Search results for " typing"
showing 10 items of 273 documents
One-step polymerase chain reaction-based typing of Helicobacter pylori vacA gene: association with gastric histopathology.
2000
Heterogeneity of the Helicobacter pylori vacA gene may be associated with bacterial virulence and presentation. In this study, the possible correlation between vacA genotypes and gastric histopathology was investigated. Using a modified one-step polymerase chain reaction (PCR)-based method, 122 of 131 H. pylori isolates obtained from 63 of 67 patients from Germany were classified into distinct vacA genotypes according to their signal sequence (s1 or s2) and their midregion alleles (m1 or m2). A possible subtype of m1, now alluded to as m3, was identified in one-third of the isolates. Signal sequence s1 was significantly associated with higher H. pylori density but not with gastric inflammat…
Mixed infection by Legionella pneumophila in outbreak patients.
2013
During the molecular epidemiological study of a legionellosis outbreak, we obtained sequence based typing (SBT) profiles from uncultured respiratory samples of 15 affected patients. We detected several distinct allelic profiles some of which were a mixture of alleles present in the more common profiles. Chromatograms from the sequences of one patient with mixed profile showed polymorphisms in several positions, which could result from the simultaneous presence of different Legionella variants in the sample. In order to test this possibility, we cloned PCR amplification products from six loci for two patients with a mixed profile and a patient with a pure profile. After obtaining around 20 s…
Fungemia due to Candida guilliermondii in a pediatric and adult population during a 12-year period.
2007
Candida guilliermondii fungemia is usually described in adults with hematologic malignancies, but in children, only 2 episodes have been published. From 1995 to 2006, 7 episodes (5 in children) were detected in our hospital. Molecular typing excluded a common infection source. C. guilliermondii fungemia may occur in children with underlying conditions other than cancer.
Outbreak of infection with Klebsiella pneumoniae sequence type 258 producing Klebsiella pneumoniae Carbapenemase 3 in an intensive care unit in Italy
2010
Gram-negative pathogens producing carbapenemases represent an alarming clinical threat with serious effects on patient outcomes ([3][1], [7][2]). In 2001, Yigit et al. ([11][3]) reported a novel β-lactamase termed “ K lebsiella pneumoniae carbapenemase” (KPC-1) in North Carolina. KPC-producing
Differentiation of Candida parapsilosis, C. orthopsilosis, and C. metapsilosis by specific PCR amplification of the RPS0 intron
2011
Although Candida parapsilosis is the most prevalent among the 3 species of the *psilosis group, studies applying DNA-based diagnostic techniques with isolates previously identified as C. parapsilosis have revealed that both C. orthopsilosis and C. metapsilosis account for 0-10% of all these isolates, depending on the geographical area. Differences in the degrees of antifungal susceptibility and virulence have been found, so a more precise identification is required. In a first approach, we reidentified 38 randomly chosen clinical isolates, previously identified as C. parapsilosis, using the RPO2 (CA2) RAPD marker. Among them, we reclassified 4 as C. metapsilosis and 5 as C. orthopsilosis. W…
NDM-1 and OXA-163 producing Klebsiella pneumoniae isolates in Cairo, Egypt, 2012
2013
Here we describe carbapenem resistance determinants in two Klebsiella pneumoniae isolates recovered from two hospitalised patients in the same intensive care unit of a cancer hospital in Cairo, Egypt. PCR and sequencing were used to detect and characterise β-lactamase genes. Clonal relationships between the isolates were analysed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The first K. pneumoniae isolate carried the blaNDM-1 gene and the second isolate carried the blaOXA-163 gene. Both isolates co-expressed the extended-spectrum β-lactamase CTX-M-15. The two isolates belonged to different sequence types (STs), ST11 and ST16, respectively. No history of …
Potential association of specific Candida parapsilosis genotypes, bloodstream infections and colonization of health workers' hands.
2014
AbstractFungal nosocomial infections continue to be a serious problem among hospitalized patients, decreasing quality of life and adding millions of euros to healthcare costs. The aim of this study was to describe the pattern of fungi associated with the hands of healthcare workers and to genotype Candida parapsilosis isolates in order to understand whether their high clinical prevalence stems from endemic nosocomial genotypes or from the real emergence of epidemiologically-unrelated strains. Approximately 39% (50/129) of healthcare workers were positive for yeasts and among 77 different fungal isolates recovered, C. parapsilosis was the most frequent (44/77; 57%). Twenty-seven diverse geno…
Direct sequencing of Legionella pneumophila from respiratory samples for sequence-based typing analysis.
2009
ABSTRACT We have developed a procedure to test the efficiency and reliability of sequencing of Legionella pneumophila genes directly from respiratory samples and have compared the results with those derived from cultured isolates. We tried to obtain the nucleotide sequences of six protein-coding loci included in the sequence-based typing scheme for Legionella pneumophila and three intergenic regions from 132 samples corresponding to 106 patients positive for urine antigen. A seminested PCR approach was used to amplify and sequence these nine loci directly from respiratory samples. Nucleotide sequences were directly obtained for 23 Legionella isolates and also for 66 respiratory secretions f…
A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates
2015
Background Columnaris disease caused by Flavobacterium columnare is a serious problem in aquaculture, annually causing large economic losses around the world. Despite considerable research, the molecular epidemiology of F. columnare remains poorly understood. Methods We investigated the population structure and spatiotemporal changes in the genetic diversity of F. columnare population in Finland by using a multilocus sequence typing (MLST) and analysis (MLSA) based on DNA sequence variation within six housekeeping genes. A total of 83 strains of F. columnare were collected from eight different areas located across the country between 2003 and 2012. Results Partial sequencing of six housekee…
Molecular typing of Agrobacterium species isolates from catheter-related bloodstream infections.
2004
AbstractAgrobacteriumisolates from intravenous catheters of three hospitalized patients were initially identified asA. tumefaciens,but inability to produce 3-ketolactose revealed that two of them wereA. vitis.However, rDNA analysis correlated all of the isolates toA. tumefaciens.Pulsed-field gel electrophoresis analysis ascertained the nosocomial transmission of the infection.