Hasil untuk "Microbiology"

J. A. Morello

F. Widdel

F. Chapelle

P. Woo, S. Lau, J. L. Teng et al.

D. Weibel, Willow R Diluzio, G. Whitesides

T. Beresford, N. Fitzsimons, Noelle L Brennan et al.

S. V. Veen, E. Claas, E. Kuijper

I. Mackay

M. Schaechter

A. Bizzini, C. Durussel, J. Billé et al.

S. C. Cary, Ian R. McDonald, John E. Barrett et al.

Raquel Behar-Lagares, Raquel Behar-Lagares, Ana Virseda-Berdices et al.

IntroductionA significant proportion of COVID-19 Intensive Care Unit (ICU) survivors develop long-term respiratory complications, including pulmonary fibrosis. Telomere attrition, a marker of cellular senescence, has emerged as a potential biomarker for post-COVID-19 sequelae. This study investigated the association between peripheral blood relative telomere length (RTL) and long-term pulmonary outcomes in COVID-19 ICU survivors, with a specific focus on gender-specific differences.MethodsICU-admitted COVID-19 patients were followed for at least one year post-discharge. RTL was quantified from peripheral blood using monochromatic multiplex quantitative PCR (MMqPCR) at hospital admission and one-year post-discharge. Primary outcomes were respiratory symptoms and diffuse parenchymal lung disease (DPLD), assessed via imaging. Data were analyzed using gender-stratified generalized linear models, adjusted for clinical covariates.ResultsAt one year, 43.8% of patients reported respiratory symptoms and 23.9% developed DPLD. A total of 73 ICU survivors were included, with 51 men and 22 women. At one year, 43.8% of patients reported respiratory symptoms and 23.9% developed DPLD. Longitudinal analysis showed significant RTL shortening in both men and women who underwent IMV (p=0.011 and p=0.016, respectively), and in men who needed pronation during their ICU stay (p=0.037). Regarding one-year symptoms, in women, repeated-measures analysis showed an association with persistent respiratory symptoms, particularly in those who needed pronation during their ICU stay [adjusted arithmetic mean ratio (aAMR)=0.73) (95%CI=0.60-0.90); p=0.003]. At follow-up, women who had undergone pronation and had shorter RTL continued to show a higher prevalence of symptoms [aAMR= 0.66 (0.58-0.76); p< 0.001]. In contrast, men with shorter RTL at one-year post-discharge had an association with the presence of DPLD [aAMR = 0.64 (0.50-0.81); p = 0.001]. This association in men was significant particularly among those who required IMV [aAMR= 0.61 (0.49-0.76); p< 0.001] or prone positioning [aAMR= 0.56 (0.44-0.71); p= 0.016]. DiscussionThese findings underscore the role of telomere attrition as a sex-specific biomarker of aging-associated pulmonary vulnerability in the aftermath of critical COVID-19 illness. RTL may serve as a prognostic marker for long-term respiratory sequelae, potentially guiding risk stratification and individualized follow-up strategies in post-ICU COVID-19 survivors.

Kim-Marie A. Dam, Harry B. Gristick, Yancheng E. Li et al.

Summary: HIV-1 broadly neutralizing antibodies (bNAbs) targeting the CD4-binding site (CD4bs) contain rare features that pose challenges to elicit these bNAbs through vaccination. The IOMA class of CD4bs bNAbs includes fewer rare features and somatic hypermutations (SHMs) to achieve broad neutralization, thus presenting a potentially accessible pathway for vaccine-induced bNAb development. Here, we created a library of IOMA variants in which each SHM was individually reverted to the inferred germline counterpart to investigate the roles of SHMs in conferring IOMA’s neutralization potency and breadth. Impacts on neutralization for each variant were evaluated, and this information was used to design minimally mutated IOMA-class variants (IOMAmin) that incorporated the fewest SHMs required for achieving IOMA’s neutralization breadth. A cryoelectron microscopy (cryo-EM) structure of an IOMAmin variant bound to Env was used to further interpret characteristics of IOMA variants to elucidate how IOMA’s structural features correlate with its neutralization mechanism, informing the design of IOMA-targeting immunogens.

Na Song, Huili Xia, Yaoru Xie et al.

Tyrosol is an important component of pharmaceuticals, nutraceuticals, and cosmetics, and their biosynthetic pathways are currently a hot research topic. d-Erythrose 4-phosphate is a key precursor for the biosynthesis of tyrosol in Saccharomyces cerevisiae. Hence, the flux of d-Erythrose 4-phosphate determined the yield of tyrosol synthesis. In this study, we first obtained an S. cerevisiae strain S19 with a tyrosol yield of 247.66 mg/L by metabolic engineering strategy. To increase the production of d-Erythrose 4-phosphate, highly active phosphoketolase BA-C was obtained by bioinformatics combined with tyrosol yield assay. The key residue sites 183, 217, and 320 were obtained by molecular docking, kinetic simulation, and tyrosol yield verification. After mutation, the highly efficient phosphoketolase BA-CHis320Met was obtained, with a 37.32 % increase in enzyme activity. The tyrosol production of strain S26 with BA-CHis320Arg increased by 43.05 % than strain S25 with BA-C and increased by 151.19 % compared with the strain S19 without phosphoketolase in a 20 L fermenter. The mining and modification of phosphoketolase will provide strong support for the de novo synthesis of aromatic compounds.

Haya Hayek, Justin Z. Amarin, Olla Hamdan et al.

ABSTRACT Inappropriate antibiotic use drives antimicrobial resistance, a global health threat causing increased morbidity and mortality. Understanding antibiotic practices in low-resource settings is essential to identify intervention targets. This study investigates antibiotic prescription practices in Amman, Jordan. We conducted three prospective viral surveillance studies at the largest public hospital in Amman, Jordan (2010–2013, 2020, and 2023) and included children <2 years old hospitalized with fever or respiratory symptoms. The data collected included antibiotic use and the results of blood, urine, and cerebrospinal fluid (CSF) cultures performed. We classified antibiotics according to the 2023 WHO AWaRe system. Nasal or throat samples were tested in a research laboratory for respiratory viruses using RT-PCR. The median age of the 4,724 children included was 3.5 months (IQR, 1.6–8.4). A clinical blood, urine, or CSF sample was collected from 2,565/4,712 children (54.4%), 356 (13.9%) of whom tested positive. During hospitalization, 4,375 children (92.6%) received at least one antibiotic, and 4,245 (97.0%) received at least one antibiotic from the Watch group. One or more respiratory viruses were detected in 3,911 children (82.8%). Providers ordered cultures most often for children 0–2 months old (n = 1,579 [73.5%]) and those with an admission diagnosis of rule-out sepsis (n = 1,164 [95.4%]). Antibiotic use and testing practices were consistent across study years, age groups, and admission diagnoses. In conclusion, widespread antibiotic use despite the preponderance of viral infections highlights a significant discrepancy in aligning treatment practices with disease etiology. Strengthening diagnostic and preventive capabilities in low-resource settings is crucial to combat antimicrobial resistance.IMPORTANCEIn this study of 4,724 children under 2 years old hospitalized in the largest public hospital in Jordan between 2010 and 2023, 92.6% received antibiotics despite 82.8% testing positive for respiratory viruses and only 13.9% of collected cultures suggesting bacterial infection. Despite the predominance of viral infections, the widespread use of antibiotics, particularly from the World Health Organization Watch group, highlights the need for improved antibiotic stewardship and diagnostic capabilities in Jordan.

Rahul Tiwari, Awnish Kumar, Vishal Kumar Singh et al.

Understanding the development and maintenance of immunological memory is important for efforts to eliminate parasitic diseases like leishmaniasis. Leishmaniasis encompasses a range of pathologies, resulting from infection with protozoan parasites belonging to the subgenera Leishmania and Viannia of the genus Leishmania. A striking feature of these infections is that natural or drug-mediated cure of infection generally confers life-long protection against disease. The generation of protective T cell responses are necessary to control Leishmania infections. CD4+ T helper (Th) cells orchestrate immune responses in leishmaniasis and IFNγ+ Tbet+ CD4+ T (Th1) cells are required for the activation of phagocytes to kill captured or resident parasites, while other Th cell subset, including FoxP3+ natural regulatory T cells and Th2 cells can promote disease progression by suppressing the activities of Th1 cells. Upon resolution of a primary Leishmania infection, different subsets of CD4+ T cells, including tissue-resident memory T cells, effector memory T cells, central memory T cells, and short-lived effector T cells, help to confer resistance against reinfection. To maintain long-term protective Leishmania-specific CD4+ T cells responses, it is believed that persistent parasites or re-exposure to parasites at regular intervals is required (concomitant immunity). Despite the advances in our understanding about the immune responses during leishmaniasis, the generation of long-lasting protective immunity via vaccination has yet to be achieved. In this review, we summarize our current understanding about the formation and maintenance of immunological memory and control of leishmaniasis at the individual and population level. We will focus on Indian visceral leishmaniasis and discuss T cell responses that contribute to susceptibility to leishmaniasis, parasite persistence in populations and the environment, as well as describing advances in the development of leishmaniasis vaccines aimed at inducing protective CD4+ T cell responses.

Hiroaki Takebe, Kento Tominaga, Tatsuhiro Isozaki et al.

ABSTRACTThe production of dissolved organic matter during phytoplankton blooms and consumption by heterotrophic prokaryotes promote marine carbon biogeochemical cycling. Although prokaryotic viruses presumably affect this process, their dynamics during blooms are not fully understood. Here, we investigated the effects of taxonomic difference in bloom-forming phytoplankton on prokaryotes and their viruses. We analyzed the dynamics of coastal prokaryotic communities and viruses under the addition of dissolved intracellular fractions from taxonomically distinct phytoplankton, the diatom Chaetoceros sp. (CIF) and the raphidophycean alga Heterosigma akashiwo (HIF), using microcosm experiments. Ribosomal RNA gene amplicon and viral metagenomic analyses revealed that particular prokaryotes and prokaryotic viruses specifically increased in either CIF or HIF, indicating that taxonomic difference in bloom-forming phytoplankton promotes distinct dynamics of not only the prokaryotic community but also prokaryotic viruses. Furthermore, combining our microcosm experiments with publicly available environmental data mining, we identified both known and novel possible host-virus pairs. In particular, the growth of prokaryotes associating with phytoplanktonic organic matter, such as Bacteroidetes (Polaribacter and NS9 marine group), Vibrio spp., and Rhodobacteriales (Nereida and Planktomarina), was accompanied by an increase in viruses predicted to infect Bacteroidetes, Vibrio, and Rhodobacteriales, respectively. Collectively, our findings suggest that changes in bloom-forming species can be followed by an increase in a specific group of prokaryotes and their viruses and that elucidating these tripartite relationships among specific phytoplankton, prokaryotes, and prokaryotic viruses improves our understanding of coastal biogeochemical cycling in blooms.IMPORTANCEThe primary production during marine phytoplankton bloom and the consumption of the produced organic matter by heterotrophic prokaryotes significantly contribute to coastal biogeochemical cycles. While the activities of those heterotrophic prokaryotes are presumably affected by viral infection, the dynamics of their viruses during blooms are not fully understood. In this study, we experimentally demonstrated that intracellular fractions of taxonomically distinct bloom-forming phytoplankton species, the diatom Chaetoceros sp. and the raphidophycean alga Heterosigma akashiwo, promoted the growth of taxonomically different prokaryotes and prokaryotic viruses. Based on their dynamics and predicted hosts of those viruses, we succeeded in detecting already-known and novel possible host-virus pairs associating with either phytoplankton species. Altogether, we propose that the succession of bloom-forming phytoplankton would change the composition of the abundant prokaryotes, resulting in an increase in their viruses. These changes in viral composition, depending on bloom-forming species, would alter the dynamics and metabolism of prokaryotes, affecting biogeochemical cycling in blooms.

Ricardo P. Teles, F. Teles, Jorge Frias-Lopez et al.

Abstract Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation elicited by specific subgingival species. In the past few decades, efforts to understand the periodontal microbiota have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best‐characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this article we will review how our comprehension of the structure and function of the subgingival microbiota has evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: (i) how the data obtained through molecular techniques have impacted our knowledge of the etiology of periodontal infections; (ii) the potential role of viruses in the etiopathogenesis of periodontal diseases; (iii) how concepts of microbial ecology have expanded our understanding of host–microbe interactions that might lead to periodontal diseases; (iv) the role of inflammation in the pathogenesis of periodontal diseases; and (v) the impact of these evolving concepts on therapeutic and preventive strategies to periodontal infections. We will conclude by reviewing how novel systems‐biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and hopefully lead to a better understanding of their mechanisms.

Alessandra Oliveira da Silva, João Alfredo Neto da Silva, Sálvio Napoleão Soares Arcoverde et al.

The domestication of Jatropha curcas L. in the Brazilian territory has been boosted by its great potential in the production of grains, oil and, in particular, its adaptation in different soil and climatic conditions. The aim of this research was evaluate the soil biological quality through the soil microbial biomass carbon and its indices derivate (metabolic and microbial quotient) under J. curcas intercropping with many forages species, legumes and annual crop rotation systems, as well as the accumulated production of J. curcas grains and oil. The experiment was conducted in a commercial area in the randomized blocks experimental design with the treatments arranged in a 12 x 2 factorial design, with four repetitions, resulting in 12 treatments with cropping systems and 2 sampling times (February 2012 and May 2012). Soil sampling was performed in February and May 2012, at 0 at 10 cm layer and four composite samples were collected in each cropping system, from five subsamples in each plot. J. curcas intercropping with B. ruziziensis, favors the maintenance of the community of soil microorganisms compared to the treatment with the species P. maximum cv. Massai and Cajanus cajan, which promoted decreasing in soil organic matter dynamics, when compared to the other cropping systems. The monocropping systems of J. curcas and intercropping in rotation systems 2 and 3 achieved higher yields of J. curcas grains and oil over three seasons.

Yan W, Wu J, Wang S et al.

Wenjuan Yan,1,&ast; Jiaojiao Wu,2,&ast; Shanmei Wang,1 Qi Zhang,1 Youhua Yuan,1 Nan Jing,1 Jiangfeng Zhang,1 Hangchan He,3 Yi Li1 1Department of Clinical Microbiology, Henan Provincial People’s Hospital, People’s Hospital of Zhengzhou University, People’s Hospital of Henan University, Zhengzhou, Henan, People’s Republic of China; 2Department of Clinical Microbiology, Xiayi People’s Hospital, Shangqiu, Henan, People’s Republic of China; 3Department of Clinical Laboratory, Baofeng Traditional Chinese Medicine Hospital, Pingdingshan, Henan, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Yi Li, Department of Clinical Microbiology, Henan Provincial People’s Hospital, People’s Hospital of Zhengzhou University, People’s Hospital of Henan University, Zhengzhou, Henan, People’s Republic of China, Tel +8615939039006, Email liyilabmed@henu.edu.cnPurpose: To analyze the risk factors and clinical outcomes of patients isolated with polymyxin B-resistant (PR) Enterobacterales from various clinical specimens to prevent and control the spread of these strains.Methods: This retrospective case-control study included 72 PR Enterobacterales-positive cases and 144 polymyxin B-susceptible (PS) Enterobacterales controls from 2018 to 2022. Patients with PR Enterobacterales isolated in various clinical cultures were defined as cases. Patients with PS Enterobacterales cultures at similar anatomic sites during the same period were randomly selected as controls. Data were collected from clinical and laboratory test records. Bivariable logistic regression and Pearson’s chi-square tests were used to assess risk factors.Results: PR strains were predominantly Klebsiella pneumoniae (72.2%) and Salmonella enteritidis (8.3%). Of the patients, 66.04% were admitted to an intensive care unit (ICU). Risk factors for isolation with PR strains included chronic heart disease (P = 0.012; odds ratio [OR] 1.15; 95% confidence interval [CI] 1.03– 1.28), immunosuppressant use (P = 0.016; OR 1.04 [1.0– 1.07), drainage tube [head] (P = 0.006; OR 1.1 [1.0– 1.1]), and polymyxin B exposure (P = 0.007; OR 1.03 [1.0– 1.06]. With respect to outcomes, admission to an ICU (P = 0.003; OR 7.1 [1.9– 25.4]), hypertension (P = 0.035; OR 1.4 [1.02– 1.83]), and drainage tube [head] (P = 0.044; OR 1.1 [1.0– 1.15]) were associated with treatment failure. Additionally, treatment failure was more frequent in patients (45.83%) than in controls (14.58%).Conclusion: The major risk factors for isolation with PR strains were chronic heart disease, exposure to immunosuppressants, use of drainage tubes, and polymyxin B exposure. The isolation of PR strains in patients was a predictor of unfavorable outcomes. These findings provide a basis for monitoring the spread of PR Enterobacterales.Keywords: polymyxin B resistance, treatment failure, Klebsiella pneumoniae, Salmonella enteritidis