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Impact of suppression of the SOS response on protein expression in clinical isolates of Escherichia coli under antimicrobial pressure of ciprofloxacin
No full textSuppression of the SOS response in combination with drugs damaging DNA has been proposed as a potential target to tackle antimicrobial resistance. The SOS response is the pathway used to repair bacterial DNA damage induced by antimicrobials such as quinolones. The extent of lexA-regulated protein expression and other associated systems under pressure of agents that damage bacterial DNA in clinical isolates remains unclear. The aim of this study was to assess the impact of this strategy consisting on suppression of the SOS response in combination with quinolones on the proteome profile of Escherichia coli clinical strains.Five clinical isolates of E. coli carrying different chromosomally- and/or plasmid-mediated quinolone resistance mechanisms with different phenotypes were selected, with E. coli ATCC 25922 as control strain. In addition, from each clinical isolate and control, a second strain was created, in which the SOS response was suppressed by deletion of the recA gene. Bacterial inocula from all 12 strains were then exposed to 1xMIC ciprofloxacin treatment (relative to the wild-type phenotype for each isogenic pair) for 1 h. Cell pellets were collected, and proteins were digested into peptides using trypsin. Protein identification and label-free quantification were done by liquid chromatography-mass spectrometry (LC-MS) in order to identify proteins that were differentially expressed upon deletion of recA in each strain. Data analysis and statistical analysis were performed using the MaxQuant and Perseus software.The proteins with the lowest expression levels were: RecA (as control), AphA, CysP, DinG, DinI, GarL, PriS, PsuG, PsuK, RpsQ, UgpB and YebG; those with the highest expression levels were: Hpf, IbpB, TufB and RpmH. Most of these expression alterations were strain-dependent and involved DNA repair processes and nucleotide, protein and carbohydrate metabolism, and transport. In isolates with suppressed SOS response, the number of underexpressed proteins was higher than overexpressed proteins.High genomic and proteomic variability was observed among clinical isolates and was not associated with a specific resistant phenotype. This study provides an interesting approach to identify new potential targets to combat antimicrobial resistanc
Sensory nerve conduction stimulus threshold measurements of the infraorbital nerve and its applicability as a diagnostic tool in horses with trigeminal-mediated headshaking
No full textTo determine whether sensory nerve conduction stimulus threshold measurements of the infraorbital nerve are able to differentiate horses with idiopathic trigeminal-mediated headshaking (i-TMHS) from healthy horses and from horses with secondary trigeminal-mediated headshaking (s-TMHS). In a prospective trial, headshaking horses were examined using a standardized diagnostic protocol, including advanced diagnostics such as computed tomography and 3-Tesla-magnetic resonance imaging (MRI), to differentiate s-TMHS from i-TMHS. Clinically healthy horses served as controls. Within this process, patients underwent general anesthesia, and the minimal sensory nerve conduction stimulus threshold (SNCT) of the infraorbital nerve was measured using a bipolar concentric needle electrode. Sensory nerve action potentials (SNAP) were assessed in 2.5-5 mA intervals. Minimal SNCT as well as additional measurements were calculated.In 60 horses, SNAP could be recorded, of which 43 horses had i-TMHS, six had suspected s-TMHS, three horses had non-facial headshaking, and eight healthy horses served as controls. Controls had a minimal SNCT ≥ 15 mA, whereas 14/43 horses with i-TMHS and 2/6 horses with s-TMHS showed a minimal SNCT ≤ 10 mA. Minimal SNCT ≤ 10 mA showed 100% specificity to distinguish TMHS from controls, but the sensitivity was only 41%.A minimal SNCT of the infraorbital nerve ≤ 10 mA was able to differentiate healthy horses from horses with TMHS. Nevertheless, a higher minimal SNCT did not exclude i-TMHS or s-TMHS and minimal SNCT does not distinguish s-TMHS from i-TMHS
Henneguya (Cnidaria: Myxobolidae) species infecting Oligosarcus jenynsii (Characiformes: Characidae) in a Neotropical shallow lake from Argentina: morphological and molecular characterisation
No full textTwo previously undescribed myxozoan species, Henneguya sardellae sp. n. and H. margaritae sp. n., found infecting connective tissues of the Neotropical characid fish Oligosarcus jenynsii (Günther) from Argentina are morphologically and molecularly characterised. Mature spores of H. sardellae sp. n. are ellipsoid, with two, straight and visibly fused caudal appendages cleaved at its blunt terminal end; measuring 33.5 ± 1.2 (30.9-35.5) μm in total length, spore body 17.5 ± 0.6 (16.3-18.6) µm, 7.8 ± 0.4 (7.0-8.8) µm wide and 6.9 ± 0.2 (6.6-7.2) µm thick, with two elongated, unequally-sized polar capsules situated at anterior end, and 11-13 turns of polar tubules. Mature spores of H. margaritae sp. n. are pyriform, with two caudal appendages visible fused together and much longer than spore body, with unequal endings; measuring 35.9 ± 2.8 (29.2-40.7) µm in total length, spore body 11.5 ± 0.9 (9.2-13.0) µm long, 5.8 ± 0.4 (5.1-6.7) µm wide and 5.5 ± 0.2 (5.1-5.8) µm thick, with two polar capsules similar in size, pyriform polar capsules containing polar tubules with 4-5 coils. Both species showed a membraneous sheath surrounding the spore body and caudal appendages; in H. sardellae sp. n. this feature can deploy laterally. Phylogenetic analyses based on SSU rDNA sequences showed that H. sardellae sp. n. and H. margaritae sp. n. clustered with other myxobolids parasitising Characiformes in Brazil, Cichliformes in Mexico and Cyprinodontiformes in Mexico and the United States. The description of these two new species of Henneguya as the first described species of the genus that parasitise freshwater fish in Argentina highlights the importance of further research on the diversity and distribution of myxozoans in this region
Chemische Zusammensetzung und ausgewählte Elementgehalte von Lebern von in Österreich erlegtem Wild
No full textIn insgesamt 106 Lebern von in Österreich erlegtem Rehwild, Rotwild, Gamswild, Auerwild, Birkwild, Muffelwild, Schwarzwild, Wildgänsen, Wildenten, Hasen, Füchsen und Murmeltieren wurden der Rohprotein-, Rohfett-, Asche- und Wassergehalt, sowie die Gehalte an Eisen, Kupfer und an Vitamin A bestimmt. Rohprotein- (16,1–21,1 g/100g Frischmasse), Rohfett- (1,0–4,1 g/100 g), Rohasche- (1,1–1,6 g/100 g)-gehalte waren in der auch bei Nutztieren berichteten Größenordnung. Die Gehalte an Eisen waren in der Leber von Wildvögeln im Bereich von 22,3–89,7 mg/kg, bei anderem Wild (mit Ausnahme von Muffelwild) im Bereich von 72–178 mg/kg. Diese Werte sind mit Literaturangaben für Huhn bzw. Rind und Schwein vergleichbar. Die Kupfergehalte waren im Bereich von 6–40 mg/kg, und damit im Bereich für Lebern heimischer landwirtschaftlicher Nutztiere wie zum Beispiel Rind, Schwein oder Schaf (5–87 mg/kg). Die Vitamin-A-Gehalte waren im Bereich von 750–946 mg/kg bei Wildvögeln, höher bei Füchsen und niedriger bei anderem Wild. Innerhalb einer Wildart konnten aber erhebliche Schwankungen in den Element- und Vitamin-A-Gehalten beobachtet werden. Aufgrund des relativ hohen pH–Wertes von über 6,0 sind die Wildlebern der untersuchten Tierarten als leicht verderbliche Lebensmittel einzuordnen; diesem Umstand wird durch niedrigere vorgeschriebene Kühltemperaturen Rechnung getragen.We examined in total 106 livers from wild game hunted in Austria (roe deer, red deer, chamois, capercaille, black grouse, mouflon, wild boar, wild geese, ducks, hare, red fox and marmot) with respect to gross composition (crude protein, fat, mineral content, moisture) and contents of iron, copper and vitamin A. Contents of crude protein, crude fat and minerals were in the range of 16.1-21.1; 1.0-4.1 and 1.1-1.6 g/100g wet weight, respectively, and, thus, in the range reported for livers from farm animals. Contents of iron in livers of wild birds (22.3-89.7 mg/kg) were lower than in those from other game (72-178 mg/kg), with exception of mouflon. Similar values are reported for liver from poultry or cattle and pig, respectively. Copper contents were from 6 to 40 mg/kg, similar to those for livers from farm animals such as cow, pig and sheep (5-87 mg/kg). Vitamin A content was from 750 to 946 mg/kg in liver from wild birds, and higher in those from red fox, but lower in other game species. Considerable intra-species variations were observed for Fe-, Cu- and vitamin-A-contents. Due to the relatively high pH-value of above 6.0 liver from hunted wild game is a perishable product, which requires low temperatures during cold storage.In insgesamt 106 Lebern von in Österreich erlegtem Rehwild, Rotwild, Gamswild, Auerwild, Birkwild, Muffelwild, Schwarzwild, Wildgänsen, Wildenten, Hasen, Füchsen und Murmeltieren wurden der Rohprotein-, Rohfett-, Asche- und Wassergehalt, sowie die Gehalte an Eisen, Kupfer und an Vitamin A bestimmt. Rohprotein- (16,1–21,1 g/100g Frischmasse), Rohfett- (1,0–4,1 g/100 g), Rohasche- (1,1–1,6 g/100 g)-gehalte waren in der auch bei Nutztieren berichteten Größenordnung. Die Gehalte an Eisen waren in der Leber von Wildvögeln im Bereich von 22,3–89,7 mg/kg, bei anderem Wild (mit Ausnahme von Muffelwild) im Bereich von 72–178 mg/kg. Diese Werte sind mit Literaturangaben für Huhn bzw. Rind und Schwein vergleichbar. Die Kupfergehalte waren im Bereich von 6–40 mg/kg, und damit im Bereich für Lebern heimischer landwirtschaftlicher Nutztiere wie zum Beispiel Rind, Schwein oder Schaf (5–87 mg/kg). Die Vitamin-A-Gehalte waren im Bereich von 750–946 mg/kg bei Wildvögeln, höher bei Füchsen und niedriger bei anderem Wild. Innerhalb einer Wildart konnten aber erhebliche Schwankungen in den Element- und Vitamin-A-Gehalten beobachtet werden. Aufgrund des relativ hohen pH–Wertes von über 6,0 sind die Wildlebern der untersuchten Tierarten als leicht verderbliche Lebensmittel einzuordnen; diesem Umstand wird durch niedrigere vorgeschriebene Kühltemperaturen Rechnung getragen
Reliability of fluoroscopic examination of nasopharyngeal dorsoventral dimension change in pugs and French bulldogs
No full textTo compare intra- and interobserver agreements in two-dimensional measurements of changes in nasopharyngeal dimensions during breathing in pugs and French bulldogs.Experimental randomized study.A total of 20 French bulldogs and 16 pugs.Four observers with different levels of experience measured the dorsoventral dimensions of the nasopharynx during inspiration and expiration on fluoroscopy videos. Measurements were performed at the maximal narrowing of the nasopharynx for the functional method and at the level of the tip of the epiglottis for the anatomically adjusted method. The intra- and interobserver agreements of the measurements, ratio of the dynamic nasopharyngeal change (ΔL), and grade of nasopharyngeal (NP) collapse (no, partial or complete) were evaluated.The functional method resulted in intraobserver correlation coefficients of 0.532 (p 0.9 for both methods.Fair interobserver agreement was found for NP collapse grade (functional method), moderate intra- and interobserver agreements were found for NP collapse grade and ΔL (both methods) while intraobserver agreement for ΔL was good (functional method).Both methods seem repeatable and reproducible but only for experienced radiologists. The use of ΔL may offer higher repeatability and reproducibility than grade of NP collapse regardless of the method used
Intraspecific divergence of sexual size dimorphism and reproductive strategies in a polytypic poison frog
No full textIntraspecific variation in body size, both among populations and between sexes, is an important factor influencing life-history strategies. This variation might be the response to different environmental conditions, as well as natural and sexual selection, and can result in differences in behavior and reproductive strategies among populations. Here, we use the dyeing poison frog (Dendrobates tinctorius) as a model to investigate how interpopulation variation in body size and sexual size dimorphism affects reproductive strategies. As body size increased, sexual size dimorphism also increased, i.e., females were larger than males, and more so in populations with overall larger frogs. This indicates that there is a stronger selection for body size in females than in males, likely as a response to divergent reproductive investment between the sexes. Females from larger-bodied populations produced larger clutches, but the overall number of froglets produced per clutch did not differ among populations. We discuss potential causes and mechanisms that might be responsible for the observed divergence in body size, sexual size dimorphism, and reproductive strategies among populations that likely represent local adaptations. Our findings demonstrate the importance of cross-population studies, cautioning against drawing general conclusions about a species\u27 ecology without accounting for intraspecific variation
Co-infecting Haemoproteus species (Haemosporida, Apicomplexa) show different host tissue tropism during exo-erythrocytic development in Fringilla coelebs (Fringillidae)
No full textAvian haemosporidians of the genera Plasmodium, Haemoproteus, and Leucocytozoon are common blood parasites in wild birds all over the world. Despite their importance as pathogens potentially compromising host fitness and health, little is known about the exo-erythrocytic development of these parasites, particularly during co-infections which predominate in wildlife. This study aimed to address this issue using Haemoproteus parasites of Fringilla coelebs, a common bird species of the Western Palearctic and host to a variety of haemosporidian parasite lineages. Blood and tissue samples of 20 F. coelebs, positive for haemosporidians by blood film microscopy, were analysed by PCR and sequencing to determine cytochrome b lineages of the parasites. Tissue sections were examined for exo-erythrocytic stages by histology and in situ hybridization applying genus-, species-, and lineage-specific probes which target the 18S rRNA of the parasites. In addition, laser microdissection of tissue stages was performed to identify parasite lineages. Combined molecular results of PCR, laser microdissection, and in situ hybridization showed a high rate of co-infections, with Haemoproteus lineages dominating. Exo-erythrocytic meronts of five Haemoproteus spp. were described for the first known time, including Haemoproteus magnus hCCF6, Haemoproteus fringillae hCCF3, Haemoproteus majoris hCCF5, Haemoproteus sp. hROFI1, and Haemoproteus sp. hCCF2. Merogonic stages were observed in the vascular system, presenting a formerly unknown mode of exo-erythrocytic development in Haemoproteus parasites. Meronts and megalomeronts of these species were distinct regarding their morphology and organ distribution, indicating species-specific patterns of merogony and different host tissue tropism. New pathological aspects of haemoproteosis were reported. Furthermore, phylogenetic analysis of Haemoproteus spp. with regard to their exo-erythrocytic stages points towards separation of non-megalomeront-forming species from megalomeront-forming species, calling for further studies on exo-erythrocytic development of haemosporidian parasites to explore the phylogenetic character of this trait
Undergraduates\u27 workplace learning in health sciences education: psychometric properties of single-item measures
No full textUndergraduates\u27 workplace learning is an important part of health sciences education. Educational psychology research considers many different aspects of self-regulated learning at the workplace, including cognition, motivation, emotions, and context. Multivariate longitudinal and diary studies in this field require fewer items than alternatives or even a single item per construct and can reveal the sub-processes of workplace learning and contribute to a better understanding of students\u27 learning. Short instruments are necessary for application in workplace settings, especially stressful ones, to mitigate survey fatigue. The present study aimed to assess the psychometric properties of single items measuring various aspects of workplace learning.Twenty-nine single items selected from the Workplace Learning Inventory in Health Sciences Education were analyzed for reliability, information reproduction, and relationships within the nomological network. The authors additionally analyzed four generally formulated single items\u27 relationships with the full Workplace Learning Inventory scales and external criteria within the nomological network. Participants were 214 ninth- or tenth-semester veterinary medicine students in Austria and Germany who were learning at varied workplaces during the winter semester of 2021/2022.Of the 29 single items selected from existing scales, 27 showed sufficient reliability, but mixed results were obtained regarding validity. Although the items\u27 relationships within the nomological network were similar to those of the full scales, information reproduction was insufficient for most items. The four general single items showed acceptable validity, but the reliability of these measures of states could not be assessed.This paper reported findings on the psychometric properties of single items for undergraduates\u27 workplace learning in health science education. The findings are crucial for deciding whether to use scales versus single-item measures in future studies. By applying the findings, researchers can be more economical in their workplace learning data collection and can include more constructs
Two novel members of Onygenales, Keratinophyton kautmanovae and K. keniense spp. nov. from soil
No full textTwo new Keratinophyton species, K. kautmanovae sp. nov. and K. keniense sp. nov., isolated from soil samples originating from two different geographical and environmental locations (Africa and Europe) are described and illustrated. Phylogenetically informative sequences obtained from the internal transcribed spacer (ITS) region and the nuclear large subunit (LSU) rDNA, as well as their unique phenotype, fully support novelty of these two fungi for this genus. Based on ITS and LSU combined phylogeny, both taxa are resolved in a cluster with eight accepted species, including K. alvearium, K. chongqingense, K. hubeiense, K. durum, K. lemmensii, K. siglerae, K. submersum, and K. sichuanense. The new taxon, K. kautmanovae, is characterized by clavate, smooth to coarsely verrucose conidia, absence of arthroconidia, slow growth at 25 °C, and no growth at 30 °C, while K. keniense is morphologically unique with a high diversity of conidial shapes (clavate, filiform, globose, cymbiform and rhomboid). Both species are described based on their asexual, a chrysosporium-like morph. While the majority of hitherto described Keratinophyton taxa came from Europe, India and China, the new species K. keniense represents the first reported taxonomic novelty for this genus from Africa