Isolierung und Charakterisierung eines phagenähnlichen Bacteriocins und eines virulenten Phagen und deren therapeutische Einsatzmöglichkeiten gegen Yersinia enterocolitica-Infektionen

Durch die wachsende Anzahl von multiresistenten Bakterien, die auch durch den Mißbrauch von Antibiotika als Masthilfsmittel in der Tierzucht entstanden sind, erlangen alternative Methoden zur Bekämpfung bakterieller Infektionen ihre Bedeutung zurück. Diese Arbeit befaßt sich mit zwei Substanzen, um Infektionen mit Yersinia (Y.) enterocolitica einzudämmen. Es wurde in dieser Arbeit ein Bacteriocin aus Y. enterocolitica isoliert und charakterisiert. Das Reinigungschema folgte den Strategien der Phagenaufreinigung, angeschlossen wurde zur Überprüfung der Reinheit ein Gelfiltrationsschritt. Die Eigenschaften des gereinigten Enterocoliticins wurden in vitro und in vivo getestet. Im Zellkulturversuch zeigte sich das Enterocoliticin in der Abtötung von an eukaryonte Zellen adhärierten Bakterien als sehr wirksam, in eukaryonte Zellen eingewanderte Bakterien wurden hingegen nicht abgetötet. Aufgrund dieser vielversprechenden Ergebnisse wurde der Therapieansatz im Mausmodell angewendet. Das Mausmodell ist für Y. enterocolitica ein bereits erprobtes Modell. Die Tiere wurden oral infiziert, um den natürlichen Infektionsweg nachzustellen, das Enterocoliticin wurde ebenfalls oral verabreicht. Die Infektion wurde durch die Enterocoliticingabe nur unwesentlich beeinflußt, auch gelang der Nachweis des Enterocoliticins weder im Gastrointestinaltrakt noch in den Faeces. Die Therapie der infizierten Mäuse gelang auf diese Weise nicht. Weiterhin wurde ein Yersinia-Phage aus Schweinegülle isoliert, gereinigt und charakterisiert. Es handelt sich um einen T4-ähnlichen, virulenten Phagen mit einer Genomgröße von ca. 50 kbp und einem weiten Wirtsspektrum in Yersinia, das sogar speziesübergreifend ist. Da der Phage bei 37°C die Wirtszelle lysiert und durch seine hohe Wirksamkeit in vitro erschien der Phage von seinen Eigenschaften her zur Phagentherapie als geeignet. Es wurden analog zum Enterocoliticin-Tierexperiment Mäuse mit Y. enterocolitica oral infiziert, diesen Tieren wurde der Phage auf unterschiedlichen Wegen und zu unterschiedlichen Zeitpunkten appliziert. Die Tiere zeigten bei der parenteralen Gabe keinerlei Unverträglichkeitserscheinungen, bei der oralen Gabe wurde der Magensaft zuvor abgepuffert. Der Therapieerfolg im Vergleich zur Kontrollgruppe war wenig vielversprechend, es zeigten sich sehr ähnliche Infektionsverläufe in Kontroll-und Therapiegruppe. Diese beiden untersuchten Alternativwege zur Behandlung von Yersiniosen erwiesen sich bei den angewendeten Methoden bislang als nicht erfolgreich, dennoch muß auf diesem Gebiet weitergeforscht werden, wie erfolgreiche Therapieansätze aus anderen Tiermodellen zeigen. Es wirken nur wenige Phagen im Organismus als Therapeutikum, dennoch müssen diese Untersuchungen unternommen werden, um im Organismus wirksame, antibakterielle Substanzen zu finden und um einen Alternativweg zur Antibiotikumtherapie zu entwickeln.The increasing number of multi-resistant bacteria, which resulted also from the abuse of antibiotics as mast additives in animal breeding, alternative methods regain importance for the combat at bacterial infections back. In this work two substances were investigated to restrict infections with Yersinia (Y.) enterocolitica. In this study a bacteriocin from Y. enterocolitica, designated enterocoliticin, was isolated and characterized. The purification strategy followed protocols of phage isolation. The purified preparations were examined by final gel filtration step. The properties of the purifed enterocoliticin were tested in vitro and in vivo. In a cell culture assay enterocoliticin was able to kill bacteria adherent to eukaryontic cells very effectively, however, bacteria invaded into eukaryotic cells were not affected. Due to these results enterocoliticin was applied in a mouse-infection-model in a therapeutic attempt. The mouse infection model is a well established system for infections with Y. enterocolitica. The animals were orally infected with Yersinia, and the enterocoliticin was orally applied, too. The infection was only insignificantly influenced by enterocoliticin. In addition of enterocoliticin was not detected succeeded in the gastro-intestinal-tract or in the faeces. The therapy of the infected mice did not succeed in this way. Furthermore, a Yersinia phage from pig manure was isolated and characterized. It is a T4 phage like virulent phage, containing a genom of approx. 50 kbp and posessing a wide host-range in Yersinia. Because of lytic properties of the phage at 37°C and his high effectiveness in vitro the phage appeared to be for phage therapy experiments. Similarly to the enterocoliticin experiment mice were infected with Y. enterocolitica orally, these animals were treated with the phage on different application routes and different time points. The animals did not show any incompatibilities upon parenteral gift. Before oral administration of the phage the gastric juice was buffered. Therapy outcome in comparison to the control group was little promising, it revealed a very similar infection process in control group and therapy group. These two investigated alternative ways for the control of Yersinia infections did not prove successful with the applied methods, however, further research must be carried out as successful therapeutical experiments from other animal models showed. It has to be considered that not all phages are appropriate as therapeutical agent however, more studies must be conducted to find more appropriate substances, which may work as effective antibacterial substances to develop alternative ways to antibiotic therapy

Defining the scope of the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet): a bottom-up and One Health approach

Background Building the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet) was proposed to strengthen the European One Health antimicrobial resistance (AMR) surveillance approach. Objectives To define the combinations of animal species/production types/age categories/bacterial species/specimens/antimicrobials to be monitored in EARS-Vet. Methods The EARS-Vet scope was defined by consensus between 26 European experts. Decisions were guided by a survey of the combinations that are relevant and feasible to monitor in diseased animals in 13 European countries (bottom-up approach). Experts also considered the One Health approach and the need for EARS-Vet to complement existing European AMR monitoring systems coordinated by the ECDC and the European Food Safety Authority (EFSA). Results EARS-Vet plans to monitor AMR in six animal species [cattle, swine, chickens (broilers and laying hens), turkeys, cats and dogs], for 11 bacterial species (Escherichia coli, Klebsiella pneumoniae, Mannheimia haemolytica, Pasteurella multocida, Actinobacillus pleuropneumoniae, Staphylococcus aureus, Staphylococcus pseudintermedius, Staphylococcus hyicus, Streptococcus uberis, Streptococcus dysgalactiae and Streptococcus suis). Relevant antimicrobials for their treatment were selected (e.g. tetracyclines) and complemented with antimicrobials of more specific public health interest (e.g. carbapenems). Molecular data detecting the presence of ESBLs, AmpC cephalosporinases and methicillin resistance shall be collected too. Conclusions A preliminary EARS-Vet scope was defined, with the potential to fill important AMR monitoring gaps in the animal sector in Europe. It should be reviewed and expanded as the epidemiology of AMR changes, more countries participate and national monitoring capacities improve.Peer reviewe

Political travel across the ‘Iron Curtain’ and Communist youth identities in West Germany and Greece in the 1970s and 1980s

This article explores tours through the Iron Curtain arranged by West German and Greek pro-Soviet Communist youth groups, in an attempt to shed light on the transformation of European youth cultures beyond the ‘Americanisation’ story. It argues that the concept of the ‘black box’, employed by Rob Kroes to describe the influence of American cultural patterns on Western European youth, also applies to the reception of Eastern Bloc policies and norms by the Communists under study. Such selective reception was part of these groups’ efforts to devise a modernity alternative to the ‘capitalist’ one, an alternative modernity which tours across the Iron Curtain would help establish. Nevertheless, the organisers did not wish such travel to help eliminate American/Western influences on youth lifestyles entirely: the article analyses the excursions’ aims with regard to two core components of youth lifestyles in Western Europe since the 1960s, which have been affected by intra-Western flows, the spirit of ‘doing one’s own thing’ and transformations of sexual practices. The article also addresses the experience of the travellers in question, showing that they felt an unresolved tension: the tours neither served as a means of Sovietisation nor as an impulse to develop an openly anti-Soviet stance.PostprintPeer reviewe

Isolierung und Charakterisierung eines phagenähnlichen Bacteriocins und eines virulenten Phagen und deren therapeutische Einsatzmöglichkeiten gegen Yersinia enterocolitica-Infektionen

Durch die wachsende Anzahl von multiresistenten Bakterien, die auch durch den Mißbrauch von Antibiotika als Masthilfsmittel in der Tierzucht entstanden sind, erlangen alternative Methoden zur Bekämpfung bakterieller Infektionen ihre Bedeutung zurück. Diese Arbeit befaßt sich mit zwei Substanzen, um Infektionen mit Yersinia (Y.) enterocolitica einzudämmen. Es wurde in dieser Arbeit ein Bacteriocin aus Y. enterocolitica isoliert und charakterisiert. Das Reinigungschema folgte den Strategien der Phagenaufreinigung, angeschlossen wurde zur Überprüfung der Reinheit ein Gelfiltrationsschritt. Die Eigenschaften des gereinigten Enterocoliticins wurden in vitro und in vivo getestet. Im Zellkulturversuch zeigte sich das Enterocoliticin in der Abtötung von an eukaryonte Zellen adhärierten Bakterien als sehr wirksam, in eukaryonte Zellen eingewanderte Bakterien wurden hingegen nicht abgetötet. Aufgrund dieser vielversprechenden Ergebnisse wurde der Therapieansatz im Mausmodell angewendet. Das Mausmodell ist für Y. enterocolitica ein bereits erprobtes Modell. Die Tiere wurden oral infiziert, um den natürlichen Infektionsweg nachzustellen, das Enterocoliticin wurde ebenfalls oral verabreicht. Die Infektion wurde durch die Enterocoliticingabe nur unwesentlich beeinflußt, auch gelang der Nachweis des Enterocoliticins weder im Gastrointestinaltrakt noch in den Faeces. Die Therapie der infizierten Mäuse gelang auf diese Weise nicht. Weiterhin wurde ein Yersinia-Phage aus Schweinegülle isoliert, gereinigt und charakterisiert. Es handelt sich um einen T4-ähnlichen, virulenten Phagen mit einer Genomgröße von ca. 50 kbp und einem weiten Wirtsspektrum in Yersinia, das sogar speziesübergreifend ist. Da der Phage bei 37°C die Wirtszelle lysiert und durch seine hohe Wirksamkeit in vitro erschien der Phage von seinen Eigenschaften her zur Phagentherapie als geeignet. Es wurden analog zum Enterocoliticin-Tierexperiment Mäuse mit Y. enterocolitica oral infiziert, diesen Tieren wurde der Phage auf unterschiedlichen Wegen und zu unterschiedlichen Zeitpunkten appliziert. Die Tiere zeigten bei der parenteralen Gabe keinerlei Unverträglichkeitserscheinungen, bei der oralen Gabe wurde der Magensaft zuvor abgepuffert. Der Therapieerfolg im Vergleich zur Kontrollgruppe war wenig vielversprechend, es zeigten sich sehr ähnliche Infektionsverläufe in Kontroll-und Therapiegruppe. Diese beiden untersuchten Alternativwege zur Behandlung von Yersiniosen erwiesen sich bei den angewendeten Methoden bislang als nicht erfolgreich, dennoch muß auf diesem Gebiet weitergeforscht werden, wie erfolgreiche Therapieansätze aus anderen Tiermodellen zeigen. Es wirken nur wenige Phagen im Organismus als Therapeutikum, dennoch müssen diese Untersuchungen unternommen werden, um im Organismus wirksame, antibakterielle Substanzen zu finden und um einen Alternativweg zur Antibiotikumtherapie zu entwickeln.The increasing number of multi-resistant bacteria, which resulted also from the abuse of antibiotics as mast additives in animal breeding, alternative methods regain importance for the combat at bacterial infections back. In this work two substances were investigated to restrict infections with Yersinia (Y.) enterocolitica. In this study a bacteriocin from Y. enterocolitica, designated enterocoliticin, was isolated and characterized. The purification strategy followed protocols of phage isolation. The purified preparations were examined by final gel filtration step. The properties of the purifed enterocoliticin were tested in vitro and in vivo. In a cell culture assay enterocoliticin was able to kill bacteria adherent to eukaryontic cells very effectively, however, bacteria invaded into eukaryotic cells were not affected. Due to these results enterocoliticin was applied in a mouse-infection-model in a therapeutic attempt. The mouse infection model is a well established system for infections with Y. enterocolitica. The animals were orally infected with Yersinia, and the enterocoliticin was orally applied, too. The infection was only insignificantly influenced by enterocoliticin. In addition of enterocoliticin was not detected succeeded in the gastro-intestinal-tract or in the faeces. The therapy of the infected mice did not succeed in this way. Furthermore, a Yersinia phage from pig manure was isolated and characterized. It is a T4 phage like virulent phage, containing a genom of approx. 50 kbp and posessing a wide host-range in Yersinia. Because of lytic properties of the phage at 37°C and his high effectiveness in vitro the phage appeared to be for phage therapy experiments. Similarly to the enterocoliticin experiment mice were infected with Y. enterocolitica orally, these animals were treated with the phage on different application routes and different time points. The animals did not show any incompatibilities upon parenteral gift. Before oral administration of the phage the gastric juice was buffered. Therapy outcome in comparison to the control group was little promising, it revealed a very similar infection process in control group and therapy group. These two investigated alternative ways for the control of Yersinia infections did not prove successful with the applied methods, however, further research must be carried out as successful therapeutical experiments from other animal models showed. It has to be considered that not all phages are appropriate as therapeutical agent however, more studies must be conducted to find more appropriate substances, which may work as effective antibacterial substances to develop alternative ways to antibiotic therapy

Isolierung und Charakterisierung eines phagenähnlichen Bacteriocins und eines virulenten Phagen und deren therapeutische Einsatzmöglichkeiten gegen Yersinia enterocolitica-Infektionen

Durch die wachsende Anzahl von multiresistenten Bakterien, die auch durch den Mißbrauch von Antibiotika als Masthilfsmittel in der Tierzucht entstanden sind, erlangen alternative Methoden zur Bekämpfung bakterieller Infektionen ihre Bedeutung zurück. Diese Arbeit befaßt sich mit zwei Substanzen, um Infektionen mit Yersinia (Y.) enterocolitica einzudämmen. Es wurde in dieser Arbeit ein Bacteriocin aus Y. enterocolitica isoliert und charakterisiert. Das Reinigungschema folgte den Strategien der Phagenaufreinigung, angeschlossen wurde zur Überprüfung der Reinheit ein Gelfiltrationsschritt. Die Eigenschaften des gereinigten Enterocoliticins wurden in vitro und in vivo getestet. Im Zellkulturversuch zeigte sich das Enterocoliticin in der Abtötung von an eukaryonte Zellen adhärierten Bakterien als sehr wirksam, in eukaryonte Zellen eingewanderte Bakterien wurden hingegen nicht abgetötet. Aufgrund dieser vielversprechenden Ergebnisse wurde der Therapieansatz im Mausmodell angewendet. Das Mausmodell ist für Y. enterocolitica ein bereits erprobtes Modell. Die Tiere wurden oral infiziert, um den natürlichen Infektionsweg nachzustellen, das Enterocoliticin wurde ebenfalls oral verabreicht. Die Infektion wurde durch die Enterocoliticingabe nur unwesentlich beeinflußt, auch gelang der Nachweis des Enterocoliticins weder im Gastrointestinaltrakt noch in den Faeces. Die Therapie der infizierten Mäuse gelang auf diese Weise nicht. Weiterhin wurde ein Yersinia-Phage aus Schweinegülle isoliert, gereinigt und charakterisiert. Es handelt sich um einen T4-ähnlichen, virulenten Phagen mit einer Genomgröße von ca. 50 kbp und einem weiten Wirtsspektrum in Yersinia, das sogar speziesübergreifend ist. Da der Phage bei 37°C die Wirtszelle lysiert und durch seine hohe Wirksamkeit in vitro erschien der Phage von seinen Eigenschaften her zur Phagentherapie als geeignet. Es wurden analog zum Enterocoliticin-Tierexperiment Mäuse mit Y. enterocolitica oral infiziert, diesen Tieren wurde der Phage auf unterschiedlichen Wegen und zu unterschiedlichen Zeitpunkten appliziert. Die Tiere zeigten bei der parenteralen Gabe keinerlei Unverträglichkeitserscheinungen, bei der oralen Gabe wurde der Magensaft zuvor abgepuffert. Der Therapieerfolg im Vergleich zur Kontrollgruppe war wenig vielversprechend, es zeigten sich sehr ähnliche Infektionsverläufe in Kontroll-und Therapiegruppe. Diese beiden untersuchten Alternativwege zur Behandlung von Yersiniosen erwiesen sich bei den angewendeten Methoden bislang als nicht erfolgreich, dennoch muß auf diesem Gebiet weitergeforscht werden, wie erfolgreiche Therapieansätze aus anderen Tiermodellen zeigen. Es wirken nur wenige Phagen im Organismus als Therapeutikum, dennoch müssen diese Untersuchungen unternommen werden, um im Organismus wirksame, antibakterielle Substanzen zu finden und um einen Alternativweg zur Antibiotikumtherapie zu entwickeln.The increasing number of multi-resistant bacteria, which resulted also from the abuse of antibiotics as mast additives in animal breeding, alternative methods regain importance for the combat at bacterial infections back. In this work two substances were investigated to restrict infections with Yersinia (Y.) enterocolitica. In this study a bacteriocin from Y. enterocolitica, designated enterocoliticin, was isolated and characterized. The purification strategy followed protocols of phage isolation. The purified preparations were examined by final gel filtration step. The properties of the purifed enterocoliticin were tested in vitro and in vivo. In a cell culture assay enterocoliticin was able to kill bacteria adherent to eukaryontic cells very effectively, however, bacteria invaded into eukaryotic cells were not affected. Due to these results enterocoliticin was applied in a mouse-infection-model in a therapeutic attempt. The mouse infection model is a well established system for infections with Y. enterocolitica. The animals were orally infected with Yersinia, and the enterocoliticin was orally applied, too. The infection was only insignificantly influenced by enterocoliticin. In addition of enterocoliticin was not detected succeeded in the gastro-intestinal-tract or in the faeces. The therapy of the infected mice did not succeed in this way. Furthermore, a Yersinia phage from pig manure was isolated and characterized. It is a T4 phage like virulent phage, containing a genom of approx. 50 kbp and posessing a wide host-range in Yersinia. Because of lytic properties of the phage at 37°C and his high effectiveness in vitro the phage appeared to be for phage therapy experiments. Similarly to the enterocoliticin experiment mice were infected with Y. enterocolitica orally, these animals were treated with the phage on different application routes and different time points. The animals did not show any incompatibilities upon parenteral gift. Before oral administration of the phage the gastric juice was buffered. Therapy outcome in comparison to the control group was little promising, it revealed a very similar infection process in control group and therapy group. These two investigated alternative ways for the control of Yersinia infections did not prove successful with the applied methods, however, further research must be carried out as successful therapeutical experiments from other animal models showed. It has to be considered that not all phages are appropriate as therapeutical agent however, more studies must be conducted to find more appropriate substances, which may work as effective antibacterial substances to develop alternative ways to antibiotic therapy

Review and Analysis of National Monitoring Systems for Antimicrobial Resistance in Animal Bacterial Pathogens in Europe: A Basis for the Development of the European Antimicrobial Resistance Surveillance Network in Veterinary Medicine (EARS-Vet)

The monitoring of antimicrobial resistance (AMR) in bacterial pathogens of animals is not currently coordinated at European level. To fill this gap, experts of the European Union Joint Action on Antimicrobial Resistance and Healthcare Associated Infections (EU-JAMRAI) recommended building the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet). In this study, we (i) identified national monitoring systems for AMR in bacterial pathogens of animals (both companion and food-producing) among 27 countries affiliated to EU-JAMRAI, (ii) described their structures and operations, and (iii) analyzed their respective strengths, weaknesses, opportunities and threats (SWOT). Twelve countries reported having at least one national monitoring system in place, representing an opportunity to launch EARS-Vet, but highlighting important gaps in AMR data generation in Europe. In total, 15 national monitoring systems from 11 countries were described and analyzed. They displayed diverse structures and operations, but most of them shared common weaknesses (e.g., data management and representativeness) and common threats (e.g., economic vulnerability and data access), which could be addressed collectively under EARS-Vet. This work generated useful information to countries planning to build or improve their system, by learning from others' experience. It also enabled to advance on a pragmatic harmonization strategy: EARS-Vet shall follow the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards, collect quantitative data and interpret AMR data using epidemiological cut-off values

Review and Analysis of National Monitoring Systems for Antimicrobial Resistance in Animal Bacterial Pathogens in Europe: A Basis for the Development of the European Antimicrobial Resistance Surveillance Network in Veterinary Medicine (EARS-Vet)

The monitoring of antimicrobial resistance (AMR) in bacterial pathogens of animals is not currently coordinated at European level. To fill this gap, experts of the European Union Joint Action on Antimicrobial Resistance and Healthcare Associated Infections (EU-JAMRAI) recommended building the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet). In this study, we (i) identified national monitoring systems for AMR in bacterial pathogens of animals (both companion and food-producing) among 27 countries affiliated to EU-JAMRAI, (ii) described their structures and operations, and (iii) analyzed their respective strengths, weaknesses, opportunities and threats (SWOT). Twelve countries reported having at least one national monitoring system in place, representing an opportunity to launch EARS-Vet, but highlighting important gaps in AMR data generation in Europe. In total, 15 national monitoring systems from 11 countries were described and analyzed. They displayed diverse structures and operations, but most of them shared common weaknesses (e.g., data management and representativeness) and common threats (e.g., economic vulnerability and data access), which could be addressed collectively under EARS-Vet. This work generated useful information to countries planning to build or improve their system, by learning from others' experience. It also enabled to advance on a pragmatic harmonization strategy: EARS-Vet shall follow the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards, collect quantitative data and interpret AMR data using epidemiological cut-off values

Review and Analysis of National Monitoring Systems for Antimicrobial Resistance in Animal Bacterial Pathogens in Europe: A Basis for the Development of the European Antimicrobial Resistance Surveillance Network in Veterinary Medicine (EARS-Vet)

The monitoring of antimicrobial resistance (AMR) in bacterial pathogens of animals is not currently coordinated at European level. To fill this gap, experts of the European Union Joint Action on Antimicrobial Resistance and Healthcare Associated Infections (EU-JAMRAI) recommended building the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet). In this study, we (i) identified national monitoring systems for AMR in bacterial pathogens of animals (both companion and food-producing) among 27 countries affiliated to EU-JAMRAI, (ii) described their structures and operations, and (iii) analyzed their respective strengths, weaknesses, opportunities and threats (SWOT). Twelve countries reported having at least one national monitoring system in place, representing an opportunity to launch EARS-Vet, but highlighting important gaps in AMR data generation in Europe. In total, 15 national monitoring systems from 11 countries were described and analyzed. They displayed diverse structures and operations, but most of them shared common weaknesses (e.g., data management and representativeness) and common threats (e.g., economic vulnerability and data access), which could be addressed collectively under EARS-Vet. This work generated useful information to countries planning to build or improve their system, by learning from others' experience. It also enabled to advance on a pragmatic harmonization strategy: EARS-Vet shall follow the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards, collect quantitative data and interpret AMR data using epidemiological cut-off values