Binding of mouse mannan-binding lectins to different bacterial pathogens of mice.

Humans have one mannan-binding lectin (MBL) in circulation but rodents, pigs, rabbits and rhesus monkeys have two, MBL-A and MBL-C. Plasma forms of these proteins have similar mannan-binding activity in vitro, but might differ in their ability to bind other microbial targets. In these studies, we compared carbohydrate-dependent binding of mouse plasma MBL-A and MBL-C to mannan-sepharose beads and to intact bacteria isolated as pathogens from mice. After incubation of mouse plasma with intact bacteria, MBL-A and MBL-C were eluted with N-acetylglucosamine (GlcNAc) and identified in nonreducing SDS-PAGE using Western blot analysis and MBL-A or MBL-C specific monoclonal antibodies. GlcNAc eluates of plasma incubated with mannan-sepharose beads, Klebsiella oxytoca and Staphylococcus aureus contained similar bands (mainly approximately 50kDa) that were immunoreactive with MBL-C antibody. Furthermore, a smaller form of MBL-C (approximately 45kDa) was detected bound to Pseudomonas aeruginosa. By comparison, immunoreactive MBL-A (a ladder of approximately 175kDa and larger bands) was identified in these GlcNAc eluates from mannan-sepharose beads, S. aureus and K. oxytoca but not P. aeruginosa. These studies demonstrate that mouse MBL-A and MBL-C in plasma are not equivalent in their ability to recognize bacteria that are pathogens for mice.

Porcine dermatitis and nephropathy syndrome associated with porcine circovirus 2 infection in a Yorkshire pig.

We describe a case of porcine dermatitis and nephropathy syndrome (PDNS) in a 14-wk-old Yorkshire pig purchased from a commercial farm for research use. Physical examination of the affected animal upon arrival revealed multifocal, red, papular skin lesions on the rump, vulva, perineum, thighs, and lower hindlegs. At necropsy, gross lesions consisted of dermatitis, bilaterally enlarged kidneys and patchy pulmonary congestion. Histologic findings included multiorgan necrotizing vasculitis with prominent lesions in the skin, kidneys, lung, spleen, and liver. Immunohistochemical staining for porcine circovirus type 2 (PCV2) was strongly positive in affected areas of kidney and spleen. In light of the clinical assessment and gross and histologic findings, a diagnosis of PDNS was made. We emphasize the importance of considering PDNS as a differential diagnosis in laboratory swine with skin lesions.

Tracheal injury after endotracheal intubation and anesthesia in rabbits.

This case report describes sublaryngeal tracheal injury and ulceration in 15 rabbits from 3 institutions as sequelae to routine intubation and general anesthesia with isoflurane in oxygen. The rabbits were intubated for general anesthesia and mechanically ventilated for experimentally diverse procedures, with periods of anesthesia lasting 1.5 to 5 h. Of the 15 animals, 6 developed minimal to moderate postanesthesia clinical signs of moist rales or cyanosis or both; 2 of these 6 rabbits later died unexpectedly, their deaths attributed to respiratory obstruction by necrotic tracheal debris. The pathogenesis of this lesion is reviewed. Our findings suggest that rabbits may be predisposed to developing serious tracheal injury and clinically significant sequelae in association with routine intubation.