For mass spectrometry-based diagnostics of microorganisms, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently routinely used to identify urinary ...tract pathogens. However, it requires a lengthy culture step for accurate pathogen identification, and is limited by a relatively small number of available species in peptide spectral libraries (≤3329). Here, we propose a method for pathogen identification that overcomes the above limitations, and utilizes the MALDI-TOF/TOF MS instrument. Tandem mass spectra of the analyzed peptides were obtained by chemically activated fragmentation, which allowed mass spectrometry analysis in negative and positive ion modes. Peptide sequences were elucidated de novo, and aligned with the non-redundant National Center for Biotechnology Information Reference Sequence Database (NCBInr). For data analysis, we developed a custom program package that predicted peptide sequences from the negative and positive MS/MS spectra. The main advantage of this method over a conventional MALDI-TOF MS peptide analysis is identification in less than 24 h without a cultivation step. Compared to the limited identification with peptide spectra libraries, the NCBI database derived from genome sequencing currently contains 20,917 bacterial species, and is constantly expanding. This paper presents an accurate method that is used to identify pathogens grown on agar plates, and those isolated directly from urine samples, with high accuracy.
rarely causes gastrointestinal diseases but shows an affinity for the endovascular epithelium.
We describe a case of
bacteremia related to vascular prosthesis and pseudoaneurysm infection, with a ...review of the literature.
A 67-year-old male was admitted with a history of fever, weakness and painful swelling of the groin. After unsuccessful treatment with ciprofloxacin, the patient was transferred to our hospital, where he had been previously treated for aortoiliac occlusive disease including a prosthetic aortobifemoral and popliteal bypass with polyester graft placement. An angiography showed a pseudoaneurysm in the groin and, therefore, repair of the pseudoaneurysm, removal of the prosthesis and biologic graft placement were performed. Blood cultures and tissue samples of the vascular prosthesis and pseudoaneurysm yielded
resistant to ciprofloxacin. The patient was treated with meropenem for four weeks, followed by amoxicillin-clavulanate for another two weeks after discharge. Eight previously published cases of
bacteremia due to infected cardiovascular prosthetic devices (prosthetic heart valves, implantable cardioverter-defibrillators and a permanent pacemaker) were summarized in the review.
To our knowledge, this is the first report of a
bacteremia related to post-surgical infection of a vascular prosthesis causing a pseudoaneurysm.
Rationale
Selective derivatization of peptide N‐terminus with 4‐formyl‐benzenesulfonic acid (FBSA) enables chemically activated fragmentation in positive and negative ion modes (ESI+/−) under charge ...reduction conditions. Overlapped positive and negative tandem mass spectra show b‐ions making the assignment of b‐ion series fragments easy and accurate.
Methods
We developed an FBSA–peptide microwave‐assisted derivatization procedure. Derivatized and nonderivatized bovine serum albumin tryptic peptides and insulin non‐tryptic peptide were compared after tandem mass spectrometry (MS/MS) analysis in positive and negative ion modes. A high‐quality data set of sulfonated b‐ions obtained in negative tandem mass spectra of singly charged FBSA–peptides were matched to detected b‐ions in positive MS/MS spectra. Moreover, negative spectra signals were converted and matched against y‐ions in positive tandem mass spectra to identify complete peptide sequences.
Results
The FBSA derivatization procedure produced a significantly improved MS/MS data set (populated by high‐intensity signals of b‐ and y‐ions) compared to commonly used N‐terminal sulfonation reagents. Undesired side reactions almost do not occur, and the procedure reduces the derivatization time. It was found that b‐ion intensities comprise 15% and 13% compared to combined ion intensities generated in positive‐ and negative ion modes, respectively. High visibility of b‐ion series in negative ion mode can be attributed to N‐terminal sulfonation that had no negative effect on the production of b‐ and y‐ion series in positive ion mode.
Conclusions
The FBSA derivatization and de novo sequencing approach outlined here is a reliable method for accurate peptide sequence assignment. Increased production of b‐ions in positive‐ and negative ion modes greatly improves peak assignment and thus enables accurate sequence reconstruction. Implementation of the named methodology would improve the quality of de novo sequencing data and reduce the number of misinterpreted spectra.
•Burkholderia gladioli was identified as a cause of healthcare-associated bacteremia.•The investigation traced to the contaminated multidose vials with saline solution.•Isolates from blood and saline ...showed the same susceptibility patterns.•Pulsed-field gel electrophoresis (PFGE) was used to genotype the strains.•PFGE profile of all B. gladioli isolates demonstrated clonal relatedness.
Burkholderia gladioli has been associated with infections in patients with cystic fibrosis, chronic granulomatous disease, and other immunocompromising conditions. The aim of this study was to better depict the outbreak of healthcare-associated bacteremia caused by B. gladioli due to exposure to contaminated multidose vials with saline solutions.
An environmental and epidemiologic investigation was conducted by the Infection Prevention and Control Team (IPCT) to identify the source of the outbreak in three Croatian hospitals.
During a 3-month period, 13 B. gladioli bacteremia episodes were identified in 10 patients in three Croatian hospitals. At the time of the outbreak, all three hospitals used saline products from the same manufacturer. Two 100-ml multidose vials with saline solutions and needleless dispensing pins were positive for B. gladioli. All 13 bacteremia isolates and two isolates from the saline showed the same antimicrobial susceptibility patterns and pulsed-field gel electrophoresis profile, demonstrating clonal relatedness.
When an environmental pathogen causes an outbreak, contamination of intravenous products must be considered. Close communication between the local IPCT and the National Hospital Infection Control Advisory Committee is essential to conduct a prompt and thorough investigation and find the source of the outbreak.
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Venous thromboembolism (VTE) is a significant public health issue causing severe morbidity and mortality. One of the most vulnerable populations for VTE development are cancer patients. And among ...them, patients with brain tumors have arguably the highest risk of developing this often fatal complication. Hyperglycemia is a well-known factor which leads to a wide variety of pro-thrombotic changes. In this article, we review the current literature on the topic of VTE in brain tumor patients. We also discuss the known correlation between VTE and glycemia, as well as the importance and frequency of glycemia dysregulation in brain tumor patients. Based on the already well-known importance of glucose metabolism in cancer patients, as well as the previous research of our group, we hypothesize that there is a significant number of brain tumor patients who have chronically elevated glycemia, a fact that so-far hasn’t been reported. We argue that these patients carry a significantly higher risk of VTE development and would benefit greatly from strict glycemic control. We present our hypothesis, the ways in which to test it, as well as the possible counter-arguments against it. Our hope is that other investigators will be inspired by our article to continue this type of research, since we consider the topic of VTE in brain tumor patients highly important and urgent, primarily due to its prevalence and severity.
Climbing gyms aim to continuously improve their offerings and make the best use of their infrastructure to provide a unique experience for their clients, the climbers. One approach to achieve this ...goal is to track and analyze climbing sessions from the beginning of the ascent until the climber’s descent. Detecting the climber’s descent is crucial because it indicates when the ascent has ended. This paper discusses an approach that preserves climber privacy (e.g., not using cameras) while considering the convenience of climbers and the costs to the gyms. To this aim, a hardware prototype has been developed to collect data using accelerometer sensors attached to a piece of climbing equipment mounted on the wall, called a quickdraw, which connects the climbing rope to the bolt anchors. The sensors are configured to be energy-efficient, making them practical in terms of expenses and time required for replacement when used in large quantities in a climbing gym. This paper describes the hardware specifications, studies data measured by the sensors in ultra-low power mode, detects sensors’ orientation patterns during descent on different routes, and develops a supervised approach to identify lowering. Additionally, the study emphasizes the benefits of multidisciplinary feature engineering, combining domain-specific knowledge with machine learning to enhance performance and simplify implementation.
Background. Campylobacter fetus rarely causes gastrointestinal diseases but shows an affinity for the endovascular epithelium. Methods. We describe a case of C. fetus bacteremia related to vascular ...prosthesis and pseudoaneurysm infection, with a review of the literature. Results. A 67-year-old male was admitted with a history of fever, weakness and painful swelling of the groin. After unsuccessful treatment with ciprofloxacin, the patient was transferred to our hospital, where he had been previously treated for aortoiliac occlusive disease including a prosthetic aortobifemoral and popliteal bypass with polyester graft placement. An angiography showed a pseudoaneurysm in the groin and, therefore, repair of the pseudoaneurysm, removal of the prosthesis and biologic graft placement were performed. Blood cultures and tissue samples of the vascular prosthesis and pseudoaneurysm yielded C. fetus resistant to ciprofloxacin. The patient was treated with meropenem for four weeks, followed by amoxicillin-clavulanate for another two weeks after discharge. Eight previously published cases of C. fetus bacteremia due to infected cardiovascular prosthetic devices (prosthetic heart valves, implantable cardioverter-defibrillators and a permanent pacemaker) were summarized in the review. Conclusions. To our knowledge, this is the first report of a C. fetus bacteremia related to post-surgical infection of a vascular prosthesis causing a pseudoaneurysm.
Purpose – Many incoming requests for quotation usually compete for the attention of accommodation service provider staff on a daily basis, while some of them might deserve more priority than others. ...Design – This research is therefore based on the correspondence history of a large booking management system that examines the features of quotation requests from aspiring guests in order to learn and predict their actual booking behavior. Approach – In particular, we investigate the effectiveness of various machine learning techniques for predicting whether a request will turn into a booking by using features such as the length of stay, the number and type of guests, and their country of origin. Furthermore, a deeper analysis of the features involved is performed to quantify their impact on the prediction task. Findings – We based our experimental evaluation on a large dataset of correspondence data collected from 2014 to 2019 from a 4-star hotel in the South Tyrol region of Italy. Numerical experiments were conducted to compare the performance of different classification models against the dataset. The results show a potential business advantage in prioritizing requests for proposals based on our approach. Moreover, it becomes clear that it is necessary to solve the class imbalance problem and develop a proper understanding of the domain-specific features to achieve higher precision/recall for the booking class. The investigation on feature importance also exhibits a ranking of informative features, such as the duration of the stay, the number of days prior to the request, and the source/country of the request, for making accurate booking predictions. Originality of the research – To the best of our knowledge, this is one of the first attempts to apply and systematically harness machine learning techniques to request for quotation data in order to predict whether the request will end up in a booking.
•RSSEs mainly output source code artifacts and experts, other types are less explored.•RSSEs providing a comprehensive support for testing phase were not identified.•RSSEs are very task specific, but ...not environment specific.
A recommendation system for software engineering (RSSE) is a software application that provides information items estimated to be valuable for a software engineering task in a given context. Present the results of a systematic literature review to reveal the typical functionality offered by existing RSSEs, research gaps, and possible research directions. We evaluated 46 papers studying the benefits, the data requirements, the information and recommendation types, and the effort requirements of RSSE systems. We include papers describing tools that support source code related development published between 2003 and 2013. The results show that RSSEs typically visualize source code artifacts. They aim to improve system quality, make the development process more efficient and less expensive, lower developer’s cognitive load, and help developers to make better decisions. They mainly support reuse actions and debugging, implementation, and maintenance phases. The majority of the systems are reactive. Unexploited opportunities lie in the development of recommender systems outside the source code domain. Furthermore, current RSSE systems use very limited context information and rely on simple models. Context-adapted and proactive behavior could improve the acceptance of RSSE systems in practice.
Traumatic events that affect physiology and behavior in the current generation may also impact future generations. We demonstrate that an ecologically realistic degree of predation risk prior to ...conception causes lasting changes in the first filial (F1) and second filial (F2) generations. We exposed male and female mice to a live rat (predator stress) or control (non-predator) condition for 5 min. Ten days later, stressed males and females were bred together as were control males and females. Adult F1 offspring from preconception-stressed parents responded to a mild stressor with more anxiety-like behavior and hyperarousal than offspring from control parents. Exposing these F1 offspring to the mild stressor increased neuronal activity (cFOS) in the hippocampus and altered glucocorticoid system function peripherally (plasma corticosterone levels). Even without the mild stressor, F1 offspring from preconception-stressed parents still exhibited more anxiety-like behaviors than controls. Cross-fostering studies confirmed that preconception stress, not maternal social environment, determined offspring behavioral phenotype. The effects of preconception parental stress were also unexpectedly persistent and produced similar behavioral phenotypes in the F2 offspring. Our data illustrate that a surprisingly small amount of preconception predator stress alters the brain, physiology, and behavior of future generations. A better understanding of the 'long shadow' cast by fearful events is critical for understanding the adaptive costs and benefits of transgenerational plasticity. It also suggests the intriguing possibility that similar risk-induced changes are the rule rather than the exception in free-living organisms, and that such multigenerational impacts are as ubiquitous as they are cryptic.
