Chorioamnionitis is associated with adverse neurodevelopmental outcomes in preterm infants. Ureaplasma spp. are the microorganisms most frequently isolated from the amniotic fluid of women diagnosed ...with chorioamnionitis. However, controversy remains concerning the role of Ureaplasma spp. in the pathogenesis of neonatal brain injury. We hypothesize that reexposure to an inflammatory trigger during the perinatal period might be responsible for the variation in brain outcomes of preterms following Ureaplasma-driven chorioamnionitis. To investigate these clinical scenarios, we performed a detailed multimodal study in which ovine neurodevelopmental outcomes were assessed following chronic intra-amniotic Ureaplasma parvum (UP) infection either alone or combined with subsequent lipopolysaccharide (LPS) exposure. We show that chronic intra-amniotic UP exposure during the second trimester provoked a decrease in astrocytes, increased oligodendrocyte numbers, and elevated 5-methylcytosine levels. In contrast, short-term LPS exposure before preterm birth induced increased microglial activation, myelin loss, elevation of 5-hydroxymethylcytosine levels, and lipid profile changes. These LPS-induced changes were prevented by chronic preexposure to UP (preconditioning). These data indicate that chronic UP exposure has dual effects on preterm brain development in utero. On the one hand, prolonged UP exposure causes detrimental cerebral changes that may predispose to adverse postnatal clinical outcomes. On the other, chronic intra-amniotic UP exposure preconditions the brain against a second inflammatory hit. This study demonstrates that microbial interactions and the timing and duration of the inflammatory insults determine the effects on the fetal brain. Therefore, this study helps to understand the complex and diverse postnatal neurological outcomes following UP driven chorioamnionitis.
Problem
Complement is a central defence against sepsis, and increasing complement insufficiency in neonates of greater prematurity may predispose to increased sepsis. Ureaplasma spp. are the most ...frequently cultured bacteria from preterm blood samples.
Method of study
A sheep model of intrauterine Ureaplasma parvum infection was used to examine in vivo Ureaplasma bacteraemia at early and late gestational ages. Complement function and Ureaplasma killing assays were used to determine the correlation between complement potency and bactericidal activity of sera ex vivo.
Results
Ureaplasma was cultured from 50% of 95‐day gestation lamb cord blood samples compared to 10% of 125‐day gestation lambs. Bactericidal activity increased with increased gestational age, and a direct correlation between functional complement activity and bactericidal activity (R2=.86; P<.001) was found for 95‐day gestational lambs.
Conclusions
Ureaplasma bacteraemia in vivo was confined to early preterm lambs with low complement function, but Ureaplasma infection itself did not diminish complement levels.
Background
respiratory infections are transmitted by aerosol and droplets in close contact.AimWe investigated global
incidence after implementation of non-pharmaceutical interventions (NPIs) against ...COVID-19 in March 2020.MethodsWe surveyed
detections from laboratories and surveillance systems (national or regional) across the world from 1 April 2020 to 31 March 2021 and compared them with cases from corresponding months between 2017 and 2020. Macrolide-resistant
(MRMp) data were collected from 1 April 2017 to 31 March 2021.ResultsThirty-seven sites from 21 countries in Europe, Asia, America and Oceania submitted valid datasets (631,104 tests). Among the 30,617
detections, 62.39% were based on direct test methods (predominantly PCR), 34.24% on a combination of PCR and serology (no distinction between methods) and 3.37% on serology alone (only IgM considered). In all countries,
incidence by direct test methods declined significantly after implementation of NPIs with a mean of 1.69% (SD ± 3.30) compared with 8.61% (SD ± 10.62) in previous years (p < 0.01). Detection rates decreased with direct but not with indirect test methods (serology) (-93.51% vs + 18.08%; p < 0.01). Direct detections remained low worldwide throughout April 2020 to March 2021 despite widely differing lockdown or school closure periods. Seven sites (Europe, Asia and America) reported MRMp detections in one of 22 investigated cases in April 2020 to March 2021 and 176 of 762 (23.10%) in previous years (p = 0.04).ConclusionsThis comprehensive collection of
detections worldwide shows correlation between COVID-19 NPIs and significantly reduced detection numbers.
Abstract Mollicutes are a diverse class of bacteria with a variety of unique characteristics that have allowed them to adapt to a range of hosts and often evade routine cultivation techniques. The ...focus of previous work has been on the major human pathogens; however, here we present a holistic introduction to the many other different genera that constitute the Mollicutes. They represent a significant One Health concern with limited available treatment options given their intrinsic and acquired resistance to many antibiotics. Bacteriophages (phages) are a promising therapeutic and one poorly explored in these bacteria and an avenue to understand gene transfer and resistance development. This review aims to emphasize the many unique and diverse qualities of the Mollicutes and synthesize our current understanding of phages of these bacteria and the challenges that have hindered their isolation and characterization.
Abstract Background Many Gram-negative bacteria, unlike Gram-positive, are directly lysed by complement. Ureaplasma can cause septic arthritis and meningitis in immunocompromised individuals and ...induce premature birth. Ureaplasma has no cell wall, cannot be Gram-stain classified and its serum susceptibility is unknown. Methods Survival of Ureaplasma serovars (SV) 1, 3, 6 and 14 (collectively Ureaplasma parvum ) were measured following incubation with normal or immunoglobulin-deficient patient serum (relative to heat-inactivated controls). Blocking monoclonal anti-C1q antibody and depletion of calcium, immunoglobulins, or lectins were used to determine the complement pathway responsible for killing. Results Eighty-three percent of normal sera killed SV1, 67% killed SV6 and 25% killed SV14; greater killing correlating to strong immunoblot identification of anti- Ureaplasma antibodies; killing was abrogated following ProteinA removal of IgG1. All normal sera killed SV3 in a C1q-dependent fashion, irrespective of immunoblot identification of anti- Ureaplasma antibodies; SV3 killing was unaffected by total IgG removal by ProteinG, where complement activity was retained. Only one of four common variable immunodeficient (CVID) patient sera failed to kill SV3, despite profound IgM and IgG deficiency for all; however, killing of SV3 and SV1 was restored with therapeutic intravenous immunoglobulin therapy. Conclusions Only the classical complement pathway mediated Ureaplasma -cidal activity, sometimes in the absence of observable immunoblot reactive bands.
Background
is a leading cause of community-acquired pneumonia, with large epidemics previously described to occur every 4 to 7 years.AimTo better understand the diagnostic methods used to detect
.
; ...to better understand
testing and surveillance in use; to identify epidemics; to determine detection number per age group, age demographics for positive detections, concurrence of epidemics and annual peaks across geographical areas; and to determine the effect of geographical location on the timing of epidemics.MethodsA questionnaire was sent in May 2016 to
experts with national or regional responsibility within the ESCMID Study Group for Mycoplasma and Chlamydia Infections in 17 countries across Europe and Israel, retrospectively requesting details on
positive samples from January 2011 to April 2016. The Moving Epidemic Method was used to determine epidemic periods and effect of country latitude across the countries for the five periods under investigation.ResultsRepresentatives from 12 countries provided data on
infections, accounting for 95,666 positive samples. Two laboratories initiated routine macrolide resistance testing since 2013. Between 2011 and 2016, three epidemics were identified: 2011/12, 2014/15 and 2015/16. The distribution of patient ages for
positive samples showed three patterns. During epidemic years, an association between country latitude and calendar week when epidemic periods began was noted.ConclusionsAn association between epidemics and latitude was observed. Differences were noted in the age distribution of positive cases and detection methods used and practice. A lack of macrolide resistance monitoring was noted.
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