Susceptibility of Escherichia coli and Enterococcus faecium isolated from pigs and broiler chickens to tetracycline degradation products and distribution of tetracycline resistance determinants in E. coli from food animals

One hundred Escherichia coli isolates from diseased and healthy pigs, cattle and broiler chickens were screened for the presence of tetracycline resistance genes tet(A), (B), (C), (D) or (E). The tet(A) gene was the most abundant (71% of the 100 isolates) followed by tet(B) (25%). The predominance of tet(A) and tet(B) applied to all three animal species, and there was no difference between the distribution of tet(A) and tet(B) genes among non-pathogenic and pathogenic E. coli in any of the animal species. The susceptibility of 20 of these isolates together with 10 tetracycline sensitive E. coli and 18 tetracycline resistant and 10 sensitive Enterococcus faecium to tetracyclines and tetracycline degradation products was determined. The resistant isolates showed reduced resistance to anhydrotetracycline, 4-epi-anhydrotetracycline, anhydrochlortetracycline and 4-epi-anhydrochlortetracycline. In general both the tetracycline resistant and susceptible E. faecium were more susceptible to the compounds tested than E. coli.     

Evaluation of assays for perinuclear antineutrophilic cytoplasmic antibodies and antibodies to Saccharomyces cerevisiae in dogs with inflammatory bowel disease

OBJECTIVE: To evaluate the use of immunofluorescence asssays for perinuclear antineutrophilic cytoplasmic antibodies (pANCAs) and antibodies to Saccharomyces cerevisiae (ASCAs) in dogs with inflammatory bowel disease (IBD) and assess the clinical value of these serologic markers of the disease. ANIMALS: 39 dogs with IBD, 18 dogs with acute diarrhea, 19 dogs with chronic non-IBD-associated diarrhea, 26 healthy dogs of various breeds and age, and 22 healthy young working dogs. PROCEDURE: Sera obtained from the dogs in each group were added to canine granulocyte- and Saccharomyces cerevisiae-mounted slides for detection of pANCAs and ASCAs via immunofluorescence techniques. Sensitivity and specificity (with 95% confidence intervals [CIs]) were calculated for the group of dogs with IBD versus each of the 2 groups of healthy dogs, the group of dogs with acute diarrhea, and the group of dogs with chronic non-IBD-associated diarrhea. RESULTS: Among the 39 dogs with IBD, 20 yielded positive results via the pANCA assay (sensitivity, 0.51 [95% CI, 0.35 to 0.67]) and 17 yielded positive results via the ASCA assay (sensitivity, 0.44 [95% CI, 0.22 to 0.69]). The specificity of the pANCA assay in the 4 groups of non-IBD-affected dogs ranged from 0.83 (95% CI, 0.85 to 0.96) to 0.95 (95% CI, 0.72 to 1.00). CONCLUSIONS AND CLINICAL RELEVANCE: Immunofluorescence assays for pANCA and ASCA appear to be useful for the detection of IBD in dogs. The pANCA immunofluorescence assay had high specificity for canine IBD, and pANCAs appear to be accurate markers of intestinal inflammation.     

Gene expression in rabbit appendices infected with Eimeria coecicola

Eimeria coecicola causes intestinal coccidiosis in rabbits and, thereby, enormous economic losses in rabbit farms. Here, we investigate the final target site of E. coecicola, the appendix of rabbits, at the level of gene expression. Rabbits, orally infected with E. coecicola, begin to shed parasitic oocysts with their feces on day 5 p.i., and approximately 1.1 million oocysts are maximally shedded on day 7 p.i. At maximal shedding, the appendix has increased in size by about 2-3-folds and reveals increased hemorrhage which is associated with increases in nitrite/nitrate, malondialdehyde and catalase activity and a decrease in glutathione. Agilent 2-color oligo whole rabbit genome microarray, in combination with quantitative real-time PCR, detects 45 and 36 genes whose expression is more than 2-fold up- and down-regulated, respectively, by E. coecicola infection on day 7 p.i. The most dramatic increase by approximately 50-fold reveals the mRNA of the pro- and anti-inflammatory pleiotropic cytokine interleukin 6 (IL-6), whereas the largest decrease by approximately 13-fold is detected for mRNAs encoding for DBP, SULT3A1, CRP and glutathione-S transferase. Also, there are up- and down-regulations in the expression of genes encoding diverse regions of antibodies. Our data suggest that IL-6 plays a central role in the infection of the appendix of rabbits by E. coecicola, presumably involved in both pathological injuries, host defences and healing processes.     

Cutaneous hyalohyphomycosis in a girdled lizard (Cordylus giganteus) caused by the Chrysosporium anamorph of Nannizziopsis vriesii and successful treatment with voriconazole

The Chrysosporium anamorph of Nannizziopsis vriesii was associated with dermatomycosis and high mortality in a group of captive giant girdled lizards (Cordylus giganteus). Treatment of one of the infected girdled lizards with voriconazole, which was selected on the basis of in vitro sensitivity testing of the isolate, resulted in resolution of lesions and negative fungal cultures from the skin. Three hours after oral administration of 10 mg/kg, the plasma level of voriconazole exceeded the 0.25‐μg/mL minimal inhibitory concentration tenfold. In conclusion, administration of voriconazole at 10 mg/kg of body weight once daily for 10 weeks resulted in clinical cure and was well tolerated. A longer follow‐up time and larger studies will be necessary to determine the long‐term efficacy and safety of this treatment in giant girdled lizards.     

The effects of formulation on the immunostimulatory activity of dihydroheptaprenol

Holstein steer calves received a single injection of Miglyol (Sasol Chemical Industries, Ltd.) subcutaneously as a placebo, dihydroheptaprenol (DHP) (4 mg/kg) emulsified with lecithin subcutaneously, DHP in solution in Miglyol (4 mg/kg) subcutaneously, or DHP in solution in Miglyol (4 mg/kg) intranasally. The DHP emulsified in lecithin emulsion administered subcutaneously caused a substantial increase in body temperature, total leukocyte count, total neutrophil count, neutrophil cytochrome-c reduction, and neutrophil iodination 24 hours after administration and, for some of the parameters, at 48 hours. The DHP formulation in Miglyol did not have any of these effects when administered subcutaneously or intranasally. The carrier and formulation of DHP apparently have major effects on the biologic activity of DHP.     

The in vitro diagnosis of anthelmintic resistance in cyathostomins

Cyathostomins are the primary parasitic pathogens of equids. For over 40 years, these nematodes have been controlled using broad spectrum anthelmintics. Three classes of anthelmintic are currently available for this use but, unfortunately, resistance to each of these has now been recorded in cyathostomin populations. As part of an optimal strategy to control cyathostomin infections in the field, it will be important to identify drug-resistant worms at as early a stage as possible. This objective needs to be supported by methodologies that will allow the accurate comparison of anthelmintic resistance in different nematode populations. At present, the faecal egg count reduction test is considered the most suitable method for initial screening for anthelmintic resistance in equine nematode populations. However, in its current state, this test lacks sensitivity. It is also costly and time-consuming to perform. Laboratory-based techniques, such as the egg hatch assay, larval development assay, larval migration inhibition assay and the larval feeding inhibition assay offer alternative options for assessing anthelmintic resistance in nematode populations. All of these tests have been investigated for their utility in measuring drug resistance in sheep nematode populations and some have proven useful. The egg hatch assay, larval development assay and larval migration inhibition assay have been investigated for use in measuring levels of drug resistance in equine nematode populations. However, at best, the results obtained thus far indicate that these tests require further refinement.