Interactions between Babesia microti merozoites and rat kidney cells in a short-term in vitro culture and animal model.

Babesiosis is one of the most common infections in free-living animals and is rapidly becoming significant among human zoonoses. Cases of acute renal failure in humans caused by Babesia spp. have been described in the literature. The kidneys are characterised by intense blood flow through the blood vessels, which increases the likelihood of contact with the intra-erythrocyte parasite. The aim of this study was to observe the influence of B. microti (ATCC 30221) on renal epithelial cells in vitro cultured (NRK-52E line) and Wistar rats' kidney. Both NRK-52E cells and rats' kidney sections were analysed by light microscopy, transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH). Necrotic changes in renal epithelial cells have been observed in vitro and in vivo. In many cross-sections through the rats' kidney, adhesion of blood cells to the vascular endothelium, accumulation of erythrocytes and emboli were demonstrated. In NRK-52E culture, elements with a distinctly doubled cell membrane resembling B. microti were found inside the cytoplasm and adjacent to the cell layer. The study indicates a chemotactic tendency for B. microti to adhere to the renal tubules' epithelium, a possibility of piroplasms entering the renal epithelial cells, their proliferation within the cytoplasm and emboli formation.

Induction of Apoptosis in Normal Human Dermal Fibroblasts Infected with Borrelia burgdorferi Sensu Lato.

The spirochete Borrelia burgdorferi s.l. can enter into different eukaryotic cells. Intracellular localization of bacteria may cause many changes in different cell pathways like apoptosis-mediated caspase cascade. The present studies focused on gene expression associated with caspase cascade after normal human dermal fibroblasts (NHDF) infection with Borrelia garinii, Borrelia afzelii, and B. burgdorferi s.s. The use of oligonucleotide microarray technique enabled an expression level comparison of genes associated with caspase cascade in NHDF infected with spirochetes. The increased expression of genes associated with caspase cascade was observed in case of CASP5, CASP2, CARD10, CASP10, MALT1, and NLRP1. The decreased expression was observed in case of CASP4, CASP6, and CASP1. The mRNA expression for CASP3 was inhibited in cells infected with three genospecies of Borrelia. However, the intensity of fluorescence was not statistically significant. In addition, cell cultures were fixed and procedure of caspase-3 detection and the TUNEL assay were performed. The in situ caspase-3 detection procedure confirmed the results obtained from microarray analyses. Only several fluorescent signals were observed. Many apoptotic cells were detected in NHDF-infected cultures with all spirochete genospecies found using the TUNEL reaction.

Cadmium effect on the ovarian structure in earthworm Dendrobaena veneta (Rosa).

Cadmium effects on the ovary structure and oocytes were tested in earthworms Dendrobaena veneta exposed to 10 and 50 mg Cd kg(-1) in soil after 10 and 20 days of the experiment. In both experimental doses cadmium caused damage to the structure of the ovary but the effects were different in each group. At 10 mg Cd kg(-1) concentration in soil, young stages of oocytes and trophocytes were most sensitive to cadmium deleterious effects whereas somatic cells in the ovarian stroma were only slightly affected. Cadmium. at a concentration of 50 mg Cd kg(-1) in soil caused most damage in the somatic cells leading to the occurrence of unnaturally swollen elements and desmosomes destruction. At both experimental concentrations cadmium induced degenerative changes in cell nuclei and an increase in number of cell organelles (RER and Golgi complex elements) in the cytoplasm of oocytes and trophocytes. These also proved to be more active. No ultrastructural changes were manifested in oogonia. In both experimental groups degenerative changes occurred as early as after 10 days of Cd exposure.