85 research outputs found

    Antimicrobial resistance gene shuffling and a three-element mobilisation system in the monophasic Salmonella typhimurium strain ST1030

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    In this study we describe the genetic elements and the antimicrobial resistance units (RUs) harboured by the Salmonella Typhimurium monophasic variant 1,4,[5],12:i:- strain ST1030. Of the three identified RUs two were chromosomal, RU1 (IS26-blaTEM-1-IS26-strAB-sul2- IS26) and RU2 (IS26-tetR(B)-tetA(B)-ΔIS26), and one, RU3 (a sul3-associated class 1 integron with cassette array dfrA12-orfF-aadA2-cmlA1-aadA1), was embedded in a Tn21-derived element harboured by the conjugative I1 plasmid pST1030-1A. IS26 elements mediated the antimicrobial resistance gene (ARG) shuffling and this gave rise to pST1030-1A derivatives with different sets of ARGs. ST1030 also harboured two ColE1-like plasmids of which one, pST1030-2A, was mobilisable and the target of an intracellular translocation of the Tn21-derived element; the second (pST1030-3) was an orphan mob-associated oriT plasmid co-transferred with pST1030-1A and pST1030-2A. pST1030-2A and pST1030-3 also carried a parA gene and a type III restriction modification system, respectively. Overall analysis of our data reinforces the role played by IS26, Tn21-derived elements and non-conjugative plasmids in the spread of ARGs and supplies the first evidence, at least in Salmonella, for the identification of a natural isolate harbouring a three-element mobilisation system in the same cell

    Filtering activity and nutrient release by the keratose sponge sarcotragus spinosulus schmidt, 1862 (Porifera, demospongiae) at the laboratory scale

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    Sponges are an important constituent of filter-feeder benthic communities, characterized by high ecological plasticity and abundance. Free bacteria constitute an important quota of their diet, making them excellent candidates in aquaculture microbial bioremediation, where bacteria can be a serious problem. Although there are studies on this topic, certain promising species are still under investigation. Here we report applied microbiological research on the filtering activity of Sarcotragus spinosulus on two different concentrations of the pathogenic bacterium Vibrio para-haemolyticus in a laboratory experiment. To evaluate the effects of the filtration on the surrounding nutrient load, the release of ammonium, nitrate, and phosphate was also measured. The results obtained showed the efficient filtration capability of S. spinosulus as able to reduce the Vibrio load with a maximum retention efficiency of 99.72% and 99.35% at higher and lower Vibrio concentrations, respec-tively, and remarkable values of clearance rates (average maximum value 45.0 ± 4.1 mL h−1 g DW−1 ) at the highest Vibrio concentration tested. The nutrient release measured showed low values for each considered nutrient category at less than 1 mg L−1 for ammonium and phosphate and less than 5 mg L−1 for nitrate. The filtering activity and nutrient release by S. spinosulus suggest that this species represents a promising candidate in microbial bioremediation, showing an efficient capability in removing V. parahaemolyticus from seawater with a contribution to the nutrient load

    Digital Workflow for Prosthetically Driven Implants Placement and Digital Cross Mounting: A Retrospective Case Series

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    Fully digital workflow in implant dentistry is ever increasing. Treatment of partial edentulous cases is well-documented; nevertheless, complete edentulous cases are still a challenge. To present several innovations in the treatment of complete edentulous patients using digital solutions, both for implant placement and restoration delivery, was the objective of this study. It was designed as a retrospective case series study, aimed to tune further research with larger sample size, and a longer follow-up. Patients requiring complete, implant-supported restoration were asked to participate in this study. Enrolled patients were treated with four implants, immediate loading and a definitive complete arch restoration. Patients were treated using computer-assisted, template-based surgery. Multi-piece surgical templates were used to accurately place the implants, to manage the bone if needed and to make immediate loading procedure quicker and easier. After osseointegration period, definitive, extra-oral, digital impressions were taken using newly developed scan analogs, connected in the patient mouth using temporary cylinders and stabilized by means of the low-shrinkage, flowable, resin composite. Outcomes were implant and prosthesis survival rate, complications, accuracy, and patient satisfaction. Radiographic evaluation performed with a preliminary, radiopaque aluminum try-in, was used to test the accuracy of the digital impressions. Overall, 20 implants were placed in five patients. All the implants osseointegrated without complications. One impression was taken a second time due to inaccuracy of the aluminum tray-in. Finally, all of the patients were completely satisfied with both surgical and prosthetic procedures. Within the limitations of this case series, multi-piece surgical templates showed promising results improving the clinician’s confidence in the case of bone reduction, post-extractive implants and immediate loading. The prosthetic template increased the trueness of the digital impression for complete edentulous patients. Finally, even if an impression was performed again, the scan-analog used for extra-oral chair-side digital impressions seemed to be a promising tool. Continuous improvements and further study are needed to confirm these preliminary results

    Association between the c. 2495 A>G ATP7B Polymorphism and Sporadic Alzheimer's Disease

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    Nonceruloplasmin-bound copper (“free”) is reported to be elevated in Alzheimer's disease (AD). In Wilson's disease (WD) Cu-ATPase 7B protein tightly controls free copper body levels. To explore whether the ATP7B gene harbours susceptibility loci for AD, we screened 180 AD chromosomes for sequence changes in exons 2, 5, 8, 10, 14, and 16, where most of the Mediterranean WD-causing mutations lie. No WD mutation, but sequence changes corresponding to c.1216 T>G Single-Nucleotide Polymorphism (SNP) and c.2495 A>G SNP were found. Thereafter, we genotyped 190 AD patients and 164 controls for these SNPs frequencies estimation. Logistic regression analyses revealed either a trend for the c.1216 SNP (P = .074) or a higher frequency for c.2495 SNP of the GG genotype in patients, increasing the probability of AD by 74% (P = .028). Presence of the GG genotype in ATP7B c.2495 could account for copper dysfunction in AD which has been shown to raise the probability of the disease

    Dorsolateral medullary ischemic infarction causing autonomic dysfunction and headache: a case report

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    Stroke can present, among other signs, with headache. Here, we describe the case of a man suffering from severe orbitary pain and autonomic dysfunction secondary to dorsolateral medullary ischemia. The anatomical relationship between lesion and symptomatology could be an indirect sign of hypothalamospinal tract involvement in the genesis of autonomic dysfunction and headache resembling a trigeminal autonomic cephalalgia
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