Functional antagonism between CagA and DLC1 in gastric cancer.

Helicobacter (H.) pylori-induced gastritis is a risk factor for gastric cancer (GC). Deleted-in-liver-cancer-1 (DLC1/ARHGAP7) inhibits RHOA, a downstream mediator of virulence factor cytotoxin-A (CagA) signalling and driver of consensus-molecular-subtype-2 diffuse GC. DLC1 located to enterochromaffin-like and MIST1+ stem/chief cells in the stomach. DLC1+ cells were reduced in H. pylori gastritis and GC, and in mice infected with H. pylori. DLC1 positivity inversely correlated with tumour progression in patients. GC cells retained an N-terminal truncation variant DLC1v4 in contrast to full-length DLC1v1 in non-neoplastic tissues. H. pylori and CagA downregulated DLC1v1/4 promoter activities. DLC1v1/4 inhibited cell migration and counteracted CagA-driven stress phenotypes enforcing focal adhesion. CagA and DLC1 interacted via their N- and C-terminal domains, proposing that DLC1 protects against H. pylori by neutralising CagA. H. pylori-induced DLC1 loss is an early molecular event, which makes it a potential marker or target for subtype-aware cancer prevention or therapy.

[Evaluation of the new German measles protection act: An online survey]. / Beurteilung des neuen Masernschutzgesetzes in Deutschland: Ergebnisse einer deutschlandweiten Befragung.

INTRODUCTION: The current COVID-19 pandemic reveals the dangerousness of infectious diseases and the threats we face. Often however, effective vaccinations are carried out insufficiently. In March 2020, the German measles protection law was introduced to raise the level of population (herd) immunity to over 95 %. METHODS: An anonymous online survey was conducted among the population on the Measles Protection Act with self-declarations on measles vaccination/illness of participants and their children and evaluation of various sanctions. RESULTS: 1,594 adults participated. 19.3 % were affected by the law. Of these, only 77.5 % were immune to measles, 14.0 % wanted to be fully vaccinated when the law came into force, which would lead to 91.5 % immunity. Assuming that participants with unclear vaccination status or measles disease are immune, an immunity of>95 % can be achieved. 86.4 % of the children (aged 2 to 17 years) had developed immunity. Parents' willingness to have their children vaccinated because of the sanctions provided for in the Measles Protection Act was only 0.8 %. CONCLUSION: The level of immunity to measles in adults and children was under 95 % in our study. The sanctions of the Measles Protection Act are a greater incentive for adults to undergo measles vaccination than for parents. Strategies to increase immunity with the target group of parents should continue to be pursued.

[Current standard of antibiotic prophylaxis in esophageal varices bleeding in Germany]. / Aktueller Stand der Antibiotikaprophylaxe bei Ösophagusvarizenblutungen in Deutschland.

OBJECTIVES: Antibiotic prophylaxis in patients with liver cirrhosis and upper gastrointestinal bleeding significantly reduces the risk of concomitant bacterial infections and early mortality. The goal of our study was to determine the current status of antibiotic prophylaxis in departments of gastroenterology in Germany. METHODS: Representatives of gastroenterology departments were asked to provide data about indication for, and duration of, antibiotic prophylaxis and choice of antibiotic in esophageal varices bleeding in patients with liver cirrhosis. RESULTS: 326 of 779 contacted departments of gastroenterology participated in the study. Whereas antibiotic prophylaxis is used in 98.5 % (n = 321/326) of cases, it is used only in 7.1 % (n = 23/322) depending on the Child-Pugh-Score. In 19.4 % (n = 62/320), a prophylaxis is given even to patients with an elective banding of esophageal varices without bleeding. Third generation cephalosporins are used most frequently (66.5 %; n = 248/373) followed by fluoroquinolones (19.9 %; n = 74/373). The duration of prophylaxis was 3 days in most cases (32.3 %; n = 104/322), 1 day in 9.3 % (n = 30/322) and 7 days as recommended by German treatment guidelines in 24.8 % (n = 80/322). A standard of procedure (SOP) for antibiotic prophylaxis in esophageal varices bleeding is available in 45.1 % (n = 147/326). CONCLUSION: Our study shows that the applied standards for antibiotic prophylaxis in esophageal varices bleeding varies greatly in Germany. Future studies about the necessary duration of prophylaxis and its dependency from the Child-Pugh-Score are needed so that unnecessary antibiotic prescriptions can be avoided. The avoidance of antibiotic prophylaxis in elective banding of non-bleeding esophageal varices, which is not recommended by guidelines and was used by about 20 % of participants in our study, can already reduce antibiotic use.

Correction to: Human skin-derived ABCB5+ stem cell injection improves liver disease parameters in Mdr2KO mice.

We wish to submit a corrigendum to the above-mentioned article. Thank you very much for consideration and publication.

Human skin-derived ABCB5+ stem cell injection improves liver disease parameters in Mdr2KO mice.

Although liver transplantation is a potential effective cure for patients with end-stage liver diseases, this strategy has several drawbacks including high cost, long waiting list, and limited availability of liver organs. Therefore, stem cell-based therapy is presented as an alternative option, which showed promising results in animal models of acute and chronic liver injuries. ABCB5+ cells isolated from skin dermis represent an easy accessible and expandable source of homogenous stem cell populations. In addition, ABCB5+ cells showed already promising results in the treatment of corneal and skin injury. To date, the effect of these cells on liver injury is still unknown. In the current study, sixteen weeks old Mdr2KO mice were i.v. injected with 500,000 ABCB5+ cells using different experimental setups. The effects of cellular therapy on inflammation, fibrosis, apoptosis, and proliferation were analyzed in the collected liver tissues. Toxicity of ABCB5+ cells was additionally investigated in mice with partial liver resection. In vitro, the fibrosis- and inflammatory-modulating effects of supernatant from ABCB5+ cells were examined in the human hepatic stellate cell line (LX-2). Cell injections into fibrotic Mdr2KO mice as well as into mice upon partial liver resection have no signs of toxicity with regard to cell transformation, cellular damage, fibrosis or inflammation as compared to controls. We next investigated the effects of ABCB5+ cells on established biliary liver fibrosis in the Mdr2KO mice. ABCB5+ cells to some extent influenced the shape of the liver inflammatory response and significantly reduced the amount of collagen deposition, as estimated from quantification of sirius red staining. Furthermore, reduced apoptosis and enhanced death compensatory proliferation resulted from ABCB5+ cell transformation. The stem cells secreted several trophic factors that activated TGF-ß family signaling in cultured LX-2 hepatic stellate cells (HSCs), therewith shaping cell fate to an αSMAhigh, Vimentinlow phenotype. Taken together, ABCB5+ cells can represent a safe and feasible strategy to support liver regeneration and to reduce liver fibrosis in chronic liver diseases.

[Lack of information and provision of information at the workplace as potential reasons for inappropriate antibiotic therapy in Germany]. / Mangel an Informationen und deren Bereitstellung am Arbeitsplatz als mögliche Gründe für inkorrekte Antibiotikatherapien in Deutschland.

BACKGROUND: The increased use of antibiotics leads to a rise in drug-resistant bacteria. It is critical to reduce inadequate prescribing of antibiotics in order to prevent a post-antibiotic era. AIM OF THE STUDY: To explore if healthcare providers in Germany have access to current treatment guidelines, information about antibiotics and local resistance data at their workplace and how they access the information in their daily routine. METHODS: An anonymous online survey was performed with hospital-based physicians, office-based medical doctors and medical students in their last year of medical training in Germany. RESULTS: 1,428 participants completed the questionnaire with a return rate of 8.4 % (n=1,428/17,055). Lack of knowledge, preexisting prescription patterns and lack of data (local resistance data, drug information) were the most frequent reasons for the inadequate use of antibiotics given by the participants. 37 % of hospital doctors (n=404/1,091) cannot access local resistance data at their workplace, 26.2 % (n=286/1,091) lack standard operating procedures (SOP), 23.2 % (n=253/1,090) have no access to a database of national guidelines and 23.7 % (n=259/1,091) cannot access a drug information database. When asked about the sources of information they frequently used when prescribing antibiotics, 27.3 % (n=341/1,251) of the participants said that they used digital media at least once a day, 17.8 % (n=223/1,251) asked their colleagues, and 11.5 % (n=143/1,249) resorted to analogue media (e.g., print media). In order to improve antibiotic prescribing practices, participants were asked to rate the effectiveness of a potential clinical decision support system (CDSS) integrating local resistance data, drug information and local SOPs at their workplace. On a scale of 1 (= very useful) to 6 (= very useless), the anticipated effectiveness of such a tool was rated as "useful" or "very useful" with 1.67±1.01. CONCLUSION: In our study, lack of knowledge and lack of local data at the workplace were considered the most important reasons for the inadequate prescribing of antibiotics. Because the majority of healthcare providers use digital media as an information source, there is a clear desire for an easily accessible CDSS integrating all necessary data. Further studies will have to show whether a CDSS can improve and sustain the quality of antibiotic prescribing.

[Insufficient Preparation of Ambulatory Physicians for Ebola Virus Disease in Germany]. / Ambulant praktizierende Ärzte in Deutschland unzureichend auf Ebolafieber vorbereitet.

BACKGROUND: Globalization and climate change increase the likelihood of a global spread of high consequence infectious diseases. OBJECTIVES: We analyzed how outpatient physicians in Germany were prepared to recognize and handle potential Ebola virus-infected patients during the recent Ebola outbreak in West Africa. MATERIALS AND METHODS: Outpatient physicians participated in 2 anonymous surveys (n=166 and 129, respectively) and were asked, among others, about their knowledge of Ebola virus disease, their subjective perception of their own knowledge and the practical implementation in their daily routine. This was compared to a minimum standard defined by 14 members of the German "Permanent Working Group of Competence and Treatment Centres for high consequence infectious diseases" (STAKOB). RESULTS: The Ebola virus-specific knowledge of participants was significantly inferior compared to the defined minimum standard. Of 8 factual questions, an average of merely 5 was answered correctly. The physicians' subjective perception of knowledge presented as 'little'. Although 56% of participants indicated that they had received standard operation procedures, 64% had not implemented them into their daily routine. Merely 22% of surveyed medical doctors participated in Ebola virus-specific education programs. Yet participation led to a significantly better subjective knowledge perception. CONCLUSIONS: Contrary to the official assessment that Germany is well prepared for high consequence infectious diseases, this study suggests that there are deficits in this area. Despite the abundance of information about Ebola virus disease, preparation of outpatient physicians in Germany was inadequate. Yet nearly half of the participants indicated the potential risk of occurrence as 'likely' or 'very likely'. The presented data show the different consequences to be drawn regarding potential future crises and further research.

Empiric antibiotic therapy in urinary tract infection in patients with risk factors for antibiotic resistance in a German emergency department.

BACKGROUND: The aim of this study was to identify clinical risk factors for antimicrobial resistances and multidrug resistance (MDR) in urinary tract infections (UTI) in an emergency department in order to improve empirical therapy. METHODS: UTI cases from an emergency department (ED) during January 2013 and June 2015 were analyzed. Differences between patients with and without resistances towards Ciprofloxacin, Piperacillin with Tazobactam (Pip/taz), Gentamicin, Cefuroxime, Cefpodoxime and Ceftazidime were analyzed with Fisher's exact tests. Results were used to identify risk factors with logistic regression modelling. Susceptibility rates were analyzed in relation to risk factors. RESULTS: One hundred thirty-seven of four hundred sixty-nine patients who met the criteria of UTI had a positive urine culture. An MDR pathogen was found in 36.5% of these. Overall susceptibility was less than 85% for standard antimicrobial agents. Logistic regression identified residence in nursing homes, male gender, hospitalization within the last 30 days, renal transplantation, antibiotic treatment within the last 30 days, indwelling urinary catheter and recurrent UTI as risk factors for MDR or any of these resistances. For patients with no risk factors Ciprofloxacin had 90%, Pip/taz 88%, Gentamicin 95%, Cefuroxime 98%, Cefpodoxime 98% and Ceftazidime 100% susceptibility. For patients with 1 risk factor Ciprofloxacin had 80%, Pip/taz 80%, Gentamicin 88%, Cefuroxime 78%, Cefpodoxime 78% and Ceftazidime 83% susceptibility. For 2 or more risk factors Ciprofloxacin drops its susceptibility to 52%, Cefuroxime to 54% and Cefpodoxime to 61%. Pip/taz, Gentamicin and Ceftazidime remain at 75% and 77%, respectively. CONCLUSIONS: We identified several risk factors for resistances and MDR in UTI. Susceptibility towards antimicrobials depends on these risk factors. With no risk factor cephalosporins seem to be the best choice for empiric therapy, but in patients with risk factors the beta-lactam penicillin Piperacillin with Tazobactam is an equal or better choice compared to fluoroquinolones, cephalosporins or gentamicin. This study highlights the importance of monitoring local resistance rates and its risk factors in order to improve empiric therapy in a local environment.

Abdominopelvic actinomycosis in three different locations with invasion of the abdominal wall and ureteric obstruction: An uncommon presentation.

INTRODUCTION: Actinomycosis is a rare chronic infectious disease caused by Gram-positive anaerobic bacteria that normally colonize the bronchial system and gastrointestinal tract in humans. The most common diseases associated with actinomycosis are orocervicofacial, thoracic and abdominal infections involving Actinomyces israelii. Due to its rarity, its various clinical presentations and often-infiltrative characteristics in radiological imaging, it can easily be mistaken for other clinical conditions, including malignancy. PRESENTATION OF CASE: We present an uncommon case of extended abdominopelvic actinomycosis with infiltrative lesions in multiple locations, including an abscess in the abdominal wall and ureteric obstruction, which underwent successful surgical and subsequent long-term antibiotic therapy. DISCUSSION: To our knowledge, such a combination of different sites of manifestation has not yet been reported for actinomycosis in the presence of an IUD. Possible differential diagnoses included diverticulitis with covered perforation, pelvic inflammatory disease, tuberculosis and inflammatory bowel disease. The possibility of a malignant process required radical resection. As in most cases of actinomycosis, diagnosis could not be established with certainty until postoperative pathology investigation. CONCLUSION: A rare actinomyceal infection should be considered in patients with a non-specific pelvic mass and atypical abdominal presentations, especially if a previous history of IUD usage is known.

Impact of actin on adhesion and translocation of Enterococcus faecalis.

This study focuses on the impact of actin on adhesion and translocation of Enterococcus (E.) faecalis OG1RF, E. faecalis Symbioflor(®), and E. faecalis V583. Insight into the role of actin aggregation in the mediation of bacterial adhesion and translocation was provided by a two-chamber translocation assay, which employed Ptk6 cells. Determination of translocation rates, cytochalasin D treatment, and laser scanning confocal microscopic observation revealed actin as a predominant brace for enterococci to pass through the epithelial cell layer. As the three enterococci had moderate adhesion ability to actin, actin-binding proteins were isolated and characterized by LC-MS/MS. The isolated proteins were identified as pyruvate formate lyase, enolase, glyceraldehyde-3-phosphate dehydrogenase, and GroEL. All these proteins belong to two major groups of moonlighting proteins, i.e., proteins, which display additional functions other than their described major biochemical catalysis. Both groups of moonlight proteins were determined to be associated with epithelial cell binding.

Can near-peer medical students effectively teach a new curriculum in physical examination?

BACKGROUND: Students in German medical schools frequently complain that the subject 'clinical examination' is not taught in a satisfying manner due to time constraints and lack of personnel resources. While the effectiveness and efficiency of practice-oriented teaching in small groups using near-peer teaching has been shown, it is rarely used in German medical schools. We investigated whether adding a new near-peer teaching course developed with student input plus patient examination under supervision in small groups improves basic clinical examination skills in third year medical students compared to a traditional clinical examination course alone. METHODS: Third year medical students registered for the mandatory curricular clinical examination course at the medical faculty of the Technische Universität München were invited to participate in a randomised trial with blinded outcome assessment. Students were randomised to the control group participating in the established curricular physical examination course or to the intervention group, which received additional near-peer teaching for the same content. The learning success was verified by a voluntary objective structured clinical examination (OSCE). RESULTS: A total of 84 students were randomised and 53 (63%) participated in the final OSCE. Students in the control group scored a median of 57% (25th percentile 47%, 75th percentile 61%) of the maximum possible total points of the OSCE compared to 77% (73%, 80%; p < 0.001) for students in the intervention group. Only two students in the intervention group received a lower score than the best student in the control group. CONCLUSION: Adding a near-peer teaching course to the routine course significantly improved the clinical examination skills of medical students in an efficient manner in the context of a resource-constrained setting.

Significant improvement of a clinical training course in physical examination after basic structural changes in the teaching content and methods.

BACKGROUND: Regular student evaluations at the Technical University Munich indicate the necessity for improvement of the clinical examination course. The aim of this study was to examine if targeted measures to restructure and improve a clinical examination course session lead to a higher level of student satisfaction as well as better self-assessment of the acquired techniques of clinical examination. METHODS: At three medical departments of the Technical University Munich during the 2010 summer semester, the quantitative results of 49 student evaluations (ratings 1-6, German scholastic grading system) of the clinical examination course were compared for a course before and a course after structured measures for improvement. These measures included structured teaching instructions, handouts and additional material from the Internet. RESULTS: 47 evaluations were completed before and 34 evaluations after the measures for improvement. The measures named above led to a significant improvement of the evaluative ratings in the following areas: short introduction to the topic of each clinical examination course (from 2.4±1.2 to1.7±1.0; p=0.0020) and to basic measures of hygiene (from 3.8±1.9 to 2.5±1.8; p=0.004), structured demonstration of each clinical examination step (from 2.9±1.5 to 1.8±1.0; p=0.001), sufficient practice of each clinical examination step (from 3.1±1.8 to 2.2±1.4; p=0.030) structured feedback on each clinical examination step (from 3.0±1.4 to 2.3±1.0; p=0.0070), use of handouts (from 5.2±1.4 to 1.8±1.4; p<0.001), advice on additional learning material (from 5.0±1.4 to 3.4±2.0; p<0.001), general learning experience (from 2.4±0.9 to 1.9±0.8; p=0.017), and self-assessment of the acquired techniques of clinical examination (from 3.5±1.3 to 2.5±1.1; p<0.01). CONCLUSION: Structured changes led to significant improvement in the evaluative ratings of a clinical examination course session concerning preparation of the tutors, structure of the course, and confidence in performing physical examinations.

Caveolin-1 protects B6129 mice against Helicobacter pylori gastritis.

Caveolin-1 (Cav1) is a scaffold protein and pathogen receptor in the mucosa of the gastrointestinal tract. Chronic infection of gastric epithelial cells by Helicobacter pylori (H. pylori) is a major risk factor for human gastric cancer (GC) where Cav1 is frequently down-regulated. However, the function of Cav1 in H. pylori infection and pathogenesis of GC remained unknown. We show here that Cav1-deficient mice, infected for 11 months with the CagA-delivery deficient H. pylori strain SS1, developed more severe gastritis and tissue damage, including loss of parietal cells and foveolar hyperplasia, and displayed lower colonisation of the gastric mucosa than wild-type B6129 littermates. Cav1-null mice showed enhanced infiltration of macrophages and B-cells and secretion of chemokines (RANTES) but had reduced levels of CD25+ regulatory T-cells. Cav1-deficient human GC cells (AGS), infected with the CagA-delivery proficient H. pylori strain G27, were more sensitive to CagA-related cytoskeletal stress morphologies ("humming bird") compared to AGS cells stably transfected with Cav1 (AGS/Cav1). Infection of AGS/Cav1 cells triggered the recruitment of p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1) to Cav1 and counteracted CagA-induced cytoskeletal rearrangements. In human GC cell lines (MKN45, N87) and mouse stomach tissue, H. pylori down-regulated endogenous expression of Cav1 independently of CagA. Mechanistically, H. pylori activated sterol-responsive element-binding protein-1 (SREBP1) to repress transcription of the human Cav1 gene from sterol-responsive elements (SREs) in the proximal Cav1 promoter. These data suggested a protective role of Cav1 against H. pylori-induced inflammation and tissue damage. We propose that H. pylori exploits down-regulation of Cav1 to subvert the host's immune response and to promote signalling of its virulence factors in host cells.

Concerted action of sphingomyelinase and non-hemolytic enterotoxin in pathogenic Bacillus cereus.

Bacillus cereus causes food poisoning and serious non-gastrointestinal-tract infections. Non-hemolytic enterotoxin (Nhe), which is present in most B. cereus strains, is considered to be one of the main virulence factors. However, a B. cereus ΔnheBC mutant strain lacking Nhe is still cytotoxic to intestinal epithelial cells. In a screen for additional cytotoxic factors using an in vitro model for polarized colon epithelial cells we identified B. cereus sphingomyelinase (SMase) as a strong inducer of epithelial cell death. Using single and double deletion mutants of sph, the gene encoding for SMase, and nheBC in B. cereus we demonstrated that SMase is an important factor for B. cereus cytotoxicity in vitro and pathogenicity in vivo. SMase substantially complemented Nhe induced cytotoxicity in vitro. In addition, SMase but not Nhe contributed significantly to the mortality rate of larvae in vivo in the insect model Galleria mellonella. Our study suggests that the role of B. cereus SMase as a secreted virulence factor for in vivo pathogenesis has been underestimated and that Nhe and SMase complement each other significantly to cause full B. cereus virulence hence disease formation.

ChePep controls Helicobacter pylori Infection of the gastric glands and chemotaxis in the Epsilonproteobacteria.

UNLABELLED: Microbes use directed motility to colonize harsh and dynamic environments. We discovered that Helicobacter pylori strains establish bacterial colonies deep in the gastric glands and identified a novel protein, ChePep, necessary to colonize this niche. ChePep is preferentially localized to the flagellar pole. Although mutants lacking ChePep have normal flagellar ultrastructure and are motile, they have a slight defect in swarming ability. By tracking the movement of single bacteria, we found that ΔChePep mutants cannot control the rotation of their flagella and swim with abnormally frequent reversals. These mutants even sustain bursts of movement backwards with the flagella pulling the bacteria. Genetic analysis of the chemotaxis signaling pathway shows that ChePep regulates flagellar rotation through the chemotaxis system. By examining H. pylori within a microscopic pH gradient, we determined that ChePep is critical for regulating chemotactic behavior. The chePep gene is unique to the Epsilonproteobacteria but is found throughout this diverse group. We expressed ChePep from other members of the Epsilonproteobacteria, including the zoonotic pathogen Campylobacter jejuni and the deep sea hydrothermal vent inhabitant Caminibacter mediatlanticus, in H. pylori and found that ChePep is functionally conserved across this class. ChePep represents a new family of chemotaxis regulators unique to the Epsilonproteobacteria and illustrates the different strategies that microbes have evolved to control motility. IMPORTANCE: Helicobacter pylori strains infect half of all humans worldwide and contribute to the development of peptic ulcers and gastric cancer. H. pylori cannot survive within the acidic lumen of the stomach and uses flagella to actively swim to and colonize the protective mucus and epithelium. The chemotaxis system allows H. pylori to navigate by regulating the rotation of its flagella. We identified a new protein, ChePep, which controls chemotaxis in H. pylori. ChePep mutants fail to colonize the gastric glands of mice and are completely outcompeted by normal H. pylori. Genes encoding ChePep are found only in the class Epsilonproteobacteria, which includes the human pathogen Campylobacter jejuni and environmental microbes like the deep-sea hydrothermal vent colonizer Caminibacter mediatlanticus, and we show that ChePep function is conserved in this class. Our study identifies a new colonization factor in H. pylori and also provides insight into the control and evolution of bacterial chemotaxis.