For a long time necrosis was thought to be an uncontrolled process but evidences recently have revealed that necrosis can also occur in a regulated manner. Necroptosis, a type of programmed necrosis is defined as a death receptor-initiated process under caspase-compromised conditions. The process requires the kinase activity of receptor-interacting protein kinase 1 and 3 (RIPK1 and RIPK3) and mixed lineage kinase domain-like protein (MLKL), as a substrate of RIPK3. The further downstream events remain elusive. We applied known inhibitors to characterize the contributing enzymes in necroptosis and their effect on cell viability and different cellular functions were detected mainly by flow cytometry. Here we report that staurosporine, the classical inducer of intrinsic apoptotic pathway can induce necroptosis under caspase-compromised conditions in U937 cell line. This process could be hampered at least partially by the RIPK1 inhibitor necrotstin-1 and by the heat shock protein 90 kDa inhibitor geldanamycin. Moreover both the staurosporine-triggered and the classical death ligand-induced necroptotic pathway can be effectively arrested by a lysosomal enzyme inhibitor CA-074-OMe and the recently discovered MLKL inhibitor necrosulfonamide. We also confirmed that the enzymatic role of poly(ADP-ribose)polymerase (PARP) is dispensable in necroptosis but it contributes to membrane disruption in secondary necrosis. In conclusion, we identified a novel way of necroptosis induction that can facilitate our understanding of the molecular mechanisms of necroptosis. Our results shed light on alternative application of staurosporine, as a possible anticancer therapeutic agent. Furthermore, we showed that the CA-074-OMe has a target in the signaling pathway leading to necroptosis. Finally, we could differentiate necroptotic and secondary necrotic processes based on participation of PARP enzyme.

A carbapenem-resistant Acinetobacter baumannii (CRAB) outbreak in an intensive care unit (ICU) was contained by an improved infection-control measure that included a disinfectant policy. In our retrospective cohort study, we describe the epidemiological investigations and infection-control measures during this outbreak. Descriptive analysis was used to summarize patient demographics, neurological diseases, surgical treatment, underlying diseases, infection, and outcomes. In December 2023, two CARB-positive patients were observed in the ICU, and four more patients became CRAB-positive in January. During this outbreak, there was an overlap of hospitalization periods among the CRAB-positive patients, and CRAB was isolated from the environment; the isolated CRAB strain was identical. Infection-control measures, including hand hygiene, contact precautions and isolation, surveillance, decolonization, environmental cleaning, and disinfection, were reviewed and modified. The aim of this study was to examine the molecular background of the effectiveness of the disinfectant shift used during successful outbreak control. Experiments were carried out to study the phenotypic sensitivity and genetic background of different disinfectant agents. A thorough analysis of the detected CRAB strain included whole-genome sequencing (WGS), investigation of the qacE and qacEΔ1 genes’ relative expression by qPCR after exposure to different disinfectant solutions, as well as an analysis of biofilm formation. WGS analysis of the CRAB strain identified that an ST2 high-risk clone was responsible for the outbreak, which produced OXA-83 and ADC-30 beta-lactamases; in addition, qacE and qacEΔ1 genes were also detected, which confer resistance to disinfectants containing quaternary ammonium compounds (QACs). A qPCR analysis demonstrated that after exposure to different disinfectants, the gene expression levels of qacE and qacEΔ1 increased and correlated with concentrations of QACs of disinfectants. During the outbreak, the standard-of-care QAC-based disinfectant was changed to a mainly alcohol-based agent in the ICU, which contributed to the successful control of this outbreak, and no additional patients were identified with CRAB. We conclude that continuous surveillance and hand hygiene training combined with fast identification and reaction to new cases, as well as an in-depth analysis of multidrug-resistant outbreak strains and investigation of their disinfectant tolerance/resistance during an outbreak, are essential to effectively control the spread of nosocomial pathogens. The smart policy of disinfectant agent selection played a crucial role in controlling the outbreak and ensuring patient safety in the ICU.

Previous research confirmed gut dysbiosis and translocation of selected intestinal bacteria into the vessel wall in abdominal aortic aneurysm patients. We studied the stool, blood, thrombus and aneurysm microbiomes of 21 abdominal aortic aneurysm patients using 16S rRNA sequencing. Our goals were to determine: 1. whether the microbiome characteristic of an aneurysm differs from that of a healthy vessel, 2. whether bacteria detectable in the aneurysm are translocated from the gut through the bloodstream, 3. whether the enzymatic activity of the aneurysm microbiome can contribute to the destruction of the vessel wall. The abundance of Acinetobacter, Burkholderia, Escherichia, and Sphingobium in the aneurysm samples was significantly higher than that in the microbiome of healthy vessels, but only a part of these bacteria can come from the intestine via the blood. Environmental bacteria due to the oral cavity or skin penetration route, such as Acinetobacter, Sphingobium, Enhydrobacter, and Aquabacterium, were present in the thrombus and aneurysm with a significantly higher abundance compared to the blood. Among the enzymes of the microbiome associated with the healthy vessel wall, Iron-chelate-transporting ATPase and Polar-amino-acid-transporting ATPase have protective effects. In addition, bacterial Peptidylprolyl isomerase activity found in the aneurysm has an aggravating effect on the formation of aneurysm.

Although otitis media with effusion (OME) is a common cause of hearing impairment in children, little is known about its microbiological background. We aimed to analyse the microbiome of the middle ear fluid (MEF) in OME to identify microbiological, demographic and environmental factors that may potentially influence the middle ear microbiome. In addition, we aimed to compare the results of conventional culture techniques and PCR-based methods. 39 samples from children with OME were investigated using conventional culture and 16S rRNA sequencing. Bioinformatic analyses were carried out to assess the microbial communities and their association with clinical data. By conventional culture technique bacteria could be cultured in 33 % of the MEF samples; the most frequent bacterium was Haemophilus influenzae, followed by Staphylococcus species, Cutibacterium acne, and Streptococcus species. The 16S rRNA analysis showed that Alloiococcus was the most abundant bacterium, followed by Haemophilus, Streptococcus. and Sphingobium. A “High Alloiococcus group” with significantly lower and a “Low Alloiococcus group” with significantly higher alpha and beta diversity could be defined. Children born by Caesarean sections had lower beta and Shannon diversity than patients born by natural birth. Breastfeeding for at least six months showed a negative correlation with alpha diversity. Age, previous antibiotic treatment, parental smoking, duration of symptoms, existence of siblings, did not alter the significantly bacterial composition of MEF samples and there were no significant differences in regard to alpha or beta diversity. The conventional culture technique and 16S rRNA results were not congruent. Remarkably, Alloiococcus could not be cultured at all, even by 16S rRNA analysis the presence of Alloiococcus seems to be important. Based on our results, A. otitidis possibly impacts the diversity of middle ear microbiome in children with OME. However, further studies are required to determine the role of A. otidis in middle ear pathologies.

Brain tumors are frequently diagnosed diseases in which etiology and progression largely depend on mutations and genetic factors. Additionally, recent reports document that the microbiome may influence tumor growth, tumor microenvironment, and response to therapy. Our goal was to examine the extent to which the bacterial composition—microbiota—and fungal composition—mycobiota—characteristic of the tumor and its microenvironment correlate with the composition of the gut and blood microbiota and mycobiota in five randomly selected brain tumor patients. The bacterial composition of the tumor, tumor-adjacent tissue (TAT), blood, and gut samples of the five patients were analyzed by 16S rRNA and ITS-based sequencing in order to determine the bacterial and fungal composition. The gut microbiome and mycobiome composition showed individual and tissue-specific signatures in each patient. The microbiome composition of the blood, TAT, and tumor tissue was very similar in each patient, dominated by Klebsiella, Enterococcus, Blautia, and Lactobacillus spp. In contrast, the mycobiome composition of the blood, TAT, and tumor showed a diverse, individual picture. The most common fungal species in the blood and TAT were Tomentella, Didymosphaeria, Alternaria, Penicillium, Mycosphaerella, and Discosia. The blood and TAT mycobiome were similar to each other but unique and characteristic of the patients. In contrast, in the tumor tissues, Alternaria, Malassezia, Schizophyllum, and Tomentella genus were the most common fungi genus. Our results showed that the presence of fungi in tumors shows a unique pattern that is independent of the pattern observed in the gut, blood, and tumor environment and that the effects of the mycobiome are distinct and cannot be associated with those of the microbiome. Elucidating the role of fungi in tumors and exploring the relationship between fungi and brain tumor types may open up further therapeutic options.

Background: An external ventricular drain (EVD) is used to release elevated intracranial pressure by draining cerebrospinal fluid (CSF) from the brain’s ventricles. The establishment of an EVD is one of the most commonly performed neurosurgical procedures to treat intracranial pressure in patients. Nevertheless, infections are very frequent complications. Identifying the risk factors for EVD-related infections is a key to improving patient safety and outcomes. Methods: We conducted a retrospective, single-center study of patients who underwent EVD implantation between January 2022 and March 2024. Patients were classified into infected and non-infected groups based on their clinical symptoms, as well as laboratory and microbiological results. Patient characteristics and possible risk factors for infection were compared between the two groups. Results: In total, 123 patients treated with 156 EVDs were included in this study, with a mean age of 55.8 (range: 25–84) years. EVD-associated infections were observed in 37 patients (30%). We found no significant association between infection risk and patient characteristics, including gender, primary diagnosis, craniotomy, or immunosuppression. There was no significant difference in terms of EVD insertion, i.e., whether the insertion took place in the operating room (OR) with antibiotic prophylaxis or outside the OR with no periprocedural antibiotic treatment. However, within the intensive care unit (ICU), EVD infection was much lower (13%) if EVD insertion took place in a single-bed room compared to multiple-bed room insertions (34%). Furthermore, there were significant differences in terms of the duration of first EVD (both single and multiple catheterizations) (p < 0.0001) and the total catheterization time (p = 0.0001). Additionally, there was a significant association with patient days in the ICU and EVD catheterization. Conclusions: Revisiting infection control measures is necessary, with special attention to the replacement of EVDs in single-bed ICU rooms, to introduce antibiotic prophylaxis in the ICU. Minimizing unnecessary EVD manipulation during catheterization is crucial in order to decrease the risk of EVD infection.