Resistance to 3rd-generation cephalosporins in Escherichia coli is mostly mediated by extended-spectrum beta-lactamases (ESBLs) or AmpC beta-lactamases. Besides overexpression of the species-specific ...chromosomal ampC gene, acquisition of plasmid-encoded ampC genes, e.g. bla
, has been described worldwide in E. coli from humans and animals. To investigate a possible transmission of bla
along the food production chain, we conducted a next-generation sequencing (NGS)-based analysis of 164 CMY-2-producing E. coli isolates from humans, livestock animals and foodstuff from Germany.
The data of the 164 sequenced isolates revealed 59 different sequence types (STs); the most prevalent ones were ST38 (n = 19), ST131 (n = 16) and ST117 (n = 13). Two STs were present in all reservoirs: ST131 (human n = 8; food n = 2; animal n = 6) and ST38 (human n = 3; animal n = 9; food n = 7). All but one CMY-2-producing ST131 isolates belonged to the clade B (fimH22) that differed substantially from the worldwide dominant CTX-M-15-producing clonal lineage ST131-O25b clade C (fimH30). Plasmid replicon types IncI1 (n = 61) and IncK (n = 72) were identified for the majority of bla
-carrying plasmids. Plasmid sequence comparisons showed a remarkable sequence identity, especially for IncK plasmids. Associations of replicon types and distinct STs were shown for IncK and ST57, ST429 and ST38 as well as for IncI1 and ST58. Additional β-lactamase genes (bla
, bla
, bla
, bla
) were detected in 50% of the isolates, and twelve E. coli from chicken and retail chicken meat carried the colistin resistance gene mcr-1.
We found isolates of distinct E. coli clonal lineages (ST131 and ST38) in all three reservoirs. However, a direct clonal relationship of isolates from food animals and humans was only noticeable for a few cases. The CMY-2-producing E. coli-ST131 represents a clonal lineage different from the CTX-M-15-producing ST131-O25b cluster. Apart from the ST-driven spread, plasmid-mediated spread, especially via IncI1 and IncK plasmids, likely plays an important role for emergence and transmission of bla
between animals and humans.
Pithanologie Pietsch, Michael; Mülke, Markus
2020, 2020-01-20, Letnik:
23
eBook
Aristoteles definiert die Rhetorik als das Vermogen, bei jedem Gegenstand das moglicherweise Glaubhafte zu sehen . Die Erkenntnis des jeweiligen p??a???, des Glaubhaften , des Uberzeugenden , ist ...dabei allein dem Menschen moglich als dem einzigen Lebewesen, das sich uberhaupt durch Redefahigkeit auszeichnet. Gleichwohl ist der Begriff des Glaubhaften, das p??a??? selbst, bisher weitgehend unberucksichtigt geblieben. Ausgehend von diesem Befund machen die in diesem Band versammelten Beitrage die Auffassung der Rhetorik als einer Pithanologie fruchtbar fur die heutige Rhetorikforschung, insbesondere fur die Anthropologie des homo rhetoricus und die Fundamentalrhetorik. Die Lehre vom Uberzeugenden : Dieses zugleich enge und weite Thema ermoglicht eine Bandbreite von Studien, die von der systematisch-theoretischen Analyse uber exemplarische Einzelfalle aus der Geschichte der Rhetorik bis hin zu Untersuchungen aktueller rhetorischer Praxis reichen. Dabei wird das Pithanon durchaus im strengen Sinn als Neutrum aufgefasst - ein Fokus liegt also genau darauf: was und wie eigentlich das Uberzeugende selbst grundsatzlich oder in einem bestimmten Zusammenhang ist oder sein soll.
Highlights • Fluoroquinolone-resistant CTX-M-15-producing Escherichia coli from human and animal populations were studied. • ST410 is the most frequent sequence type, harbouring five different ...clades. • Two clades (B and C) harbour chromosomally inserted CTX-M-15. • ST410 clones circulate in animals, humans and the environment in Germany.
One of the most demanding challenges in infection control is the worldwide dissemination of multidrug-resistant (MDR) bacteria in clinical settings. Especially the increasing prevalence of ...carbapenemase producing Gram-negative pathogens poses an urgent threat to public health, as these enzymes confer resistance to almost all β-lactam antibiotics including carbapenems. In this study, we report a prolonged nosocomial outbreak of various NDM-1-producing
Enterobacterales
species due to clonal spread and cross-species exchange of plasmids and possibly transposons. Between July 2015 and September 2017, a total of 51 carbapenemase-positive isolates were collected from 38 patients and three environmental sources in a single German hospital. Combining molecular typing methods and whole genome sequencing, the metallo-β-lactamase gene
bla
NDM–1
was found to be present in 35 isolates of which seven additionally carried the carbapenemase gene
bla
KPC–2
. Core genome MLST (cgMLST) revealed different clusters of closely related isolates of
Escherichia coli
,
Klebsiella pneumoniae
,
Citrobacter freundii
,
Morganella morganii
or
Enterobacter cloacae
indicating clonal spread. The detailed reconstruction of the plasmid sequences revealed that in all outbreak-associated isolates
bla
NDM–1
was located on similar composite transposons, which were also very similar to Tn
125
previously described for
Acinetobacter baumannii
. In contrast to Tn
125
, these structures were flanked by IS
26
elements, which could facilitate horizontal gene transfer. Moreover, the identical plasmid was found to be shared by
E. coli
and
M. morganii
isolates. Our results highlight the importance of detailed genome-based analyses for complex nosocomial outbreaks, allowing the identification of causal genetic determinants and providing insights into potential mechanisms involved in the dissemination of antibiotic resistances between different bacterial species.
(1) Background: Resistance plasmids are under selective conditions beneficial for the bacterial host, but in the absence of selective pressure, this carriage may cause fitness costs. Compensation of ...this fitness burden is important to obtain competitive ability under antibiotic-free conditions. In this study, we investigated fitness effects after a conjugative transfer of plasmids containing various beta-lactamase genes transferred into Escherichia coli. (2) Methods: Fourteen beta-lactamase-encoding plasmids were transferred from clinical donor strains to E. coli J53. Growth rates were compared for all transconjugants and the recipient. Selected transconjugants were challenged in long-term growth experiments. Growth rates were assessed at different time points during growth for 500 generations. Whole-genome sequencing (WGS) of initial and evolved transconjugants was determined. Results: Most plasmid acquisitions resulted in growth differences, ranging from −4.5% to 7.2%. Transfer of a single blaCMY-16-carrying plasmid resulted in a growth burden and a growth benefit in independent mating. Long-term growth led to a compensation of fitness burdens and benefits. Analyzing WGS revealed genomic changes caused by Single Nucleotide Polymorphisms (SNPs) and insertion sequences over time. Conclusions: Fitness effects associated with plasmid acquisitions were variable. Potential compensatory mutations identified in transconjugants’ genomes after 500 generations give interesting insights into aspects of plasmid–host adaptations.
Despite extensive monitoring programs and preventative measures,
spp. continue to cause tens of thousands human infections per year, as well as many regional and international food-borne outbreaks, ...that are of great importance for public health and cause significant socio-economic costs. In Germany, salmonellosis is the second most common cause of bacterial diarrhea in humans and is associated with high hospitalization rates. Whole-genome sequencing (WGS) combined with data analysis is a high throughput technology with an unprecedented discriminatory power, which is particularly well suited for targeted pathogen monitoring, rapid cluster detection and assignment of possible infection sources. However, an effective implementation of WGS methods for large-scale microbial pathogen detection and surveillance has been hampered by the lack of standardized methods, uniform quality criteria and strategies for data sharing, all of which are essential for a successful interpretation of sequencing data from different sources. To overcome these challenges, the national GenoSalmSurv project aims to establish a working model for an integrated genome-based surveillance system of
spp. in Germany, based on a decentralized data analysis. Backbone of the model is the harmonization of laboratory procedures and sequencing protocols, the implementation of open-source bioinformatics tools for data analysis at each institution and the establishment of routine practices for cross-sectoral data sharing for a uniform result interpretation. With this model, we present a working solution for cross-sector interpretation of sequencing data from different sources (such as human, veterinarian, food, feed and environmental) and outline how a decentralized data analysis can contribute to a uniform cluster detection and facilitate outbreak investigations.
Hebräisch Michael Pietsch, Martin Rösel / Michael Pietsch, Martin Rösel
2016, 2016-01-15
eBook
Die Grammatik ist als begleitendes Lehrbuch für den Hebräischunterricht konzipiert. Es gewährt den Lehrenden einen möglichst großen Freiraum für die Auswahl und Anwendung unterschiedlicher ...Lehrmethoden. Den Studierenden wird durch eine übersichtliche Strukturierung des Unterrichtsstoffes das Lernen, Nachschlagen und Wiederholen erleichtert. Die Konzeption verzichtet auf eine Gliederung in Lektionen und geht bei der Erarbeitung des Stoffes von Anfang an von den biblischen Texten aus. Dem Werk sind ein umfangreicher Textteil sowie ein aufwendig gestaltetes Vokabular und ein ausführliches Glossar grammatikalischer Fachbegriffe beigegeben.
Carbapenems are last-resort antibiotics used in human medicine. The increased detection of carbapenem-resistant Enterobacteriaceae (CRE) is therefore worrying. In 2011 we reported the first ...livestock-associated VIM-1-producing
(
.)
serovar Infantis (R3) isolate from dust, sampled in a German chicken fattening farm. Due to this observation we retrospectively investigated more than 536 stored bacterial cultures, isolated from 45 chicken fattening farms during the years 2011 and 2012. After a non-selective overnight incubation, the bacteria were transferred to selective media.
and
growing on these media were further investigated, including antibiotic susceptibility testing, carbapenemase gene screening and whole genome sequencing (WGS). In total, four CRE were found in three out of 45 investigated farms: Besides R3, one additional
(G-336-1a) as well as two
isolates (G-336-2, G-268-2). All but G-268-2 harbored the
gene.
isolates R3 and G-336-1 were closely related although derived from two different farms. All three
-encoding isolates possessed identical plasmids and the
containing transposon showed mobility at least
. In isolate G-268-2, the AmpC beta-lactamase gene
but no known carbapenemase gene was identified. However, a transfer of the phenotypic resistance was possible. Furthermore, G-268-2 contained the
gene, combining phenotypical carbapenem- as well as colistin resistance in one isolate. Carbapenem-resistant Enterobacteriaceae have been found in three out of 45 investigated chicken flocks. This finding is alarming and emphasizes the importance of intervention strategies to contain the environmental spread of resistant bacteria in animals and humans.
PDF
