Search results for " pulsed-field"

GyrA sequence-based typing of Legionella.

2000

Comparative sequence analysis of a 423-bp segment of the gyrA gene including a region homologous to the quinolone resistance-determining region (QRDR) of other species was evaluated as a novel typing method for Legionella strains. The study was performed with 29 reference strains representing 11 different Legionella species, with various serogroups, and with 13 clinical isolates of L. pneumophila. Pulsed-field gel electrophoresis and serotyping were employed for comparison of the clinical isolates. QRDR sequencing proved to be a highly discriminative tool for typing Legionellae, and permitted identification of species, serogroups and even different strains within serogroup 1. None of the is…

Characterization of Listeria monocytogenes isolates from human listeriosis cases in Italy.

2009

ABSTRACT The objective of this study was to characterize by serotyping, pulsed-field gel electrophoresis (PFGE), and PCR amplification of virulence genes and markers of epidemic clones I, II, and III (ECI, ECII, and ECIII) 54 human isolates from apparently sporadic cases of infection occurring in the Lombardy region and in the province of Florence, Tuscany, Italy, in the years 1996 to 2007. Listeria monocytogenes isolates were provided by the clinical microbiology laboratories of the Lombardy region and the “Careggi” Hospital of Florence, Tuscany, Italy. Serotyping, PFGE after digestion with the AscI and ApaI enzymes, and PCR amplification for the inlA , inlC , and inlJ genes and ECI, ECII,…

Multiclonal emergence of carbapenem-resistant Klebsiella pneumoniae in Tuscany, Italy

2010

Characterization of Shiga toxin-producing Escherichia coli O157:H7 isolated in Italy and in France

2002

ABSTRACT 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 Xba I-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 al…

Identification of Shigella sonnei biotype g isolates carrying class 2 integrons in Italy in 2001-2003

2005

ABSTRACT Phenotyping and genotyping have been carried out on 64 epidemic and sporadic isolates of Shigella sonnei identified in Italy in the years 2001 to 2003. Class 2 integron carriage has been also investigated. Isolates from four of the five outbreaks and four of six sporadic cases were biotype g , pulsed-field gel electrophoresis type B, and class 2 integron positive, suggesting emergence and spread of an epidemic clone in Italy.

Mitotic Recombination and Genetic Changes in Saccharomyces cerevisiae during Wine Fermentation

2000

Natural strains of Saccharomyces cerevisiae are prototrophic homothallic yeasts that sporulate poorly, are often heterozygous, and may be aneuploid. This genomic constitution may confer selective advantages in some environments. Different mechanisms of recombination, such as meiosis or mitotic rearrangement of chromosomes, have been proposed for wine strains. We studied the stability of the URA3 locus of a URA3/ura3 wine yeast in consecutive grape must fermentations. ura3/ura3 homozygotes were detected at a rate of 1 x 10(-5) to 3 x 10(-5) per generation, and mitotic rearrangements for chromosomes VIII and XII appeared after 30 mitotic divisions. We used the karyotype as a meiotic marker an…

Cloning and characterization of PRB1, a Candida albicans gene encoding a putative novel endoprotease B and factors affecting its expression

2002

Abstract Several cDNA fragments corresponding to transcripts differentially expressed under conditions that favor mycelial growth of Candida albicans were identified by the “differential display” technique. One of these was cloned and used as a probe to rescue the full gene from a genomic library of the fungus. The sequence identified a single, uninterrupted open reading frame of 1395 nucleotides encoding a putative protein of 465 residues and a theoretical molecular weight of 50.3 kDa, present in the genome as a single copy located at chromosome 2 in different strains. The gene product showed high homology with subtilisin-like proteases, mainly PRB1, the vacuolar B protease from Saccharomy…

Natural hybrids fromSaccharomyces cerevisiae,Saccharomyces bayanusandSaccharomyces kudriavzeviiin wine fermentations

2006

Several wine isolates of Saccharomyces were analysed for six molecular markers, five nuclear and one mitochondrial, and new natural interspecific hybrids were identified. The molecular characterization of these Saccharomyces hybrids was performed based on the restriction analysis of five nuclear genes ( CAT8 , CYR1 , GSY1 , MET6 and OPY1 , located in different chromosomes), the ribosomal region encompassing the 5.8S rRNA gene and the two internal transcribed spacers, and sequence analysis of the mitochondrial gene COX2 . This method allowed us to identify and characterize new hybrids between Saccharomyces cerevisiae and Saccharomyces kudriavzevii , between S. cerevisiae and Saccharomyces ba…

Salmonella enterica serotype Typhimurium DT 104 antibiotic resistance genomic island I in serotype paratyphi B

2002

We have identified Salmonella genomic island I (SGI1) in an isolate of Salmonella enterica serotype Paratyphi B. This antibiotic-resistance gene cluster, which confers multidrug resistance, has been previously identified in S. enterica serotype Typhimurium phage types DT 104 and DT 120 and in S. enterica serotype Agona.

Serotypes, Antibiotic Resistance, and Class 1 Integrons in Salmonella Isolates from Pediatric Cases of Enteritis in Tehran, Iran

2011

The present study was conducted to investigate serotype distribution, antimicrobial resistance patterns, carriage of class 1 integron, and clonality of Salmonella strains isolated from patients aged 0-12 years in Tehran, Iran, during 2007-2008. A total of 139 Salmonella isolates were studied. Salmonella serotypes Enteritidis, Infantis, and Typhimurium included 84.9% of isolates, Enteritidis accounting for 41.7%. The most prevalent resistances were to doxycycline (64.7%), nalidixic acid (61.2%), tetracycline (51.8%), and streptomycin (42.8%). Fifty-three (38.1%) isolates contained class 1 integron. Eight different gene cassettes were identified, aadA1 being the most frequently encountered. P…