Complete Genome Sequence of the Disinfectant Susceptibility Testing Reference Strain Staphylococcus aureus subsp. aureus ATCC 6538

We report here the complete genome sequence of the methicillin-sensitive Staphylococcus aureus subsp. aureus strain ATCC 6538 (FDA 209, DSM 799, WDCM 00032, and NCTC 10788)

Complete Genome Sequence of the Livestock-Associated Methicillin-Resistant Strain Staphylococcus aureus subsp. aureus 08S00974 (Sequence Type 398)

We report here the complete genome sequence of the livestock-associated methicillin-resistant Staphylococcus aureus strain 08S00974 from sequence type 398 (ST398 LA-MRSA) isolated from a fatting pig at a farm in Germany

Effects of a Four-Week High-Dosage Zinc Oxide Supplemented Diet on Commensal Escherichia coli of Weaned Pigs

Strategies to reduce economic losses associated with post-weaning diarrhea in pig farming include high-level dietary zinc oxide supplementation. However, excessive usage of zinc oxide in the pig production sector was found to be associated with accumulation of multidrug resistant bacteria in these animals, presenting an environmental burden through contaminated manure. Here we report on zinc tolerance among a random selection of intestinal Escherichia coli comprising of different antibiotic resistance phenotypes and sampling sites isolated during a controlled feeding trial from 16 weaned piglets: In total, 179 isolates from “pigs fed with high zinc concentrations” (high zinc group, [HZG]: n = 99) and a corresponding “control group” ([CG]: n = 80) were investigated with regard to zinc tolerance, antimicrobial- and biocide susceptibilities by determining minimum inhibitory concentrations (MICs). In addition, in silico whole genome screening (WGSc) for antibiotic resistance genes (ARGs) as well as biocide- and heavy metal tolerance genes was performed using an in-house BLAST-based pipeline. Overall, porcine E. coli isolates showed three different ZnCl2 MICs: 128 μg/ml (HZG, 2%; CG, 6%), 256 μg/ml (HZG, 64%; CG, 91%) and 512 μg/ml ZnCl2 (HZG, 34%, CG, 3%), a unimodal distribution most likely reflecting natural differences in zinc tolerance associated with different genetic lineages. However, a selective impact of the zinc-rich supplemented diet seems to be reasonable, since the linear mixed regression model revealed a statistically significant association between “higher” ZnCl2 MICs and isolates representing the HZG as well as “lower ZnCl2 MICs” with isolates of the CG (p = 0.005). None of the zinc chloride MICs was associated with a particular antibiotic-, heavy metal- or biocide- tolerance/resistance phenotype. Isolates expressing the 512 μg/ml MIC were either positive for ARGs conferring resistance to aminoglycosides, tetracycline and sulfamethoxazole-trimethoprim, or harbored no ARGs at all. Moreover, WGSc revealed a ubiquitous presence of zinc homeostasis and – detoxification genes, including zitB, zntA, and pit. In conclusion, we provide evidence that zinc-rich supplementation of pig feed selects for more zinc tolerant E. coli, including isolates harboring ARGs and biocide- and heavy metal tolerance genes – a putative selective advantage considering substances and antibiotics currently used in industrial pork production systems

Molecular epidemiology of methicillin-resistant S. aureus (MRSA) in veterinary medicine

Deckblatt-Impressum Inhaltsverzeichnis Abkürzungen Einleitung Schrifttum Material Methoden Ergebnisse Diskussion Zusammenfassung Summary Referenzen Danksagung SelbständigkeitserklärungEinige S. aureus-Populationen, die sich im hospitalassoziierten Milieu seit vielen Jahren etabliert haben, erlangen multiple Resistenzen durch die Akkumulation verschiedener Resistenzdeterminaten. Insbesondere Methicillin- resistente Staphylococcus aureus (MRSA) sind heute weltweit einer der häufigsten Verursacher von sporadischen sowie endemischen Infektionen in Krankenhäusern, anderen Gesundheitseinrichtungen und auch in ambulanten Bereichen. Seit den frühen 70er Jahren werden MRSA-Fälle auch bei Tieren berichtet. In den letzten Jahren kam es jedoch zu einem deutlichen Anstieg von Berichten über MRSA-infizierte Tiere, insbesondere bei Kleintieren und Pferden in klinischen Einrichtungen. Auch die Frage nach dem zoonotischen Charakter animaler MRSA wird zunehmend diskutiert. Diese Arbeit verfolgte deshalb vier wesentliche Ziele. Zunächst wurden vergleichend Untersuchungen zu verschiedenen phänotypischen Nachweisverfahren für die MRSA-Diagnostik in der Veterinärmedizin durchgeführt. Ein zweiter Punkt war die Erfassung von Daten über das Vorkommen, die Typisierung sowie die genetische Charakterisierung von MRSA-Isolaten von Pferden und Kleintieren. In Zusammenarbeit mit der Klinik und Poliklinik für kleine Haustiere der Freien Universität Berlin wurde das dritte Ziel verfolgt, die Aufdeckung von möglichen zoonotischen Transmissionswegen sowie die nosokomiale Verbreitung von MRSA in klinischen Einrichtungen der Veterinärmedizin unter Einbeziehung von Tieren, Menschen und Gegenständen. Das vierte angestrebte Ziel dieser Arbeit umfasste die Analyse der gesammelten Daten unter epidemiologischen Gesichtspunkten und Einordnung der untersuchten Isolate in die bislang bekannten S. aureus- Population sowie den Vergleich zu einigen häufig auftretenden humanen Epidemiestämmen. Um alle MRSA-Isolate zu typisieren, wurden verschiedene international gebräuchliche Methoden eingesetzt. Durch den Einsatz einer Pulsfeld-Gel-Elektrophorese (PFGE) nach Makrorestriktion mittels der Endonuklease SmaI war ein Vergleich der Restriktionsmuster des Gesamtgenoms aller Isolate realisierbar. Unter Anwendung der Multi-Locus-Sequenztypisierung (MLST) war eine Zuordnung der hier aufgetretenen mit bereits bekannten und in einer Online-Datenbank (www.mlst.net) hinterlegten Sequenztypen (ST) möglich. Die Typisierung des mobilen Staphylokokken-Austauschsystems (SCCmec), welches den mec-Komplex beinhaltet, wurde in dieser Arbeit mit einer bereits beschriebenen Multiplex- Strategie verfolgt, die jedoch nicht in jedem Fall zu einem eindeutigen Ergebnis führte. Insgesamt sind in dieser Arbeit 1544 Einzelproben (davon 144 vordifferenzierte Keimisolate aus anderen veterinärmedizinischen diagnostischen Laboren) von Tieren, Menschen und Gegenständen untersucht worden. Im ersten Abschnitt wurden die verschiedenen Verfahren für den phänotypischen Nachweis animaler MRSA vergleichend getestet, wobei festgestellt werden konnte, dass der Agardiffusionstest mit Cefoxitin (30µg) anderen Methoden, wie z.B. dem Agardiffusionstest mit Oxacillin 1 und 5µg sowie dem Einsatz eines Oxacillin-Screeningagars, deutlich unterlegen ist. Der Goldstandard für den Nachweis der Resistenzdeterminante mecA ist jedoch noch immer ein spezifischer Gennachweis mittels Polymerase-Kettenreaktion (PCR), möglichst verbunden mit einem eindeutigen Speziesnachweis. Zu diesem Zweck wurde eine Triplex-PCR erarbeitet, die neben dem für die ß-Lactamresistenz verantwortlichen Gen mecA gleichzeitig Spezies-spezifische Nachweise von S. aureus und S. intermedius ermöglicht. Im zweiten Teil der Ergebnisse wurden MRSA-Isolaten von Pferden und Kleintieren analysiert. In den insgesamt 135 untersuchten Proben (davon 70 S. aureus) von Pferden aus unterschiedlichen Bundesländern von verschiedenen klinisch infizierten Tieren konnte in 11 Proben (15,7%) ein MRSA-Nachweis geführt werden. Die dabei aufgetretenen Genotypen, welche in dieser Arbeit mit den Großbuchstaben "A", "B", "C" benannt wurden, erzielten in der Analyse dieser Muster aus der PFGE einen genetischen Übereinstimmungsgrad von ca. 86%, der sich auch in der engen Verwandtschaft der mittels MLST ermittelten Sequenztypen ST8 und ST254 widerspiegelt. Diese ST unterscheiden sich tatsächlich lediglich in einem Basenpaar im ersten Allel der für die Bestimmung herangezogenen definierten Abschnitte von sieben konservativen Haushaltsgenen. Leider schränkt die begrenzte Anzahl der untersuchten Isolate von Pferden die Aussagekraft der Daten ein. Alle Staphylokokken-Genkassetten (SCCmec) aus equinen MRSA-Isolaten waren Vertreter der bislang kleinsten bekannten Kassette vom Typ SCCmec IV. Weitere 6 MRSA-Isolate von Kleintieren aus anderen Bundesländern zeigten die PFGE- Muster: "F", "D" und "H" sowie Subtypen. Die hier durch MLST ermittelten Sequenztypen waren ST254, ST225 und ST239. Während bei fünf Isolaten ebenfalls SCCmec IV auftrat, zeigte sich ein Isolat aus Gießen (ST225) positiv für SCCmec II. Im dritten Abschnitt dieser Arbeit wurde S. aureus in der Kleintierklinik über einen Zeitraum von 20 Monaten in insgesamt 6,9% (60/866) der klinischen Proben gefunden. 26 von diesen waren mecA-positiv, darunter auch Isolate von so exotischen Tieren wie Papagei, Schildkröte oder Fledermaus. Außerdem wurden Nasentupfer von Hunden (257 Tupfer von 191 Tieren), von Menschen (dreimal n=62, n=62 und n=88) und Objekten (20) untersucht. Dabei wurde in 6 Fällen bei Hunden, bei 20 Personen und an 3 Objekten ein MRSA Nachweis geführt. Lokal dominierten hier überwiegend zwei verschiedene PFGE Typen, hier als "G" und "D" bezeichnet. Die MLST-Analyse zeigte zwei genetisch unterschiedliche MRSA-Klone: PFGE-Typ "G" entspricht dem ST22, der PFGE-Typ "D" hingegen entspricht dem ST239. Neben dem SCCmec IV, der generell bei PFGE Typ "D" nachzuweisen war, schlug die eindeutige Charakterisierung der Genkassette des PFGE-Typs "G" mit denen in dieser Arbeit eingesetzten Techniken fehl. Eine Auswertung der Daten aus der Kleintierklinik unter einigen epidemiologischen Aspekten zeigte, dass eine zeitweise nosokomiale Verbreitung der genannten Klone innerhalb dieser Institution angenommen werden darf. Den Abschluss dieser Arbeit bildete die Einordnung der bei animalen MRSA-Isolaten dieser Arbeit aufgetretenen STen in einen S. aureus-Populationszusammenhang, der hier unter Einbeziehung von Daten über bislang bekannte S. aureus-STen aus der Datenbank www.mlst.net durch die Erstellung eines Minimum-Spannig-Trees. Dabei konnte gezeigt werden, dass alle in dieser Arbeit aufgetreten STen (ST8, ST239, ST254, ST225, ST22) bereits häufig in der Humanmedizin als MRSA in Erscheinung getreten sind und etablierten klonalen Komplexen angehören, also keinesfalls "neue" genotypische Linien begründen oder vertreten. Die vorliegenden Daten belegen, dass sich nosokomiale Infektionen, insbesondere solche durch MRSA, sich in der Veterinärmedizin etabliert haben. Aufgrund der ständigen Anpassungsvorgänge der Infektionserreger an ihre Umgebung und ihr hohes Adaptionsvermögen an Wirtsorganismen anderer Spezies ist die Erarbeitung standardisierter Hygienerichtlinien, die der Transmission von Tier zu Tier aber auch zwischen Mensch und Tier entgegenwirken, auch für veterinärmedizinischen Praxen und Kliniken erforderlich. Die Bedeutung von MRSA-Infektionen bei Tieren als Quelle und / oder Reservoir für MRSA-Erkrankungen beim Menschen ist bislang noch vollkommen ungeklärt. Durch die nachweislich leichte Übertragbarkeit, insbesondere in einer Umgebung mit Selektionsdruck (Praxis, Klinik), ist jedoch davon auszugehen, dass das Risiko für Transmissionen zwischen Mensch und Tier bei engem Kontakt bzw. mangelnder Hygiene nicht zu unterschätzen ist.Various populations of S. aureus, which have established themselves in the hospital environment over the last decades, have acquired different resistance factors and are now difficult to combat, even in the field of veterinary medicine. In particular, Methicillin-resistant Staphylococcus aureus (MRSA) are one of the most predominant causes of sporadic and endemic infections in hospitals as well as in hospital-adapted institutions. Since the early `70s, infections due to MSRA have also been reported in animals. In the last years, however, there have been increasing reports about MRSA infections in small animals and horses. Recently published studies address the potential of interspecies transferability, or the zoonotic character of MRSA. The aim of this work was to compile data and knowledge about the occurrence and relevance of MRSA in the field of veterinary medicine. Therefore, four main goals were defined prior to this work. First of all, a comparative investigation of different methods for phenotypical identification of MRSA of animal origin was performed. A second point of interest was the recording of data concerning occurrence, patterns of resistance and characterization of relevant genetic markers. In close cooperation with the clinic and policlinic for small animals of the Free University of Berlin, a third goal was set: To pinpoint the zoonotic potential of some MRSA lineages and detection of potential nosocomial transmission pathways in a clinical setting. The last intention of this investigation was to analyze all recorded data from an epidemiological point of view. Therefore, isolates originating from animals were compared to a set of data from human MRSA strains and assigned to a database that provided information about several S. aureus-genotypes. International recommended methods were applied to characterize the MRSA isolates in this work. Clonal analysis was performed by employing endonuclease SmaI digestion, followed by pulsed-field gel-electrophoresis (PFGE) in order to compare the genomic marcrorestriction patterns of all isolates. Multilocus sequence typing (MLST), which is based on the sequence analysis of defined sections of seven housekeeping genes, enabled the assignment of sequence types (ST) to each MRSA and into the whole S. aureus population analysed so far (www.mlst.net). Typing of the mobile genetic element (SCCmec), which harbours the mec-complex in staphylococci, was carried out using a previously published Multiplex polymerase chain reaction (PCR) strategy. Unfortunately, this PCR typing did not always produce satisfying results. A total of 1,544 specimens (including 144 isolates from other veterinary facilities) from animals, humans and everyday objects were examined in this work. Comparing different phenotypical methods to diagnose MRSA from animal origin revealed that the agar diffusion test with Cefoxitin (30ug) seems to be superior to other methods, e.g. agar diffusion test with Oxacillin 1µg and 5µg as well as an Oxacillin screening agar. Despite these results, the best method for MRSA verification still is PCR, detecting the mecA gene that codes for the resistance determinant as well as a species-specific marker like the nuc gene and/or a specific 16S rDNA sequence. Samples from 135 S. aureus infected horses were sent in from different veterinary microbiological institutions in Germany. Upon examination, 70 samples proved to contain S. aureus, 11 of those turned out to be positive for MRSA (15.7%). By applying PFGE, three clonal types were identified and designated as "A", "B", "C". Surprisingly, these clonaltypes showed a degree of genetic similarity of 86%. A second examination emphasized these findings, proving this close relationship. The detected STs, determined by MLST, turned out to be the closely-related ST8 and ST254, which differ from each other only by substitution of a single base-pair (bp) in one of the seven housekeeping genes sequenced (arcC, aroE, glpF, gmk, pta, tpi, ypiL). Unfortunately, the restricted number of horse isolates investigated here is a limiting factor in the interpretation of these results. All recorded staphylococcal chromosomal cassettes (SCCmec) from equine MRSA isolates in this work proved to be SCCmec IV. Additional 6 MRSA isolates of small animals from different sources in Germany showed different PFGE types: "F", "D" and "H" as well as subtypes. The obtained sequence types determined by MLST were ST254, ST225 and ST239. While five isolates proved to contain SCCmec IV, one isolate (out of those related to ST225) was positive for SCCmec II. In the third part of this work, during an investigation period of 20 months, S. aureus was found in 6.9% (60/866) of all clinical samples being sent to our laboratory for diagnostic purposes from the small animal hospital. Twenty-six of these tested positive for mecA (including isolates from exotic animals such as parrots, turtles as well as a bat). In addition, we collected and investigated nasal specimens from dogs (257 specimens of 191 animals) and humans (tested three times: n=62; n=62; and n=88). Furthermore, 20 samples of everyday objects were analysed. MRSA was detected in six canine cases, in nasal specimens from 20 persons, and on 3 objects. Two different PFGE types dominated in this setting during the investigation period, namely type "G" and "D". MLST analysis showed two genetically different MRSA clones: PFGE type "G" corresponded to ST22, and PFGE type "D" was determined to ST239. Despite the SCCmec IV, which was found to be related to type "D", the utilized SCC-typing techniques used in this work failed in typing SCCmec in PFGE type "G". In regard to epidemiological aspects, evaluating data from this small animal hospital indicated that an occasional nosocomial spread of the aforementioned MRSA clones may have occurred within this institution. The final part of this investigation was to classify all MRSA ST which had been identified during this work, in an epidemical context by using additional data from www.mlst.net in performing a Minimum spanning tree analysis. This approach could demonstrate that all MRSA STs in this thesis (ST8, ST239, ST254, ST225, ST22) have also been frequently observed in isolates from human MRSA infections with an almost global occurrence. The data presented here are evidence of nosocomial infections due to MSRA in veterinary medicine facilities. Due to the constant adaptation processes of infectious agents to their environment and their high adaptability to host organisms of different (animal) species, the development of standardized hygienic guidelines for veterinary practice and hospitals should be enforced. Especially the potential nosocomial transmission of MRSA from animal to animal as well as between human and animal should be the focus of hygienic measures as well as future research. The current relevance of MRSA infections in animals as a potential source and/or reservoir for MRSA mediated infections in humans is still unknown. The apparent ready transferability of MRSA, in particular in an environment with a certain selection pressure (practice, hospital), showed that the risk for nosocomial transmission between human and animal with close contact and/or lack of hygienic measures must be taken seriously

Sharing more than friendship - nasal colonization with coagulase-positive staphylococci (CPS) and co-habitation aspects of dogs and their owners

Background Since the relationship between dogs and their owners has changed, and dogs moved from being working dogs to family members in post-industrial countries, we hypothesized that zoonotic transmission of opportunistic pathogens like coagulase positive staphylococci (CPS) is likely between dogs and their owners. Methodology/Principal Findings CPS- nasal carriage, different aspects of human-to-dog relationship as well as potential interspecies transmission risk factors were investigated by offering nasal swabs and a questionnaire to dog owners (108) and their dogs (108) at a dog show in 2009. S. aureus was found in swabs of 20 (18.5%) humans and two dogs (1.8%), and spa types which correspond to well known human S. aureus lineages dominated (e.g. CC45, CC30 and CC22). Multilocus sequence typing (MLST) of the two canine strains revealed ST72 and ST2065 (single locus variant of ST34). Fifteen dogs (13.9%) and six owners (5.6%) harboured S. pseudintermedius, including one mecA-positive human isolate (MRSP). Pulsed field gel electrophoresis (PFGE) revealed that one dog/owner pair harboured indistinguishable S. pseudintermedius- isolates of ST33. Ten (48%) of the 21 S. pseudintermedius-isolates showed resistance towards more than one antimicrobial class. 88.9% of the dog owners reported to allow at least one dog into the house, 68.5% allow the dog(s) to rest on the sofa, 39.8% allow their dogs to come onto the bed, 93.5% let them lick their hands and 52.8% let them lick their face. Bivariate analysis of putative risk factors revealed that dog owners who keep more than two dogs have a significantly higher chance of being colonized with S. pseudintermedius than those who keep 1–2 dogs (p<0.05). Conclusions/Recommendations In conclusion, CPS transmission between dog owners and their dogs is possible. Further investigation regarding interspecies transmission and the diverse adaptive pathways influencing the epidemiology of CPS (including MRSA and MRSP) in different hosts is needed

Zoonotic sources and the spread of antimicrobial resistance from the perspective of low and middle-income countries

Background: Antimicrobial resistance is an increasing challenge in low and middle-income countries as it is widespread in these countries and is linked to an increased mortality. Apart from human and environmental factors, animal-related drivers of antimicrobial resistance in low- and middle-income countries have special features that differ from high-income countries. The aim of this narrative review is to address the zoonotic sources and the spread of antimicrobial resistance from the perspective of low- and middle-income countries. Main body: Contamination with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is highest in poultry (Africa: 8.9–60%, Asia: 53–93%) and there is a risk to import ESBL-producing E. coli through poultry meat in Africa. In aquacultures, the proportion of ESBL-producers among E. coli can be high (27%) but the overall low quality of published studies limit the general conclusion on the impact of aquacultures on human health. ESBL-producing E. coli colonization of wildlife is 1–9% in bats or 2.5–63% birds. Since most of them are migratory animals, they can disperse antimicrobial resistant bacteria over large distances. So-called ‘filth flies’ are a relevant vector not only of enteric pathogens but also of antimicrobial resistant bacteria in settings where sanitary systems are poor. In Africa, up to 72.5% of ‘filth flies’ are colonized with ESBL-producing E. coli, mostly conferred by CTX-M (24.4–100%). While methicillin-resistant Staphylococcus aureus plays a minor role in livestock in Africa, it is frequently found in South America in poultry (27%) or pork (37.5–56.5%) but less common in Asia (poultry: 3%, pork: 1–16%). Conclusions: Interventions to contain the spread of AMR should be tailored to the needs of low- and middle-income countries. These comprise capacity building of diagnostic facilities, surveillance, infection prevention and control in small-scale farming.Peer Reviewe

The mecC-Harboring Region Is a Recombination Hot Spot in Staphylococcus stepanovicii

Introduction Horizontal gene transfer (HGT) is an important driver for resistance- and virulence factor accumulation in pathogenic bacteria such as Staphylococcus aureus. Methods Here, we have investigated the downstream region of the bacterial chromosomal attachment site (attB) for the staphylococcal cassette chromosome mec (SCCmec) element of a commensal mecC- positive Staphylococcus stepanovicii strain (IMT28705; ODD4) with respect to genetic composition and indications of HGT. S. stepanovicii IMT28705 was isolated from a fecal sample of a trapped wild bank vole (Myodes glareolus) during a screening study (National Network on “Rodent-Borne Pathogens”) in Germany. Whole genome sequencing (WGS) of IMT28705 together with the mecC- negative type strain CM7717 was conducted in order to comparatively investigate the genomic region downstream of attB (GenBank accession no. KR732654 and KR732653). Results The bank vole isolate (IMT28705) harbors a mecC gene which shares 99.2% nucleotide (and 98.5% amino acid) sequence identity with mecC of MRSA_LGA251. In addition, the mecC-encoding region harbors the typical blaZ-mecC-mecR1-mecI structure, corresponding with the class E mec complex. While the sequences downstream of attB in both S. stepanovicii isolates (IMT28705 and CM7717) are partitioned by 15 bp direct repeats, further comparison revealed a remarkable low concordance of gene content, indicating a chromosomal “hot spot” for foreign DNA integration and exchange. Conclusion Our data highlight the necessity for further research on transmission routes of resistance encoding factors from the environmental and wildlife resistome

The contemporary "Trojan Horse"

Pathogens frequently associated with multi-drug resistant (MDR) phenotypes, including extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and Acinetobacter baumannii isolated from horses admitted to horse clinics, pose a risk for animal patients and personnel in horse clinics. To estimate current rates of colonization, a total of 341 equine patients were screened for carriage of zoonotic indicator pathogens at hospital admission. Horses showing clinical signs associated with colic (n = 233) or open wounds (n = 108) were selected for microbiological examination of nostril swabs, faecal samples and wound swabs taken from the open wound group. The results showed alarming carriage rates of Gram-negative MDR pathogens in equine patients: 10.7% (34 of 318) of validated faecal specimens were positive for ESBL-E (94%: ESBL-producing Escherichia coli), with recorded rates of 10.5% for the colic and 11% for the open wound group. 92.7% of the ESBL-producing E. coli were phenotypically resistant to three or more classes of antimicrobials. A. baumannii was rarely detected (0.9%), and all faecal samples investigated were negative for Salmonella, both directly and after two enrichment steps. Screening results for the equine nostril swabs showed detection rates for ESBL-E of 3.4% among colic patients and 0.9% in the open wound group, with an average rate of 2.6% (9/340) for both indications. For all 41 ESBL-producing E. coli isolated, a broad heterogeneity was revealed using pulsed-field gel electrophoresis (PFGE) patterns and whole genome sequencing (WGS) -analysis. However, a predominance of sequence type complex (STC)10 and STC1250 was observed, including several novel STs. The most common genes associated with ESBL-production were identified as blaCTX-M-1 (31/41; 75.6%) and blaSHV-12 (24.4%). The results of this study reveal a disturbingly large fraction of multi-drug resistant and ESBL-producing E. coli among equine patients, posing a clear threat to established hygiene management systems and work-place safety of veterinary staff in horse clinics

Stationsprüfbericht Schaf 2010

Ergebnisse der 15. Mast- und Schlachtleistungsprüfung beim Schaf aus der Prüfstation Köllitsch 201

In situ characterization of polycaprolactone fiber response to quasi-static tensile loading in scanning electron microscopy

Microstructural responses to the mechanical load of polymers used in tissue engineering is notably important for qualification at in vivo testing, although insufficiently studied, especially regarding promising polycaprolactone (PCL). For further investigations, electrospun PCL scaffolds with different degrees of fiber alignment were produced, using two discrete relative drum collector velocities. Development and preparation of an adjusted sample geometry enabled in situ tensile testing in scanning electron microscopy. By analyzing the microstructure and the use of selected tracking techniques, it was possible to visualize and quantify fiber/fiber area displacements as well as local fractures of single PCL fibers, considering quasi-static tensile load and fiber alignment. The possibility of displacement determination using in situ scanning electron microscopy techniques for testing fibrous PCL scaffolds was introduced and quantified. © 2021 by the authors. Licensee MDPI, Basel, Switzerland