RESUMO
An epidemiological survey on sarcosporidiosis was carried out with a cross sectional investigation on macroscopic and microscopic Sarcocystis spp. in Sarda breed sheep slaughtered in different abbatoirs of Sardinia, Italy. For the macroscopic survey, muscular samples (diaphragm, abdominal and intercostals muscles, cutaneous muscles and muscles of the thigh) from 769 slaughtered Sarda sheep, oesophagus (n=365) and laryngeal and pterygoid muscles (n=521) were macroscopically investigated and Polymerase Chain Reaction (PCR) on selected macroscopic cysts was performed for a molecular identification of macroscopic Sarcocystis species. For the microscopic investigation 112 heart samples from slaughtered Sarda sheep were collected and investigated with two different protocols: unstained (compression) examination and a molecular technique. The overall prevalence of infection for macroscopic forms of sarcocysts was of 23.3% (179/769) with prevalences higher in the oesophagus (31.6%; 125/395) compared with the other investigated tissue type; two different morphotypes, classified as large oval (LO) macroscopic cysts, identified as Sarcocystis gigantea, and slender fusiform (SF) sarcocysts, were identified. The examination of heart samples revealed an overall prevalence of 77.7% (87/112) for Sarcocystis spp.; the nested-PCR analysis of heart samples allowed to identify the microscopic species, Sarcocystis tenella and Sarcocystis arieticanis, with prevalences of 95.5% (107/112) and 17.8% (5/112) respectively. Reported results highlight the high prevalence of Sarcocystis infection in the island and suggests the need of an improvement of control and prevention strategies for this parasitosis.
RESUMO
BACKGROUND: Shepherd and stray dogs are thought to represent the primary definitive hosts of Coenurosis by Taenia multiceps, due to their feeding habits which translate into high chances of coming into contact with infected intermediate hosts. Nonetheless, little attention has been paid to the role of the red fox (Vulpes vulpes) in the epidemiology of coenurosis. In fact a knowledge gap exists on the role played by red foxes in the epidemiology of Taenia multiceps and the capability of this parasite to produce fertile and viable eggs in this wild canid, i.e. on the occurrence of a sylvatic cycle. This study investigates the role of the red fox (Vulpes vulpes) in the epidemiology of T. multiceps and related metacestodoses. METHODS: The small intestine of 63 red foxes was macroscopically examined for the presence of cestodes. Adult parasites were identified morphologically as being T. multiceps. Tapeworm eggs were counted and stored at 4 °C in physiological saline solution prior to experimental infection of four sheep and one goat. Sheep were inoculated orally on Day 0 with 3000 (sheep 1), 5000 (sheep 2 and 3) or 7000 eggs (sheep 4), while the goat was infected with 5000 eggs of T. multiceps. The animals were followed-up regularly by MRI and underwent surgical treatment between days 180 to day 240 post infection. Collected coenuri were identified using morphological and molecular methods. RESULTS: A total of 6.3 % of red foxes were found infected with T. multiceps and the eggs obtained from the worms were determined to have a viability of 45.4 %. Two of the challenged sheep and the goat developed disease compatible with T. multiceps. Morphometrical features of the cysts were consistent with those of T. multiceps; nucleotide amplification and sequencing of mitochondrial genes (i.e., cox1 and Nd1) from the metacestode material confirmed the identification. CONCLUSIONS: The present study is the first to provide evidence of the role of the red fox as a competent definitive host for T. multiceps, thus changing the epidemiological scenarios of infections by this cestode.
