Differences in the outer membrane protein pattern of Salmonella typhimurium DT8, DT10 and DT104 strains

The most practicable methods for epidemiological classification of S. Typhimurium are serotyping (determination of serovar) and phage typing in order to disclose their infection routes

Competitive exclusion of Salmonella enteritidis by Salmonella gallinarum in poultry.

Salmonella Enteritidis emerged as a major egg-associated pathogen in the late 20th century. Epidemiologic data from England, Wales, and the United States indicate that S. Enteritidis filled the ecologic niche vacated by eradication of S. Gallinarum from poultry, leading to an epidemic increase in human infections. We tested this hypothesis by retrospective analysis of epidemiologic surveys in Germany and demonstrated that the number of human S. Enteritidis cases is inversely related to the prevalence of S. Gallinarum in poultry. Mathematical models combining epidemiology with population biology suggest that S. Gallinarum competitively excluded S. Enteritidis from poultry flocks early in the 20th century

The dual role of wild phages for the horizontal gene transfer among Salmonella strains

Horizontal gene transfer (e.g. transduction, transformation, conjugation) has a great impact on the evolution of bacteria. Several transducing phages related P22 have been reported, transfering chromosomal as well as plasmid born determinants (Schicklmaier & Schmieger, 1995)

Epidemiological and molecular analysis of an outbreak of Salmonella Typhimurium DT12 associated with consumption of pork in Thuringia

In the course of a sentinel-study the National Reference Centre (NRC) observed in February 1999 a considerable increase of human infections due to S. Typhimurium. These strains ofS. Typhimurium typed as phage type DT12 in the NRC were isolated in four counties in the north of Thuringia (Nordhausen, Eichsfeld, Kyffhiiuser, Unstrut-Hainich)

Isolierung und Charakterisierung von Shigatoxin-produzierendenE. coli-Stämmen aus Stuhlproben: Ergebnisse einer Sentinel-Studie

Zur Erfassung der Häufigkeit und des Typenspektrums von Shigatoxin-produzierendenE. coli-Stämmen (EHEC-Bakterien) sowie zur Evaluierung der Praktikabilität, Spezifität und Sensitivität eines Verfahrens zur Diagnostik von EHEC wurde eine Sentinel-Studie im Einzugsbereich (1,1 Mio. Einwohner) eines privat niedergelassenen Untersuchungslabors durchgeführt. Von 3835 untersuchten Durchfallstühlen konnten in ca. 3 % EHEC-Bakterien nachgewiesen werden, die zu einem ungewöhnlich breiten Spektrum von Serovaren und Klonen mit sehr verschiedenen Virulenzfaktoren gehörten. So ließen sich nur ca. 10 % der isolierten EHEC-Stämme als O157 identifizieren, aber ebenso häufig auch O103, O26, O8 oder Ont-Stämme. Ein kombiniertes Verfahren von bestimmten kulturellen und molekularen Methoden erwies sich als praktikabel für die Routinediagnostik unter den zeitlichen und ökonomischen Anforderungen und Bedingungen von privat niedergelassenen Laboratorien.In order to record the incidence and clonal types of shigatoxin-producing E. coli of human origin (EHEC) and to evaluate the feasibility, sensitivity and specificity of a protocol for screening and isolation of EHEC under conditions clinical stool diagnostics a pilot study (Sentinel-study) was carried out with private clinical laboratory (covering 1.1 Mio. inhabitants). 3 % EHEC bacteria were detected among 3835 stool samples investigated from patients suffering with watery and bloody diarrhoea. These isolates belong to a broad range of serovars and clones with a spectrum of various virulence factors. Thus, about 10 % of the isolates have been identified as E. coli O157:H7/-, only, but with the same frequency E. coli O103:H2, O26:H11/-, O8:H or Ont. The protocol of combined bacterial enrichment and molecular methods turned out to be valuable and feasible under conditions and economic requests of private diagnostic laboratories covering ca. 85 % of primary diagnostics

Phage typing and clonal analysis of Salmonella Heidelberg strains isolated from animals and other sources from Minnesota (USA) and Germany

Salmonella Heidelberg isolates has become an emerging pathogen during the 80s in the United States (Martin et al., 1989). Approximately 60% of human cases reported to the CDC in 1995 were caused by only four serovars, including S. Enteridis (24,7%), S. Typhimurium (23,5%), S. Newport (6,2%) and S. Heidelberg (5,1%), (CDC, Salmonella surveillance) and were frequently isolated from chicken and pork (Sawari et al., 2001)

An outbreak caused by S. Typhimurium DT177, BTa in Bavaria characterized by an unusual antibiotic resistance and plasmid profile

Additional to the cases of S.Typhimurium infections due to the phage types DTI04 [1] and DTI20 an unusual high number of severe illness were observed in August/September 2000. Most of the cases came from Heiligenstadt, a town in n01thern Bavaria

Loss of yata, a Novel Gene Regulating the Subcellular Localization of APPL, Induces Deterioration of Neural Tissues and Lifespan Shortening

Background: The subcellular localization of membrane and secreted proteins is finely and dynamically regulated through intracellular vesicular trafficking for permitting various biological processes. Drosophila Amyloid precursor protein like (APPL) and Hikaru genki (HIG) are examples of proteins that show differential subcellular localization among several developmental stages. Methodology/Principal Findings: During the study of the localization mechanisms of APPL and HIG, we isolated a novel mutant of the gene, CG1973, which we named yata. This molecule interacted genetically with Appl and is structurally similar to mouse NTKL/SCYL1, whose mutation was reported to cause neurodegeneration. yata null mutants showed phenotypes that included developmental abnormalities, progressive eye vacuolization, brain volume reduction, and lifespan shortening. Exogenous expression of Appl or hig in neurons partially rescued the mutant phenotypes of yata. Conversely, the phenotypes were exacerbated in double null mutants for yata and Appl. We also examined the subcellular localization of endogenous APPL and exogenously pulse-induced APPL tagged with FLAG by immunostaining the pupal brain and larval motor neurons in yata mutants. Our data revealed that yata mutants showed impaired subcellular localization of APPL. Finally, yata mutant pupal brains occasionally showed aberrant accumulation of Sec23p, a component of the COPII coat of secretory vesicles traveling from the endoplasmic reticulum (ER) to the Golgi

Comparative transcriptome profiling of amyloid precursor protein family members in the adult cortex

<p>Abstract</p> <p>Background</p> <p>The β-amyloid precursor protein (APP) and the related β-amyloid precursor-like proteins (APLPs) undergo complex proteolytic processing giving rise to several fragments. Whereas it is well established that Aβ accumulation is a central trigger for Alzheimer's disease, the physiological role of APP family members and their diverse proteolytic products is still largely unknown. The secreted APPsα ectodomain has been shown to be involved in neuroprotection and synaptic plasticity. The γ-secretase-generated APP intracellular domain (AICD) functions as a transcriptional regulator in heterologous reporter assays although its role for endogenous gene regulation has remained controversial.</p> <p>Results</p> <p>To gain further insight into the molecular changes associated with knockout phenotypes and to elucidate the physiological functions of APP family members including their proposed role as transcriptional regulators, we performed DNA microarray transcriptome profiling of prefrontal cortex of adult wild-type (WT), APP knockout (APP^-/-), APLP2 knockout (APLP2^-/-) and APPsα knockin mice (APP^α/α) expressing solely the secreted APPsα ectodomain. Biological pathways affected by the lack of APP family members included neurogenesis, transcription, and kinase activity. Comparative analysis of transcriptome changes between mutant and wild-type mice, followed by qPCR validation, identified co-regulated gene sets. Interestingly, these included heat shock proteins and plasticity-related genes that were both down-regulated in knockout cortices. In contrast, we failed to detect significant differences in expression of previously proposed AICD target genes including <it>Bace1</it>, <it>Kai1</it>, <it>Gsk3b</it>, <it>p53</it>, <it>Tip60</it>, and <it>Vglut2</it>. Only <it>Egfr </it>was slightly up-regulated in APLP2^-/-mice. Comparison of APP^-/-and APP^α/αwith wild-type mice revealed a high proportion of co-regulated genes indicating an important role of the C-terminus for cellular signaling. Finally, comparison of APLP2^-/-on different genetic backgrounds revealed that background-related transcriptome changes may dominate over changes due to the knockout of a single gene.</p> <p>Conclusion</p> <p>Shared transcriptome profiles corroborated closely related physiological functions of APP family members in the adult central nervous system. As expression of proposed AICD target genes was not altered in adult cortex, this may indicate that these genes are not affected by lack of APP under resting conditions or only in a small subset of cells.</p