In this outbreak, caused by an unusual E. coli strain, cases of the hemolytic-uremic syndrome occurred predominantly in adults, with a preponderance of cases occurring in women. The hemolytic-uremic syndrome developed in more than 20% of the identified cases.

Our investigations identified sprouts as the most likely outbreak vehicle, underlining the need to take into account food items that may be overlooked during subjects' recall of consumption.

Reductive dehalogenation of vinyl chloride (VC) to ethene is the key step in complete anaerobic degradation of chlorinated ethenes. VC-reductive dehalogenase was partially purified from a highly enriched culture of the VC-respiring Dehalococcoides sp. strain VS. The enzyme reduced VC and all dichloroethene (DCE) isomers, but not tetrachloroethene (PCE) or trichloroethene (TCE), at high rates. By using reversed genetics, the corresponding gene (vcrA) was isolated and characterized. Based on the predicted amino acid sequence, VC reductase is a novel member of the family of corrinoid/iron-sulfur cluster containing reductive dehalogenases. The vcrA gene was found to be cotranscribed with vcrB, encoding a small hydrophobic protein presumably acting as membrane anchor for VC reductase, and vcrC, encoding a protein with similarity to transcriptional regulators of the NosR/NirI family. The vcrAB genes were subsequently found to be present and expressed in other cultures containing VC-respiring Dehalococcoides organisms and could be detected in water samples from a field site contaminated with chlorinated ethenes. Therefore, the vcrA gene identified here may be a useful molecular target for evaluating, predicting, and monitoring in situ reductive VC dehalogenation.Contamination of groundwater with the chlorinated solvents tetrachloroethene (PCE) and trichloroethene (TCE) threatens numerous drinking water supplies (6, 36). Conventional approaches for groundwater remediation have placed a multibillion-dollar burden on society and have consequently stimulated research in alternative clean-up strategies (22). One such strategy, the removal of these contaminants by naturally occurring, chloroethene-degrading microorganisms (bioremediation), appears to be a viable and cost-effective alternative. The microbial degradation of PCE and TCE has been observed most frequently under anaerobic conditions where the chlorinated ethenes can be reductively dehalogenated via the less chlorinated ethenes cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC) to harmless ethene. However, at many chloroethene-contaminated sites, reductive dehalogenation ceases or is significantly slowed down at the level of VC, resulting in its accumulation. Because VC is a known human carcinogen and is the most toxic compound of all chloroethenes, reduction of VC to ethene is the key step in the complete anaerobic degradation of these compounds.Reductive dehalogenation of VC has been linked to the genus Dehalococcoides (3, 7-9, 18). Dehalococcoides ethenogenes strain 195, the first microorganism isolated in pure culture that dehalogenates VC to ethene (18), catalyzes this reduction only in a slow, cometabolic reaction (14,15,19). Recently, enrichment cultures containing Dehalococcoides-like organisms which couple VC reduction with energy conservation have been reported (3, 7). The isolation of an axenic culture of one of those organisms, strain BAV1, was subsequently described (8).While reductive dehalogenation of higher chlorinated ethenes and of some chlorin...

Acetylene hydratase of the mesophilic fermenting bacterium Pelobacter acetylenicus catalyzes the hydration of acetylene to acetaldehyde. Growth of P. acetylenicus with acetylene and specific acetylene hydratase activity depended on tungstate or, to a lower degree, molybdate supply in the medium. The specific enzyme activity in cell extract was highest after growth in the presence of tungstate. Enzyme activity was stable even after prolonged storage of the cell extract or of the purified protein under air. However, enzyme activity could be measured only in the presence of a strong reducing agent such as titanium(III) citrate or dithionite. The enzyme was purified 240-fold by ammonium sulfate precipitation, anion-exchange chromatography, size exclusion chromatography, and a second anion-exchange chromatography step, with a yield of 36%. The protein was a monomer with an apparent molecular mass of 73 kDa, as determined by sodium dodecyl sulfatepolyacrylamide gel electrophoresis. The isoelectric point was at pH 4.2. Per mol of enzyme, 4.8 mol of iron, 3.9 mol of acid-labile sulfur, and 0.4 mol of tungsten, but no molybdenum, were detected. The K m for acetylene as assayed in a coupled photometric test with yeast alcohol dehydrogenase and NADH was 14 M, and the V max was 69 mol ⅐ min ؊1 ⅐ mg of protein ؊1. The optimum temperature for activity was 50؇C, and the apparent pH optimum was 6.0 to 6.5. The N-terminal amino acid sequence gave no indication of resemblance to any enzyme protein described so far.The strictly anaerobic fermenting bacterium Pelobacter acetylenicus converts the unsaturated hydrocarbon ethine (trivial name, acetylene) to acetate and ethanol via acetaldehyde as an intermediate (36). The first step of the fermentation pathway, the hydration of acetylene to acetaldehyde, is catalyzed by the enzyme acetylene hydratase. The reaction is highly exergonic: C 2 H 2 ϩ H 2 O 3 CH 3 CHO (⌬GЊЈ ϭ Ϫ111.9 kJ/mol) (36). Until recently, attempts to demonstrate this enzyme activity in cell extracts of P. acetylenicus have failed (27,36). Also the aerobic acetylene-degrading bacteria Mycobacterium lacticola, Nocardia rhodochrous, Rhodococcus strain A1, and Rhodococcus rhodochrous have been reported to convert acetylene to acetaldehyde (7,16,20,25); the reaction was proposed to be catalyzed by an acetylene hydratase activity. Yet acetylene hydratase activity could be demonstrated in cell extracts of Rhodococcus strain A1 only when the assay was performed under anoxic conditions (16). Therefore, acetylene appears to be the only hydrocarbon that is converted in the presence and absence of molecular oxygen by the same type of enzyme (36).Tungsten-containing enzymes have been reported so far to catalyze redox reactions of a low reduction potential (E 0 Ј Ͻ Ϫ400 mV), such as those involving formate dehydrogenase of Clostridium thermoaceticum (51) and Clostridium formicoaceticum (13), aldehyde ferredoxin oxidoreductase of Pyrococcus furiosus (30), formaldehyde ferredoxin oxidoreductase of Thermococcus litoralis (31), carboni...

Campylobacter infection is the most commonly notified bacterial enteritis in Germany. We performed a large combined case-control and source attribution study (Nov 2011-Feb 2014) to identify risk factors for sporadic intestinal Campylobacter infections and to determine the relative importance of various animal sources for human infections in Germany. We conducted multivariable logistic regression analysis to identify risk factors. Source attribution analysis was performed using the asymmetric island model based on MLST data of human and animal/food isolates. As animal sources we considered chicken, pig, pet dog or cat, cattle, and poultry other than chicken. Consumption of chicken meat and eating out were the most important risk factors for Campylobacter infections. Additional risk factors were preparation of poultry meat in the household; preparation of uncooked food and raw meat at the same time; contact with poultry animals; and the use of gastric acid inhibitors. The mean probability of human C. jejuni isolates to originate from chickens was highest (74%), whereas pigs were a negligible source for C. jejuni infections. Human C. coli isolates were likely to originate from chickens (56%) or from pigs (32%). Efforts need to be intensified along the food chain to reduce Campylobacter load, especially on chicken meat.

BackgroundYersiniosis is the third most common zoonotic bacterial disease in Germany and the European Union. Sequelae of Yersinia enterocolitica infections, such as reactive arthritis, have been reported. Consumption of pork and its products, especially eaten raw or undercooked, is an important risk factor of yersiniosis. Infection with Y. enterocolitica is notifiable through the national surveillance system for infectious diseases in Germany and several thousands of cases are being reported each year. We present recent data on the epidemiology of reported yersiniosis in Germany.MethodsSurveillance data on yersiniosis, accessed through the national level database (SurvNet), were analyzed with regard to time trends, demographical and geographical distribution, serotypes, and hospitalization, for the time period 2001-2008.ResultsA total of 47,627 cases of yersiniosis were reported. The mean annual incidence of yersiniosis was 7.2/100,000 population. A downward trend in the number of reportable cases has occurred since 2002. Almost all Y. enterocolitica infections were reported as single cases, i.e., with no apparent links to other cases. The number of reported infections showed substantially less seasonal variation than in other zoonotic enteric diseases. The incidence was highest in children under five years (58/100,000 population), in particular in one-year-old children (108/100,000 population). Almost 97% of infections were acquired domestically. High incidences occurred in the eastern German federal states Thuringia, Saxony, and Saxony-Anhalt. Differences in incidences across federal states were driven primarily by incidence differences in children under five years. Hospitalization was reported for 17% of cases, the proportion being highest among teenagers. Almost 90% of Y. enterocolitica strains were diagnosed as serotype O:3, which is the serotype most frequently isolated from pigs.ConclusionsYersiniosis is a zoonotic foodborne disease of relevance to public health in Germany because of its high incidence and risk for sequelae. The incidence of reported yersiniosis in Germany varies markedly from state to state, mainly due to incidence difference among young children. More research efforts should be directed towards the elucidation of risk factors of yersiniosis in this age group.

BackgroundCampylobacteriosis caused by Campylobacter spp. is the most common notifiable bacterial gastrointestinal disease in Germany and a major problem in many other European countries as well. In contrast to other infectious diseases, e.g., salmonellosis, the annual number of notified campylobacteriosis cases has increased in Germany and other European countries from 2001–2010.MethodsNational surveillance data from 2001 through 2010 were the basis of a detailed description of the epidemiological pattern of Campylobacter infections in Germany. Special focus was placed on geographical distribution and time trends of Campylobacter infections as well as the identification of risk groups.ResultsIn total, 588,308 cases of campylobacteriosis were recorded during the observed time period. The mean annual incidence increased from 67 cases/100,000 population in 2001 to 80/100,000 population in 2010. Almost 92% of the notified Campylobacter infections were acquired in Germany. A seasonal distribution was observed with a large peak in the summer months and a small peak in January. Incidence was highest in children ≤4 years and young adults 20–29 years of age. Especially young children living in rural regions in Germany seemed to be at high risk of Campylobacter infection.ConclusionsCampylobacter is the leading cause of bacterial gastroenteritis in Germany, and has been of rising public health concern. There is a need for enhanced prevention of Campylobacter infections and the data presented here may contribute to better target prevention measures with focus on identified risk groups such as children and young adults.

Molecular typing patterns of human isolates were indistinguishable from a mung bean sprouts isolate. Traceback of sprouts led to distributors and producer A in the Netherlands. Since sprouts are frequently contaminated with microorganisms, consumers need to be aware that consumption of raw or insufficiently cooked sprouts may pose a health risk.