Pojava i određivanje Thermoanaerobacterium i Thermoanaerobacter u konzerviranoj hrani u limenkama

In order to determine the reason for loss of vacuum in canned food, obligately anaerobic, spore forming thermophilic organisms were isolated from shelf-stable canned food containing vegetables, noodles and potatoes as main ingredients. Thermophilic bacteria from 44 canned food samples that had been stored under anaerobic conditions at 37 °C for at least 7 days were isolated. In addition, organic fertilizer used for the cultivation of some of the foods’ ingredients was examined and anaerobic, thermophilic bacteria could also be isolated from this source. Identification of bacterial strains was carried out by partial and complete 16S-rRNA-gene sequencing. Some of the obtained gene sequences showed a high level of similarity to existing 16S-rRNA gene sequences towards strains of the genera Thermoanaerobacter, Thermoanaerobium and Thermoanaerobacterium respectively, which have not yet been reported to be of importance as food spoilers. In the course of identification of these thermophilic bacteria we developed genera specific PCR-based approaches for detecting isolates belonging to the genera Thermoanaeroacterium and Thermoanaerobacter. Direct capturing of free DNA from contaminated samples using oligonucleotides coupled with paramagentic beads allowed the reduction of the detection time to six hours with a lower limit of 104 cells/mL.Da bi se odredio uzrok nestanka vakuuma u limenkama konzervirane hrane, obligatni anaerobi, termofilni organizmi koji stvaraju spore, izolirani su iz hrane u limenkama s glavnim sastojcima: povrće, rezanci i krumpir. Izolirane su termofilne bakterije iz 44 uzorka limenki uskladištenih pod anaerobnim uvjetima pri 37 °C barem 7 dana. Osim toga, ispitana su organska gnojiva upotrijebljena za uzgoj navedenog povrća pa su i iz tog izvora izolirane anaerobne termofilne bakterije. Identifikacija bakterijskih sojeva provedena je djelomičnim i potpunim sekvencioniranjem 16S-rRNA gena. Neke od dobivenih genskih sekvencija pokazale su visoki stupanj sličnosti s postojećim sekvencijama 16S-rRNA gena sojeva rodova Thermoanaerobacter, Thermoanaerobium i Thermoanaerobacterium. Do sada još nije bila ustanovljena važnost tih sojeva kao onečišćavača hrane. Tijekom identifikacije navedenih termofilnih bakterija autori su razvili genetički specifičan pristup utemeljen na PCR za određivanje izolata koji pripadaju rodovima Thermoanaerobacterium i Thermoanaerobacter. Izravno vezanje slobodne DNA iz onečišćenih uzoraka, koristeći oligonukleotide povezane s paramagnetskim zrncima omogućilo je smanjenje vremena detekcije na 6 sati s donjom granicom od 104 stanica/mL

SxsA, a novel surface protein mediating cell aggregation and adhesive biofilm formation of Staphylococcus xylosus

Biofilm formation of staphylococci has been an emerging field of research for many years. However, the underlying molecular mechanisms are still not fully understood and vary widely between species and strains. The aim of this study was to identify new effectors impacting biofilm formation of two Staphylococcus xylosus strains. We identified a novel surface protein conferring cell aggregation, adherence to abiotic surfaces, and biofilm formation. The S. xylosus surface protein A (SxsA) is a large protein occurring in variable sizes. It lacks sequence similarity to other staphylococcal surface proteins but shows similar structural domain organization and functional features. Upon deletion of sxsA, adherence of S. xylosus strain TMW 2.1523 to abiotic surfaces was completely abolished and significantly reduced in TMW 2.1023. Macro- and microscopic aggregation assays further showed that TMW 2.1523 sxsA mutants exhibit reduced cell aggregation compared with the wildtype. Comparative genomic analysis revealed that sxsA is part of the core genome of S. xylosus, Staphylococcus paraxylosus, and Staphylococcus nepalensis and additionally encoded in a small group of Staphylococcus cohnii and Staphylococcus saprophyticus strains. This study provides insights into protein-mediated biofilm formation of S. xylosus and identifies a new cell wall-associated protein influencing cell aggregation and biofilm formation.Peer Reviewe

Effect of High Pressure and Heat on Bacterial Toxins

Even though the inactivation of microorganisms by high pressure treatment is a subject of intense investigations, the effect of high pressure on bacterial toxins has not been studied so far. In this study, the influence of combined pressure/temperature treatment (0.1 to 800 MPa and 5 to 121 °C) on bacterial enterotoxins was determined. Therefore, heat-stable enterotoxin (STa) of cholera toxin (CT) from Vibrio cholerae, staphylococcal enterotoxins A-E, haemolysin BL (HBL) from Bacillus cereus, and Escherichia coli (STa) were subjected to different treatment schemes. Structural alterations were monitored in enzyme immunoassays (EIAs). Cytotoxicity of the pressure treated supernatant of toxigenic B. cereus DSM 4384 was investigated with Vero cells. High pressure of 200 to 800 MPa at 5 °C leads to a slight increase of the reactivity of the STa of E. coli. However, reactivity decreased at 800 MPa and 80 °C to (66±21) % after 30 min and to (44±0.3) % after 128 min. At ambient pressure no decrease in EIA reactivity could be observed after 128 min. Pressurization (0.1 to 800 MPa) of heat stable monomeric staphylococcal toxins at 5 and 20 °C showed no effect. A combined heat (80 °C) and pressure (0.1 to 800 MPa) treatment lead to a decrease in the immuno-reactivity to 20 % of its maximum. For cholera toxin a significant loss in latex agglutination was observable only at 80 °C and 800 MPa for holding times higher than 20 min. Interestingly, the immuno-reactivity of B. cereus HBL toxin increased with the increase of pressure (182 % at 800 MPa, 30 °C), and high pressure showed only minor effects on cytotoxicity to Vero cells. Our results indicate that pressurization can increase inactivation observed by heat treatment, and combined treatments may be effective at lower temperatures and/or shorter incubation time

Genomic analysis reveals Lactobacillus sanfranciscensis as stable element in traditional sourdoughs

Sourdough has played a significant role in human nutrition and culture for thousands of years and is still of eminent importance for human diet and the bakery industry. Lactobacillus sanfranciscensis is the predominant key bacterium in traditionally fermented sourdoughs

Grexit News and Stock Returns

During the first eight months of 2015, there was an ongoing debate about whether or not Greece should remain in the euro area. Using an event study approach, we quantify the effects of Grexit-related statements made by six important euro area politicians (Merkel, Schaeuble, Tsipras, Varoufakis, Juncker, and Schulz) on intraday stock returns in Germany, Greece, and the euro area during the period of January 1, 2015 - August 19, 2015. We show that positive statements indicating that a Grexit is less likely lead to higher returns, and negative statements to lower returns. The overall impact of negative statements is more pronounced. The cumulative absolute effects on stock returns are sizeable as the statements contribute to a variation of up to 58 percentage points in the ATHEX. These large effects are of particular relevance as our study only captures an eight month snapshot of the Greek government debt crisis

Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip

The ATLAS Collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing pixel detector and the vacuum pipe of the Large Hadron Collider. The extreme operating conditions at this location have necessitated the development of new radiation hard pixel sensor technologies and a new front-end readout chip, called the FE-I4. Planar pixel sensors and 3D pixel sensors have been investigated to equip this new pixel layer, and prototype modules using the FE-I4A have been fabricated and characterized using 120 GeV pions at the CERN SPS and 4 GeV positrons at DESY, before and after module irradiation. Beam test results are presented, including charge collection efficiency, tracking efficiency and charge sharing.Comment: 45 pages, 30 figures, submitted to JINS

Party Affiliation Rather than Former Occupation: The Background of Central Bank Governors and its Effect on Monetary Policy

In this paper, we analyze the relationship between certain characteristics of incumbent central bank governors and their interest-rate-setting behavior. We focus on (i) occupational backgrounds, (ii) party affiliation, and (iii) experience in office and estimate augmented Taylor rules for 20 OECD countries and the period 1974-2008. Our findings are as follows. First, the tenures of central bank governors who are affiliated with a political party are characterized by a relatively dovish monetary policy stance, irrespective of their partisan ideology. Second, party affiliation appears to be more important than occupational background, i.e., all bankers with(out) a party affiliation behave very similarly to each regardless of their specific occupational background. Third, party members react significantly less to inflation and more to output the longer they stay in office

The (Home) Bias of European Central Bankers: New Evidence Based on Speeches

Speeches are an important vehicle for central bankers to convey individual views on the preferred policy stance. In this paper, we employ an automated text linguistic approach to create an indicator that measures the tone of the 1,618 speeches delivered by members of the Governing Council (GC) during the period 1999M1..2014M4. We then relate this variable to euro-area and national macroe- conomic forecasts. Our key findings are as follows. First, inflation and growth expectations have a positive and significant impact on the hawkishness of a speech. Second, the voiced preferences of national central bankers largely coincide with the level of independence their banks had at the time of the Maastricht Treaty. Third, country-specific macroeconomic conditions matter for speeches delivered inside the central banker's home country but not for those made abroad. Fourth, differences in central banker preferences are the key source of variation in their speeches before the financial crisis, whereas divergent national economic conditions are the main factor in the second part of the sample

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570