Salmonella Enteritidis phage type 21 outbreak in Austria, 2005.

We report an outbreak of gastroenteritis due to Salmonella Enteritidis PT 21 associated with attending an annual traditional fair in a small Austrian village on 4 May 2005. The outbreak lasted from 4 to 8 May. Descriptive and analytical epidemiological investigations were conducted in order to determine the extent of the outbreak and to identify outbreak risk factors. Of the 115 persons who visited the fair, 85 persons fulfilled the criteria of an outbreak case (attack rate = 73.9%). Stool specimens from 52 patients, including two kitchen staff, were tested for salmonella, and 20 specimens were positive for Salmonella Enteritidis PT 21. The cohort study revealed mixed salad (which included potatoes) as the likely cause of the outbreak (RR: 10.4, 95%CI 2.8 - 39.1; P = < 0.001). The causative agent of the outbreak was cultured from the stock of eggs used at the fair and from all three drag swabs and one barn dust sample collected from the responsible egg laying flock. Molecular subtyping by pulsed-field gel electrophoresis of genomic DNA after XbaI digestion showed that isolates from eggs, from the flock and from humans were indistinguishable. We hypothesise that cross contamination from eggs to boiled potatoes occurred in the kitchen area, where raw eggs were handled by village residents preparing a traditional Viennese egg dressing. Unrefrigerated storage of peeled potatoes may have favoured bacterial growth. Eggs from small rural flocks of laying hens kept in a traditional 'natural' way should not be assumed to be salmonella-free.

Salmonella Enteritidis phage type 21 outbreak in Austria, 2005.

We report an outbreak of gastroenteritis due to Salmonella Enteritidis PT 21 associated with attending an annual traditional fair in a small Austrian village on 4 May 2005. The outbreak lasted from 4 to 8 May. Descriptive and analytical epidemiological investigations were conducted in order to determine the extent of the outbreak and to identify outbreak risk factors. Of the 115 persons who visited the fair, 85 persons fulfilled the criteria of an outbreak case (attack rate=73.9%). Stool specimens from 52 patients, including two kitchen staff, were tested for salmonella, and 20 specimens were positive for Salmonella Enteritidis PT 21. The cohort study revealed mixed salad (which included potatoes) as the likely cause of the outbreak (RR: 10.4, 95%CI 2.8 - 39.1; P=<0.001). The causative agent of the outbreak was cultured from the stock of eggs used at the fair and from all three drag swabs and one barn dust sample collected from the responsible egg laying flock. Molecular subtyping by pulsed-field gel electrophoresis of genomic DNA after XbaI digestion showed that isolates from eggs, from the flock and from humans were indistinguishable. We hypothesise that cross contamination from eggs to boiled potatoes occurred in the kitchen area, where raw eggs were handled by village residents preparing a traditional Viennese egg dressing. Unrefrigerated storage of peeled potatoes may have favoured bacterial growth. Eggs from small rural flocks of laying hens kept in a traditional 'natural' way should not be assumed to be salmonella-free.

Adenosine potentiates coronary flow and inhibits oxygen consumption during isoprenaline infusion in isolated perfused guinea pig hearts.

It has been shown that adenosine, a potent coronary vasodilator, is released during cardiac sympathetic stimulation and that infusion of adenosine reduces the increase in myocardial contractile force elicited by catecholamines. The purpose of our study was: 1) to examine if adenosine also attenuates the rise in O2 consumption (MVO2) induced by infusing isoprenaline; and 2) to determine whether such a fall in MVO2 occurs primarily because of a relative decrease in tissue O2 extraction or a change in coronary flow. We isolated guinea pig hearts, perfused the vasculature at constant pressure and measured coronary flow, inflow and outflow pO2, and isovolumetric left ventricular pressure (PLV) and its derivative (dP/dt). Before, during and after infusing isoprenaline, we infused adenosine at increasing rates; but both drugs were infused at rates which did not maximally increase flow. We observed that adenosine reduced the increases in PLV and +dP/dt due to isoprenaline from 52 to 24% and from 81 to 55%. Moreover, linear regression analysis showed that the rise in MVO2 by isoprenaline was antagonised as a function of adenosine. This relative fall in MVO2 resulted primarily because of a decrease in O2 extraction since coronary flow was enhanced as a function of adenosine. Thus, although adenosine enhances the increase in flow due to isoprenaline overall it attenuates tissue O2 extraction and MVO2. Our study suggests that during sympathetic cardiac stimulation, endogenously released adenosine may not only produce vasodilatation and enhance the delivery of O2, but may also attenuate cardiac muscle work and the extraction of O2 with a net inhibition of MVO2.