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Identification and detection of genetic markers associated with antimicrobial susceptibility and evaluation of efflux pump mechanisms in <i>Mycoplasma iowae</i>

by Dominika Buni, Áron Botond Kovács, Enikő Wehmann, Dénes Grózner, Krisztián Bányai, Eszter Zsófia Nagy, Janet Bradbury, Marco Bottinelli, Elisabetta Stefani, Salvatore Catania, Inna Lysnyansky, László Kovács, Miklós Gyuranecz, Zsuzsa Kreizinger

Mycoplasma iowae is an economically significant pathogen that causes reduced hatchability, late embryo mortality and leg deformities, chondrodystrophy and skeletal lesions in poults. While prevention is essential in the control of infection, the appropriate administration of antibiotics may reduce economic losses during outbreaks. As a first step in the exploration of antimicrobial resistance mechanisms in M. iowae, target modification and efflux pump activity were examined in the present study. Point mutations were analyzed in previously described antibiotic binding sites in the whole genome sequences of 99 M. iowae strains. Mismatch amplification mutation assays (MAMAs) were designed and validated for the differentiation of mutations corresponding to elevated minimum inhibitory concentration (MIC) values for fluoroquinolones. Broth microdilution assays were performed to evaluate the effect of efflux pump inhibitors. In the presence of orthovanadate (OV), MIC values were significantly lower than in the absence of OV for spiramycin, tilmicosin, tylosin and oxytetracycline, which may indicate the presence of an active efflux system in M. iowae. Putative promoter regions of efflux-related genes were predicted and characterized. Genetic mutations, previously described in other bacteria, were described to be associated with elevated fluoroquinolone, macrolide and lincomycin MICs in M. iowae, although certain resistant phenotypes remained unexplained, promoting future examinations for deeper insights. The developed MAMAs may support rapid identification of M. iowae strains with elevated MIC values for fluoroquinolones. The better understanding of the efflux pump mechanisms enables the development of alternative methods for the support of therapy against this pathogen.

Time-lapse imaging systems for embryo incubation and assessment to improve reproductive outcomes in women undergoing in vitro fertilisation: study protocol for an individual participant data meta-analysis of randomised controlled trials

Por: Bhide · P. · Chan · D. Y. L. · Ahlström · A. · del Campo · L. · Kieslinger · D. · Lundin · K. · Park · H. · Fauque · P. · Kahraman · S. · Khan · K. S. · Kovacs · P. · Lambalk · C. B. · Thangaratinam · S. · Vergouw · C. G. · van Wely · M. · Zamora · J.
Introduction

Time-lapse imaging (TLI) systems for embryo incubation and assessment are hypothesised to improve the success rates of in vitro fertilisation (IVF) treatment by providing undisturbed culture conditions for embryos and/or providing more information on embryo development (morphokinetic parameters) to improve predictive accuracy for embryo selection. Despite numerous aggregate meta-analyses showing uncertainty of benefit, IVF clinics globally continue to invest significant resources into this technology with little translation of evidence into guidelines or policy frameworks. This may be attributed to heterogeneity in participant populations and/or variations in the use of TLI, as highlighted in the aggregate meta-analyses.

Methods and analysis

Our research proposal for evidence synthesis using individual participant data meta-analysis will provide greater power than aggregate meta-analysis to detect differential treatment effects for effectiveness (live birth, clinical pregnancy) and safety (pregnancy loss, multiple births, congenital malformations) outcomes across three comparisons (overall effect, undisturbed culture and morphokinetic parameters). We will also analyse if there are specific subgroups of women who may benefit from the intervention and if variations in use of the intervention show any benefits. We have incorporated the results of the literature search used for the latest Cochrane review (7 January 2019) into this review and will include all the trials included therein. We will further update the literature search to include new evidence by searching the electronic databases MEDLINE, EMBASE, CINAHL and CENTRAL from 07/01/2019 to date, outcomes for all ongoing trials reported in the 2019 Cochrane review, trial registers for newer ongoing/completed trials and the citation lists of all the newly identified trials for any relevant references. The search strategy will include a combination of subject headings and text words relating to or describing the participants and the intervention, with no language restrictions. Two authors will independently screen the titles and abstracts, and full text of articles retrieved from the search, to finalise a list of trials suitable for inclusion in the review. We will include randomised controlled trials that assess TLI systems for either undisturbed culture and/or use of morphokinetic parameters for embryo selection in women having IVF/ICSI treatment using their own oocytes.

Ethics and dissemination

Ethical approval is not required for this study. We plan to disseminate the findings of the research to all stakeholders, including the National Institute for Health and Care Excellence and other international guideline development groups, through publication in peer-reviewed journals, presentation at conferences, newsletters, meetings and websites of the funders, fertility charities and patient support groups.

PROSPERO registration number

CRD42024564332.

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