Helicobacter pylori encodes homologues of PilM, PilN and PilO from bacteria with Type IV pili, where these proteins form a pilus alignment complex. Inactivation of pilO changes H. pylori motility in semi-solid media, suggesting a link to the chemosensory pathways or flagellar motor.
View Article and Find Full Text PDFCampylobacter jejuni is a very common cause of gastroenteritis, and is frequently transmitted to humans through contaminated food products or water. Importantly, C. jejuni infections have a range of short- and long-term sequelae such as irritable bowel syndrome and Guillain Barre syndrome.
View Article and Find Full Text PDFThe bacterial flagellar motor is a molecular nanomachine, the assembly and regulation of which requires many accessory proteins. Their identity, structure and function are often discovered through characterisation of mutants with impaired motility. Here, we demonstrate the functional association of the Helicobacter pylori peptidoglycan-associated lipoprotein (HpPal) with the flagellar motor by analysing the motility phenotype of the ∆pal mutant, and present the results of the preliminary X-ray crystallographic analysis of its globular C-terminal domain HpPal-C.
View Article and Find Full Text PDFReactive oxygen species (ROS), including the superoxide radical anion (O), hydrogen peroxide (HO), and the hydroxyl radical (HO), are inherent components of bacterial metabolism in an aerobic environment. Bacteria also encounter exogenous ROS, such as those produced by the host cells during the respiratory burst. As ROS have the capacity to damage bacterial DNA, proteins, and lipids, detoxification of ROS is critical for bacterial survival.
View Article and Find Full Text PDFInt J Environ Res Public Health
February 2023
"Land Use and Land Cover Change (LULCC)" is increasingly being affected by ecosystem services value. LULCC patterns have been subjected to significant changes over time, primarily due to an ever-increasing population. It is rare to attempt to analyze the influence of such changes on a large variety of ecosystem benefits in Madagascar island.
View Article and Find Full Text PDFHaemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis are bacterial species which frequently co-colonise the nasopharynx, but can also transit to the middle ear to cause otitis media. Chronic otitis media is often associated with a polymicrobial infection by these bacteria. However, despite being present in polymicrobial infections, the molecular interactions between these bacterial species remain poorly understood.
View Article and Find Full Text PDFFront Cell Infect Microbiol
April 2022
is the leading cause of bacterial paediatric meningitis after the neonatal period worldwide, but the bacterial factors and pathophysiology that drive pneumococcal meningitis are not fully understood. In this work, we have identified differences in raffinose utilization by isolates of identical serotype and sequence type from the blood and cerebrospinal fluid (CSF) of a single pediatric patient with meningitis. The blood isolate displayed defective raffinose metabolism, reduced transcription of the raffinose utilization pathway genes, and an inability to grow when raffinose was the sole carbon source.
View Article and Find Full Text PDFObjective: To analyze the treatment of patients with severe stroke requiring respiratory support, and identify predictors of death.
Material And Methods: A multicenter observational clinical study «REspiratory Therapy for Acute Stroke» (RETAS) was conducted under the aegis of the «Federation of Anaesthesiologists and Reanimatologists» (FAR). The study involved 14 clinical centers and included 1289 stroke patients with respiratory support.
The LuxS protein, encoded by , is required for the production of autoinducer 2 (AI-2) in . The AI-2 molecule serves as a quorum sensing signal, and thus regulates cellular processes such as carbohydrate utilisation and biofilm formation, as well as impacting virulence. The role of in biology and lifestyle has been predominantly assessed in the laboratory strain D39.
View Article and Find Full Text PDFThe outgrowth of e-commerce has advanced the development of countries' economies. Today, online marketplaces are targeting not only their local customers but are also spreading their interests overseas, expanding cross-border e-commerce. The current study aims to analyze the interaction of customer's personal traits, such as national culture, disposition to trust, and perceived trustworthiness, and their effect on the purchase intention within different e-commerce contexts.
View Article and Find Full Text PDFThis research investigates the impact of transformational leadership (TL) style on project success (PS) in the indirect effect of serial mediation of team-building and teamwork quality (TWQ). A quantitative research approach was used for this study. Data were gathered from 374 professional information system development (ISD) project managers in Pakistan.
View Article and Find Full Text PDFThe emergence of coronavirus disease 2019 (COVID-19) has considerably changed global food production, processing, and consumption at different levels. Sojourners are among those who have experienced a higher level of food insecurity during the crisis of the COVID-19 outbreak. The current research aimed to investigate the immediate consumption behavioral intentions of the Pakistani international students in the Peoples Republic of China (PRC) during the wake of COVID-19 pandemic.
View Article and Find Full Text PDFAcridinium 9-carboxylic acid derivatives have been extensively used as chemiluminescent labels in diagnostic assays. Triggering acridinium with basic hydrogen peroxide produces a highly strained dioxetanone intermediate, which converts into an acridone in an electronically excited state and emits light at 420-440 nm. Here, we introduce a novel acridinium-fluorescein construct emitting at 530 nm, in which fluorescein is covalently attached to the acridinium N-10 nitrogen via a propyl sulfonamide linker.
View Article and Find Full Text PDFFactors facilitating the chronicity of otitis media (OM) in children are, to date, not fully understood. An understanding of molecular factors aiding bacterial persistence within the middle ear during OM could reveal pathways required for disease. This study performed a detailed analysis of Streptococcus pneumoniae populations isolated from the nasopharynx and middle ear of one OM case.
View Article and Find Full Text PDF(the pneumococcus) is a formidable human pathogen that is capable of asymptomatically colonizing the nasopharynx. Progression from colonization to invasive disease involves adaptation to distinct host niches, which vary markedly in the availability of key nutrients such as sugars. We previously reported that cell-cell signaling via the autoinducer 2 (AI-2)/LuxS quorum-sensing system boosts the capacity of to utilize galactose as a carbon source by upregulation of the Leloir pathway.
View Article and Find Full Text PDFEthoxzolamide (EZA), acetazolamide, and methazolamide are clinically used sulphonamide drugs designed to treat non-bacteria-related illnesses (e.g. glaucoma), but they also show antimicrobial activity against the gastric pathogen EZA showed the highest activity, and was effective against clinical isolates resistant to metronidazole, clarithromycin, and/or amoxicillin, suggesting that EZA kills mechanisms different from that of these antibiotics.
View Article and Find Full Text PDFSupramolecular modulation of reduction potentials of two series of bis(pyridinium)alkane salts is described. Study of the encapsulation of bis(pyridinium)alkane guests within the CB[7] cavity revealed the critical influence of the linker length and the position of the heteroatom on the reduction potentials of encapsulated guests. CB[7] complexation of pyridinium salts induced reduction potential changes ranging between +50 and -430 mV.
View Article and Find Full Text PDFDNA damage induced by noncatalytic aerobic oxidation of pyridinocyanine dyes is described. The dyes are generated in situ during spontaneous oxidations of tetrakis- and bis( N-methylpyridin-4-ium)alkane salts. The mechanism of aerobic oxidation of the latter compound is proposed, and a rare direct catalyst-free transition from saturated alkane to a gem-diol is demonstrated.
View Article and Find Full Text PDFNon-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and its detection in the general population has reached a global scale. Despite the fact that in the early stages the disease is characterized by a relatively mild period, the development during its natural course of nonalcoholic steatohepatitis, cirrhosis and hepatocellular carcinoma causes deterioration of long-term forecast. Growing evidence indicates that NAFLD is a complex, multifaceted etiology, involving many factors, including genetic.
View Article and Find Full Text PDFHaemophilus influenzae and Streptococcus pneumoniae are known aetiologic agents of chronic otitis media, frequently as a multispecies infection. In this study, we show that the outcome of H. influenzae/S.
View Article and Find Full Text PDFThe tetrapyridinium salt 1 was found to undergo quantitative air oxidation upon dissolving it in water. The corresponding alkene and the epoxide were found as the only products of the oxidation. A mechanism that involves an alkyl hydroperoxide intermediate 1″ undergoing a transformation that yields both products is proposed.
View Article and Find Full Text PDFGeneral control non-repressible 5 (GCN5)-related N-acetyltransferases (GNAT) catalyze the transfer of an acyl moiety from acyl coenzyme A (acyl-CoA) to a diverse group of substrates and are widely distributed in all domains of life. This review of the currently available data acquired on GNAT enzymes by a combination of structural, mutagenesis and kinetic methods summarizes the key similarities and differences between several distinctly different families within the GNAT superfamily, with an emphasis on the mechanistic insights obtained from the analysis of the complexes with substrates or inhibitors. It discusses the structural basis for the common acetyltransferase mechanism, outlines the factors important for the substrate recognition, and describes the mechanism of action of inhibitors of these enzymes.
View Article and Find Full Text PDFInt J Risk Saf Med
March 2016
Background: In Russia, the incidence of melanoma is increasing steadily. The approved standard of specialized medical care for melanoma of the skin defined the range of drugs, recommended for the provision of quality health care. However, it appears that the most effective innovative and safe medicines are at the same time the most expensive drugs.
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