Preventive antibiotic treatment of calves: emergence of dysbiosis causing propagation of obese state-associated and mobile multidrug resistance-carrying bacteria

In agriculture, antibiotics are used for the treatment and prevention of livestock disease. Antibiotics perturb the bacterial gut composition but the extent of these changes and potential consequences for animal and human health is still debated. Six calves were housed in a controlled environment. Three animals received an injection of the antibiotic florfenicol (Nuflor), and three received no treatment. Faecal samples were collected at 0, 3 and 7 days, and bacterial communities were profiled to assess the impact of a therapy on the gut microbiota. Phylogenetic analysis (16S‐rDNA) established that at day 7, antibiotic‐treated microbiota showed a 10‐fold increase in facultative anaerobic Escherichia spp, a signature of imbalanced microbiota, dysbiosis. The antibiotic resistome showed a high background of antibiotic resistance genes, which did not significantly change in response to florfenicol. However, the maintenance of Escherichia coli plasmid‐encoded quinolone, oqxB and propagation of mcr‐2, and colistin resistance genes were observed and confirmed by Sanger sequencing. The microbiota of treated animals was enriched with energy harvesting bacteria, common to obese microbial communities. We propose that antibiotic treatment of healthy animals leads to unbalanced, disease‐ and obese‐related microbiota that promotes growth of E. coli carrying resistance genes on mobile elements, potentially increasing the risk of transmission of antibiotic resistant bacteria to humans

Oxidation of tertiary amine-derivatized surfaces to control protein adhesion

Selective oxidation of omega-tertiary amine self-assembled thiol monolayers to tertiary amine N-oxides is shown to transform the adhesion of model proteins lysozyme and fibrinogen upon them. Efficient preparation of both secondary and tertiary linker amides as judged by X-ray photoelectron spectroscopy (XPS) and water droplet contact angle was achieved with an improved amide bond formation on gold quartz crystal microbalance (QCM) sensors using 2-(1H-7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyl hexafluorophosphate methanaminium uronium (HATU). Oxidation with hydrogen peroxide was similarly assessed, and adhesion of lysozyme and fibrinogen from phosphate buffered saline was then assayed by QCM and imaged by AFM. Tertiary amine-functionalized sensors adsorbed multilayers of aggregated lysozyme, whereas tertiary amine N-oxides and triethylene glycol-terminated monolayers are consistent with small protein aggregates. The surface containing a dimethylamine N-oxide headgroup and ethyl secondary amide linker showed the largest difference in adsorption of both proteins. Oxidation of tertiary amine decorated surfaces therefore holds the potential for selective deposition of proteins and cells through masking and other patterning techniques

Environmental evaluation of chosen oxbow lakes of the Vistula in Warsaw

Celem badań była waloryzacja przyrodnicza trzech wybranych starorzeczy Wisły znajdujących się na terenie Warszawy. Jako organizmy wskaźnikowe przyjęto makrobezkręgowce bentosowe strefy brzegowej, łowione za pomocą zestawów kolonizacyjnych [PN-EN ISO 9391:2001]. Analizowane obszary to: Jezioro Gocławskie oraz kompleks starorzeczy Jezioro Powsinkowskie i Jezioro Wilanowskie. Badania wykazały wysokie bogactwo i różnorodność makrobezkręgowców zasiedlających badane starorzecza. Stwierdzono dużą zmienność zespołu w obrębie zbiorników jak i w trakcie prowadzonych badań. Duża liczba taksonów złowionych w poszczególnych zbiornikach spowodowała, że przy zastosowaniu metody BMWP-PL, jakość wody tych akwenów oceniono jako wysoką i najwyższą (Gocławskie: klasa I, Powsinkowskie i Wilanowskie: klasa II). Średnia liczba punktów przypadająca na rodzinę (wskaźnik ASPT) jest jednak nie wysoka. Zastosowanie formuły Jaccarda pozwoliło na stwierdzenie, iż najbardziej podobne pod względem makrobezkręgowców są jeziora Gocławskie i Wilanowskie, następnie Gocławskie i Powsinkowskie. Najniższą wartość podobieństwa otrzymano dla kompleksu jezior Powsinkowskiego i Wilanowskiego. Przeprowadzone badania wskazują, iż wybrane starorzecza Wisły charakteryzują się bogatym i różnorodnym zespołem makrobezkręgowców bentosowych, co może świadczyć o ich dużej wartości przyrodniczej.The aim of the study was an environmental evaluation of three chosen oxbow lakes of the Vistula in Warsaw. Benthic macroinvertebrates that inhabit littoral zone were used as bioindicators. They were collected using slag-filled mesh bags introduced substrate [PN-EN ISO 9391:2001]. The researches were conducted on the Gocławskie lake and on the Powsinkowskie and Wilanowskie lakes which form a complex. The researches revealed high richness and diversity of macroinvertebrates that inhabit studied oxbow lakes. High variation of invertebrates assemblage was assessed during conducted researches and within studied lakes. Due to identification of many taxa water quality assessed according to the BMWP-PL method was good and very good (Gocławskie: I class, Powsinkowskie and Wilanowskie: II class). Meanwhile Average Score Per Taxon index was not so high. Using Jaccard formula the highest similarity was obtained for the Gocławskie and the Wilanowskie lakes, then the Gocławskie and the Powsinkowskie. The lowest value of similarity was assessed for the Powsinkowskie and the Wilanowskie lakes which compose a lakes complex. This researches shows that chosen oxbow lakes are characterized by rich and diverse assemblage of benthic macroinvertebrates that can be an evidence of their high environmental value

Identification of live caddies flies larvae for the purpose of zoological indication

The pre-studies were conducted in order to elaborate methodology for identification of live caddis fl ies larvae. Moreover, the possibilities of using these methods are shown. The study showed that it is possible to identify live caddies flies larvae to family level. Cultures conducted in natural habitat revealed that caddies flies can rebuild cases but their quality varies