National population prevalence of antibodies to SARS-CoV-2 among pregnant women in Scotland during the second wave of the COVID-19 pandemic: a prospective national serosurvey.

OBJECTIVES: This study aimed to determine SARS-CoV-2 seroprevalence among pregnant women in the Scottish population during the second wave of the COVID-19 pandemic. STUDY DESIGN: Prospective national serosurvey. METHODS: We tested 13,428 residual samples retrieved from pregnant women participating in the first trimester combined ultrasound and biochemical screening for fetal trisomy across Scotland for SARS-CoV-2 antibodies over a 6-month period from November 2020 to April 2021. Seroprevalence estimates were adjusted for the sensitivity and specificity of the assays and weighted to reference populations. RESULTS: Seroprevalence rates in the antenatal samples significantly increased from 5.5% (95% confidence interval [CI] 4.7%-6.5%) in the 5-week period up to and including International Organization for Standardization (ISO) Week 51 (w/b Monday 14 December 2020) to 11.3% (95% CI 10.1%-12.6%) in the 5-week period up to and including ISO Week 14 (w/b Monday 5 April 2021). Increasing seroprevalence trends across the second wave were observed among all age groups. CONCLUSIONS: By the end of the second wave of the COVID-19 pandemic, approximately one in 10 women tested around the end of the first trimester of pregnancy had antibodies to SARS-CoV-2, suggesting that the vast majority were still susceptible to COVID-19 as they progressed to the later stages of pregnancy, when risks from infection are elevated for both mother and baby.

Hepatic steatosis and non-alcoholic fatty liver disease are not associated with decline in renal function in people with Type 2 diabetes.

AIMS: We aimed to determine whether the presence of hepatic steatosis and/or non-alcoholic fatty liver disease was associated with decline in renal function or onset of microalbuminuria in a cohort of people with Type 2 diabetes, including those managed in both primary and secondary care. METHODS: Nine hundred and thirty-three patients from the Edinburgh Type 2 Diabetes Study, a cohort of Scottish men and women aged 60-74 years with Type 2 diabetes, underwent assessment for hepatic steatosis by liver ultrasonography 1 year after recruitment. Non-alcoholic fatty liver disease was defined as the presence of steatosis following exclusion of secondary causes of liver disease. Patients were followed for 4 years and decline in renal function was assessed by the change in estimated glomerular filtration rate over time. RESULTS: Of the 933 subjects, 530 had hepatic steatosis and, of those with hepatic steatosis, 388 had non-alcoholic fatty liver disease. Neither hepatic steatosis nor non-alcoholic fatty liver disease were significantly associated with rate of decline in renal function, with the mean rate of decline in estimated glomerular filtration rate being -1.55 ml min(-1) 1.73 m(-2) per year for participants with hepatic steatosis compared with -1.84 ml min(-1) 1.73 m(-2) for those without steatosis (P = 0.19). Similar results were obtained when the analysis was restricted to participants with and without non-alcoholic fatty liver disease (-1.44 vs. -1.64 ml min(-1) 1.73 m(-2) per year, respectively; P = 0.44). Additionally, neither hepatic steatosis nor non-alcoholic fatty liver disease were associated with the onset or regression of albuminuria during follow-up (all P ≥ 0.05). CONCLUSIONS: The presence of hepatic steatosis/non-alcoholic fatty liver disease was not associated with decline in renal function during a 4-year follow-up in our cohort of older people with Type 2 diabetes.

Survival of Mycobacterium avium subsp. paratuberculosis in biofilms on livestock watering trough materials.

Mycobacterium avium subsp. paratuberculosis (Map) is the causative agent of Johne's disease, a chronic enteric infection that affects ruminants. Despite the ubiquitous occurrence of Mycobacterium sp. in nature and the fact that Johne's disease has been reported worldwide, little research has been done to assess its survival in agricultural environments. The goal of this 365-day study was to evaluate the ability of Map to persist in mixed-community biofilms on materials commonly used to construct livestock watering troughs. Map was inoculated into 32l of trough water containing either concrete, plastic, galvanized or stainless steel trough materials. The concentration of Map was determined by using quantitative, real-time PCR to target the IS900 sequence in DNA extracts. High concentrations of Map were detected on all trough materials after 3 days (around 1 x 10(5)cells cm(-2)). Based on the best-fit slopes, the time required for a 99% reduction (t(99)) in biofilm-associated Map cells was 144 and 115 days for plastic and stainless steel trough materials, respectively. Map concentrations did not decrease on concrete and galvanized steel trough materials. These results suggest that Map survives well in biofilms present on livestock watering trough materials. To inhibit spread of this organism and exposure of susceptible animals to Map on infected farms, best management practices aimed at maintaining biofilm-free trough surfaces should be included in any Johne's control plan.

Optimization of methods for detecting Mycobacterium avium subsp. paratuberculosis in environmental samples using quantitative, real-time PCR.

Detection of Johne's disease, an enteric infection of cattle caused by Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis), has been impeded by the lack of rapid, reliable detection methods. The goal of this study was to optimize methodologies for detecting M. paratuberculosis in manure from an infected dairy cow or in contaminated soil samples using a quantitative, real-time PCR (QRT-PCR) based analysis. Three different nucleic acid extraction techniques, the efficiency of direct versus indirect sample extraction, and sample pooling were assessed. The limit of detection was investigated by adding dilutions of M. paratuberculosis to soil. Results show that the highest yield (19.4+/-2.3 microg(-1) DNA extract) and the highest copy number of the targeted M. paratuberculosis IS900 sequence (1.3+/-0.2x10(8) copies g(-1) manure) were obtained with DNA extracted from manure using Qbiogene's Fast DNA Spin kit for soil. Pooling ten samples of M. paratuberculosis-contaminated soil improved the limit of detection ten fold (between 20 and 115 M. paratuberculosis cells g(-1) soil). Detection was between 65% and 95% higher when samples were extracted directly using bead-beating than when using pre-treatment with cell extraction buffers. The final soil-sampling and extraction regime was applied for detection of M. paratuberculosis in pasture soil after the removal of a M. paratuberculosis culture positive dairy cow. M. paratuberculosis remained in the pasture soil for more than 200 days. Results from these studies suggest that DNA extraction method, sampling protocol and PCR conditions each critically influence the outcome and validity of the QRT-PCR analysis of M. paratuberculosis concentrations in environmental samples.

Inhibition of IL-4 responses after T cell priming in the context of LFA-1 costimulation is not reversed by restimulation in the presence of CD28 costimulation.

Costimulation is one of several factors that influence the differentiation of CD4+ Th cell responses. Previously, we have shown that Ag presentation in the context of LFA-1 costimulation by fibroblasts transfected with class II and ICAM-1 (ProAd-ICAM) can drive naive CD4-positive T cells into cell cycle, but these T cells die by apoptosis 4-5 days after stimulation. In this report we show that the death of these cells can be prevented by the addition of exogenous IL-2 (20 U/ml) or by restimulation with Ag presented in the context of CD28 costimulation. Under these conditions, T cells go through extensive cell division and normal cell expansion. However, when T cells that have been primed by Ag presented in the context of LFA-1 costimulation are restimulated, they secrete IL-2 and IFN-gamma, but little or no IL-4. The inability of ProAd-ICAM-primed T cells to produce IL-4 was restored by the addition of IL-4 to the priming culture. However, IL-4 responses were not restored by representation of Ag in the context of CD28 costimulation, even as early as 24 h after priming with Ag presented by ProAd-ICAM cells. These findings suggest that differential expression of B7-1 and ICAM-1 by APCs during the initiation of immune responses may alter the differentiation of Th populations.