An opportunity to study progression toward endemic stability to Babesia bigemina arose when cattle were reintroduced onto a game ranch in 1999 after an absence of three years. The study was conducted between August 2000 and June 2001. The unvaccinated breeding cows were sampled only once. Calves born during October 1999 were initially vaccinated against B. bigemina and Babesia bovis at the age of 4 months and were then bled at 10, 17 and 20 months of age. Calves born during 2000 were bled at 7 and 8 months of age. Sera were collected from all the cattle sampled and later tested for antibodies against B. bigemina and B. bovis using the indirect fluorescent antibody (IFA) test. Although endemic stability to B. bigemina had not been achieved at Nooitgedacht 2 years after resumption of cattle ranching, the high seroprevalence in the unvaccinated 8- month-old calves suggested that the situation was approaching stability and that calf vaccination against bovine babesiosis was not required. Tick control should therefore be restricted to prevent excessive tick worry. Only vaccinated cattle were positive to B. bovis and it was concluded that the parasite was absent from the ranch.

Objective--To evaluate the immunologic response of a killed tachyzoite vaccine against Neospora caninum and its effectiveness in preventing fetal loss associated with experimentally induced neosporosis in sheep. Animals--30 Dorset ewes. Procedure--Ewes were randomly allocated to receive vaccination on days 1 and 60 of the study with a killed N caninum tachyzoite preparation in a commercially available adjuvant or a saline-adjuvant mixture. A ram was placed on pasture with the ewes from days 15 to 60. Blood was collected from ewes before primary and booster vaccinations and prior to experimental challenge with N caninum tachyzoite performed on day 90; sera were assessed via Neospora agglutination (NA) and immunofluorescence antibody (IFA) assays. Blood was collected from lambs before they suckled, and sera were tested for antibodies against N caninum. Results--Of the 14 vaccinated ewes that became pregnant, 12 gave birth to live-born lambs; in contrast, 5 of 11 pregnant control ewes gave birth to live-born lambs. Whereas vaccination improved fetal survival in pregnant ewes challenged with N caninum tachyzoites, it did not appear to have any appreciable effect on transmission of N caninum to offspring, as indicated by results of NA and IFA assays. Conclusions and Clinical Relevance--The N caninum tachyzoite vaccine used in this study appeared to provide protection against fetal loss associated with experimentally induced neosporosis in a high proportion of pregnant ewes.

The purpose of this in vitro study is to clarify some of the underlying mechanisms leading to the decreased migratory capacity of polymorphonuclear leukocytes (PMN) during mastitis in dairy cows soon after calving. Surface expression of Mac-1 (CD11b, CR3) on PMN and of CD14 on monocytes was measured in early- (EL), peak- (PL), and midlactation (ML) by flow cytometric analysis. In addition, we evaluated the effect of lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α on CD11b surface expression in PMN at different stages of lactation in a whole blood model. During EL, while resting monocytes expressed diminished levels of CD14, the basal expression of CD11b on PMN was not significantly altered. The relative increase of CD11b on PMN after incubation with LPS or TNF-α did not significantly differ among EL, PL, or ML at any of the concentrations tested. The current findings do not support an important role for basal CD11b levels nor for a defective mobilization of CD11b by LPS and TNF-α in the reduced migratory capacity of PMN during EL.

Archival specimens of gastric mucosa of 10 raccoons (Procyon lotor), 9 porcupines (Erethizon dorsatum), 6 grey foxes (Urocyon cinereoargenteus), 6 bobcats (Lynx rufus), 4 skunks (Mephitis mephitis), and 3 black bears (Ursus americanus) were microscopically examined for evidence of Helicobacter-like organisms. Such organisms were seen in the specimens from the grey foxes and bobcats only. Histochemical stains (modified Steiner and carbol fuchsin methods) revealed long spiral organisms within lumina of gastric glands; however, neither gross nor microscopic lesions were observed. By electron microscopy (EM), the organisms were found to be free in the glandular lumina and were seen occasionally in the cytoplasm of gastric epithelial cells. Morphologically, 2 different phenotypes of spiral organisms were identified by EM. The organisms associated with bobcats appeared to be more tightly coiled than those seen in grey foxes. The presence of Helicobacter-like organisms in the gastric mucosa of grey foxes has not previously been described.

Objective-To compare Salmonella isolates cultured from feedyard and nonfeedyard (control) playas (ie, temporary shallow lakes) of the Southern High Plains. Sample Population-Water and muck (sediment) samples were obtained from 7 feedyard playas and 3 nonfeedyard playas in the winter and summer. Procedure-Each water and muck sample was enriched with sulfur-brilliant-green broth and incubated in a shaker at 37°C for 24 hours. A sample (100 mL) of the incubated bacterial-enriched broth was then mixed with 100 mL of fresh sulfur-brilliant-green enrichment broth and incubated in a shaker at 37°C for 24 hours. After the second incubation, a swab sample was streaked on differential media. Suspect Salmonella isolates were further identified by use of biochemical tests, and Salmonella isolates were confirmed and serovar determinations made. Results-Salmonella isolates were not recovered from the 3 control playas. Seven Salmonella enterica serovars were isolated from 5 of 7 feedyard playas in the summer, and 13 S enterica serovars were isolated from 7 of 7 feedyard playas in the winter. In the summer, 296 isolates were cultured, and 47 were Salmonella organisms. In the winter, 288 isolates were cultured, and 171 were Salmonella organisms. Conclusions and Clinical Relevance-Results indicated that feedyard playas are frequently contaminated with many Salmonella serovars. These pathogens should be considered whenever feedyard managers contemplate the use of water from these playas. Water from feedyard playas should not be used to cool cattle in the summer or for dust abatement.

Six pregnant gilts were purchased from a high health herd and were found to be serologically positive for swine influenza virus (SIV) subtype H3N2. Three of the gilts, at 80 to 82 days of gestation, were experimentally exposed a second time to the same SIV subtype --- H3N2. No clinical signs resulted from the second exposure to SIV and hemagglutination-inhibition (HI) titers for SIV at 4 weeks postexposure were unchanged suggesting that the gilts had not been reinfected. However, the second exposure to SIV affected the number of pigs born alive. Each of the 3 litters from the twice exposed gilts suffered 2 or 3 stillborn piglets per litter. In contrast the 3 matched, sero-positive gilts that were not exposed to SIV (controls) had no stillborn piglets. These differences were statistically significant using a t-test for unequal variances (P = 0.0086). Sera from 2 of the stillborn piglets were negative for HI antibodies and there was no indication from the pigs born alive that the H3N2 virus had crossed the placenta.

The efficacy of several povidone-iodine (PVP-I) products, a number of other chemical agents, and various physical conditions were evaluated for their ability to inactivate the severe acute respiratory syndrome coronavirus (SARS-CoV). Treatment of SARS-CoV with PVP-I products for 2 min reduced the virus infectivity from 1.17 x 10**6 TCID sub(50)/ml to below the detectable level. The efficacy of 70% ethanol was equivalent to that of PVP-I products. Fixation of SARS-CoV-infected Vero E6 cells with a fixative including formalin, glutaraldehyde, methanol, and acetone for 5 min or longer eliminated all infectivity. Heating the virus at 56 deg C for 5 min dramatically reduced the infectivity of the virus from 2.6 x 10**7 to 40 TCID sub(50)/ml, whereas heating the virus for 60 min or longer eliminated all infectivity. Irradiation with ultraviolet light at 134MicroW/square cm for 15 min reduced the infectivity from 3.8 x 10**7 to 180 TCID sub(50)/ml; however, prolonged irradiation (60 min) failed to eliminate the remaining virus, leaving 18.8 TCID sub(50)/ml. We believe that these findings will be useful for the implementation of infection contiol measures against SARS, and for the establishment of effective guidelines for the prevention of SARS outbreaks.

In MRJ/MpJ mice, there is a genetic mutation of exonuclease 1 (Exol), in which the exon 9 is sometimes deleted. In the present study, to check the gen-eration of the spliced exons, exon 8-intron 8-exon 9 (pCX/Ex/EIE/B and pCX/ Ex/EIE/M) plasmids were temporally transfected in vitro into BALB 3T3 cells, and RT-PCR using appropriate primer pair was carried out 1 day after transfection. In these constructions, pCX/Ex/EIE/B was derived from genomic sequence of C57BL/6 mice, and pCX/Ex/EIE/M was from MRL/MpJ. A spliced band was detected in pCX/Ex/EIE/B , but was present little or very weakly in pCX/Ex/EIE/M . Next, the same spliced band was demonstrated in pCX/Ex/EIE/M(T) plasmid, in which the branchpoint sequence (BPS) of pCX/Ex/EIE/M including the exon 9 was changed into that of pCX/Ex/EIE/B. The splicing did not occur in the del1/B mutant, in which 1960 nucleotides of the intron 8 were deleted, whereas it was detected in the del2/B plasmid deleted 1036 nucleotides in its middle region. These results suggest that the nucleotide T to A mutation of the BPS in the intron 8 is at least a sufficient for generation of splice variants (tr-l and tr-2 Exol).