Effects of chemical treatments on pH and bacterial population in poultry litter: a laboratory experiment

1. The goal of this study was to evaluate the effects of three chemical treatments on pH and bacterial populations (total aerobic bacteria and gram-negative bacteria) in poultry litter under laboratory conditions. 2. Litter obtained from poultry houses was treated with three chemical treatments (alum, AlCl(3) and FeSO(4)) at the same concentration (8 g/100 g litter), while untreated litter served as a control. The study was conducted for 3 weeks. 3. All of the chemical treatments reduced total aerobic bacteria (22 to 87% of the untreated control) and gram-negative bacteria (63 to 99% of the untreated controls) populations and lowered litter pH values (5.95 to 6.64). However, a significant difference in gram-negative bacteria did not exist among chemical treatments at 0, 1 and 2 weeks. 4. These results suggest that the reduction in total aerobic bacteria and gram-negative bacteria populations is highly related to a decrease in litter pH, and acidifying treatment (alum, AlCl(3) and FeSO(4)) of poultry litter may serve as a means to help the reduction in pathogen populations and to improve economical benefits under commercial production conditions.     

Genetic analysis of ORF5 of recent Korean porcine reproductive and respiratory syndrome viruses (PRRSVs) in viremic sera collected from MLV-vaccinating or non-vaccinating farms

The 23 open reading frame (ORF) 5 sequences of Korean type II porcine reproductive and respiratory syndrome virus (PRRSV) were collected from viremic sera from the (modified live vaccine) MLV-vaccinating and non-vaccinating farms from 2007 to 2008. The samples were phylogenetically analyzed with previous ORF5 sequences, including type I Korean PRRSV, and previously reported or collected sequences from 1997 to 2008. A MN184-like subgroup of type II Korean PRRSV was newly identified in the viremic sera collected from 2007 to 2008. And of the type I PRRSVs, one subgroup had 87.2~88.9% similarity with the Lelystad virus, showing a close relationship with the 27~2003 strain of Spain. The maximum parsimony tree of type II PRRSV from 1997 to 2008 showed that they had evolved to four lineages, subgroups 1, 2, 3 and 4. Most of the recently collected type II PRRSVs belonged to subgroup 4 (48%). The region of three B-cell epitopes and two T-cell epitopes of ORF5 amino acids sequences was considerably different from the MLV in subgroups 3 and 4. In conclusion, the existence of type I PRRSV, which was genetically different from Lelystad virus (Prototype of type I PRRSV), and heterologous type II PRRSVs of viremic pigs detected even in the MLV-vaccinating farms indicated the need for new vaccine approaches for the control of PRRSV in Korea.     

Gingival overgrowth in dogs associated with clinically relevant cyclosporine blood levels: observations in a canine renal transplantation model

Objective— To investigate the development of gingival hyperplasia in dogs after renal transplantation and administration of microemulsified cyclosporine A (MCsA).
Study Design— Experimental study.
Animals— Healthy adult mongrel dogs (n=5).
Methods— As part of study on renal transplantation, dogs administered MCsA (20 mg/kg/day), azathioprine, and prednisolone to prevent graft rejection were monitored for development of gingival changes. Prednisolone was discontinued after 3 months. MCsA dose was adjusted to maintain whole blood trough concentration of 400–700 ng/mL. Gingival change was evaluated by weekly examination and photodocumentation, and gingival biopsy for histopathology was performed at 28 weeks.
Results— One dog was lost because of acute graft rejection. Gingival hyperplasia developed in 3 of 4 dogs. The earliest gingival changes occurred in the interdental papillae at 20 weeks after transplantation. On histopathology, the underlying connective tissue was thickened and contained increase numbers of fibroblasts and inflammatory infiltrates.
Conclusions— Long-term immunosuppression with an MCsA-based treatment likely induces substantial gingival hyperplasia when therapeutic, immunosuppressive blood levels of MCsA were maintained for 32 weeks.
Clinical Relevance— MCsA is used for immune-mediated diseases and preventing rejection after transplant in dogs. MCsA blood levels, and gingival hyperplasia should be monitored by routine examination of the interdental papilla in dogs administered MCsA for long periods.     

Treatment of dogs with oral melanoma by hypofractionated radiation therapy and platinum-based chemotherapy (1987-1997)

This retrospective study in 39 dogs with incompletely resected oral melanoma examined the efficacy of hypofractionated radiation therapy and platinum-containing chemotherapy. All dogs were completely staged, with the majority of dogs classified as stage 1. Dogs received 6 weekly fractions of 6-gray (Gy) megavoltage irradiation with a cobalt-60 unit or a 4-MeV (megaelectron volts) linear accelerator. Dogs received cisplatin (10-30 mg/m2 IV) or carboplatin (90 mg/m2 IV) chemotherapy 60 minutes before radiation delivery. Durations of local control, metastasis-free survival time, and overall survival time were recorded. By the Kaplan-Meier method, 15% of the dogs had local recurrence within a median time of 139 days. Fifty-one percent of the dogs developed metastatic disease within a median time of 311 days (range, 24-2, 163 days). Median survival time for all 39 dogs was 363 days. The combined use of chemotherapy and radiation therapy in this protocol provided local control consistent with previous studies. Low-dose chemotherapy was used with the intent of enhancing radiation therapy for the local control of an incompletely excised tumor. Survival times were longer than previously reported for dogs with oral malignant melanoma. Additional studies are required to determine whether these results were due to the effects of chemotherapy on microscopic disease or the enhanced local control provided by chemoradiation therapy.     

Characterization of an avianpox virus isolated from an Andean condor (Vultur gryphus)

A novel pox virus, condorpox virus (CPV) isolated from the spleen of an Andean condor (Vultur gryphus) by inoculation of chorioallantoic membranes (CAM) of specific pathogen free (SPF) chicken embryos was compared biologically, antigenically and genetically with fowlpox virus (FPV), the type species of the genus Avipoxvirus. Susceptible chickens inoculated with CPV developed only mild localized lesions but were not protected against subsequent challenge with FPV. Based on Western blotting, in addition to the presence of cross-reacting antigens, distinct differences in antigenic profiles of CPV and FPV were observed. Sequence analysis of a 4.5 kb HindIII fragment of CPV genomic DNA revealed the presence of eight co-linear genes corresponding to FPV open reading frame (ORF)193-198, 201 and 203. Interestingly, reticuloendotheliosis virus (REV) sequences present in the genome of all FPV were absent in CPV. Although, the results of a phylogenic analysis suggested that CPV is a member of the genus Avipoxvirus, its unique antigenic, biologic and genetic characteristics distinguish it from FPV to be considered as a new member of this genus.