Feline eosinophilic dermatoses: a retrospective immunohistochemical and ultrastructural study of extracellular matrix remodelling.

BACKGROUND: Feline eosinophilic dermatoses (FEDs) are common diseases of cats with an unknown pathogenesis. They are histologically characterized by an eosinophilic infiltration and often by the presence of flame figures (FFs) and/or areas of loss of tissue architecture, here termed necrotic foci (NF). It has been postulated that an alteration in the degradation of the extracellular matrix could be responsible for these histological features. Matrix metalloproteinases (MMPs) are a group of proteases that are fundamental in extracellular matrix remodelling. HYPOTHESIS/OBJECTIVES: The aim of the study was to investigate retrospectively the expression of a subgroup of MMPs, in particular MMP-2 and MMP-9 gelatinases, in FEDs. The expression of one of their inhibitors, TIMP-2, was also investigated in order to establish the role of these molecules in the pathogenesis of FEDs. The ultrastructural characteristics of extracellular matrix in FFs and NF were subsequently assessed. METHODS: Fifty-one formalin-fixed, paraffin-embedded specimens from cutaneous and mucosal biopsies diagnosed as FEDs were investigated immunohistochemically. Two selected samples were processed for electron microscopy. RESULTS: This study revealed an increased expression of MMP-2 in NF and a decreased expression of this gelatinase in FFs. An imbalance between MMP-2 and TIMP-2 was evident using immunohistochemistry. No significative results were observed for MMP-9 expression. Electron microscopy confirmed the lack of normal collagen fibres in NF, whereas in FFs only occasional, amorphous material was observed among normal collagen fibres. CONCLUSIONS AND CLINICAL IMPORTANCE: Our study suggests that an imbalance in the expression of matrix metalloproteinases could be responsible for different morphological findings in FEDs. Further studies are needed to assess the role of matrix metalloproteinases in the pathogenesis of FEDs.

Detection of Testudinid alphaherpesvirus, Chlamydia spp., Mycoplasma spp., and Salmonella spp. in free­ranging and rescued Italian Testudo hermanni hermanni.

Testudo hermanni is included as near­threatened in the Red List of the International Union for Conservation of Nature, while T. hermanni hermanni is considered endangered in the Italian Red List. Appropriate management of smuggled or seized wild individuals is recommended before their reintroduction into the wild. Accordingly, a health monitoring study was carried out. During 2014­2016, 133 oral swabs and 121 cloacal swabs were collected from a total of approximately 180 free­ranging and rescued T. hermanni hermanni from eight different Italian regions to investigate the presence of DNA of Testudinid alphaherpesvirus (TeAHV), Chlamydia spp. and Mycoplasma spp. in the oral cavity, and Salmonella spp. isolates in the cloaca. Mycoplasma spp. was detected in 52 out of 87 (59.77%) of rescued and in 1 out of 46 free­ranging (2.17%) individuals; 33 out of 53 (62.26%) Mycoplasma spp. positive samples were typed as M. agassizii by PCR. Salmonella spp. was isolated from 45 out of 121 (37.19%) cloacal swabs, typed into 14 serovars, and characterized for complete antimicrobial susceptibility. A significantly different distribution of Salmonella spp. isolates was found in 2016 in comparison with 2014 and 2015, without any difference between free­ranging and rescued tortoises. All the tested tortoises were negative for TeAHV and Chlamydia spp. These results are considered a baseline information critical to monitor the dynamics of these microorganisms in free­ranging and rescued populations of T. h. hermanni, and to correctly approach the management of rescued animals and possible relocation programs.