th 1998 May : 17-21 :;Washington, DC). -- Washington, DC. -- p. -- 28 cm. -- Molecularstudies on the Colombian vibrio choleare 01;isolates / Elizabeth Castañeda ... [et al.]. -- En: American Society for microbiology (98th 1998 May : 17-21 :;Washington, DC). -- Washington, DC. -- p. -- 28 cm. -- ARTICULO(S) EN REVISTA: Determinacion del origen clonal;de aislamientos colombianos de vibrio cholerae 01 / ElizabethCastañeda ... [et al.]. -- En: Biomedica. --;Vol. 19, sup. 1 (feb. 1999); p. 142.;PONENCIA(S) EN CONGRESO: Determinacion del origen clonal de aislamientos colombianos de vibrio cholerae 01

Étude phylogénétique des Pseudomonas sensu lato par séquençage du gène rpoB

Phylogenetic relationships within the genus Pseudomonas were examined by sequencing the rpoB gene. The phylogenetic resolution of the rpoB tree was three times higher than that of the rrs tree. Ribogroups and DNA-DNA hybridization published earlier were correlated well with rpoB sequence clusters of Pseudomonas species and P. syringae complex (pathovars). The rpoB sequence database generated by this study was used for identification. Phylogenies deduced from sequencing rpoB, gyrB and rrs were compared for the Burkholderia, Comamonadaceae, Brevundimonas and related species. One gene can be used for identification but not in phylogeny.Le séquençage du gène rpoB apporte une résolution taxonomique trois fois plus élevée que celle donnée par le gène rrs codant l'ARNr 16S. L'application aux Pseudomonas rend plus facile l'identification des espèces. Une bonne corrélation a été obtenue entre les séquences rpoB et les hybridations ADN-ADN ainsi qu'avec la ribotypie, pour toutes les espèces de Pseudomonas et le complexe syringae (pathovars). La base de données obtenue est utilisée en identification. Le travail a été étendu aux Burkholderia, Comamonadaceae, Brevundimonas et bactéries apparentées en séquencant les gènes rpoB, gyrB et rrs. Un seul gène est utilisable en identification mais non en phylogénie.CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Identification of Major Streptococcal Species by rrn-Amplified Ribosomal DNA Restriction Analysis

Amplified ribosomal DNA restriction analysis (rrn-ARDRA) is based on PCR amplification and restriction of a fragment of rRNA genes including 16S and 23S genes and the intergenic spacer. rrn-ARDRA was evaluated for the identification of species within the genus Streptococcus. A total of 148 type and reference strains of pyogenic, oral, and group D streptococci were examined in order to construct a database for identification of streptococci. The amplified product was a single band approximately 4,500 bp long. This amplicon was digested separately with three (HhaI, MboII, and Sau3A) restriction endonucleases. Respectively, 27, 26, and 28 major patterns were observed after HhaI, MboII, and Sau3A restrictions. Streptococcal strains belonging to different species had different patterns or different combination of patterns. An identification system based upon a combination of the three restriction patterns in a single database was then proposed. rrn-ARDRA was successfully applied to 11 clinical isolates whose identification to the species level was difficult to obtain by phenotypic analysis. Using a database of well-characterized strains, rrn-ARDRA is a powerful method for the identification of streptococcal isolates

Persistent Endemicity of Salmonella bongori 48:z(35):− in Southern Italy: Molecular Characterization of Human, Animal, and Environmental Isolates

From 1984 to 1999, we collected 31 isolates of the rare serovar Salmonella bongori 48:z(35):− in southern Italy. Twenty-four of the isolates were from cases of acute enteritis in humans. Pulsed-field gel electrophoresis analysis showed that all but one of our isolates were at least 80% similar. Our findings suggest that genetically related S. bongori 48:z(35):− strains are endemically circulating in southern Italy

Characterization of Shiga Toxin-Producing Escherichia coli O157:H7 Isolated in Italy and in France

Twenty-one Escherichia coli O157:H7 strains isolated in northern Italy from sporadic cases of hemolytic-uremic syndrome and from cattle and food were characterized by virulence gene analysis, pulsed-field gel electrophoresis (PFGE) of XbaI-digested DNA, enterobacterial repetitive intergenic consensus (ERIC) sequence-based PCR (ERIC-PCR), and antibiotic resistance patterns and compared to 18 strains isolated in France from human cases of diarrhea, cattle, and the environment. Strains isolated in Sicily (southern Italy) from a local farm (one strain) and from calves just imported from France (11 strains) and Spain (six strains) were also typed. Whereas the eae and hlyA genes were always detected, Shiga toxin gene (stx) analysis showed some differences related to geographic areas. Isolates from northern Italy showed a high frequency of stx(1) and stx(2), while strains isolated in France and from French and Spanish calves imported to Sicily more frequently possessed the stx(2c) gene. The majority of the strains isolated in northern Italy were also resistant to one or more antibiotics, while most of the strains isolated in France and Sicily were fully susceptible. ERIC-PCR analysis was not able to differentiate the strains. PFGE typing after XbaI DNA digestion produced a total of 54 distinct restriction endonuclease digestion profiles (REDPs) among the 57 strains. Phylogenetic analysis was unable to cluster REDPs according to geographic origin. All epidemiologically related isolates showed either identical or ≥91% similar REDPs. Our findings suggest a peculiar circulation of antibiotic-resistant, genetically unrelated strains in northern Italy

Endemic, Epidemic Clone of Salmonella enterica Serovar Typhi Harboring a Single Multidrug-Resistant Plasmid in Vietnam between 1995 and 2002

Salmonella enterica serovar Typhi strains resistant to ampicillin, chloramphenicol, tetracyclines, streptomycin, and cotrimoxazole, isolated from sporadic cases and minor outbreaks in Vietnam between 1995 and 2002, were typed and compared. Plasmid fingerprinting, Vi bacteriophage typing, XbaI pulsed-field gel electrophoresis, and PstI ribotyping showed that endemic, epidemic multidrug-resistant typhoid fever was due, for at least 74.1% of the isolates, to one or two clones of serovar Typhi harboring a single resistance plasmid. PstI ribotyping was used as a basic technique to ensure that a serovar Typhi expansion was clonal