A case of necrotizing fasciitis with septic shock in a cat caused by Acinetobacter baumannii

A 4-year-old, neutered female, domestic shorthair cat admitted to the animal hospital for recurrent constipation presumed to be due to post-traumatic injuries, went into shock with signs including fever and ataxia followed by stupor. On the fifth day of hospitalization, the cat developed severe, diffuse oedema of the ventral abdomen with multifocal to coalescing erythematous areas and small vesicle formation. The results of bacteriological cultures of liver, spleen and kidney specimens led to the diagnosis of Acinetobacter baumannii sepsis. Histopathological findings of skin samples taken during necropsy showed an extensive epidermal and dermal necrosis with septic vasculitis and numerous intralesional gram-negative bacteria. Detection of the bla(OXA-51-like) gene specific for A. baumannii by PCR, performed retrospectively on samples of the deep layers of the skin, confirmed the presence of A. baumannii also in the cutaneous lesions. To our knowledge this is the first report of a necrotizing fasciitis with septic shock in a cat caused by A. baumannii.

Fluorescent annexin A1 reveals dynamics of ceramide platforms in living cells

Upon its genesis during apoptosis, ceramide promotes gross reorganization of the plasma membrane structure involving clustering of signalling molecules and an amplification of vesicle formation, fusion and trafficking. The annexins are a family of proteins, which in the presence of Ca(2+), bind to membranes containing negatively charged phospholipids. Here, we show that ceramide increases affinity of annexin A1-membrane interaction. In the physiologically relevant range of Ca(2+) concentrations, this leads to an increase in the Ca(2+)sensitivity of annexin A1-membrane interaction. In fixed cells, using a ceramide-specific antibody, we establish a direct interaction of annexin A1 with areas of the plasma membrane enriched in ceramide (ceramide platforms). In living cells, the intracellular dynamics of annexin A1 match those of plasmalemmal ceramide. Among proteins of the annexin family, the interaction with ceramide platforms is restricted to annexin A1 and is conveyed by its unique N-terminal domain. We demonstrate that intracellular Ca(2+)overload occurring at the conditions of cellular stress induces ceramide production. Using fluorescently tagged annexin A1 as a reporter for ceramide platforms and annexin A6 as a non-selective membrane marker, we visualize ceramide platforms for the first time in living cells and provide evidence for a ceramide-driven segregation and internalization of membrane-associated proteins.

Porcine ulcerative dermatitis syndrome in sows: a form of vesicular cutaneous lupus erythematosus?

Severe ulcerative lesions were observed in the skin of two sows in a herd of 540 hybrid sows. Annular to polycyclic, severe crusting dermal ulcerations were found on the abdomen and flanks; moderate lesions were also found at the base of the tail and on the perineum. The lesions were histologically characterised as cell-poor interface dermatitis and folliculitis, basal cell vacuolisation, vesicle formation at the dermal-epidermal junction and serocellular crusts. A subepidermal mild to moderate band, characterised as a mixed inflammatory infiltrate, was present. A test for antinuclear antibodies was negative; however, immunofluorescence testing revealed a linear pattern of IgG precipitation in the skin. Staphylococcus hyicus was demonstrated in the serocellular crusts of one sow. Treatment with antibiotics, topical antiseptics and corticosteroids did not improve the sows' condition. Porcine circovirus and porcine respiratory and reproductive syndrome virus were not isolated from samples taken at postmortem examination. The observed gross lesions, the absence of response to treatment and the exclusion of other skin diseases suggested that the sows were affected with porcine ulcerative dermatitis syndrome.