Detection of Fowlpox virus carrying distinct genome segments of Reticuloendotheliosis virus.

Fowlpox virus (FWPV), the type species of the genus Avipoxvirus family Poxviridae, is a large double-stranded DNA virus that causes fowlpox in chickens and turkeys. Notably, sequences of the avian retrovirus reticuloendotheliosis virus (REV) are frequently found integrated into the genome of FWPV. While some FWPV strains carry remnants of the REV long terminal repeats (LTRs), other strains have been shown to contain insertions of nearly the full-length REV provirus in their genome. In the present study we detected heterogeneous FWPV populations carrying the REV LTR or the near full-length REV provirus genome in a Merriam's wild turkey (Meleagris gallopavo merriami). The bird presented papules distributed throughout the non-feathered areas of the head. Avipoxvirus-like virions were observed in the lesions by transmission electron microscopy and the presence of FWPV was confirmed by DNA sequencing. Metagenomic sequencing performed on nucleic acid extracted from the skin lesions revealed two FWPV genome populations carrying either a 197-nt remnant of the REV LTR or a 7939-nt long fragment corresponding to the full-length REV provirus. Notably, PCR amplification using primers targeting FWPV sequences flanking the REV insertion site, confirmed the natural occurrence of the heterogeneous FWPV genome populations in one additional clinical sample from another turkey affected by fowlpox. Additionally, sequencing of a historical FWPV isolate obtained from chickens in the US in 2000 also revealed the presence of the two FWPV-REV genome populations. Results here demonstrate distinct FWPV populations containing variable segments of REV genome integrated into their genome. These distinct genome populations are likely a result of homologous recombination events that take place during FWPV replication.

Draft Genome Sequences of Three Flavobacterium psychrophilum Strains Isolated from Coldwater Disease Outbreaks at Three Production Hatcheries.

We report here the genome sequences of three Flavobacterium psychrophilum strains causing a bacterial coldwater disease (BCWD) outbreak, isolated from infected rainbow trout from hatcheries in Montana and South Dakota. The availability of these virulent outbreak-causing strain genome sequences will help further understand the pathogenesis of BCWD.

Hepatic element concentrations of lesser scaup (Aythya affinis) during spring migration in the upper Midwest.

High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 µg/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 µg/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction.

Outbreak of Salmonella enterica serotype Newport in a beef cow-calf herd associated with exposure to bovine viral diarrhea virus.

CASE DESCRIPTION: Severe disease and death in cows and calves affected 1 of 3 separate groups (A, B, and C) of cattle on a commercial cow-calf operation. CLINICAL FINDINGS: Clinical illness consisting of severe watery and bloody diarrhea, dehydration, weakness, and death affected adult cows and calves in 1 group (group B). Salmonella enterica serotype Newport was recovered from tissues of cows and calves from group B. TREATMENT AND OUTCOME: Despite supportive and antimicrobial treatment of cattle in group B, cow mortality rate attributable to salmonellosis in that group was 7.9% (32/407); calf mortality rate was 14.4% (52/361). None of the cows in Groups A or C died, and the calf mortality rate in those groups was low. Salmonella enterica serotype Newport was recovered from pooled fecal samples subsequently collected from each group of cows. Bovine viral diarrhea virus (BVDV) antigen was identified in an ear notch sample collected from a necropsied calf from group B. Subsequently, ear notch specimens from cattle in all 3 groups were tested for BVDV antigen. A significantly higher proportion of calves persistently infected with BVDV was identified in group B (8/295 [2.7%]), compared with the proportion in groups A and C combined (1/287 [0.3%]). CLINICAL RELEVANCE: Outbreaks of disease attributable to Salmonella Newport infection in beef cattle are unusual. Because of the immunosuppressive nature of BVDV, the possibility of animals persistently infected with BVDV within the herd should be considered during investigation of unusual outbreaks of infectious diseases.

Hepatic minerals of white-tailed and mule deer in the southern Black Hills, South Dakota.

Because there is a paucity of information on the mineral requirements of free-ranging deer, data are needed from clinically healthy deer to provide a basis for the diagnosis of mineral deficiencies. To our knowledge, no reports are available on baseline hepatic mineral concentrations from sympatric white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) using different habitats in the Northern Great Plains. We assessed variation in hepatic minerals of female white-tailed deer (n = 42) and mule deer (n = 41). Deer were collected in February and August 2002 and 2003 from study areas in Custer and Pennington Counties, South Dakota, in and adjacent to a wildfire burn. Hepatic samples were tested for levels (parts per million; ppm) of aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), boron (B), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), mercury (Hg), molybdenum (Mo), nickel (Ni), phosphorus (P), potassium (K), selenium (Se), sodium (Na), sulfur (S), thalium (Tl), and zinc (Zn). We predicted that variability in element concentrations would occur between burned and unburned habitat due to changes in plant communities and thereby forage availability. We determined that Zn, Cu, and Ba values differed (P

Bovine arsenic toxicosis.

A ranch in central South Dakota had a number of dead calves because of arsenic poisoning. The clinical picture included diarrhea, central nervous system signs, and death. Gross necropsy findings included adequate body fat, stomachs full of normal-appearing ingesta, and large amounts of greenish brown watery fluid in the intestine and colon. Microscopically there was severe lymphoid tissue necrosis in the mesenteric lymph nodes and gut-associated lymphoid tissue. Chemical analysis of kidneys showed no significant amounts of lead; however, kidney arsenic concentrations were 25 to 44 ppm. The source was a small pile of Paris Green (common name for cupric acetoarsenite) found in an old dump site in the pasture.

Porcine enteritis associated with Eimeria spinosa Henry, 1931 infection.

Coccidia of the genus Eimeria are present in most pigs raised on dirt in the United States. They are generally considered nonpathogenic in weaned pigs. Oocysts of Eimeria spinosa Henry, 1931 were observed in tissue sections and intestinal contents of a weaned male pig that died suddenly on a farm in Iowa. Microscopically, necrotizing enteritis associated with many thick-walled coccidial oocysts was present in intestinal sections. Examination of intestinal contents demonstrated oocysts that were thick-walled and had small projections on the surface of the oocyst wall, characteristic of E. spinasa Henry, 1931 of swine. Twenty-live oocysts in intestinal contents measured 20.4 by 14.2 microm. No pathogenic bacteria were detected in the pig by culture methods, but lesions suggestive of salmonellosis were observed in some tissues. The specific cause of death was not determined; however, E. spinosa infection was considered to have contributed to the death of this pig. The results suggest that E. spinosa may be pathogenic for pigs.