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The ectoparasite Ixodes ricinus is an important vector for many tick-borne diseases (TBD) in the northern hemisphere, such as Lyme borreliosis, rickettsiosis, human granulocytic anaplasmosis, or tick-borne encephalitis virus. As climate change will lead to rising temperatures in the next years, we expect an increase in tick activity, tick population, and thus in the spread of TBD. Consequently, it has never been more critical to understand relationships within the microbial communities in ticks that might contribute to the tick's fitness and the occurrence of TBD. Therefore, we analyzed the microbiota in different tick tissues such as midgut, salivary glands, and residual tick material, as well as the microbiota in complete Ixodes ricinus ticks using 16S rRNA gene amplicon sequencing. By using a newly developed DNA extraction protocol for tick tissue samples and a self-designed mock community, we were able to detect endosymbionts and pathogens that have been described in the literature previously. Further, this study displayed the usefulness of including a mock community during bioinformatic analysis to identify essential bacteria within the tick.

Lyme borreliosis is a vector-borne disease in humans and animals caused by bacteria from the Borrelia burgdorferi sensu lato complex ( Bb sl). The possible transmission of Bb sl from companion animals to humans via ticks makes this disease important in terms of One Health approaches. Thus, early and accurate diagnosis and treatment are of utmost importance. Today's standard for the detection of specific antibodies against Bb sl is a two-tiered test system based on an ELISA for screening combined with a line immunoassay (LIA) for confirmation. In this study, 200 canine and 200 equine serum samples with known antibody status were tested with two different LIAs (A and B). Results were compared regarding sensitivity, specificity, the diagnostic outcome for dogs and horses, as well as operability of the test. The results for canine serum samples corresponded to 94.0%, making both LIAs a good choice for LB diagnostic in dogs. For equine serum samples, the agreement of both tests was 65.5%, displaying the challenge equine samples still provide in LB diagnostic. Major concerns were the interpretation of the OspA antigen (AG) signal and the use of unspecific (i.e., p100/p83) or too sensitive signals on the LIA. The operability of both LIAs was equally user-friendly. Regarding the tests' evaluation, the scanning process provided by LIA A was a major advantage considering the comparability of the tests.

Stachybotrys chartarum is a toxigenic fungus that is frequently isolated from damp building materials or improperly stored forage. Macrocyclic trichothecenes and in particular satratoxins are the most potent mycotoxins known to be produced by this fungus. Exposure of humans or animals to these secondary metabolites can be associated with severe health problems. To assess the pathogenic potential of S. chartarum isolates, it is essential to cultivate them under conditions that reliably promote toxin production. Potato dextrose agar (PDA) was reported to be the optimal nutrition medium for satratoxin production. In this study, the growth of S. chartarum genotype S strains on PDA from two manufacturers led to divergent results, namely, well-grown and sporulating cultures with high satratoxin concentrations (20.8 ± 0.4 µg/cm 2 ) versus cultures with sparse sporulation and low satratoxin production (0.3 ± 0.1 µg/cm 2 ). This finding is important for any attempt to identify toxigenic S. chartarum isolates. Further experiments performed with the two media provided strong evidence for a link between satratoxin production and sporulation. A comparison of three-point and one-point cultures grown on the two types of PDA, furthermore, demonstrated an inter-colony communication that influences both sporulation and mycotoxin production of S. chartarum genotype S strains.

Measuring antibodies to evaluate dogs' immunity against canine parvovirus (CPV) is useful to avoid unnecessary re-vaccinations. The study aimed to evaluate the quality and practicability of four point-of-care (POC) tests for detection of anti-CPV antibodies. The sera of 198 client-owned and 43 specific pathogen-free (SPF) dogs were included; virus neutralization was the reference method. Specificity, sensitivity, positive and negative predictive value (PPV and NPV), and overall accuracy (OA) were calculated. Specificity was considered to be the most important indicator for POC test performance. Differences between specificity and sensitivity of POC tests in the sera of all dogs were determined by McNemar, agreement by Cohen's kappa. Prevalence of anti-CPV antibodies in all dogs was 80% (192/241); in the subgroup of client-owned dogs, it was 97% (192/198); and in the subgroup of SPF dogs, it was 0% (0/43). FASTest ® and CanTiCheck ® were easiest to perform. Specificity was highest in the CanTiCheck ® (overall dogs, 98%; client-owned dogs, 83%; SPF dogs, 100%) and the TiterCHEK ® (overall dogs, 96%; client-owned dogs, 67%; SPF dogs, 100%); no significant differences in specificity were observed between the ImmunoComb ® , the TiterCHEK ® , and the CanTiCheck ® . Sensitivity was highest in the FASTest ® (overall dogs, 95%; client-owned dogs, 95%) and the CanTiCheck ® (overall dogs, 80%; client-owned dogs, 80%); sensitivity of the FASTest ® was significantly higher compared to the one of the other three tests (McNemars p -value in each comparison: <0.001). CanTiCheck ® would be the POC test of choice when considering specificity and practicability. However, differences in the number of false positive results between CanTiCheck ® , TiterCHEK ® , and ImmunoComb ® were minimal., Competing Interests: Katrin Hartmann has given talks for MSD, Boehringer Ingelheim, and IDEXX. Katrin Hartmann and Michèle Bergmann participated in research funded by or using products from MSD, Merial, Boehringer, Zoetis, Megacor, Biogal, and Scil. There is no commercial conflict of interest, as the information generated here is solely for scientific dissemination.

Leptospirosis is a zoonotic disease of global importance, especially in tropical countries. The current Leptospira spp. seroprevalence in cattle from central and northern Madagascar is unknown. Thus, the aim of this study was to determine the seroprevalence resulting from infections with pathogenic Leptospira spp. in zebu cattle from these areas. Serum samples from 194 animals were tested by microscopic agglutination test (MAT) using a panel of 12 serovars as antigens. Samples with a titer of ≥1:100 were considered positive. The overall seroprevalence was 59.3% (95% CI; 52.0-66.2%) with titers ranging from 1:100 to 1:1600. Among the seropositive animals, the most frequent antibody reactions were against serovar L. Tarassovi (serogroup L. Tarassovi) with 40.2% (33.3-47.5%), followed by L. Hardjo ( L. Sejroe) with 13.9% (9.5-19.8%), L. Grippotyphosa ( L. Grippotyphosa) with 9.8% (6.2-15.1%), L. Pomona ( L. Pomona) with 7.7% (4.5-12.7%) and L. Autumnalis ( L. Autumnalis) with 5.2% (2.6-9.5%). Less than 5% of the samples reacted positively against the remaining serovars. These results indicate a very high exposure of Malagasy cattle to Leptospira spp. which, consequently, poses a definite risk for people working with cattle acquiring this zoonotic infection.