A requirement for flow to enable the development of Ureaplasma parvum biofilms in vitro

Aims To use a flow-based method to establish, quantify and visualize biofilms of Ureaplasma parvum. Methods and Results Absorbance readings of a U. parvum HPA5 culture were taken at 550 nm every 3 h for 30 h in order to establish a growth curve, with viability determined by the number of colour changing units (CCUs). Biofilms were established using the DTU flow-cell with a flow rate of 0·01 ml min−1 and compared to the static control. Titres of bacteria were determined by CCU and biofilm biomass was quantified by Syto9 staining and COMSTAT analysis. High-resolution images were obtained by scanning electron microscopy (SEM). Flow resulted in significantly more biofilm and higher cell titre (0·599 µm3/µm2 ± 0·152 and 4 × 108 CCU per ml, respectively) compared with static conditions (0·008 µm3/µm2 ± 0·010 and no recoverable cells, respectively). SEM revealed pleomorphic cells, with signs of budding and possible membrane vesicle formation. Conclusions Flow is an essential requirement for the establishment of U. parvum biofilms. Significance and Impact of the Study This is the first quantification of biofilm biomass formed by U. parvum. It is now possible to establish viable biofilms of U. parvum which will allow for future testing of antimicrobial agents and understanding of virulence-associated with adhesion

Assessing phage therapy against Pseudomonas aeruginosa using a Galleria mellonella infection model

The Galleria mellonella infection model was used to assess the in vivo efficacy of phage therapy against laboratory and clinical strains of Pseudomonas aeruginosa. In a first series of experiments, Galleria were infected with the laboratory strain P. aeruginosa PAO1 and were treated with varying multiplicity of infection (MOI) of phages either 2 h post-infection (treatment) or 2 h pre-infection (prevention) via injection into the haemolymph. To address the kinetics of infection, larvae were bled over a period of 24 h for quantification of bacteria and phages. Survival rates at 24 h when infected with 10 cells/larvae were greater in the prevention versus treatment model (47% vs. 40%, MOI = 10; 47% vs. 20%, MOI = 1; and 33% vs. 7%, MOI = 0.1). This pattern held true when 100 cells/larvae were used (87% vs. 20%, MOI = 10; 53% vs. 13%, MOI = 1; 67% vs. 7%, MOI = 0.1). By 24 h post-infection, phages kept bacterial cell numbers in the haemolymph 1000-fold lower than in the non-treated group. In a second series of experiments using clinical strains to further validate the prevention model, phages protected Galleria when infected with both a bacteraemia (0% vs. 85%) and a cystic fibrosis (80% vs. 100%) isolate. Therefore, this study validates the use of G. mellonella as a simple, robust and cost-effective model for initial in vivo examination of P. aeruginosa-targeted phage therapy, which may be applied to other pathogens with similarly low infective doses

Corrigendum: Chronic Intra-Uterine Ureaplasma parvum infection induces injury of the enteric Nervous System in Ovine Fetuses

Michael L. Beeton was not included as an author in the published article. The corrected Author Contributions Statement appears below

Serum killing of Ureaplasma parvum shows serovar-determined susceptibility for normal individuals and common variable immuno-deficiency patients

Nephrolog

Prophylactic Intra-Uterine β-Cyclodextrin Administration during Intra-Uterine Ureaplasma parvum Infection Partly Prevents Liver Inflammation without Interfering with the Enterohepatic Circulation of the Fetal Sheep

Chorioamnionitis can lead to inflammation and injury of the liver and gut, thereby predisposing patients to adverse outcomes such as necrotizing enterocolitis (NEC). In addition, intestinal bile acids (BAs) accumulation is causally linked to NEC development. Plant sterols are a promising intervention to prevent NEC development, considering their anti-inflammatory properties in the liver. Therefore, we investigated whether an intra-amniotic (IA) Ureaplasma parvum (UP) infection affected the liver and enterohepatic circulation (EHC) and evaluated whether an IA administered plant sterol mixture dissolved in β-cyclodextrin exerted prophylactic effects. An ovine chorioamnionitis model was used in which liver inflammation and the EHC were assessed following IA UP exposure in the presence or absence of IA prophylactic plant sterols (a mixture of β-sitosterol and campesterol dissolved in β-cyclodextrin (carrier)) or carrier alone. IA UP exposure caused an inflammatory reaction in the liver, histologically seen as clustered and conflated hepatic erythropoiesis in the parenchyma, which was partially prevented by IA administration of sterol + β-cyclodextrin, or β-cyclodextrin alone. In addition, IA administration of β-cyclodextrin prior to UP caused changes in the expression of several hepatic BAs transporters, without causing alterations in other aspects of the EHC. Thereby, the addition of plant sterols to the carrier β-cyclodextrin did not have additional effects

Mycoplasma pneumoniae detections before and during the COVID-19 pandemic : results of a global survey, 2017 to 2021

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 &lt; 0.01). Detection rates decreased with direct but not with indirect test methods (serology) (-93.51% vs + 18.08%; p &lt; 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&nbsp;numbers.</p

Mycoplasma pneumoniae detections before and detections before and during the COVID-19 pandemic: results of a global survey, 2017 to 2021.

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 &lt; 0.01). Detection rates decreased with direct but not with indirect test methods (serology) (-93.51% vs + 18.08%; p &lt; 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&nbsp;numbers.</p