Lack of a type-2 glycosyltransferase in the fish pathogen Flavobacterium psychrophilum determines pleiotropic changes and loss of virulence

Flavobacterium psychrophilum is an important fish pathogen, responsible for Cold Water Disease, with a significant economic impact on salmonid farms worldwide. In spite of this, little is known about the bacterial physiology and pathogenesis mechanisms, maybe because it is difficult to manipulate, being considered a fastidious microorganism. Mutants obtained using a Tn4351 transposon were screened in order to identify those with alteration in colony morphology, colony spreading and extracellular proteolytic activity, amongst other phenotypes. A F. psychrophilum mutant lacking gliding motility showed interruption of the FP1638 locus that encodes a putative type-2 glycosyltransferase (from here on referred to as fpgA gene, Flavobacterium psychrophilum glycosyltransferase). Additionally, the mutant also showed a decrease in the extracellular proteolytic activity as a consequence of down regulation in the fpgA mutant background of the fpp2-fpp1 operon promoter, responsible for the major extracellular proteolytic activity of the bacterium. The protein glycosylation profile of the parental strain showed the presence of a 22 kDa glycosylated protein which is lost in the mutant. Complementation with the fpgA gene led to the recovery of the wild-type phenotype. LD₅₀ experiments in the rainbow trout infection model show that the mutant was highly attenuated. The pleiotropic phenotype of the mutant demonstrated the importance of this glycosyltranferase in the physiology and virulence of the bacterium. Moreover, the fpgA mutant strain could be considered a good candidate for the design of an attenuated vaccine.     

The Importance of Egg Protein in Reduced Protein Diets Designed for Dogs With Renal Failure

The effects of two reduced-protein diets and a canine maintenance diet on renal function, nutrition, serum and urine acid-base and electrolyte values, and divalent ion metabolism were compared in Beagle dogs with induced chronic renal failure. Two reduced-protein (18%) diets differed in their protein sources. One 18% protein diet was formulated using egg protein as the only protein source. The other 18% protein diet was formulated using a mixture of animal and vegetable proteins. The 42% protein diet contained a mixture of animal and vegetable protein sources. Results of this study indicate that the egg-based and mixed protein-based diets had similar effects on most clinical and laboratory evaluations in dogs with chronic renal failure. However, the egg protein diet appeared to promote hyperchloremic metabolic acidosis. Both reduced-protein diets were beneficial in reducing azotemia, polyuria, hypermagnesemia, and fractional excretion of phosphorus compared with the 42% protein diet.     

Bilateral hydronephrosis secondary to endometriosis managed by endoscopic ureteral stent placement in a captive Guinea baboon (Papio papio)

Spontaneous endometriosis is an estrogen-dependent, progressive and painful disease that affects a variety of nonhuman primates, including several species of baboons (Papio sp.). This case documents multimodal management of severe endometriosis in a captive female baboon within a zoological institution. An 18-yr-old, intact female Guinea baboon (Papio papio) was found to have an enlarged uterus. Fifteen months post ovariohysterctomy, scarring associated with endometrial tissue resulted in ureteral strictures, bilateral hydronephrosis, and azotemia. Cystoscopic placement of bilateral ureteral stents with fluoroscopy was performed and resulted in short-term clinical improvement. The animal's condition declined and euthanasia was elected 4 mo after ureteral stent placement. Severe endometriosis with secondary inflammation resulting in bilateral hydroureter and hydronephrosis, as well as concurrent cystitis, ureteritis, and pyelonephritis were confirmed at necropsy. Despite possible complications, ureteral stents can be considered a useful therapeutic option in patients with ureteral disease.     

Blastomycotic osteomyelitis associated with severe lameness in a horse

A 12-year-old Quarter horse gelding was presented for evaluation of severe right forelimb lameness, 2 draining tracts over the lateral aspect of the right proximal antebrachium, and weight loss. A presumptive diagnosis of blastomycotic osteomyelitis was established based on radiographs and cytology of the exudate. This diagnosis was confirmed at necropsy.     

Seroprevalence of bovine viral diarrhea virus neutralizing antibodies in finisher hogs in Ontario swine herds and targeted diagnostic testing of 2 suspect herds

A pilot study was initiated to determine the seroprevalence of bovine viral diarrhea virus (BVDV) neutralizing antibodies in finisher hogs in Ontario swine herds, including 2 swine herds with clinical syndromes suspicious of BVDV. No herds were positive for BVDV antibodies by virus neutralization. The 2 swine herds with clinical disease suggestive of pestivirus infection were also negative for antibodies to BVDV in indirect fluorescent antibody assays. Prevalence of BVDV in Ontario swine farms is negligible.