Cryptosporidium parvum causes a zoonotic infection with worldwide distribution. Besides humans, cryptosporidiosis affects a wide range of animals leading to significant economic losses due to severe enteritis in neonatal livestock.... more
Cryptosporidium parvum causes a zoonotic infection with worldwide distribution. Besides humans, cryptosporidiosis affects a wide range of animals leading to significant economic losses due to severe enteritis in neonatal livestock. Neutrophil extracellular trap (NET) formation has been demonstrated as an important host effector mechanism of PMN acting against several invading pathogens. In the present study, C. parvum-mediated NET formation was investigated in human and bovine PMN in vitro. We here demonstrate that C. parvum sporozoites indeed trigger NET formation in a time-dependent manner. Thereby, the classical characteristics of NETs were demonstrated by co-localization of extracellular DNA with histones, neutrophil elastase (NE) and myeloperoxidase (MPO). A significant reduction of NET formation was measured following treatments of PMN with NADPH oxidase-, NE- and MPO-inhibitors, confirming the key role of these enzymes in C. parvum-induced NETs. Additionally, sporozoite-trigg...
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Eimeria (E.) bovis sporozoites as well as Toxoplasma (T.) gondii and Neospora (N.) caninum tachyzoites can invade bovine endothelial cells (BUVEC) in vitro and develop to next stage meronts within 15-20 and 3-4 days, respectively. The... more
Eimeria (E.) bovis sporozoites as well as Toxoplasma (T.) gondii and Neospora (N.) caninum tachyzoites can invade bovine endothelial cells (BUVEC) in vitro and develop to next stage meronts within 15-20 and 3-4 days, respectively. The latter differences suggest different immune evasion strategies, particularly concerning innate reactions. Realtime RT-PCR techniques were used to determine transcript levels of genes relevant in this sense, i.e. adhesion molecule, chemokine, growth factor GM-CSF, cyclooxygenase 2 (COX-2) and iNOS genes in infected cells. In addition, adhesion of neutrophils (PMN) to infected BUVEC monolayers was quantified. Effects differed between E. bovis and T. gondii/N. caninum as the latter two species strongly enhance the transcription of all genes in question and induce PMN adhesion to infected BUVEC whereas E. bovis either caused only weak responses or failed to enhance gene transcription as in case of CXC chemokines and COX-2. It even down regulates adhesion m...
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Research Interests: Microbiology, Immune response, Cytokines, Macrophages, Innate immunity, and 15 moreVeterinary Parasitology, Intestinal Mucosa, Adaptive Immunity, Animals, Fisheries Sciences, Eimeria, Cattle, Phagocytosis, Monocytes, Coccidiosis, Veterinary Sciences, Cell Proliferation, Lymphocytes, Chemokines, and Lymph nodes
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Research Interests: Immune response, Confocal Microscopy, Veterinary, Cercopithecus aethiops, Endothelial Cells, and 14 moreAnimals, Male, Host-parasite interactions, Laser Scanning Confocal Microscopy, Eimeria, Cattle, Rats, Coccidiosis, Veterinary Sciences, Internal Structure, Cell Surface Markers, Vero cells, Immune electron microscopy, and Phospholipase C
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Research Interests: Microbiology, Immune response, Cytokines, Transmission Electron Microscopy, Innate immunity, and 16 moreVeterinary Parasitology, Animals, Fisheries Sciences, Experimental Infection, Eimeria, Cattle, Neutrophils, Phagocytosis, Endothelial cell, Time Factors, Coccidiosis, Veterinary Sciences, Chemokines, Pseudopodia, Respiratory Burst, and Gene Expression Regulation
Research Interests: Microbiology, Apoptosis, Veterinary, Veterinary Parasitology, Cercopithecus aethiops, and 18 moreEndothelial Cells, Animals, Cytochrome C, Fisheries Sciences, Programmed cell death, Laser Scanning Confocal Microscopy, Single Cell, Caspase, Eimeria, Cattle, Endothelial cell, Gastrointestinal Tract, Veterinary Sciences, Light microscopy, Cell Surface Markers, Cell Survival, Vero cells, and Gene Expression Regulation
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Research Interests: Zoology, Immune response, Flow Cytometry, Real-time RT-PCR, Escherichia coli, and 15 moreAnimals, Regulatory Network, Cattle, IL, Immune system, Local adaptation, Shiga Toxin, Transforming Growth Factor Beta, Immunophenotyping, Veterinary Sciences, Lymphocytes, Enzymatic Activity, Ileum, Interleukin, and Interferon gamma
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Research Interests: Microbiology, Parasitology, Flow Cytometry, Medical Microbiology, Fluorescent Dyes and Reagents, and 15 moreConfocal Microscopy, In Vitro, Endothelial Cells, Movement, Parasite, Animals, Vascular endothelium, Host-parasite interactions, Laser Scanning Confocal Microscopy, Eimeria, Cattle, Endothelial cell, Major histocompatibility complex, Coccidiosis, and Veterinary Sciences
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PF 1022A, a novel anthelmintically active cyclodepsipeptide, and Bay 44-4400, a semisynthetic derivative of PF 1022A were tested for filaricidal efficacy in Mastomys coucha infected with Litomosoides sigmodontis, Acanthocheilonema viteae... more
PF 1022A, a novel anthelmintically active cyclodepsipeptide, and Bay 44-4400, a semisynthetic derivative of PF 1022A were tested for filaricidal efficacy in Mastomys coucha infected with Litomosoides sigmodontis, Acanthocheilonema viteae and Brugia malayi. The parent compound PF 1022A showed limited anti-filarial efficacy in L. sigmodontis and B. malayi infected animals. Oral doses of 5 x 100 mg/kg on consecutive days caused only a temporary decrease of microfilariaemia levels. By contrast, Bay 44-4400 was highly effective against microfilariae of all three species in single oral, subcutaneous and cutaneously applied (spot on) doses. Minimum effective doses (MED, reducing parasitaemia density by > or =95%) determined 3 and 7 days after treatment were 3.125-6.25 and 6.25-12.5mg/kg, respectively. Using the spot on formulation, doses of 6.25mg/kg (L. sigmodontis), 12.5mg/kg (A. viteae) and 25mg/kg (B. malayi) were required to cause reductions of microfilaraemia levels by > or =95% until day 56. Adulticidal effects, determined as minimum curative doses (MCD, eliminating adult parasites within 56 days by >95%) after single dose treatment were limited to A. viteae (MCD, 100mg/kg independent of the route of administration). Repeated oral treatment (100mg/kg on 5 consecutive days) killed all adult L. sigmodontis but did not affect B. malayi. However, single doses of 6.25 and 25mg/kg resulted in severe pathological alterations of intrauterine stages of L. sigmodontis and B. malayi, respectively. These alterations may be responsible for long-lasting reductions of microfilaraemia even when curative effects could not be achieved.