Hasil untuk "Microbiology"

J. B. Murray, J. Nadel

J. Farber

R. W. Weaver, S. Mickelson

P. Goovaerts

Dennis P. Han, S. Wisniewski, L. Wilson et al.

M. Bertoldi, G. Vallini, A. Pera

M. Raimbault

P. Schäfer, B. Fink, D. Sandow et al.

H. Klunder, J.C.M. Wolkers-Rooijackers, J. Korpela et al.

S. Preston, G. Drusano, Adam L. Berman et al.

José Luis Guerrero-Orriach, Maria Dolores Carmona-Luque, Guillermo Quesada Muñoz et al.

Background: The effects of anesthetic drugs on myocardial cells have been a subject of research for the last 50 years. The clinical benefits of halogenated agents, particularly sevoflurane, have been demonstrated in cardiac surgery patients. These benefits are due to the action of different enzymes and a variety of molecular pathways mediated by the action of small noncoding RNAs (sRNA) such as microRNAs (miRNAs). However, the modulation potential induced by anesthetic drugs on the miRNA expression and their cardioprotective effects is unknown. Objective: To analyze the variation in the expression of a panel of miRNAs induced by halogenated agents to identify their cardioprotective effects. Aims: Variations in the expression of specific miRNAs induce the potential cardioprotective effects of halogenated agents. Methods: An ischemia/reperfusion (I/R) in vitro model of primary human cardiac myocytes (HCMs) was performed. Four study groups were performed: control group (standard culture conditions), I/R group (without hypnotic drugs exposition), I/R-propofol group (I/R-P), and I/R-sevoflurane group (I/R-S). The secretion of p53 and Akt1 cytokines was quantified in the different cell study groups using an Enzyme-Linked ImmunoSorbent Assay, and the differentially expressed miRNAs were identified carrying out a complete genomic sequencing using the Next Generation Sequencing (NGS). Results: HCMs subjected to the I/R procedure and exposed to sevoflurane showed lower secretion levels of p53 factor and higher levels of Akt-1 cytokine compared to HCMs exposed to propofol (p53: I/R-S: 10.43 ± 0.91 ng/mL; I/R-P: 137.92 ± 7.53 ng/mL; <i>p</i> > 0.05); (Akt1: I/R-S: 0.62 ± 0.12 ng/mL; I/R-P: 0.23 ± 0.05 ng/mL; <i>p</i> > 0.05). The miRNA gene expression analysis (NGS) showed significantly increased expression of the hsa-miR-140-5p and hsa-miR-455-5p, both miRNAs associated with cardiac function; the hsa-miR-98-5p and hsa-miR-193a-5p, both related to apoptosis inhibition; and the hsa-let-7d-5p associated with myocardial protection. This increase was observed in the HCMs group exposed to sevoflurane in comparison to the propofol group. Conclusions: Sevoflurane-induced miRNAs overexpression confers cardioprotection through various mechanisms at the DNA level and the different signaling pathways levels, such as Akt/ERK.

Nguyen Dinh-Hung, Samuel Mwakisha Mwamburi, Ha Thanh Dong et al.

This study aims to genomically elucidate six isolates of rapidly growing non-tuberculous mycobacteria (RGM) derived from Siamese fighting fish (<i>Betta splendens</i>). These isolates had previously undergone phenotypic and biochemical characterization, antibiotic susceptibility testing, and in vivo virulence assessment. Initial DNA barcoding using the 16S rRNA sequence assigned these six isolates to five different species, namely <i>Mycobacterium chelonae</i> (BN1983), <i>M. cosmeticum</i> (BN1984 and N041), <i>M. farcinogenes</i> (SNSK5), <i>M. mucogenicum</i> (BN1956), and <i>M. senegalense</i> (BN1985). However, the identification relied solely on the highest percent identity of the 16S rRNA gene, raising concerns about the taxonomic ambiguity of these species. Comprehensive whole genome sequencing (WGS) and extended genomic comparisons using multilocus sequence typing (MLST), average nucleotide identity (ANI), and digital DNA–DNA hybridization (dDDH) led to the reclassification of BN1985 and SNSK5 as <i>M. conceptionense</i> while confirming BN1983 as <i>M. chelonae</i> and BN1984 and N041 as <i>M. cosmeticum</i>. Notably, the analysis of the BN1956 isolate revealed a potential new species that is proposed here as <i>M. mucogenicum</i> subsp. <i>phocaicum</i> sp. nov. Common genes encoding “mycobacterial” virulence proteins, such as PE and PPE family proteins, MCE, and YrbE proteins, were detected in all six isolates. Two species, namely <i>M. chelonae</i> and <i>M. cosmeticum</i>, appear to have horizontally acquired T6SS-II (<i>clpB</i>), catalase (<i>katA</i>), GroEL (<i>groel</i>), and capsule (<i>rmlb</i>) from distantly related environmental bacteria such as <i>Klebsiella</i> sp., <i>Neisseria</i> sp., <i>Clostridium</i> sp., and <i>Streptococcus</i> sp. This study provides the first draft genome sequence of RGM isolates currently circulating in <i>B. splendens</i> and underscores the necessity of WGS for the identification and classification of mycobacterial species.

Giulio Camarlinghi, Eva Maria Parisio, Alberto Antonelli et al.

Gina Alessandra Donayre-Salvatierra, Julissa Amparo Dulanto-Vargas, Raul M. Olaechea et al.

Conclusions: Disinfection of TBs with CHX, WV, and MWs produces a significant effective reduction in the count of Ef.

Laura I. Levi, Emily A. Madden, Jeremy Boussier et al.

Chikungunya virus (CHIKV) is a mosquito-borne RNA virus that poses an emerging threat to humans. In a manner similar to other RNA viruses, CHIKV encodes an error-prone RNA polymerase which, in addition to producing full-length genomes, gives rise to truncated, non-functional genomes, which have been coined defective viral genomes (DVGs). DVGs have been intensively studied in the context of therapy, as they can inhibit viral replication and dissemination in their hosts. In this work, we interrogate the influence of viral RNA secondary structures on the production of CHIKV DVGs. We experimentally map RNA secondary structures of the CHIKV genome using selective 2′-hydroxyl acylation analyzed by primer extension and mutational profiling (SHAPE-MaP), which couples chemical labelling with next-generation sequencing. We correlate the inferred secondary structure with preferred deletion sites of CHIKV DVGs. We document an increased probability of DVG generation with truncations at unpaired nucleotides within the secondary structure. We then generated a CHIKV mutant bearing synonymous changes at the nucleotide level to disrupt the existing RNA secondary structure (CHIKV-D2S). We show that CHIKV-D2S presents altered DVG generation compared to wild-type virus, correlating with the change in RNA secondary structure obtained by SHAPE-MaP. Our work thus demonstrates that RNA secondary structure impacts CHIKV DVG production during replication.

Ragaey A Eid, Marwa O Elgendy, Ahmed M Sayed et al.

Introduction: At the beginning in July 2023, there has been a significant increase in daily hospital admissions attributed to the new variant of COVID-19. Aim of this study is to explore the clinical benefits and outcomes of using linezolid in the management of pneumonic COVID-19 patients. Methodology: The study included 230 patients with SARS-CoV-2 infection confirmed by RT-PCR. Group 1: 118 patients were managed with Linazolid alongside steroids. Group 2: (control group) patients treated according to the Protocol for Egyptian COVID-19 management outlines and WHO guidelines (112 patients). Each patient group was categorized into 3 age groups: 20-40 years, 41-65 years, and over 65 years. Patients were carefully followed up until recovery or mortality. A docking analysis was carried out to investigate the potential of linezolid to act as an Mpro inhibitor. Results: Group 1's average recovery time was 15.1 days in contrast to 18.7 days for Group 2 (control). There were no deaths reported. In silico investigations revealed that Linezolid was able to achieve a binding mode comparable to that of the co-crystalized inhibitor. Conclusions: Linazolid is considered an effective antiviral weapon against SARS-COV-2. It could be used in the management plan of pneumonic individuals due to SARS-COV-2 infection. We recommend using it to combat the current wave caused by Omicron EG-5 Variant.

R. Wallace, B. Brown-Elliott, Steven G. McNulty et al.

Xiaoyu Fu, Da Cheng, Zhenwu Luo et al.

Abstract Background . Up to 20% of people with HIV (PWH) who undergo virologically suppressed antiretroviral therapy (ART) fail to experience complete immune restoration. We recently reported that plasma anti-CD4 IgG (antiCD4IgG) autoantibodies from immune non-responders specifically deplete CD4 + T cells via antibody-dependent cytotoxicity. However, the mechanism of antiCD4IgG production remains unclear. Methods . Blood samples were collected from 16 healthy individuals and 25 PWH on suppressive ART. IgG subclass, plasma lipopolysaccharide (LPS), and antiCD4IgG levels were measured by ELISA. Gene profiles in B cells were analyzed by microarray and quantitative PCR. Furthermore, a patient-derived antiCD4IgG–producing B cell line was generated and stimulated with LPS in vitro. B cell IgG class switch recombination (CSR) was evaluated in response to LPS in splenic B cells from C57/B6 mice in vitro. Results . Increased plasma anti-CD4 IgGs in PWH were predominantly IgG1 and associated with increased plasma LPS levels as well as B cell expression of TLR2, TLR4, and MyD88 mRNA in vivo. Furthermore, LPS stimulation induced antiCD4IgG production in the antiCD4IgG B cell line in vitro. Finally, LPS promoted CSR in vitro. Conclusion . Our findings suggest that persistent LPS translocation may promote anti-CD4 autoreactive B cell activation and antiCD4IgG production in PWH on ART, which may contribute to gradual CD4 + T cell depletion. This study suggests that reversing a compromised mucosal barrier could improve ART outcomes in PWH who fail to experience complete immune restoration.

Wentao Jiang, Zhuo Xie, Shuheng Huang et al.

ABSTRACTNovel ecological antimicrobial approaches to dental caries focus on inhibiting cariogenic pathogens while enhancing the growth of health-associated commensal communities or suppressing cariogenic virulence without affecting the diversity of oral microbiota, which emphasize the crucial role of establishing a healthy microbiome in caries prevention. Considering that the acidified cariogenic microenvironment leads to the dysbiosis of microecology and demineralization of enamel, exploiting the acidic pH as a bioresponsive trigger to help materials and medications target cariogenic pathogens is a promising strategy to develop novel anticaries approaches. In this study, a pH-responsive antimicrobial peptide, LH12, was designed utilizing the pH-sensitivity of histidine, which showed higher cationicity and stronger interactions with bacterial cytomembranes at acidic pH. Streptococcus mutans was used as the in vitro caries model to evaluate the inhibitory effects of LH12 on the cariogenic properties, such as biofilm formation, biofilm morphology, acidurance, acidogenicity, and exopolysaccharides synthesis. The dual-species model of Streptococcus mutans and Streptococcus gordonii was established in vitro to evaluate the regulation effects of LH12 on the mixed species microbial community containing both cariogenic bacteria and commensal bacteria. LH12 suppressed the cariogenic properties and regulated the bacterial composition to a healthier condition through a dual-functional mechanism. Firstly, LH12-targeted cariogenic pathogens in response to the acidified microenvironment and suppressed the cariogenic virulence by inhibiting the expression of multiple virulence genes and two-component signal transduction systems. Additionally, LH12 elevated H2O2 production of the commensal bacteria and subsequently improved the ecological competitiveness of the commensals. The dual-functional mechanism made LH12 a potential bioresponsive approach to caries management.

S. Brantley, J. Kubicki, A. White