Iva Mayer

MOLECULAR EVIDENCE OF NATURAL INFECTION WITH BABESIA CANIS CANIS IN CROATIA

The aim of the present study was to detect and characterise the species and subspecies of Babesia spp. that cause canine babesiosis in Croatia. Twenty-eight dogs with typical signs of babesiosis (lethargy, anorexia, fever, dark urine and thrombocytopenia) were included in this study. Their blood smears showed the presence of Babesia canis . The results showed the detection of one subspecies, namely Babesia canis canis using PCR, and subsequent sequence analysis demonstrated portions of the nss rRNA gene in 27 out of 28 samples. Sequence analysis of the isolates showed 100% identity in 11 samples, 99.7% identity (one nucleotide difference) in 11 samples and 99.4% identity (two nucleotides difference) in 5 samples with B. canis canis . The results of this study confirm the presence of B. canis canis in infected dogs in Croatia and demonstrate a slightly new genetic variant of Babesia subspecies.

MCP-1, KC-like and IL-8 as critical mediators of pathogenesis caused by Babesia canis

Canine babesiosis caused by the intraerythrocytic protozoan parasite Babesia canis is a tick-borne disease characterized by a host response that involves both cellular and humoral immunity. This study focuses on the secretion of cytokines Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF), Keratinocyte Chemotactic-like (KC-like), Interleukins (IL)-2, IL-7, IL-8, IL-10, IL-15, IL-18 and Monocyte Chemotactic Protein-1 (MCP-1) in babesiosis caused by Babesia canis upon treatment with Imizol®. We assessed time dependent changes in cytokine levels and tested whether these changes correlate with pathogenesis of the disease. Sixteen healthy dogs and 31 dogs infected with Babesia canis, of which 18 showed complications, were treated with Imizol®. One dog died during the study (3.2%). Longitudinal study was perfomed by monitoring dogs at the first day of presentation (day 1) and 6 days later (day 7). Our results show that higher MCP-1 levels on day 1 are positively associated with the occurrence of complications, (complicated vs. uncomplicated; p = 0.00016). A similar pattern was observed for KC-like on day 1 (p = 0.0326) and day 7 (p = 0.044). Moreover, babesiosis caused by B. canis produced a steady increase in IL-8 levels with a moderate to strong negative correlation with erythrocyte counts and hematocrit in uncomplicated diseased dogs only (Spearmans rank correlation coefficient rs = -0.582 and rs = -0.598 respectively). Like for MCP-1, KC-like levels also differed in complicated and uncomplicated diseased dogs on day 1 (p = 0.03236) and day 7 (p = 0.044). Furthermore, KC-like levels were strongly correlated with IL-8 levels (rs = 0.663–0.7) and non-segmented neutrophil counts (rs = 0.572–0.732) in both diseased groups. Analysis of ROC suggests the use of serum levels of MCP-1 and IL-7 as predictors of the occurrence of complications with an AUC of 0.906 and 0.896 respectively and linear combinations of MCP-1, KC-Like, IL-7 and GM-CSF with values up to AUC = 0.983. Cytokine cluster analysis presented in this study can contribute to a better understanding of the pathogenesis of babesiosis and serve as a prognostic tool for the early detection of cases with highest likelihood of developing complications. Overall, our studies show that infection by B. canis elicits a cytokine pattern that is distinct from that observed with B. rossi, and that some of the inflammatory mediators can be useful to predict complications. Our results also suggest targets for the development of novel therapeutic strategies in babesiosis caused by B. canis.

Co-oximetry in clinically healthy dogs and effects of time of post sampling on measurements.

OBJECTIVES Co-oximetry is a complex and valuable laboratory method that measures haemoglobin species and oxygenation status by multi-wavelength spectrophotometry. The purpose of this study was to establish reference intervals for clinically healthy dogs and to determine the effect of time of analyses and sex of animals on the accuracy of results. METHODS Blood was collected from 27 healthy adult dogs of various breeds and sex. Co-oximetry was performed on a CCX co-oximeter that measures eight haemoglobin and oxygen transport related parameters: carboxyhaemoglobin (COHb), deoxyhaemoglobin (HHb), oxyhaemoglobin (O(2)Hb), methaemoglobin (MetHb), total haemoglobin (tHb), oxygen saturation (SO(2)%), oxygen content (O(2)Ct) and oxygen capacity (O(2)Cap). RESULTS Results obtained after 2 and 4 hours were not significantly different from those obtained immediately after sampling. But after 48 hours, the results for total haemoglobin, oxygen saturation, oxyhaemoglobin, oxygen content and oxygen capacity were significantly lower, and carboxyhaemoglobin and deoxyhaemoglobin values were significantly higher than determination immediately after sampling. Gender had no significant impact on co-oximetry values. CLINICAL SIGNIFICANCE Co-oximetry offers several advantages compared with other methods, including ease of use, increased accuracy and greater differentiation among haemoglobin species.