Einträge, Vorkommen, Verbreitung und gesundheitliche Bedeutung antibiotikaresistenter Bakterien in Abwasser und Gewässern : Ein sozial-ökologischer Beitrag zur Geographischen Gesundheitsforschung

Antibiotika gelangen über natürliche Ausscheidung von Mensch und Tier sowie unsachgemäße Entsorgung in die Umwelt. Wichtige Eintragspfade stellen Abwasser, Klärschlamm und Gülle dar. Mikroorganismen können Resistenzen gegen Antibiotika entwickeln, was zu Problemen bei der medizinischen Behandlung führt. Ziel der Arbeit war es, am Beispiel eines Kläranlagen-Einzugsgebietes ohne angeschlossenem Krankenhaus, zugehörigem Vorfluter und Abwasser-unbeeinflussten Oberläufen, die Verbreitung erworbener bakterieller Antibiotika-Resistenzen durch kommunales Abwasser aus Sicht der geographischen Gesundheitsforschung zu analysieren. Die Untersuchungen im Einzugsgebiet der Swist mit den Krankheitserregern Pseudomonas aeruginosa und Campylobacter spp. sowie nicht-pathogene Gewässerbakterien der Familie Rhodospirillaceae haben gezeigt, dass sich ganzjährig sowohl Antibiotika-resistente Krankheitserreger als auch resistente Nicht-Pathogene in Abwasser und Gewässern nachweisen lassen. Bereits in Siedlungsabwasser-unbeeinflussten Oberläufen waren Antibiotika-resistente Isolate zu finden. Der Resistenzanteil variiert sowohl zwischen den Probenahmestellen und Spezies als auch mit den einzelnen Antibiotika. Ein allgemeingültiger Einfluss des Siedlungsabwassers auf die Resistenzsituation ließ sich für Resistenzen gegen Einzelsubstanzen nicht ableiten. Jedoch war mit zunehmendem Siedlungsabwassereinfluss bei den Pathogenen eindeutig ein Anstieg der Multi-Resistenzen gegen humanmedizinisch genutzte Antibiotika festzustellen. Bezüglich der Rhodospirillaceae schien bei Betrachtung der Abwasserbeeinflussung der Resistenzlage eher ein Verdünnungseffekt für die in der Umwelt vorhandenen Multiresistenzen durch das eingeleitete Abwasser vorzuliegen: Der Anteil hochgradig multi-resistenter Isolate in den Oberläufen war höher als im Vorfluter mit Abwassereinfluss. Eine Übertragbarkeit von Resistenzen durch horizontalen Gentransfer zwischen Pathogenen und Umweltbakterien wurde durch erfolgreiche Konjugation mit Übertragung einer Piperacillin-Resistenz von C. jejuni auf zwei Rhodospirillaceae in Filtermating-Experimenten belegt. Unter Fließgewässer-simulierenden Bedingungen waren die Konjugationsfrequenzen geringer. Gentransfer im freien Wasser scheint demnach seltener aufzutreten als in Biofilmen an der Grenzfläche zum Gewässerbett. Eine Erhebung des Risikoverhaltens im Kläranlagen-Einzugsgebiet ergab, dass die Risikowahrnehmung und das Wissen um Antibiotika-Resistenzen bei der Bevölkerung eher gering sind. Arzneimittel werden von rund einem Drittel der Haushalte im Ausguss entsorgt. Ein Eintrag von Antibiotika in die Umwelt wird damit aktiv unterstützt. Die Therapie-Untreue ist ähnlich dem bundesweiten Durchschnitt. Analysen der „Falschentsorger“ und „Therapieuntreuen“ ermöglichten eine Charakterisierung beider Problemgruppen. Der methodischen Dreiklang der Studienabschnitte, der im Sinne sozial-ökologischer Forschung auch die Triangulation der betrachteten Subjekte Umwelt, Mikroorganismen und Mensch spiegelt, mündete in einer Risikoabschätzung. Eine Gesundheitsgefährdung und Infektionen mit resistenten Pathogenen bei den vielfältigen Nutzungen des untersuchten Fließgewässers kann demnach nicht ausgeschlossen werden. Da ein Zusammenhang zwischen Anwendungsmengen und Fehlanwendungen von Antibiotika mit der Resistenzverbreitung Konsens unter Experten ist, wird der adäquaten Risikokommunikation eine hohe Bedeutung im Kampf gegen Antibiotika-Resistenzen zugewiesen. Zudem wird eine bundesweit einheitliche Strategie zur Arzneimittelentsorgung empfohlen.Input, occurence, spread and health impact of antibiotic resistant bacteria in sewage and surface waters – a socio-ecologic contribution to geographical health research Antibiotics enter the environment through human and animal excretion and inappropriate disposal. As a result, the most important emission pathways are wastewater, sludge and liquid manure. Microorganisms can develop resistance to antibiotics. This causes problems in medical therapy and in the antibiotic treatment of illness. The aim of the thesis was to produce an analysis of the spread of bacterial antibiotic resistances though municipal wastewater from the perspective of geographical health research. It takes as examples the catchment area of a municipal sewage treatment plant that does not receive wastewater from any hospital and the corresponding receiving stream and its tributaries without any influence from wastewater. The analysis of the pathogenic species Pseudomonas aeruginosa and Campylobacter spp, as well as non-pathogenic aquatic bacteria of the Rhodospirillaceae family within the catchment area of the river Swist have shown that antibiotic-resistant pathogens, as well as non-pathogenic bacteria, are present in wastewater and surface waters throughout the year. Antibiotic resistant isolates could even be found in tributaries without any influence from wastewater. The percentage of resistant isolates varied between sampling sites and species as well as among the different antibiotics. An universal impact by wastewater on the levels of resistance against single antibiotics could not be detected, but an increase in multi-resistances of pathogens against medically used antibiotics with increasing volumes of wastewater in the river was found. The effect on multi-resistance by wastewater was different for Rhodospirillaceae: The proportion of high-level multi-resistant isolates was higher in water samples from tributaries than from the receiving stream influenced by sewage. The resistance spread by horizontal genetic transfer between pathogens and environmental bacteria was proven in filtermating-experiments by successful conjugational gene transfer of piperacillin resistance by C. jejuni on two different Rhodospirillaceae. The conjugation frequency was reduced with simulation of running water conditions. For that, the importance of gene transfer in bulk water seems to be less than the transfer at the boundary layer between sediment and water. A study about risk behavior of the people living within the catchment area showed, that public risk perception and knowledge about antibiotic resistance is low. Approximately one third of all households dispose pharmaceuticals down the drain. Therefore antibiotic entry into the environment is actively enhanced. Non-compliance is similar to the nationwide average. Analysis of groups showing incorrect disposal behavior or therapy non-compliance were carried out. In terms of socio-ecological research, the methodological triad of the study parts reflects the triangulation of environment, micro-organism and human as the subjects investigated. The findings result in a qualitative microbial risk assessment. Health hazards and infections with resistant pathogens through the manifold use of watercourses cannot be excluded. Due to the consensus among experts that there is a relationship between the amounts of antibiotics used and their misuse, risk communication is an important component in the fight against antibiotic resistance. In addition, a nationwide strategy for pharmaceutical disposal is advised

Maßnahmen zur Offenhaltung von Grünlandstandorten: Effekte auf die P-Fraktionen im Boden vierzig Jahre nach Versuchseinrichtung

Artenreiches Grünland, das nicht mehr bewirtschaftet wird, kann kostengünstig durch Maßnahmen wie Mulchen offen gehalten werden. Inwieweit Mulchen im Vergleich zu ungestörter Sukzession die P-Verfügbarkeit (labile, moderat labile und stabile Fraktionen) im Boden beeinflusst, untersuchten wir auf sechs Standorten auf der Schwäbischen Alb und im Schwarzwald 40 Jahre nach Versuchseinrichtung. Die Maßnahme Mulchen zweimal jährlich reduzierte vor allem auf silikatischem Ausgangsgestein im Schwarzwald die P-Gehalte der labilen, moderat labilen und stabilen Fraktionen im Vergleich mit den Varianten Mulchen jedes zweite Jahr und Sukzession. Zwischen 2014 und der Versuchseinrichtung im Jahr 1975 verzögerte das Mulchen die pedogenetisch bedingte Reduktion der P-Verfügbarkeit labiler Fraktionen im Boden

The cuticle mutant eca2 modifies plant defense responses to biotrophic and necrotrophic pathogens and herbivory insects

We isolated previously several Arabidopsis thaliana mutants with constitutive expression of the early microbe-associated molecular pattern–induced gene ATL2, named eca (expresión constitutiva de ATL2). Here, we further explored the interaction of eca mutants with pest and pathogens. Of all eca mutants, eca2 was more resistant to a fungal pathogen (Botrytis cinerea) and a bacterial pathogen (Pseudomonas syringae) as well as to a generalist herbivorous insect (Spodoptera littoralis). Permeability of the cuticle is increased in eca2; chemical characterization shows that eca2 has a significant reduction of both cuticular wax and cutin. Additionally, we determined that eca2 did not display a similar compensatory transcriptional response, compared with a previously characterized cuticular mutant, and that resistance to B. cinerea is mediated by the priming of the early and late induced defense responses, including salicylic acid– and jasmonic acid–induced genes. These results suggest that ECA2-dependent responses are involved in the nonhost defense mechanism against biotrophic and necrotrophic pathogens and against a generalist insect by modulation and priming of innate immunity and late defense responses. Making eca2 an interesting model to characterize the molecular basis for plant defenses against different biotic interactions and to study the initial events that take place in the cuticle surface of the aerial organs

Genome-wide mapping of genetic determinants influencing DNA methylation and gene expression in human hippocampus

Emerging evidence emphasizes the strong impact of regulatory genomic elements in neurodevelopmental processes and the complex pathways of brain disorders. The present genome-wide quantitative trait loci analyses explore the cis-regulatory effects of single-nucleotide polymorphisms (SNPs) on DNA methylation (meQTL) and gene expression (eQTL) in 110 human hippocampal biopsies. We identify cis-meQTLs at 14,118 CpG methylation sites and cis-eQTLs for 302 3'-mRNA transcripts of 288 genes. Hippocampal cis-meQTL-CpGs are enriched in flanking regions of active promoters, CpG island shores, binding sites of the transcription factor CTCF and brain eQTLs. Cis-acting SNPs of hippocampal meQTLs and eQTLs significantly overlap schizophrenia-associated SNPs. Correlations of CpG methylation and RNA expression are found for 34 genes. Our comprehensive maps of cis-acting hippocampal meQTLs and eQTLs provide a link between disease-associated SNPs and the regulatory genome that will improve the functional interpretation of non-coding genetic variants in the molecular genetic dissection of brain disorders

Reconstruction of cellular variability from spatiotemporal patterns of Dictyostelium discoideum

Variability in cell properties can be an important driving mechanism behind spatiotemporal patterns in biological systems, as the degree of cell-to-cell differences determines the capacity of cells to locally synchronize and, consequently, form patterns on a larger spatial scale. In principle, certain features of spatial patterns emerging with time may be regulated by variability or, more specifically, by certain constellations of cell-to-cell differences. Similarly, measuring variability in a system (i.e. the spatial distribution of cell-cell differences) may help predict properties of later-stage patterns

Lasp-1 Regulates Podosome Function

Eukaryotic cells form a variety of adhesive structures to connect with their environment and to regulate cell motility. In contrast to classical focal adhesions, podosomes, highly dynamic structures of different cell types, are actively engaged in matrix remodelling and degradation. Podosomes are composed of an actin-rich core region surrounded by a ring-like structure containing signalling molecules, motor proteins as well as cytoskeleton-associated proteins

Neuroprotective Effect of Inhaled Nitric Oxide on Excitotoxic-Induced Brain Damage in Neonatal Rat

BACKGROUND: Inhaled nitric oxide (iNO) is one of the most promising therapies used in neonates. However, little information is known about its impact on the developing brain submitted to excitotoxic challenge. METHODOLOGY/PRINCIPAL FINDINGS: We investigated here the effect of iNO in a neonatal model of excitotoxic brain lesions. Rat pups and their dams were placed in a chamber containing 20 ppm NO during the first week of life. At postnatal day (P)5, rat pups were submitted to intracranial injection of glutamate agonists. At P10, rat pups exposed to iNO exhibited a significant decrease of lesion size in both the white matter and cortical plate compared to controls. Microglia activation and astrogliosis were found significantly decreased in NO-exposed animals. This neuroprotective effect was associated with a significant decrease of several glutamate receptor subunits expression at P5. iNO was associated with an early (P1) downregulation of pCREB/pAkt expression and induced an increase in pAkt protein concentration in response to excitotoxic challenge (P7). CONCLUSION: This study is the first describe and investigate the neuroprotective effect of iNO in neonatal excitotoxic-induced brain damage. This effect may be mediated through CREB pathway and subsequent modulation of glutamate receptor subunits expression

How Reliable Is Ki-67 Immunohistochemistry in Grade 2 Breast Carcinomas? A QA Study of the Swiss Working Group of Breast- and Gynecopathologists

Adjuvant chemotherapy decisions in breast cancer are increasingly based on the pathologist's assessment of tumor proliferation. The Swiss Working Group of Gyneco- and Breast Pathologists has surveyed inter- and intraobserver consistency of Ki-67-based proliferative fraction in breast carcinomas. Methods Five pathologists evaluated MIB-1-labeling index (LI) in ten breast carcinomas (G1, G2, G3) by counting and eyeballing. In the same way, 15 pathologists all over Switzerland then assessed MIB-1-LI on three G2 carcinomas, in self-selected or pre-defined areas of the tumors, comparing centrally immunostained slides with slides immunostained in the different laboratoires. To study intra-observer variability, the same tumors were re-examined 4 months later. Results The Kappa values for the first series of ten carcinomas of various degrees of differentiation showed good to very good agreement for MIB-1-LI (Kappa 0.56–0.72). However, we found very high inter-observer variabilities (Kappa 0.04–0.14) in the read-outs of the G2 carcinomas. It was not possible to explain the inconsistencies exclusively by any of the following factors: (i) pathologists' divergent definitions of what counts as a positive nucleus (ii) the mode of assessment (counting vs. eyeballing), (iii) immunostaining technique, and (iv) the selection of the tumor area in which to count. Despite intensive confrontation of all participating pathologists with the problem, inter-observer agreement did not improve when the same slides were re-examined 4 months later (Kappa 0.01–0.04) and intra-observer agreement was likewise poor (Kappa 0.00–0.35). Conclusion Assessment of mid-range Ki-67-LI suffers from high inter- and intra-observer variability. Oncologists should be aware of this caveat when using Ki-67-LI as a basis for treatment decisions in moderately differentiated breast carcinomas