Assessment of Antimicrobial Effects on Broiler Gut Barrier Through Histopathology and Immunohistochemistry of Tight-Junction Proteins

In recent years, antimicrobial (AM) use in poultry farming has been attracting attention worldwide mainly due to AM resistance spreading. The role of AM prophylaxis in the modulation of gut microbiota, as well as of gut health, is still not clearly understood. Therefore, this study aimed to investigate the role of different prophylaxis protocols in the modulation of the gut barrier in broilers by applying a histopathological approach. Intestinal tissue samples were collected from a total of 240 male broilers (Ross 306), reared and treated with different AM protocols. Haematoxylin and Eosin (HE) staining and a multiple scoring system were used to evaluate the presence of lesions in ileum, cecum and colon of treated broilers. Moreover, immunohistochemistry (IHC) was performed to assess the expression of claudin-3 and ZO-1 proteins in intestinal tissues. The application of a semi-quantitative scoring system was used in IHC stained samples. HE results revealed that intestinal tissues were mainly characterized by epithelial detachment and fusion of the intestinal villi, but also by the presence of lymphocytic infiltrate in the mucosa and submucosa of AM-treated broilers. However, the IHC approach for the evaluation of claudin-3 and ZO-1 proteins showed that their expression was not affected by the different AM treatments. Nevertheless, the presence of intestinal lesions highlighted by histopathology suggests that AM treatments could harm the gut health of broilers, inducing an inflammatory response and consequent epithelial lesions. In order to clarify the role of AM treatments in the modulation of gut barrier in broilers, further studies are needed

Case-report: Massive infection by Cysticercus longicollis in a captive Lemur catta from Italy

An adult male ring-tailed lemur (Lemur catta) from a biopark of northern Italy was submitted to necropsy. A multi-organ parasitic infection was macroscopically evident. Abundant sero-hemorrhagic fluid with larval parasites was present in all cavities. The microscopic evaluation of parasites and the molecular characterization revealed the presence of Cysticercus longicollis (the larval stage of Taenia crassiceps). Histology of liver, lungs, intestine and urinary bladder revealed several larval parasites surrounded by a severe lymphocytic infiltrate, fibrous tissue and hemorrhages. This is the first report of a ring-tailed lemur with an infection of C. longicollis in Italy. The source of infection is still not known however, the discovery of this parasite in a captive lemur poses more attention on the control of parasitic diseases implementing monitoring tests and biosecurity measures

Prevalence of new and known species of haemoparasites in feral pigeons in northwest Italy

Background: Haemoparasites in feral pigeons have been studied in several countries but no data are available from Italy. The aim of this work was to evaluate the prevalence and diversity of Haemoproteus spp./Plasmodium spp. and Leucocytozoon spp. in feral pigeons from northwest Italy, as well as the association between infection and host age or sex. Methods: Feral pigeons were collected during a regional culling programme from the Piedmont region (northwest Italy) and subjected to necropsy. Infections were detected from DNA extracted from the spleen following a nested PCR protocol. The association between sex or age and infection status was evaluated using the chi-squared test for independence or Fisher’s exact test. Results: Out of 51 animals, 15 were positive for Haemoproteus/Plasmodium spp. and eight for Leucocytozoon spp., with a significant difference between haemoparasites prevalence. There was no significant association between age or sex and infection status. The coinfection with different haemoparasites was very significant (p < 0.01), showing a greater relative risk to be infected by a second haemoparasite in birds already infected, in particular in male and in adult pigeons. DNA sequencing of Leucocytozoon spp. showed six different lineages in pigeons, and one of Haemoproteus and Plasmodium, respectively. Conclusions: Blood parasites are continuously circulating around the world, and the results presented in the paper suggest that cross infection of feral pigeons with haemoparasites typical of other migratory or nonmigratory bird species is possible. Moreover, the geographical location of Italy along the main migratory routes is a crucial factor to be considered for migratory birds, because they can be affected by blood parasites detected in feral pigeons, and vice versa