Shiga toxin-producing Escherichia coli O157 associated with human infections in Switzerland, 2000-2009

Shiga toxin-producing Escherichia coli (STEC), an important foodborne pathogen, can cause mild to severe bloody diarrhoea (BD), sometimes followed by life-threatening complications such as haemolytic uraemic syndrome (HUS). A total of 44 O157 strains isolated from different patients from 2000 through 2009 in Switzerland were further characterized and linked to medical history data. Non-bloody diarrhoea was experienced by 15·9%, BD by 61·4% of the patients, and 29·5% developed HUS. All strains belonged to MLST type 11, were positive for stx2 variants (stx2 and/or stx2c), eae and ehxA, and only two strains showed antibiotic resistance. Of the 44 strains, nine phage types (PTs) were detected the most frequent being PT32 (43·2%) and PT8 (18·2%). By PFGE, 39 different patterns were found. This high genetic diversity within the strains leads to the conclusion that STEC O157 infections in Switzerland most often occur as sporadic case

Gravitational waves from supernova matter

We have performed a set of 11 three-dimensional magnetohydrodynamical core collapse supernova simulations in order to investigate the dependencies of the gravitational wave signal on the progenitor's initial conditions. We study the effects of the initial central angular velocity and different variants of neutrino transport. Our models are started up from a 15 solar mass progenitor and incorporate an effective general relativistic gravitational potential and a finite temperature nuclear equation of state. Furthermore, the electron flavour neutrino transport is tracked by efficient algorithms for the radiative transfer of massless fermions. We find that non- and slowly rotating models show gravitational wave emission due to prompt- and lepton driven convection that reveals details about the hydrodynamical state of the fluid inside the protoneutron stars. Furthermore we show that protoneutron stars can become dynamically unstable to rotational instabilities at T/|W| values as low as ~2 % at core bounce. We point out that the inclusion of deleptonization during the postbounce phase is very important for the quantitative GW prediction, as it enhances the absolute values of the gravitational wave trains up to a factor of ten with respect to a lepton-conserving treatment.Comment: 10 pages, 6 figures, accepted, to be published in a Classical and Quantum Gravity special issue for MICRA200

Shiga toxin-producing Escherichia coli O157 associated with human infections in Switzerland, 2000-2009

Shiga toxin bildende Escherichia coli (STEC), wichtige durch Lebensmittel übertragbare Erreger, können milde bis schwere blutige Durchfälle (BD), manchmal gefolgt von lebensbedrohlichen Komplikationen wie dem Hämolytisch-urämische Syndrom (HUS), verursachen. Insgesamt wurden 44 STEC O157 Stämme, die von verschiedenen Patienten in den Jahren 2000 bis 2009 in der Schweiz isoliert wurden, weiter charakterisiert und die dazugehörigen anamnestischen Daten aufgearbeitet. 15.9% der Patienten hatten nicht blutigen Durchfall, 61.4% der Patienten zeigten BD und 29.5% entwickelten ein HUS. Alle Stämme gehörten zum MLST Typ 11, waren stx2, eae und ehxA positiv und nur zwei Stämme zeigten Antibiotikaresistenzen. Unter den 44 Stämmen wurden 9 Phagen-Typen (PT) nachgewiesen, die häufigsten waren; PT 32 (43.2%) und PT 8 (18.2%). Die Genotypisierung (Pulsfeld Gelelektrophorese) ergab 39 verschiedene Muster. Die hohe genetische Vielfalt innerhalb der Stämme führt zu der Schlussfolgerung, dass STEC O157 Infektionen in der Schweiz häufig als Einzelfälle und nicht als grössere Ausbrüche aufgetreten sind. Summary: Shiga toxin-producing Escherichia coli (STEC), an important foodborne pathogen, can cause mild up to severe bloody diarrhoea (BD), sometimes followed by life-threatening complications such as haemolytic uraemic syndrome (HUS). A total of 44 STEC O157 strains isolated from different patients from 2000 through 2009 in Switzerland were further characterized and linked to anamnestic data. Non-bloody diarrhoea was experienced by 15.9%, BD by 61.4% of the patients, and 29.5% developed HUS. All strains belonged to MLST type 11, were positive for stx2, eae and ehxA and only two strains showed antibiotic resistances. Among the 44 strains, 9 phage types (PTs) were detected, the most frequent ones being PT 32 (43.2%) and PT 8 (18.2%). By pulsed-field gel electrophoresis (PFGE), 39 different patterns were found. This high genetic diversity within the strains leads to the conclusion that STEC O157 infections in Switzerland most often occur as single and sporadic cases

Salmonella enterica serotype Kentucky associated with human infections in Switzerland: genotype and resistance trends 2004-2009

Salmonella serotype Kentucky emerged since 2002 and now ranks among the top ten serovars isolated from humans in Europe, and 8th to 10th in Switzerland. A total of 106 strains isolated from different patients from 2004 through 2009 in Switzerland were further characterized by (i) assessing phenotypic antibiotic resistance profiles using the disk diffusion method and (ii) by genotyping using pulsed-field gel electrophoresis (PFGE) after macrorestriction with XbaI in order to evaluate strain relationships and trends. In Switzerland, there is evidence for an outbreak in 2006 as the annual incidence almost doubled. A total of 30 strains (28%) were resistant or showed intermediate resistance to one to three antimicrobials and 48 strains (45%) displayed resistance to more than three antibiotics. We found a high prevalence (67%) of nalidixic acid resistance, and 58% were resistant to ciprofloxacin. One strain was a producer of extended-spectrum β-lactamase (ESBL). PFGE discriminated four clusters (similarity coefficient cut off at 80%). The resistance situation among the strains isolated from 2004 to 2009 in Switzerland is discussed and shown to coincide with findings in other European countries. Based on genetic subtyping, a so far undetected outbreak is likely to have occurred in Switzerland in 2006. Finally, our data identified travelling to Northern Africa as a risk factor for S. Kentucky infections