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Waddlia chondrophila is a strict intracellular bacterium belonging to the Chlamydiales order, which also encompasses important human and animal pathogens, including Chlamydia trachomatis and Chlamydia psittaci. Like all other members of the order, W. chondrophila displays a biphasic developmental cycle, alternating between infectious extracellular and replicative intracellular forms.First isolated from a bovine aborted foetus, W. chondrophila was later demonstrated to be associated, in women, with adverse pregnancy outcomes, such as miscarriage. Furthermore, recent studies have demonstrated a high prevalence of anti-W. chondrophila antibodies in asymptomatic women who consulted doctors regarding infertility problems, and in the male patients of infertile couples. Additionally, a role for this bacterium in respiratory tract infections has been suggested, as it has also been recovered from respiratory samples.Although the cause of miscarriage is not identified in ∼50% of cases, nowadays, no systematic diagnostic testing for the presence of W. chondrophila is routinely performed. Implementing large-scale testing in women with reproductive health issues would undoubtedly increase our knowledge of W. chondrophila prevalence and its implications for disease outcomes.
Secretions are central to the ability of the salmon louse Lepeophtheirus salmonis to parasitize salmonid hosts by promoting immunomodulation and feeding. Previous characterizations of secretory and excretory products (SEPs) have relied on pooled individuals, preventing assessment of inter-individual variation and responses to host-derived cues. A novel SEP collection method was developed to obtain samples from individual adult female L. salmonis, enabling evaluation of secretory profiles following exposure to conditioned seawater from a susceptible host, Atlantic salmon (Salmo salar), or a resistant host, coho salmon (Oncorhynchus kisutch). SEP concentrations ranged from 328 to 1597 µg mL⁻¹ , with no effects of host species or conditioning treatment on protein yield. Across 16 individuals, a mean of 101.4 proteins were detected per replicate, including 61.2 secretory proteins, indicating substantial inter-individual variation. Conditioning did not alter protein richness, yet conditioned treatments showed clear qualitative differences in composition. S. salar-conditioned lice uniquely secreted 40 proteins, including proteases, protease inhibitors, C-type lectins, gamma crystallins, and labial gland factors, whereas controls yielded a single unique protein. O. kisutch conditioning was further associated with additional proteases, protease inhibitors, epidermal growth factor-like proteins, and other putative virulence factors. Detection of chitin deacetylase-7 and an LY6/uPAR domain protein across multiple conditions highlights previously uncharacterised candidates relevant to louse-host interactions. In total, these findings establish individual-level SEP collection as a robust and sensitive approach for resolving secretomic diversity in L. salmonis and detecting host-associated modulation of parasite secretory activity obscured by pooled analyses.
Random forest-based source attribution models were developed from a ‘One Health’ resource comprising 4,230 high-quality whole-genome assemblies from Escherichia coli . These were isolated from a wide range of sources, predominantly originating in Scotland, including wastewater, livestock, food and clinical infections of humans and dogs. Using these models, we derived a probabilistic assignment of E. coli isolates from food, shellfish and water samples to potential livestock and human sources of contamination. The incorporation of E. coli sequences from wastewater alongside those from human clinical infections enabled us to capture a wide diversity of human strains in our analyses. The sequence types (STs) of isolates from human bacteraemia and urinary tract infection (UTI) were compared with livestock and food isolates. While only 2.3% of the E. coli isolated from food samples in the study were from STs primarily associated with human bacteraemia and UTI, the models found a livestock signal associated with 15% of the human clinical isolates. In the food and private water samples, livestock-human co-attribution of E. coli isolates was common and consistent with routine human exposure to specific subsets of livestock E. coli , potentially a result of selection during food and water processing. Overall, this research demonstrates the potential value of including source attribution models in national surveillance programmes to understand the transmission of E. coli through the agri-food chain and support risk management to protect public health.
Cerebellar disease in ruminants is often virus-induced and non-genetic, but there are also rare inherited forms of cerebellar hypoplasia and cerebellar abiotrophy (CA). So far, no causal variant has been reported for these conditions in cattle. Two inbred Angus calves suspected of having cerebellar disease were reported in Scotland. The aims of this study were to characterize the clinicopathological phenotype of Angus calves affected by a cerebellar disease, to identify a causal variant assuming autosomal monogenic recessive inheritance and to evaluate its prevalence in Angus populations. Clinicopathological investigations were performed, including the exclusion of prevalent teratogenic viruses as well as a multiple-case whole-genome sequencing (WGS) approach. The two affected Angus calves showed congenital intention tremor and brain examination detected cerebellar abiotrophy. Genetic analysis identified a private homozygous missense variant in the bovine CACNA2D2 gene (XP_024839037.1:p.(Cys395Arg)), which is linked to neurological disorders in other species, including a form of cerebellar atrophy in humans. This variant was classified as pathogenic and shown to be absent in sequence data from over 5000 other cattle with available WGS data as well as in a cohort of 16 purebred Angus cattle from Switzerland. The variant is proposed to cause a rare form of CA in Angus and therefore should be monitored in the Angus global population, as previous similar cases were reported elsewhere. For the first time, we characterized a genetic form of cerebellar disease in cattle, providing the first large animal model for a condition related to the CACNA2D2 gene.
