Serratia marcescens endocarditis in a horse.

Serratia marcescens was the causative agent of bacterial endocarditis in a 2-year-old Arabian stallion. The horse was treated with broad-spectrum antibiotics for 1 month. The horse died several months after treatment was discontinued. To our knowledge, Serratia marcescens has not been reported as the cause of bacterial endocarditis in horses; however, multiple cases of bacterial endocarditis attributable to Serratia marcescens have been documented in human beings. The bacteria is most commonly isolated in immune-compromised patients.     

Serratia marcescens septicaemia in the dog

A non-pigmented strain of Serratia marcescens was isolated ante-mortem and at post-mortem from the blood of six dogs under intensive medical care. Clinical, bacteriological and pathological evidence confirmed death to be associated with septicaemia from this Gram-negative organism. Résumé. On a isolé, avant la mort et à l'autopsie, une souche non-pigmentée de bactérie prodigieuse (Serratia marcescens) du sang de six chiens soumis à des soins vétérinaires intensifs. L'évidence clinique, bactériologique et pathologipue a confirmé que la mort était associéc à une septicémie de cet organisme gramnègatif. Zusammenfassung. Ein pigmentfreier Stamm von Serratia marcescens wurde von dem Blut vor und nach dem Tod von sechs Hunden, die unter intensiver medizinischer Pflege standen, isoliert. Der klinische, bakteriologische und pathologische Beweis bestätigte, dass der Tod mit Blut-vergiftung von diesem gramnegativen Organismus verbunden war.     

Cutaneous Serratia marcescens infection in two dogs

We describe two canine cases of cutaneous infection caused by Serratia marcescens. A 2-year-old castrated male mixed dog (Case 1) presented with multiple ulcerations on the dorsal trunk, which were observed 4 days after shampooing. A 4-year-old male wolf shepherd mix dog (Case 2) presented with ulceration and purulent discharge on the nasal bridge. Cytological examination of both cases revealed pyogranulomatous inflammatory cells with rod-like infectious agents identified as S. marcescens in aerobic bacterial culture. Both patients were treated with oral antibiotics and topical chlorhexidine. Case 1 received enrofloxacin 10 mg/kg once daily for 1 week, followed by trimethoprim/sulfamethoxazole 15 mg/kg twice daily for 3 weeks. Case 2 received doxycycline 10 mg/kg twice daily for 4 weeks. No skin lesions were detected 2 weeks after the initial administration. The antibiotics were discontinued after a total 4 weeks of administration, and the skin lesions did not reappear.     

Abdominal aortic aneurysm associated with systemic fungal infection in a German shepherd dog

A 2 yr old spayed female German shepherd presented with a chief complaint of acute onset paraparesis and weight loss. At presentation, the dog was pyrexic, nonambulatory, and had generalized muscle wasting. Neurolocalization was consistent with a thoracolumbar spinal cord lesion. An abdominal ultrasound was performed and revealed a focal dilation (4 cm) of the terminal aorta with evidence of blood stasis consistent with an aortic aneurysm. The dog was euthanized shortly after admission to the hospital and a post mortem examination was performed. Fungal organisms were identified in the aortic aneurysm as well as from the thoracic vertebrae, mesenteric lymph nodes, axillary lymph nodes, spleen, kidneys, liver, lungs, and heart. Although the morphology was consistent with Candida spp., immunohistochemistry and PCR could not definitively identify the causative organism. Mycotic aortic aneurysms are a rare finding in humans and have not been previously reported in the dog. To the authors' knowledge, this is the first known report of an aortic aneurysm associated with systemic fungal infection in a dog.     

Innate immune response to intramammary infection with Serratia marcescens and Streptococcus uberis

Streptococcus uberis and Serratia marcescens are Gram-positive and Gram-negative bacteria, respectively, that induce clinical mastitis. Once initial host barrier systems have been breached by these pathogens, the innate immune system provides the next level of defense against these infectious agents. The innate immune response is characterized by the induction of pro-inflammatory cytokines, as well as increases in other accessory proteins that facilitate host recognition and elimination of the pathogens. The objective of the current study was to characterize the innate immune response during clinical mastitis elicited by these two important, yet less well-studied, Gram-positive and Gram-negative organisms. The pro-inflammatory cytokine response and changes in the levels of the innate immune accessory recognition proteins, soluble CD14 (sCD14) and lipopolysaccharide (LPS)-binding protein (LBP), were studied. Decreased milk output, induction of a febrile response, and increased acute phase synthesis of LBP were all characteristic of the systemic response to intramammary infection with either organism. Infection with either bacteria similarly resulted in increased milk levels of IL-1 beta, IL-8, IL-10, IL-12, IFN-gamma, TNF-alpha, sCD14, LBP, and the complement component, C5a. However, the duration of and/or maximal changes in the increased levels of these inflammatory markers were significantly different for several of the inflammatory parameters assayed. In particular, S. uberis infection was characterized by the sustained elevation of higher milk levels of IL-1 beta, IL-10, IL-12, IFN-gamma, and C5a, relative to S. marcescens infection. Together, these data demonstrate the variability of the innate immune response to two distinct mastitis pathogens.     

Fatal thrombocytopenic hemorrhagic diathesis associated with dapsone administration to a dog

Dapsone was given for six days to a dog with chronic skin disease. The dog then became weak and anorectic, and it vomited and had purpura caused by severe thrombocytopenic hemorrhagic diathesis. Despite treatment, the dog died a week later. There were clinical and pathologic evidence that the dog's platelets and megakaryocytes had been destroyed during the first few days of dapsone therapy. It was concluded that the syndrome was dapsone-induced and that thrombocytopenia should be considered among the adverse reactions to dapsone in the dog.     

Aortic endocarditis associated with a perforated septal membranous aneurysm in a boxer dog

Perimembranous ventricular septal defect is a common congenital heart disease in the dog. It can partially or completely close with age by development of a membranous ventricular septal aneurysm. Aortic endocarditis is a reported complication of ventricular septal defect and membranous ventricular septal aneurysm in human beings. This report describes a case of aortic endocarditis associated with a membranous ventricular septal aneurysm perforated by a small ventricular septal defect in a boxer dog.     

Serratia marcescens septicemia associated with infusion of an amino acid solution in two horses

Clinical septicemia developed in 2 clinically normal horses after both were administered a portion of an amino acid solution IV. Serratia marcescens was subsequently isolated from blood of both horses. The isolates were shown to be identical on the basis of antibiograms and plasmid biochemistry, incriminating the infusate as the source of bacterial infection. The horses recovered after supportive and antimicrobial treatment.