Contamination of food during processing is recognized as a main transmission route of
To prevent microbial contamination, biocides are widely applied as disinfectants in food processing plants. ...However, there are concerns about the development of antimicrobial resistance in foodborne pathogens due to widespread biocide usage. In our study, 93
isolates from German food production facilities were (i) tested for biocide and antibiotic susceptibility using broth microdilution assays, (ii) analyzed for links between reduced biocide susceptibility and antibiotic resistance, and (iii) characterized by whole-genome sequencing, including the detection of genes coding for biocide tolerance, antibiotic resistance, and other virulence factors. Fifteen
isolates were tolerant to benzalkonium chloride (BAC), and genes conferring BAC tolerance were found in 13 of them. Antibiotic resistance was not associated with biocide tolerance. BAC-tolerant isolates were assigned to 6 multilocus sequence type (MLST) clonal complexes, and most of them harbored internalin A pseudogenes with premature stop codons or deletions (
= 9). Our study demonstrated a high genetic diversity among the investigated isolates including genotypes that are frequently involved in human infections. Although
adaptation studies to biocides have raised concerns about increasing cross-resistance to antibiotics, our results do not provide evidence for this phenomenon in field isolates.
Foodborne pathogens such as
can persist in food production environments for a long time, causing perennial outbreaks. Hence, bacterial pathogens are able to survive cleaning and disinfection procedures. Accordingly, they may be repeatedly exposed to sublethal concentrations of disinfectants, which might result in bacterial adaptation to these biocides. Furthermore, antibiotic coresistance and cross-resistance are known to evolve under biocide selection pressure
Hence, antimicrobial tolerance seems to play a crucial role in the resilience and persistence of foodborne pathogens in the food chain and might reduce therapeutic options in infectious diseases.
A cluster of seven human cases of listeriosis occurred in Austria and in Germany between April 2011 and July 2013. The Listeria monocytogenes serovar (SV) 1/2b isolates shared pulsed-field gel ...electrophoresis (PFGE) and fluorescent amplified fragment length polymorphism (fAFLP) patterns indistinguishable from those from five food producers. The seven human isolates, a control strain with a different PFGE/fAFLP profile and ten food isolates were subjected to whole genome sequencing (WGS) in a blinded fashion. A gene-by-gene comparison (multilocus sequence typing (MLST)+) was performed, and the resulting whole genome allelic profiles were compared using SeqSphere+ software version 1.0. On analysis of 2298 genes, the four human outbreak isolates from 2012 to 2013 had different alleles at ≤6 genes, i.e. differed by ≤6 genes from each other; the dendrogram placed these isolates in between five Austrian unaged soft cheese isolates from producer A (≤ 19-gene difference from the human cluster) and two Austrian ready-to-eat meat isolates from producer B (≤8-gene difference from the human cluster). Both food products appeared on grocery bills prospectively collected by these outbreak cases after hospital discharge. Epidemiological results on food consumption and MLST+ clearly separated the three cases in 2011 from the four 2012–2013 outbreak cases (≥48 different genes). We showed that WGS is capable of discriminating L. monocytogenes SV1/2b clones not distinguishable by PFGE and fAFLP. The listeriosis outbreak described clearly underlines the potential of sequence-based typing methods to offer enhanced resolution and comparability of typing systems for public health applications.
We report here the draft genome sequence of a
strain, core genome multilocus sequence typing (cgMLST) complex type 2521 (CT2521), isolated from ready-to-eat meat sausage related to a protracted and ...supraregional listeriosis outbreak (Sigma1) in Germany from 2014 to 2019.
The interaction of two selected isolates of Botrytis cinerea with bean suspension cells and bean leaf discs was compared in relation to levels of reactive oxygen intermediates (ROI). Isolate B 1.7 ...was arrested by a hypersensitive‐like necrosis of bean leaf tissue. According to its inability to spread and produce conidia on the bean leaf tissue it was classified as non‐aggressive. The second isolate induced a fast expanding light brownish necrosis of the leaf tissue. It was able to produce conidia on bean leaf discs and was classified as aggressive. The generation of superoxide was followed biochemically in inoculated bean cell suspensions. Both isolates induced a similar early superoxide peak approximately 18‐h post inoculation (hpi). While the non‐aggressive isolate induced a much stronger secondary superoxide burst at 33 hpi, the level of superoxide of suspension cells inoculated with the aggressive isolate was below the control level. This is the first report on the occurrence of a biphasic oxidative burst in plant cells induced by a fungal pathogen. Such a suppression of superoxide generation was also observed in bean leaf discs inoculated with the aggressive isolate. An oxidative burst‐suppressing agent was extracted from inoculated cell culture medium and determined as 2‐methyl‐succinate (2‐MS) by GC/MS analysis. The compound was detected approximately 20 hpi in the aggressive fungus–plant interaction. 2‐MS was able to suppress the hypersensitive response‐like necrosis on leaf discs as well as the second superoxide burst in suspension cells when inoculated with the non‐aggressive isolate. The early superoxide burst at 18 hpi was not affected. The results confirm the important role of enhanced production of ROI in plant resistance reactions, also for a necrotrophlike B. cinerea.
Aims: To verify the presence of Escherichia coli Nissle 1917 as a natural isolate in swine and to characterize in vitro probiotic properties as well as in vivo persistence in a feeding experiment.
...Methods and Results: During studies on the intestinal microflora of pigs, we isolated E. coli Nissle 1917 sporadically from a pig population over a period of 1 year. The identity of the isolates as E. coli Nissle 1917 was verified by serotyping, Nissle‐specific PCR, macrorestriction analysis (pulsed field gel electrophoresis) and the determination of in vitro probiotic properties in invasion and adhesion assays using a porcine intestinal epithelial cell line. Both the E. coli isolates and the E. coli Nissle 1917 strain showed strong reductions in adhesion of porcine enteropathogenic E. coli and invasion of Salmonella typhimurium with epithelial cells in vitro, with a probiotic effect. Screening of five epidemiologically unlinked swine farms and two wild boar groups showed one farm positive for E. coli Nissle 1917. A feeding experiment with four piglets showed viable E. coli Nissle 1917 in the intestine of three animals.
Conclusions: The results of this study suggest that the E. coli Nissle 1917 strain is already partially established in swine herds, but the colonization of individual animals is variable.
Significance and Impact of the Study: We report natural, long‐term colonization and transmission of the probiotic E. coli Nissle 1917 strain in a swine herd, characterized individual persistence and colonization properties in swine and established an in vitro porcine intestinal epithelial cell model of probiotic action. The results of this study would have implications in the use of this strain as a probiotic in swine and contribute to a better understanding of the individual nature of intestinal bacterial persistence and establishment.
In 2013, contaminated liquid soap was detected by routine microbiological monitoring of consumer products through state health authorities. Because of its high load of Klebsiella oxytoca, the liquid ...soap was notified via the European Union Rapid Alert System for Dangerous Non-Food Products (EU-RAPEX) and recalled. Here, we present two draft genome sequences and a summary of their general features.
Purpose
NT-proBNP is an important prognostic predictor in patients with heart failure. However, it is unknown whether a change of NT-proBNP plasma levels in the early phase of decompensation might be ...of additional prognostic value in patients with acute decompensation of heart failure.
Methods and results
NT-proBNP plasma levels of 116 patients with decompensated heart failure from ischemic/non-ischemic origin were measured at baseline and at 12, 24 and 48 h after hospital admission. Baseline levels and changes of plasma levels within the first 48 h were correlated with 30-day mortality. In all patients, NT-proBNP 12 h after admission was highest and superior with respect to the prediction of 30-day mortality compared to plasma levels on admission. In total, 38 patients died within the first 30 days. In these patients absolute NT-proBNP plasma levels were significantly higher and the increase within 12 h after admission was more pronounced compared to survivors (
p
<0.001). NT-proBNP at 12 h after admission also had the highest predictive value for the 30-day mortality rate in patients with acute myocardial infarction. The increase of NT-proBNP plasma levels within 12 h after admission had the highest predictive value in patients suffering from decompensated heart failure.
Conclusions
NT-proBNP is a powerful marker of 30-day mortality in patients with decompensated heart failure of ischemic and non-ischemic origin. Compared with single baseline measurements, serial measurements of NT-proBNP plasma levels within 12 h after hospital admission may be used to increase the predictive value of NT-proBNP with regard to the early identification of patients who are at high risk of mortality.
In vitro studies on the pathogenesis in swine have been hampered by the lack of relevant porcine cell lines. Since many bacterial infections are swine-specific, studies on pathogenic mechanisms ...require appropriate cell lines of porcine origin. We have characterized the permanent porcine intestinal epithelial cell line, IPEC-J2, using a variety of methods in order to assess the usefulness of this cell line as an in vitro infection model. Electron microscopic analyses and histochemical staining revealed the cells to be enterocyte-like with microvilli, tight junctions and glycocalyx-bound mucin. The functional integrity of monolayers was determined by transepithelial electrical resistance (TEER) measurements. Both commensal bacteria and important bacterial pathogens were chosen for study based on their principally different infection mechanisms: obligate extracellular Escherichia coli, facultative intracellular Salmonella and obligate intracellular Chlamydia. We determined the colonization and proliferation of the bacteria on and within the host cells and monitored the host cell response. We verified the expression of mRNAs encoding the cytokines IL-1alpha, -6, -7, -8, -18, TNF-alpha and GM-CSF, but not TGF-beta or MCP-1. IL-8 protein expression was enhanced by Salmonella invasion. We conclude that the IPEC-J2 cell line provides a relevant in vitro model system for porcine intestinal pathogen-host cell interactions.
In contrast with the setting of acute myocardial infarction, there are limited data regarding the impact of diabetes mellitus on clinical outcomes in contemporary cohorts of patients with chronic ...coronary syndromes. We aimed to investigate the prevalence and prognostic impact of diabetes according to geographical regions and ethnicity.
CLARIFY is an observational registry of patients with chronic coronary syndromes, enrolled across 45 countries in Europe, Asia, America, Middle East, Australia, and Africa in 2009-2010, and followed up yearly for 5 years. Chronic coronary syndromes were defined by ≥1 of the following criteria: prior myocardial infarction, evidence of coronary stenosis >50%, proven symptomatic myocardial ischaemia, or prior revascularization procedure.Among 32 694 patients, 9502 (29%) had diabetes, with a regional prevalence ranging from below 20% in Northern Europe to ∼60% in the Gulf countries. In a multivariable-adjusted Cox proportional hazards model, diabetes was associated with increased risks for the primary outcome (cardiovascular death, myocardial infarction, or stroke) with an adjusted hazard ratio of 1.28 (95% confidence interval 1.18, 1.39) and for all secondary outcomes (all-cause and cardiovascular mortality, myocardial infarction, stroke, heart failure, and coronary revascularization). Differences on outcomes according to geography and ethnicity were modest.
In patients with chronic coronary syndromes, diabetes is independently associated with mortality and cardiovascular events, including heart failure, which is not accounted by demographics, prior medical history, left ventricular ejection fraction, or use of secondary prevention medication. This is observed across multiple geographic regions and ethnicities, despite marked disparities in the prevalence of diabetes.
ISRCTN43070564.
Fusarium proliferatum is able to produce fumonisins and is considered a pathogen of many economically important plants (e.g. corn, rice, asparagus) 1. The occurrence of fumonisin FB1 inF. ...proliferatum infected asparagus spears from Germany was investigated using a liquid chromatography/electrospray ionization-mass spectrometry (LC-ESI-MS) method with isotopically labeled fumonisin FB1-d6 as internal standard. Asparagus samples were harvested in July 2000 and screened forFusarium species. AltogetherF. oxysporum, F. proliferatum and F. sambucinum were isolated from the spears. The samples infected with F.proliferatum were subsequently analyzed for fumonisins. FB1 was detected in 9 of the 10 samples in amounts ranging from 36.4 ng/g to 4513.7 ng/g (based on dry weight). Fumonisins FB2 and FB3 were found in six samples in lower concentrations. In asparagus spears of June 2002 we could findF. proliferatum in 6% of the samples, however no fumonisins were detectable.Furthermore the capability of producing FB1 by the fungus in garlic bulbs was investigated. Therefore garlic was cultured inF. proliferatum contaminated soil and the bulbs were screened for infection with F.proliferatum and for the occurrence of fumonisins by LC-MS. F.proliferatum was detectable in the garlic tissue and all samples contained FB1 (26.0 ng/g to 94.6 ng/g).This is the first report of the natural occurrence of FB1 in German asparagus spears and furthermore our findings suggest a potential for natural contamination of garlic bulbs with fumonisins. For detailed results and methods see Ref. 2.
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