DEAE/Catechol-Chitosan Conjugates as Bioactive Polymers: Synthesis, Characterization, and Potential Applications.

This work provides the first description of the synthesis and characterization of water-soluble chitosan (Cs) derivatives based on the conjugation of both diethylaminoethyl (DEAE) and catechol groups onto the Cs backbone (Cs-DC) in order to obtain a Cs derivative with antioxidant and antimicrobial properties. The degree of substitution [DS (%)] was 35.46% for DEAE and 2.53% for catechol, determined by spectroscopy. Changes in the molecular packing due to the incorporation of both pendant groups were described by X-ray diffraction and thermogravimetric analysis. For Cs, the crystallinity index was 59.46% and the maximum decomposition rate appeared at 309.3 °C, while for Cs-DC, the values corresponded to 16.98% and 236.4 °C, respectively. The incorporation of DEAE and catechol groups also increases the solubility of the polymer at pH > 7 without harming the antimicrobial activity displayed by the unmodified polymer. The catecholic derivatives increase the radical scavenging activity in terms of the half-maximum effective concentration (EC50). An EC50 of 1.20 µg/mL was found for neat hydrocaffeic acid (HCA) solution, while for chitosan-catechol (Cs-Ca) and Cs-DC solutions, concentrations equivalent to free HCA of 0.33 and 0.41 µg/mL were required, respectively. Cell culture results show that all Cs derivatives have low cytotoxicity, and Cs-DC showed the ability to reduce the activity of reactive oxygen species by 40% at concentrations as low as 4 µg/mL. Polymeric nanoparticles of Cs derivatives with a hydrodynamic diameter (Dh) of around 200 nm, unimodal size distributions, and a negative ζ-potential were obtained by ionotropic gelation and coated with hyaluronic acid in aqueous suspension, providing the multifunctional nanoparticles with higher stability and a narrower size distribution.

Sequence-Function Relationships in Phage-Encoded Bacterial Cell Wall Lytic Enzymes and Their Implications for Phage-Derived Product Design.

Phage (endo)lysins are thought to be a viable alternative to usual antibiotic chemotherapy to fight resistant bacterial infections. However, a comprehensive view of lysins' structure and properties regarding their function, with an applied focus, is somewhat lacking. Current literature suggests that specific features typical of lysins from phages infecting Gram-negative bacteria (G-) (higher net charge and amphipathic helices) are responsible for improved interaction with the G- envelope. Such antimicrobial peptide (AMP)-like elements are also of interest for antimicrobial molecule design. Thus, this study aims to provide an updated view on the primary structural landscape of phage lysins to clarify the evolutionary importance of several sequence-predicted properties, particularly for the interaction with the G- surface. A database of 2,182 lysin sequences was compiled, containing relevant information such as domain architectures, data on the phages' host bacteria, and sequence-predicted physicochemical properties. Based on such classifiers, an investigation of the differential appearance of certain features was conducted. This analysis revealed different lysin architectural variants that are preferably found in phages infecting certain bacterial hosts. In particular, some physicochemical properties (higher net charge, hydrophobicity, hydrophobic moment, and aliphatic index) were associated with G- phage lysins, appearing specifically at their C-terminal end. Information on the remarkable genetic specialization of lysins regarding the features of the bacterial hosts is provided, specifically supporting the nowadays-common hypothesis that lysins from G- usually contain AMP-like regions. IMPORTANCE Phage-encoded lytic enzymes, also called lysins, are one of the most promising alternatives to common antibiotics. The potential of lysins as novel antimicrobials to tackle antibiotic-resistant bacteria not only arises from features such as a lower chance to provoke resistance but also from their versatility as synthetic biology parts. Functional modules derived from lysins are currently being used for the design of novel antimicrobials with desired properties. This study provides a view of the lysin diversity landscape by examining a set of phage lysin genes. We have uncovered the fundamental differences between the lysins from phages that infect bacteria with different superficial architectures and, thus, the reach of their specialization regarding cell wall structures. These results provide clarity and evidence to sustain some of the common hypotheses in current literature, as well as making available an updated and characterized database of lysins sequences for further developments.

Partially open stent after balloon catheter iatrogenic perforation. How to solve this complication using a novel technique? The Mij-Her technique.

Complications related to pulmonary artery stenting are potentially life-threatening. We reported a novel technique of how to achieve the introduction of a partial dilated stent into a long sheath using a snare in the event of a iatrogenic perforation of a balloon catheter.There are no publications of similar techniques describing successful resolution of this type of complication.

Transcatheter Closure of Perimembranous Ventricular Septal Defects Using Different Generations of Amplatzer Devices: Multicenter Experience.

OBJECTIVES: To demonstrate safety and efficacy of using different generations of softer Amplatzer™ devices for ventricular septal defect (VSD) closure to avoid serious complications at follow-up. BACKGROUND: Transcatheter closure of perimembranous ventricular septal defects (PmVSD) is a well-established procedure; however, it is associated with unacceptable incidence of complete heart block. Great advantages have been achieved by using softer devices for VSD transcatheter closure. The first and second generation of Amplatzer™ occluders (AVP II, ADO, and ADO II) seem to offer a safe and attractive alternative for this procedure. These devices can be delivered using either an arterial (retrograde) or venous (prograde) approach. METHODS AND RESULTS: Patients with congenital PmVSD who underwent transcatheter closure using ADO, ADO II, and AVP II devices were included. Primary end point was to determine efficacy and safety of these generations of devices and to determine the incidence of complications at follow-up (complete AV block and aortic/tricuspid/mitral regurgitation). One hundred and nineteen patients underwent VSD closure at a median age of 5 years (8 months-54 years). During the catheterization, there were only minor complications and at follow-up of 36 ± 25.7 months (up to 99 months), the closure rate was high of 98.3% and freedom from AV block was 100%. CONCLUSIONS: The use of softer Amplatzer™ devices is a good alternative to achieve PmVSD closure safely with no risk of AVB during the procedure or at midterm follow-up.

Atrial septal defect closure with the new Cardia Ultrasept II™ device with interposed Goretex patch: Mexican experience - has the perforation of Ivalon's membrane been solved?

OBJECTIVES: The objective of this study was to demonstrate the safety and feasibility of using the new Cardia Ultrasept II™ device with interposed Goretex patch referring to the perforation of polyvinyl alcohol membrane. BACKGROUND: Great advances have been made in the development of devices for closure of atrial septal defect. The Cardia Ultrasept II™ with interposed Goretex patch is the modified last generation of Cardia devices, having the advantage of a super-low profile within the atria and an integral locking delivery-retrieval mechanism that ensures safe deployment. In addition, with the interposition of the Goretex, it has been possible to abolish perforation of Ivalon's membrane as a complication.Methods and resultsPatients with ostium secundum atrial septal defect with surrounding rims with a minimum length of 5 mm and who underwent atrial septal defect closure with the new Ultrasept II™ with Goretex patch were included from two paediatric cardiac centres. Primary end point was to determine perforation of the Goretex membrane at follow-up; secondary end point included right ventricular diastolic diameter. In total, 30 patients underwent atrial septal defect closure at a median age of 6 (1-29) years. At follow-up for 6 (range, 1-15) months, freedom from perforations was 100%. A continuous decrease in right ventricular diastolic diameter was found with an initial median of 30 (25-49) mm and after catheterisation of 27.5 (18-33) mm, p=0.01, and Z-score of 2.6 (1.7-3.6) versus 1.9 (1-2.9) after procedure, p=0.01. CONCLUSIONS: The new modified generation of the Ultrasept II™ device with interposed Goretex patch is a good alternative to achieve atrial septal defect closure safely and feasibly with no membrane perforation at follow-up.

Aortic iatrogenic perforation during transseptal puncture and successful occlusion with Amplatzer ductal occluder in a case of mitral paravalvular leak closure.

Complications of transseptal puncture are significant and potentially life threatening. Aortic perforation is one of these complications and it needs to be repaired immediately. We report the case of a 48-year-old female with a history of rheumatic mitral valve disease. She underwent three previous mitral valve replacements. Her last echocardiogram reported an anterolateral leak in the mitral prosthesis. Catheterization was performed. During the procedure, when attempting to perform transseptal puncture, catheterization was complicated by a forcefully puncture of the aortic root by the Brockenbrough needle followed by an immediately advancement of an 8-Fr Mullins sheath. We decided to leave the 8-Fr sheath in the aortic root recognizing the danger of removing the sheath and finally we advanced a 6/4 mm Amplatzer ductal occluder (ADO I) through the Mullins sheath and under fluoroscopy and TEE guidance we achieved a successful deployment of the device and closure of the perforation. Subsequently, the paravalvular leak was closed with an Amplatzer Vascular Plug (AVP III 10/5 mm). There are only three cases of a similar technique for the same injury in which the authors describe successful closing of aortic perforation with percutaneous closure devices. Our case is the first described during a mitral paravalvular leak closure. It is also the first to describe a different technique of leaving the Mullins sheath in the aortic root and advancing the Amplatzer device through it to achieve successful closure of the aortic perforation. We preferred the percutaneous closure over open-heart repair. © 2015 Wiley Periodicals, Inc.

Full-length genome characterization and genetic relatedness analysis of hepatitis A virus outbreak strains associated with acute liver failure among children.

Clinical infection by hepatitis A virus (HAV) is generally self-limited but in some cases can progress to liver failure. Here, an HAV outbreak investigation among children with acute liver failure in a highly endemic country is presented. In addition, a sensitive method for HAV whole genome amplification and sequencing suitable for analysis of clinical samples is described. In this setting, two fatal cases attributed to acute liver failure and two asymptomatic cases living in the same household were identified. In a second household, one HAV case was observed with jaundice which resolved spontaneously. Partial molecular characterization showed that both households were infected by HAV subtype IA; however, the infecting strains in the two households were different. The HAV outbreak strains recovered from all cases grouped together within cluster IA1, which contains closely related HAV strains from the United States commonly associated with international travelers. Full-genome HAV sequences obtained from the household with the acute liver failure cases were related (genetic distances ranging from 0.01% to 0.04%), indicating a common-source infection. Interestingly, the strain recovered from the asymptomatic household contact was nearly identical to the strain causing acute liver failure. The whole genome sequence from the case in the second household was distinctly different from the strains associated with acute liver failure. Thus, infection with almost identical HAV strains resulted in drastically different clinical outcomes.

Knowledge and technology transfer to improve the municipal solid waste management system of Durango City, Mexico.

As society evolves its welfare level increases, and as a consequence the amount of municipal solid waste increases, imposing great challenges to municipal authorities. In developed countries, municipalities have established integrated management schemes to handle, treat, and dispose of municipal solid waste in an economical and environmentally sound manner. Municipalities of developing and transition countries are not exempted from the challenges involving municipal solid waste handling, but their task is not easy to accomplish since they face budget deficits, lack of knowledge, and deficiencies in infrastructure and equipment. In the northern territory of Mexico, the municipality of Durango is facing the challenge of increased volumes of waste with a lack of adequate facilities and infrastructure. This article analyses the evolution of the municipal solid waste management of Durango city, which includes actions such as proper facilities construction, equipment acquisition, and the implementation of social programmes. The World Bank, offering courses to municipal managers on landfill operation and waste management, promoted the process of knowledge and technology transfer. Thereafter, municipal authorities attended regional and some international workshops on waste management. In addition they followed suggestions of international contractors and equipment dealers with the intention to improve the situation of the waste management of the city. After a 15-year period, transfer of knowledge and technology resulted in a modern municipal solid waste management system in Durango municipality. The actual system did not reach the standard levels of an integrated waste management system, nevertheless, a functional evaluation shows clear indications that municipality actions have put them on the right pathway.

[Interventionism in congenital heart disease in Chiapas. The history after thousand cases performed]. / El intervencionismo en cardiopatías congénitas en Chiapas. La historia luego de mil casos realizados.

Background: Congenital heart disease is the most common birth defect and the leading cause of childhood mortality in high-income countries. In these countries, the prognosis for a child born with congenital heart disease is excellent, with over 90% achieving adulthood. However, in the low and lower-middle-income countries, as ours, the outlook is starkly different. In Chiapas, because of the progress of the hemodynamics program, more and more types of congenital heart diseases are susceptible to being treated by cardiac catheterization. Objective: To show the global experience of the interventionism in congenital heart diseases in Chiapas from its inception to recent days. Method: Through a retrospective study from April 2016 to June 2023, we reviewed the electronic files of the total of patients who underwent cardiac catheterism during the same period of time. Results: A total of 1000 procedures were performed, 581 in female patients, with a median age of 4 years (1 day to 77 years). Of the total procedures, 115 (11.5%) were diagnostic catheterizations and 885 (88.5%) were interventional. Conclusions: Cardiac catheterization in pediatrics in Chiapas has displaced cardiac surgery in a large percentage, and the results that have been obtained are undoubtedly encouraging, which already represents a decentralization in the care of congenital heart diseases in our country.

Antecedentes: Las cardiopatías congénitas son el defecto congénito más común y la primera causa de mortalidad infantil en los países de alto ingreso económico. En estos países, el pronóstico de los pacientes nacidos con estos defectos es excelente, llegando el 90% de ellos hasta la edad adulta. Sin embargo, en los países de mediano o bajo ingreso económico, como el nuestro, el pronóstico es completamente distinto. En el Estado de Chiapas, como resultado del avance del programa de hemodinamia, cada vez más tipos de cardiopatías congénitas son susceptibles de ser tratadas por cateterismo cardiaco. Objetivo: Mostrar la experiencia global actual de la hemodinamia en cardiopatías congénitas en Chiapas después de haber alcanzado los primeros 1000 casos realizados desde el inicio de nuestro programa. Método: A través de un estudio retrospectivo que abarcó de abril de 2016 a junio de 2023 revisamos los expedientes electrónicos del total de pacientes que fueron llevados a cateterismo cardiaco durante ese periodo. Resultados: Se realizaron un total de 1000 procedimientos, 581 en pacientes del sexo femenino, con una mediana de edad de 4 años (1 día a 77 años). Del total de los procedimientos, 115 (11.5%) fueron cateterismos diagnósticos y 885 (88.5%) intervencionistas. Conclusiones: El cateterismo cardiaco en cardiopatías congénitas en el Estado de Chiapas ha desplazado a la cirugía cardiaca en un amplio porcentaje, y los resultados obtenidos son sin duda alentadores, lo cual representa ya una descentralización en la atención de las cardiopatías congénitas en nuestro país.

The New SH3b_T Domain Increases the Structural and Functional Variability Among SH3b-Like CBDs from Staphylococcal Phage Endolysins.

Endolysins, proteins encoded by phages to lyse their hosts and release their progeny, have evolved to adapt to the structural features of each host. The endolysins from Staphylococcus-infecting phages typically feature complex architectures with two enzymatically active domains (EADs) and one cell wall-binding domain (CBD) belonging to the bacterial SH3 (SH3b) superfamily. This study focuses on three SH3b-like CBDs from representative staphylococcal phage endolysins (LysRODI, LysC1C and LysIPLA5) that were structurally and functionally characterized. While RODI_CBD and C1C_CBD were assigned to the well-known SH3_5 family, a new family, SH3b_T (PF24246), was identified using the CBD from LysIPLA5 as a model. GFP-fused CBDs were created to assess their differential binding to a collection of staphylococcal strains. IPLA5_CBD showed enhanced binding to Staphylococcus epidermidis, while RODI_CBD and C1C_CBD exhibited distinct binding profiles, with RODI_CBD targeting Staphylococcus aureus specifically and C1C_CBD displaying broad binding. Sequence comparisons suggested that a few differences in key amino acids could be responsible for the latter binding difference. The CBDs modulated the activity spectrum of synthetic EAD-CBD combinations in accordance with the previous binding profiles, but in a manner that was also dependent on the EAD present in the fusion protein. These results serve as a context for the diversity and versatility of SH3b domains in staphylococcal endolysins, providing insights on how (i) the CBDs from this superfamily have diverged to adapt to diverse bacterial ligands in spite of sharing a common fold; and (ii) the evolution of specificity relies on the EAD-CBD combination rather than solely the CBD.

You get what you test for: The killing effect of phage lysins is highly dependent on buffer tonicity and ionic strength.

The phage lysin field has done nothing but grow in the last decades. As a result, many different research groups around the world are contributing to the field, often with certain methodological differences that pose a challenge to the interpretation and comparison of results. In this work, we present the case study of three Acinetobacter baumannii-targeting phage lysins (wild-type endolysin LysMK34 plus engineered lysins eLysMK34 and 1D10) plus one lysin with broad activity against Gram-positive bacteria (PlySs2) to provide exemplary evidence on the risks of generalization when using one of the most common lysin evaluation assays: the killing assay with resting cells. To that end, we performed killing assays with the aforementioned lysins using hypo-, iso- and hypertonic buffers plus human serum either as the reaction or the dilution medium in a systematic manner. Our findings stress the perils of creating hypotonic conditions or a hypotonic shock during a killing assay, suggesting that hypotonic buffers should be avoided as a test environment or as diluents before plating to avoid overestimation of the killing effect in the assayed conditions. As a conclusion, we suggest that the nature of both the incubation and the dilution buffers should be always clearly identified when reporting killing activity data, and that for experimental consistency the same incubation buffer should be used as a diluent for posterior serial dilution and plating unless explicitly required by the experimental design. In addition, the most appropriate buffer mimicking the final application must be chosen to obtain relevant results.

(Preoperative instillation of epinephrine and lidocaine may reduce the surgical time of endoscopic treatment of GTPS.). / La instilación preoperatoria de epinefrina y lidocaína puede reducir el tiempo quirúrgico del tratamiento endoscópico de SDTM.

INTRODUCTION: Greater Trochanteric Pain Syndrome (GTPS) is a multifactorial clinical condition affecting the lateral area of the hip. Although conservative treatment shows good results, some patients may still require surgical bursectomy, which can be performed either openly or endoscopically. One of the main technical difficulties of the endoscopic procedure is intraoperative bleeding, which can hinder the medical team's vision and increase the operation time for endoscopic treatment of GTPS. HYPOTHESIS: An instillation of vasoconstrictors and local anesthetics before endoscopy will cause less intraoperative bleeding, which will translate into shorter surgical time. MATERIALS AND METHODS: A prospective cohort was retrospectively divided based on the use or absence of a preoperative instillation of physiological saline solution with epinephrine and lidocaine. Surgical time was measured in each procedure and compared between the two groups. RESULTS: 139 hips from 139 patients were included in the analysis. 102 patients were included in the instillation group versus 37 in the control group. The surgical time was significantly shorter in the instillation group than in the control group, with an average (standard deviation) of 52.01 (14.71) and 72.30 (11.70) minutes, respectively (p < 0.001). CONCLUSION: The instillation of a physiological saline solution with epinephrine and lidocaine prior to the surgical treatment of GTPS is effective in reducing surgical times, likely due to a reduction in intraoperative bleeding. Future research should focus on more direct outcomes such as intraoperative blood loss and between different instillation protocols.

Thermotogota diversity and distribution patterns revealed in Auka and JaichMaa 'ja 'ag hydrothermal vent fields in the Pescadero Basin, Gulf of California.

Discovering new deep hydrothermal vent systems is one of the biggest challenges in ocean exploration. They are a unique window to elucidate the physical, geochemical, and biological processes that occur on the seafloor and are involved in the evolution of life on Earth. In this study, we present a molecular analysis of the microbial composition within the newly discovered hydrothermal vent field, JaichMaa 'ja 'ag, situated in the Southern Pescadero Basin within the Gulf of California. During the cruise expedition FK181031 in 2018, 33 sediment cores were collected from various sites within the Pescadero vent fields and processed for 16S rRNA amplicon sequence variants (ASVs) and geochemical analysis. Correlative analysis of the chemical composition of hydrothermal pore fluids and microbial abundances identified several sediment-associated phyla, including Thermotogota, that appear to be enriched in sediment horizons impacted by hydrothermal fluid flow. Comparative analysis of Thermotogota with the previously explored Auka hydrothermal vent field situated 2 km away displayed broad similarity between the two locations, although at finer scales (e.g., ASV level), there were notable differences that point to core-to-core and site-level factors revealing distinct patterns of distribution and abundance within these two sediment-hosted hydrothermal vent fields. These patterns are intricately linked to the specific physical and geochemical conditions defining each vent, illuminating the complexity of this unique deep ocean chemosynthetic ecosystem.

Meeting Report of the Second Symposium of the Belgian Society for Viruses of Microbes and Launch of the Phage Valley.

The second symposium of the Belgian Society for Viruses of Microbes (BSVoM) took place on 8 September 2023 at the University of Liège with 141 participants from 10 countries. The meeting program covered three thematic sessions opened by international keynote speakers: two sessions were devoted to "Fundamental research in phage ecology and biology" and the third one to the "Present and future applications of phages". During this one day symposium, four invited keynote lectures, nine selected talks and eight student pitches were given along with thirty presented posters. The president of the Belgian Society for Viruses of Microbes, Prof. Yves Briers, took advantage of this symposium to launch the Phage Valley concept that will put the spotlight on the exceptionally high density of researchers investigating viruses of microbes as well as the successful triple helix approach between academia, industry and government in Belgium.

Low-performance diagnosis of covered anaerobic lagoons as a waste management strategy in the intensive dairy industry.

Covered anaerobic lagoons (CALs) are Latin America's main livestock waste treatment systems. Mexico has 680 CALs that present low biogas yields (0.05 m3 m-3 digester d-1) and low COD removal rates (< 60%). This work focused on diagnosing CAL´s low performance in dairy farms by determining and analyzing operational parameters. Seven CALs located in the main dairy basin of Mexico were analyzed. The sampling areas for each CAL were the supernatant, the active zone, settled sludge, and digester inlet and outlet. The variation of the process parameter values corroborated that CALs appeared stratified and not working as expected. The sludge zone, comprising 50-58% of total solids content and 1-15% of total CALs volume, showed an elemental compounds content suitable for organic fertilizer (340, 48, and 5 kg t-1 of C, N, and S, respectively). However, this zone contained, at least, 85% of the slowly hydrolysable material; the methanogenic potential was less than 87 mL CH4 g VS-1, and the C/N ratio ranged from 4.9 to 17, outside of the optimal range. The biogas produced did not exceed 60% of methane content and more than 3000 ppm of H2S. The sludge zone significantly influences the lagoon's dynamics since it is a nutrient sink. Furthermore, the lack of agitation is the leading cause for the low energy yield and the low removal of organic matter rate. This work provides valuable information to address the operational problems within the CALs improving our understanding that shall allow proposing reactivation alternatives.

What's in a Name? An Overview of the Proliferating Nomenclature in the Field of Phage Lysins.

In the last few years, the volume of research produced on phage lysins has grown spectacularly due to the interest in using them as alternative antimicrobials. As a result, a plethora of naming customs has sprouted among the different research groups devoted to them. While the naming diversity accounts for the vitality of the topic, on too many occasions it also creates some confusion and lack of comparability between different works. This article aims at clarifying the ambiguities found among names referring to phage lysins. We do so by tackling the naming customs historically, framing their original adoption, and employing a semantic classification to facilitate their discussion. We propose a periodization of phage lysin research that begins at the discovery era, in the early 20th century, enriches with a strong molecular biology period, and grows into a current time of markedly applied research. During these different periods, names referring to the general concepts surrounding lysins have been created and adopted, as well as other more specific terms related to their structure and function or, finally, names that have been coined for the antimicrobial application and engineering of phage lysins. Thus, this article means to serve as an invitation to the global lysin community to take action and discuss a widely supported, standardized nomenclature.

Enzybiotic-mediated antimicrobial functionalization of polyhydroxyalkanoates.

Polymeric nanoparticles (NPs) present some ideal properties as biomedical nanocarriers for targeted drug delivery such as enhanced translocation through body barriers. Biopolymers, such as polyhydroxyalkanoates (PHAs) are gaining attention as nanocarrier biomaterials due to their inherent biocompatibility, biodegradability, and ability to be vehiculized through hydrophobic media, such as the lung surfactant (LS). Upon colonization of the lung alveoli, below the LS layer, Streptococcus pneumoniae, causes community-acquired pneumonia, a severe respiratory condition. In this work, we convert PHA NPs into an antimicrobial material by the immobilization of an enzybiotic, an antimicrobial enzyme, via a minimal PHA affinity tag. We first produced the fusion protein M711, comprising the minimized PHA affinity tag, MinP, and the enzybiotic Cpl-711, which specifically targets S. pneumoniae. Then, a PHA nanoparticulate suspension with adequate physicochemical properties for pulmonary delivery was formulated, and NPs were decorated with M711. Finally, we assessed the antipneumococcal activity of the nanosystem against planktonic and biofilm forms of S. pneumoniae. The resulting system displayed sustained antimicrobial activity against both, free and sessile cells, confirming that tag-mediated immobilization of enzybiotics on PHAs is a promising platform for bioactive antimicrobial functionalization.

Distinct mode of action of a highly stable, engineered phage lysin killing Gram-negative bacteria.

IMPORTANCE: Engineered lysins are considered as highly promising alternatives for antibiotics. Our previous screening study using VersaTile technology identified 1D10 as a possible lead compound with activity against Acinetobacter baumannii strains under elevated human serum concentrations. In this manuscript, we reveal an unexpected mode of action and exceptional thermoresistance for lysin 1D10. Our findings shed new light on the development of engineered lysins, providing valuable insights for future research in this field.

Alterations of the Ca2+ clearing mechanisms by type 2 diabetes in aortic smooth muscle cells of Zucker diabetic fatty rat.

Type 2 Diabetes Mellitus (T2DM) is a rapidly rising disease with cardiovascular complications constituting the most common cause of death among diabetic patients. Chronic hyperglycemia can induce vascular dysfunction through damage of the components of the vascular wall, such as vascular smooth muscle cells (VSMCs), which regulate vascular tone and contribute to vascular repair and remodeling. These functions are dependent on intracellular Ca2+ changes. The mechanisms by which T2DM affects Ca2+ handling in VSMCs still remain poorly understood. Therefore, the objective of this study was to determine whether and how T2DM affects Ca2+ homeostasis in VSMCs. We evaluated intracellular Ca2+ signaling in VSMCs from Zucker Diabetic Fatty rats using Ca2+ imaging with Fura-2/AM. Our results indicate that T2DM decreases Ca2+ release from the sarcoplasmic reticulum (SR) and increases the activity of store-operated channels (SOCs). Moreover, we were able to identify an enhancement of the activity of the main Ca2+ extrusion mechanisms (SERCA, PMCA and NCX) during the early stage of the decay of the ATP-induced Ca2+ transient. In addition, we found an increase in Ca2+ entry through the reverse mode of NCX and a decrease in SERCA and PMCA activity during the late stage of the signal decay. These effects were appreciated as a shortening of ATP-induced Ca2+ transient during the early stage of the decay, as well as an increase in the amplitude of the following plateau. Enhanced cytosolic Ca2+ activity in VSMCs could contribute to vascular dysfunction associated with T2DM.