Antimicrobial Resistance Surveillance: Data Harmonisation and Data Selection within Secondary Data Use.

Resistance to last-resort antibiotics is a global threat to public health. Therefore, surveillance and monitoring systems for antimicrobial resistance should be established on a national and international scale. For the development of a One Health surveillance system, we collected exemplary data on carbapenem and colistin-resistant bacterial isolates from human, animal, food, and environmental sources. We pooled secondary data from routine screenings, hospital outbreak investigations, and studies on antimicrobial resistance. For a joint One Health evaluation, this study incorporates epidemiological metadata with phenotypic resistance information and molecular data on the isolate level. To harmonise the heterogeneous original information for the intended use, we developed a generic strategy. By defining and categorising variables, followed by plausibility checks, we created a catalogue for prospective data collections and applied it to our dataset, enabling us to perform preliminary descriptive statistical analyses. This study shows the complexity of data management using heterogeneous secondary data pools and gives an insight into the early stages of the development of an AMR surveillance programme using secondary data.

Correlative light and electron microscopy of wall formation in Eimeria nieschulzi.

Coccidian parasites possess complex life cycles involving asexual proliferation followed by sexual development leading to the production of oocysts. Coccidian oocysts are persistent stages which are secreted by the feces and transmitted from host to host guaranteeing life cycle progression and disease transmission. The robust bilayered oocyst wall is formed from the contents of two organelles, the wall-forming bodies type I and II (WFBI, WFBII), located exclusively in the macrogametocyte. Eimeria nieschulzi has been used as a model parasite to study and follow gametocyte and oocyst development. In this study, the gametocyte and oocyst wall formation of E. nieschulzi was analyzed by electron microscopy and immuno-histology. A monoclonal antibody raised against the macrogametocytes of E. nieschulzi identified a tyrosine-rich glycoprotein (EnGAM82) located in WFBII. Correlative light and electron microscopy was used to examine the vesicle-specific localization and spatial distribution of GAM82-proteins during macrogametocyte maturation by this monoclonal antibody. In early and mid-stages, the GAM82-protein is ubiquitously distributed in WFBII. Few hours later, the protein is arranged in subvesicular structures. It was possible to show that the substructure of WFBII and the spatial distribution of GAM82-proteins probably represent pre-synthesized cross-linked materials prior to the inner oocyst wall formation. Dityrosine-cross-linked gametocyte proteins can also be confirmed and visualized by fluorescence microscopy (UV light, autofluorescence of WFBII).

Distribution and Processing of Eimeria nieschulzi OWP13, a New Protein of the COWP Family.

Eimeria species are important veterinary coccidian parasites and are transmitted between hosts via oocysts. The infectious sporozoites are protected by the oocyst and sporocyst wall. Tyrosine-rich proteins are well-known components of the Eimeria oocyst wall. Recently, cysteine motif containing proteins (COWP family), as described in Toxoplasma gondii and Cryptosporidium spp., have also been characterized in Eimeria. Here, we identified a novel COWP-related protein, EnOWP13, and tracked it via transfection technology in Eimeria nieschulzi. The subsequent analysis suggests that the mCherry-tagged EnOWP13 localizes to the wall-forming bodies I and the outer wall. Immunohistochemical analysis confirmed the distribution of wall-forming bodies similar to avian Eimeria species and revealed that the wall-forming bodies I show peroxidase activity. The EnOWP13 amino acid composition and FITC-cadaverine-positive wall-forming bodies I suggest a participation of an enzyme with transglutaminase activity. This is the first description and characterization of this novel outer oocyst wall protein, which is also orthologous to other Eimeria species and Toxoplasma gondii, suggesting a new potential cross-linking mechanism of wall-forming proteins via isopeptide bonds.