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Grall, N.

Publications and source records attributed to Grall, N..

2 recordsLinked to original sources

Stress-responsive Mycobacterium tuberculosis subpopulations manipulate macrophage polarization and can be targeted to limit inflammation

Tuberculosis is characterized by broad clinical heterogeneity that hinders infection control, with differences in lesion development, progression, and treatment outcomes. This complexity is likely associated with Mycobacterium tuberculosis inherent phenotypic variation and its capacity to diversify under host microenvironmental and antimicrobial stressors. Here, we analyze M. tuberculosis at the single-cell and subpopulation level using fluorescent reporters, imaging, transcriptomic, and functional assays. We identify RNA signatures specific to stress-responsive bacilli with translational potential. Focusing on the clinically validated chaperone GroEL2, we find that it correlates with M. tuberculosis growth rate and stress tolerance in vitro and intracellularly. Furthermore, GroEL2 phenotypic diversity influences innate responses in macrophages, which experience different polarization, in turn affecting GroEL2 expression. We also show that targeting GroEL2 impairs pathogen survival and dampens inflammation. This study provides a link between pathogen phenotypic variation and macrophage fates, with implications for early infection outcomes, local disease progression, and subpopulation-targeted interventions.

microbiology↗

Vaginal microbiota as a predictor of preterm birth: an observational cohort study

RationaleIncreasing evidence links vaginal microbiota composition and preterm birth (PTB). However, most metagenomic studies are relatively small-sized, do not systematically adjust for confounders, and are difficult to transpose in clinical settings. ObjectiveTo identify, using routine vaginal microbiological cultures, signatures of preterm labor (PTL), preterm premature rupture of membranes (PPROM), and PTB. MethodsWe conducted an observational cohort study from August 2018 until June 2023 in France. Pregnant women were enrolled in three groups: control, PTL and PPROM. Demographic, clinical data, and pregnancy outcome were collected. Vaginal swabs were collected at enrollment and microbiological cultures were performed. The association between bacterial species and PTL, PPROM, and PTB was studied in univariate analyses. Adjusted odds ratio (aOR) and 95% confidence intervals (CI) were calculated in multivariable analyses adjusting for confounding variables. Results1,848 women were included: 1,048 in the control group, 417 with PTL, and 383 with PPROM. Among women with PTL or PPROM, 328/646 (50.8%) spontaneously delivered preterm. Vaginal samples enriched in enterobacteria and in Gardnerella spp. were signatures of PTL. Lactobacilli depletion and enterobacteria enrichment were signatures of PPROM. In multivariable analysis, lactobacilli depletion was the strongest risk factor for spontaneous PTB (aOR 2.29, 95% CI 1.52-3.48). ConclusionsOur study corroborates previous findings demonstrating the protective role of lactobacilli during pregnancy and highlights enterobacteria as signatures of PTL and PPROM. Furthermore, it provides perspectives for the management of women at high risk of PTB using standard microbiological techniques. HighlightsO_LIVaginal microbiological analysis of 800 women with preterm labor or PPROM C_LIO_LIPreterm labor signatures include enterobacteria and Gardnerella enrichment C_LIO_LIPPROM signatures include lactobacilli depletion and enterobacteria enrichment C_LIO_LILactobacilli depletion is the strongest risk factor for preterm birth C_LI

microbiology↗