Hasil untuk "Microbiology"

Yi-Wei Tang, Jonathan E. Schmitz, D. Persing et al.

The COVID-19 outbreak has had a major impact on clinical microbiology laboratories in the past several months. This commentary covers current issues and challenges for the laboratory diagnosis of infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In the preanalytical stage, collecting the proper respiratory tract specimen at the right time from the right anatomic site is essential for a prompt and accurate molecular diagnosis of COVID-19. Appropriate measures are required to keep laboratory staff safe while producing reliable test results. ABSTRACT The COVID-19 outbreak has had a major impact on clinical microbiology laboratories in the past several months. This commentary covers current issues and challenges for the laboratory diagnosis of infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In the preanalytical stage, collecting the proper respiratory tract specimen at the right time from the right anatomic site is essential for a prompt and accurate molecular diagnosis of COVID-19. Appropriate measures are required to keep laboratory staff safe while producing reliable test results. In the analytic stage, real-time reverse transcription-PCR (RT-PCR) assays remain the molecular test of choice for the etiologic diagnosis of SARS-CoV-2 infection while antibody-based techniques are being introduced as supplemental tools. In the postanalytical stage, testing results should be carefully interpreted using both molecular and serological findings. Finally, random-access, integrated devices available at the point of care with scalable capacities will facilitate the rapid and accurate diagnosis and monitoring of SARS-CoV-2 infections and greatly assist in the control of this outbreak.

A. M. Eren, E. Kiefl, Alon Shaiber et al.

Athanasios Typas, M. Banzhaf, C. Gross et al.

Jan Hudzicki

W. Martin, J. Baross, D. Kelley et al.

K. Lewis

E. Rosenberg, O. Koren, L. Reshef et al.

R. Gibson, J. Burns, B. Ramsey

Martin Sindelar, Anna Kocurkova, Matej Simek et al.

ABSTRACT The ability of gut microbes to degrade host‐ and diet‐derived glycans is central to microbiome ecology and host interactions, yet predicting these functions in silico remains challenging. Hyaluronan (HA), a glycosaminoglycan (GAG) abundant in host tissues and dietary supplements, is depolymerized by specialized polysaccharide utilization loci (PULs) in Bacteroides. Here, we combined comparative protein analysis, functional assays, and quantitative proteomics to evaluate the reliability of sequence‐based predictions of HA utilization. Clustering of more than 3900 PL8 and GH88 protein sequences from 54 Bacteroides species did not distinguish known HA degraders from nondegraders, underscoring the limited predictive power of these enzymes alone. Experimental validation in Bacteroides acidifaciens DSM 111135 and Bacteroides thetaiotaomicron DSM 2079 confirmed HA degradation, as HA‐derived fragments were identified by liquid chromatography–mass spectrometry. Proteomic profiling revealed coordinated induction of both canonical GAG‐specific PULs‐encoded proteins and noncanonical accessory proteins (BT4410/BT4411) in response to HA in both species. Incorporating such noncanonical components into comparative frameworks may improve prediction of glycan utilization potential and help link microbial genomic content to ecological function in the gut.

Martha Patricia Islas-Islas, Aleida Monserrat Coss-Orozco, Diana Moroni-González et al.

<b>Background/Objectives</b>: Type 2 diabetes (T2D) and obesity are chronic metabolic disorders associated with cognitive impairment and neuronal damage. The hippocampus, a region sensitive to nutrient excess, is critical for integrating sensory and metabolic signals. This study aimed to determine the early onset of cognitive and motor deficits induced by obesity and/or hyperglycemia and to characterize associated hippocampal alterations in Zucker Diabetic Fatty (ZDF) rats. <b>Methods:</b> Male ZDF rats (13 weeks old) were categorized into three groups: lean control, obese normoglycemic (ZDF-NG), and obese hyperglycemic (ZDF-HG). Assessments included zoometric parameters (weight and adiposity), biochemical assays (glucose tolerance, insulin response, and lipid profile), and behavioral tests (Open Field and Novel Object Recognition). Hippocampal health was evaluated through stereological neuronal density analysis and redox balance markers. <b>Results:</b> Both obese groups exhibited significant visceral adiposity and hyperlipidemia. The ZDF-HG group was further characterized by glucose intolerance, hepatic insulin resistance, and reduced β-cell function. Behavioral results showed that while obesity decreased motor activity, hyperglycemia significantly exacerbated the loss of both short- and long-term recognition memory. Histologically, obesity was associated with decreased neuronal density in the hippocampal DG and CA1 regions. Furthermore, hippocampal ROS was significantly elevated in the ZDF-HG group, and glutathione reductase activity was reduced in both obese phenotypes. <b>Conclusions:</b> The findings demonstrate that obesity initiates hippocampal neurodegeneration and motor decline, and that hyperglycemia severely impairs recognition memory. These results emphasize the critical interplay between metabolic dysfunction and cognitive decline, highlighting the necessity of managing both obesity and T2D to prevent early neurodegenerative changes.

Zilin Zhao, Hejia Wan, Xiaohui Liu et al.

Bartosz Orzechowski, Jan Miciński, Katarzyna Ząbek et al.

With the aim to investigate the immunomodulatory potential of selenitetriglycerides (SeTG), a new lipophilic Se (IV) compound, 30 sheep (15 sheep/treatment) were used in a completely random design to receive the SeGT supplement as follows: (1) no SeGT supplement (Control) and (2) daily dosage of 2 mL of SeGT (equivalent to 1 mg Se/kg BW) during the first 7 days of the evaluation, which lasted 28 d. Individually, blood samples were collected on days 0, 14, and 28 to measure and assess parameters of innate cellular and humoral immunity, including respiratory burst activity (RBA) and potential killing activity (PKA) of monocytes and granulocytes, proliferative response of lymphocytes stimulated with ConA (Concovalin A) and LPS (lipopolisaccharidde), lysozyme activity, ceruloplasmin activity, and gamma globulin levels. From the 14th day, supplemental SeTG saw significant increases (<i>p</i> ≤ 0.001) in RBA and PKA parameters, as well as enhanced proliferative responses of lymphocytes compared with controls. Both innate humoral immunity (elevated lysozyme activity) and adaptive humoral immunity (increased gamma globulin levels) were positively influenced (<i>p</i> ≤ 0.01), whereas ceruloplasmin activity remained unchanged. Under the conditions in which the current experiment was carried out, SeGT showed good promise to modulate immunity in a short period (28 d). Further research should explore experiments with a greater number of animals over long-term periods of evaluation under production system conditions.

Xin Luo, Ting Mao, Xi Wang et al.

Abstract Cholestasis, a bile flow disorder common to many liver diseases, currently lacks effective treatments. Emerging evidence links gut microbiota disturbances to cholestatic liver injury. Here, an antibiotic cocktail (ABX)-treated mouse model confirmed the indispensable role of the intestinal microbiota, with marked shifts including increased Alistipes putredinis (A. putredinis) and decreased Clostridium spp. (C. spp.). In vitro, ferulic acid and wogonin effectively modulated the gut flora, and in vivo they alleviated liver injury. Administration of A. putredinis exacerbated hepatic inflammation by disrupting intestinal barrier integrity and facilitating bacterial translocation, an effect reversed by ferulic acid. Conversely, treatment with C. spp. and wogonin enhanced bile salt hydrolase activity and bile acid excretion. Notably, combined treatment with ferulic acid and wogonin or C. spp. significantly ameliorated cholestatic liver injury. These findings underscore the critical role of gut microbiota in cholestasis and suggest therapeutic potential for microbiota-targeted and natural compound-based interventions.

Maximilien Lora, H. A. Ménard, Anastasia Nijnik et al.

ABSTRACT Low dose methotrexate (LD‐MTX) remains the gold standard in rheumatoid arthritis (RA) therapy. Multiple mechanisms on a variety of immune cells contribute to the anti‐inflammatory effects of LD‐MTX. Inflammatory signaling is deeply implicated in hematopoiesis by regulating hematopoietic stem and progenitor cell (HSPC) fate decisions; raising the question of whether HSPC are also modulated by LD‐MTX. This is the first study to characterize the effects of LD‐MTX on HSPC. CD34+ HSPC were isolated from healthy donors' non‐mobilized peripheral blood. Resting and/or cycling HSPCs were treated with LD‐MTX [dose equivalent to that used in RA patients]. Flow cytometry was performed to assess HSPC viability, cell cycle, surface abundance of reduced folate carrier 1 (RFC1), proliferation, reactive oxygen species (ROS) levels, DNA double‐strand breaks, p38 activation, and CD34+ subpopulations. HSPC clonogenicity was tested in colony‐forming cell assays. Our results indicate that in cycling HSPC, membrane RFC1 is upregulated and, following LD‐MTX treatment, they accumulate more intracellular MTX than resting HSPC. In cycling HSPC, LD‐MTX inhibits HSPC expansion by promoting S‐phase cell‐cycle arrest, increases intracellular HSPC ROS levels and DNA damage, and reduces HSPC viability. Those effects involve the activation of the p38 MAPK pathway and are rescued by folinic acid. The effects of LD‐MTX are more evident in CD34+ CD38High progenitors. In non‐cycling HSPC, LD‐MTX also reduces the proliferative response while preserving their clonogenicity. In summary, HSPC uptake LD‐MTX differentially according to their cycling state. In turn, LD‐MTX results in reduced proliferation and the preservation of HSPC clonogenicity.

Plamen Georgiev, Marina Nicolova, Irena Spasova et al.

Copper slag, a by-product of copper ore and concentrate smelting, is rich in non-ferrous metals; therefore, it has been considered a valuable raw material in recent years. This study aimed to compare the extraction of zinc, copper, and cobalt from two types of copper slag from a dump located near the village of Eliseyna, Bulgaria, which differ in mineralogical composition and chemical content, using indirect bioleaching with a spent medium of <i>Aspergillus niger</i> and <i>Penicillium ochrochloron</i>. Chemical leaching with sulphuric acid revealed that zinc and cobalt existed mainly as an acidic-soluble phase in both types of copper slag. In contrast, it contained 50–75% of the total copper content. Each fungal species was cultivated for one week, and the biomass and the spent medium were separated a week later. Owing to the production of a higher concentration of citric acid, <i>A. niger</i> facilitated more efficient base metal recovery. However, their effective recovery from the acidic-soluble phase required leaching at a 5% pulp density and supplementing the spent medium with sulphuric acid. The temperature played a secondary role. Conclusions: Non-ferrous metal extraction from copper slag exposed to weathering using a spent medium supplemented with sulphuric acid was achieved under milder leaching conditions and with better selectivity. In contrast, slag unaffected by weathering behaved as a refractory due to the worsened results of base metal extraction under similar experimental conditions.

Kohei Ando, Satoshi Miyahara, Shuhei Hanada et al.

ABSTRACT Bone and soft tissue infections caused by biofilm-forming bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), remain a significant clinical challenge. While the control of local infection is necessary, systemic treatment is also required, and biofilm eradication is a critical target for successful management. Topical antibiotic treatments, such as antibiotic-loaded bone cement (ALBC), have been used for some time, and continuous local antibiotic perfusion therapy, a less invasive method, has been developed by our group. However, the optimal antibiotics and concentrations for biofilms of clinical isolates are still not well understood. We examined the efficacy of high concentrations of gentamicin against MRSA biofilms and the role of gentamicin resistance genes in biofilm eradication. We collected 101 MRSA samples from a hospital in Japan and analyzed their gene properties, including methicillin and gentamicin resistance, and their minimum biofilm eradication concentration (MBEC) values. Our results showed that high concentrations of gentamicin are effective against MRSA biofilms and that even concentrations lower than the MBEC value could eliminate biofilms after prolonged exposure. We also identified three aminoglycoside/gentamicin resistance genes [aac(6′)-aph(2″), aph(3′)-III, and ant(4′)-IA] and found that the presence or absence of these genes may inform the selection of treatments. It was also found that possession of the aac(6′)-aph(2″) gene correlated with the minimum inhibitory concentration/MBEC values of gentamicin. Although this study provides insight into the efficacy of gentamicin against MRSA biofilms and the role of gentamicin resistance genes, careful selection of the optimal treatment strategy is needed for clinical application.IMPORTANCEOur analysis of 101 MRSA clinical isolates has provided valuable insights that could enhance treatment selection for biofilm infections in orthopedics. We found that high concentrations of gentamicin were effective against MRSA biofilms, and even prolonged exposure to concentrations lower than the minimum biofilm eradication concentration (MBEC) value could eliminate biofilms. The presence of the aac(6′)-aph(2″) gene, an aminoglycoside resistance gene, was found to correlate with the minimum inhibitory concentration (MIC) and MBEC values of gentamicin, providing a potential predictive tool for treatment susceptibility. These results suggest that extended high concentrations of local gentamicin treatment could effectively eliminate MRSA biofilms in orthopedic infections. Furthermore, testing for gentamicin MIC or the possession of the aac(6′)-aph(2″) gene could help select treatment, including topical gentamicin administration and surgical debridement.

Fen Li, Yu-Ting Si, Jia-Wei Tang et al.

WHO classified Helicobacter pylori as a Group I carcinogen for gastric cancer as early as 1994. However, despite the high prevalence of H. pylori infection, only about 3 % of infected individuals eventually develop gastric cancer, with the highly virulent H. pylori strains expressing cytotoxin-associated protein (CagA) and vacuolating cytotoxin (VacA) being critical factors in gastric carcinogenesis. It is well known that H. pylori infection is divided into two types in terms of the presence and absence of CagA and VacA toxins in serum, that is, carcinogenic Type I infection (CagA+/VacA+, CagA+/VacA-, CagA-/VacA+) and non-carcinogenic Type II infection (CagA-/VacA-). Currently, detecting the two carcinogenic toxins in active modes is mainly done by diagnosing their serological antibodies. However, the method is restricted by expensive reagents and intricate procedures. Therefore, establishing a rapid, accurate, and cost-effective way for serological profiling of carcinogenic H. pylori infection holds significant implications for effectively guiding H. pylori eradication and gastric cancer prevention. In this study, we developed a novel method by combining surface-enhanced Raman spectroscopy with the deep learning algorithm convolutional neural network to create a model for distinguishing between serum samples with Type I and Type II H. pylori infections. This method holds the potential to facilitate rapid screening of H. pylori infections with high risks of carcinogenesis at the population level, which can have long-term benefits in reducing gastric cancer incidence when used for guiding the eradication of H. pylori infections.

E. Koneman

E. Clercq

H. Benson