Evidence of avian pneumovirus spread beyond Minnesota among wild and domestic birds in central North America.

To detect avian pneumovirus (APV) in central North America, nasal turbinates or choanal deft tissues from domestic turkeys and wild birds were examined for the presence of APV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), whereas serum samples from domestic turkeys were analyzed for APV antibodies by enzyme-linked immunosorbent assay (ELISA). In 2002, the seroprevalence of disease in domestic turkeys in Minnesota remained high (42.3% of the flocks). In addition, there is evidence the disease has spread to turkey flocks in North Dakota (8.2%), South Dakota (7%), Iowa (10%), and Wisconsin (8.6%) as detected by RT-PCR and/or ELISA. House sparrows and ring-billed gulls sampled in Minnesota and snow geese from Saskatchewan, Canada, were found to harbor APV RNA. Sequence analysis of wild bird APV strains showed high amino acid sequence identity among wild bird isolates (<97%) and between wild bird and turkey viral isolates (93.2%-99.3%). This study demonstrated that APV infections were present in domestic turkey flocks and wild birds outside the state of Minnesota; however, the role of wild birds in spreading APV to domestic turkeys remains unclear.

Expression of mucin-type glycoprotein K88 receptors strongly correlates with piglet susceptibility to K88(+) enterotoxigenic Escherichia coli, but adhesion of this bacterium to brush borders does not.

Three antigenic variants of the K88 fimbrial adhesin exist in nature, K88ab, K88ac, and K88ad. Enterotoxigenic Escherichia coli (ETEC) strains that produce these fimbriae cause life-threatening diarrhea in some but not all young pigs. The susceptibility of pigs to these organisms has been correlated with the adherence of bacteria to isolated enterocyte brush borders. Whether that correlation holds for multiple K88 variants and over a broad genetic base of pigs is unknown and was the impetus for this study. We also desired to examine the correlation of the expression of a porcine intestinal brush border mucin-type glycoprotein (IMTGP) which binds K88ab and K88ac with the susceptibility of piglets to K88(+) ETEC. Of 31 neonatal gnotobiotic pigs inoculated with K88ab+ or K88ac+ ETEC, 13 developed severe diarrhea, became dehydrated, and died or became moribund. Another pig became severely lethargic but not dehydrated. In vitro brush border adherence analysis was not possible for 10 of the severely ill pigs due to colonization by challenge strains. However, of the 17 pigs that did not become severely ill, 8 (47%) had brush borders that supported the adherence of K88ab+ and K88ac+ bacteria in vitro, suggesting a poor correlation between in vitro brush border adherence and piglet susceptibility to K88(+) ETEC. By contrast, the expression of IMTGP was highly correlated with susceptibility to K88(+) ETEC. Of the 12 pigs that produced IMTGP, 11 developed severe diarrhea. The other pig that produced IMTGP became lethargic but not severely diarrheic. Only 2 of 18 pigs that did not produce IMTGP became severely diarrheic. Colonizing bacteria were observed in histologic sections of intestines from all pigs that expressed IMTGP except for the one that did not develop severe diarrhea. However, colonizing bacteria were observed in histologic sections from only one pig that did not produce IMTGP. The bacterial concentration in the jejuna and ilea of pigs expressing IMTGP was significantly greater (P < 0.005) than that in pigs not expressing IMTGP. These observations suggest the IMTGP is a biologically relevant receptor for K88ab+ and K88ac+ E. coli or a correlate for expression for such a receptor.

Effects of an allicin-based product on cryptosporidiosis in neonatal calves.

OBJECTIVE: To evaluate effectiveness of an allicin-based product in neonatal calves inoculated with Cryptosporidium parvum. DESIGN: Randomized controlled study. ANIMALS: 43 neonatal calves. PROCEDURE: Calves were inoculated with 1.5 x 10(8) or 7.5 x 10(5) C parvum oocysts within 2 days after birth. Calves were given an allicin-based product once after inoculation or daily for 7 days after inoculation or were not treated. Calves that developed diarrhea were treated by administration of the product. Fecal consistency scores and weight gains were statistically evaluated. RESULTS: Mean daily weight gain and severity of diarrhea in calves 4 to 21 days old were unaffected by prophylactic use of the product. However, intensive prophylactic administration may have delayed onset of C parvum-induced diarrhea in calves inoculated with the lower dose of oocysts. CLINICAL IMPLICATIONS: Administration of an allicin-based product did not alter duration of C parvum-induced diarrhea or enhance weight gain in neonatal calves. However, intensive prophylactic administration of an allicin-based product may delay onset of diarrhea in calves exposed to C parvum oocysts.

Application of multiplex polymerase chain reaction for rapid identification of Campylobacter jejuni and C coli associated with reproductive failure.

OBJECTIVE: To evaluate a multiplex polymerase chain reaction (PCR) to distinguish Campylobacter jejuni from C coli as causes of reproductive failure. PROCEDURE: Review of clinical cases of reproductive failure attributed to C jejuni or C coli. RESULTS: A case of swine abortion was attributable to infection with C coli. The porcine abortion isolates were verified as C coli by restriction fragment length polymorphism and multiplex PCR. Cases of endometritis in a fox and in mink caused by C jejuni were reviewed, and isolates were confirmed as C jejuni by results of the multiplex PCR. CONCLUSION: Multiplex PCR was useful in identifying C coli and C jejuni recovered from atypical cases of reproductive failure. Multiplex PCR in conjunction with conventional assays may be useful for verifying other unusual instances of campylobacteriosis.

Prevalence of intestinal chlamydial infection in pigs in the midwest, as determined by immunoperoxidase staining.

OBJECTIVE: To determine prevalence of intestinal chlamydial infection in pigs and to compare prevalence of diarrhea in infected pigs with that in noninfected pigs to evaluate the importance of Chlamydia sp as causes of diarrhea in pigs. ANIMALS AND PROCEDURES: Intestines from 351 sick pigs submitted to 2 veterinary diagnostic laboratories and from 96 healthy pigs that were part of an Escherichia coli susceptibility study were examined by immunoperoxidase staining for chlamydial antigen. The proportion of Chlamydia-infected pigs in each group was calculated and compared. The proportion of Chlamydia-infected pigs with diarrhea was compared with the proportion of noninfected pigs with diarrhea. RESULTS: 15% of the sick and healthy pigs were infected with Chlamydia sp. Prevalence of diarrhea was equal between infected and noninfected pigs. Chlamydia sp were the third most common pathogens identified, and prevalence of chlamydial infection increased after 3 weeks of age. CONCLUSIONS AND CLINICAL RELEVANCE: Intestinal chlamydiosis is common in commercial pigs, but most, if not all, infections are subclinical Without collaborative evidence, simply identifying Chlamydia sp in feces or the intestinal tract of pigs with enteritis or diseases of other organ systems should not be considered proof that the organism caused the clinical signs of disease.

Colonization of the tracheal epithelium of pigs by filamentous bacteria resembling cilia-associated respiratory bacillus.

Warthin Starry staining revealed filamentous bacteria colonizing the tracheal epithelium of 41 of 88 (46.6%) pigs submitted for necropsy at 2 midwestern veterinary diagnostic laboratories. The bacteria were interspersed between and oriented parallel to the cilia. In 4 of 4 colonized pig tracheas, filamentous bacteria were demonstrated by transmission electron microscopy. The bacteria were approximately the same length and diameter as cilia, and in areas of heavy colonization the bacteria outnumbered cilia. The filamentous bacteria were similar in location and morphologic characteristics to cilia-associated respiratory (CAR) bacilli of rats, mice, rabbits, and cattle. Results of immunoperoxidase staining and polymerase chain reaction analysis indicated that the pig CAR bacillus is a different bacterium than the rat CAR bacillus. Rat CAR bacillus causes chronic respiratory disease in rats and mice. The association, if any, between pig CAR bacillus and swine respiratory disease is unknown.

Copper toxicosis in sibling ferrets.

Two sexually intact female silver-shaded domestic ferret siblings from different litters were examined because of CNS depression and lethargy. Ferret 1 was dehydrated and hypothermic, whereas ferret 2 was icteric and febrile and had serum bilirubin concentration > 12.0 mg/dl and BUN of 59 mg/dl. Despite supportive treatment, the ferrets died within days of evaluation. On necropsy, ferret 1 had chronic hepatopathy, with diffuse vacuolation of hepatocytes. In ferret 2, the liver had centrilobular degeneration and necrosis, and hemoglobinuric nephrosis was evident, with hemoglobin in the renal tubules. In both ferrets, Kupffer's cells and macrophages contained eosinophilic material in the cytoplasm. Special staining revealed copper pigment in hepatocytes and phagocytic cells in both livers. Analysis of liver specimens revealed 850 and 700 ppm of copper in ferrets 1 and 2, respectively. Copper values > 200 ppm in liver are considered evidence of toxicosis in most animal species. Copper toxicosis was diagnosed on the basis of the findings from histologic examination of the liver and high hepatic copper values. Lack of related illness in 11 other ferrets in the same environment and fed the same diet, plus sibling relationship and same phenotypic coat color in the affected ferrets, suggested that these ferrets had an inherited defect in their ability to metabolize normal amounts of ingested copper.

A survey of G6 and G10 serotypes of group A bovine rotaviruses from diarrheic beef and dairy calves using monoclonal antibodies in ELISA.

Group A bovine rotaviruses (BRV) have been identified worldwide as a major cause of diarrhea in the young of many species, including humans. Group A rotaviruses are classified into serotypes on the basis of the outer capsid proteins, VP7 (G types) and VP4 (P types). To date, there are 14 G types of group A rotaviruses, with G1, G6, G8, and G10 described for BRV isolates. In this study, G6- and G10-specific monoclonal antibodies (MAbs) were used in an enzyme-linked immunosorbent assay (ELISA) for the G typing of BRV-positive stool samples from diarrheic beef and dairy calves from South Dakota, Ohio, Michigan, Nebraska, and Washington, USA, and Ontario, Canada. ELISA plates were coated using a broadly reactive VP7 MAb (Common 60) or with G6- or G10-specific MAbs. BRV-positive fecal samples were diluted and added to duplicate wells, followed by the addition of polyclonal guinea pig anti-group A rotavirus serum as the secondary antibody. Several reference G6 and G10 BRV strains as well as other G types previously reported in cattle (G1, G2, G3, G8) and BRV-negative samples were included as G type specificity and negative controls. From a total of 308 field samples analyzed, 79% (244/308) tested positive by the broadly reactive VP7 MAb; of these, 54% (131/244) were G6 positive, 14% (35/244) were G10 positive, 4% (9/244) were both G6 and G10 positive, and 28% (69/244) were G6 and G10 negative.(ABSTRACT TRUNCATED AT 250 WORDS)

Cryptosporidiosis in neonatal calves: 277 cases (1986-1987).

From January 1986 through December 1987, 277 cases of cryptosporidiosis in calves were diagnosed by the South Dakota State University Diagnostic Laboratory. Cryptosporidium sp was the only pathogen identified in 142 (51.3%) of the calves. Concurrent infections with rotavirus, coronavirus, Escherichia coli, Salmonella sp, bovine viral diarrhea virus, or other pathogens were identified in the remaining 135 calves. After elimination of cases involving autolyzed specimens or calves with chronic diarrhea, records of 11 calves with acute, severe cryptosporidiosis were identified in which Cryptosporidium sp was the only pathogen.

Experimental haemarthrosis in rhesus monkeys: morphometric, biochemical and metabolic analyses.

The effects of a single episode of massive haemarthrosis in rhesus monkeys were studied. Autologous whole blood was injected into a femorotibial joint of 16 anaesthetized monkeys, equally divided into four groups and killed 7 days, 2, 3 and 6 months post-injection (PI). Synovial membrane and femoral articular cartilage were analysed morphometrically and articular cartilage was further analysed biochemically and metabolically. At 7 days PI, morphometric evaluation revealed a significant increase (P less than 0.05) in synovial membrane cellularity and synovial intimal thickness of injected joints versus control joints. This change was no longer evident 2 months PI. There was also an overall (n = 16) significant increase (P less than 0.05) in femoral articular cartilage cellularity in injected joints. The average chondrocyte lacuna area of injected joints was not statistically different from the control joints. Biochemical analyses of femoral articular cartilage revealed a significant decrease in hexosamine concentration (P less than 0.05) of injected joints. There was no significant difference between the injected and control joints in hydroxyproline or total protein concentration. Metabolic analyses revealed a significant increase (P less than 0.05) in cartilage collagenous protein production by injected joints compared with control joints. There were no significant differences in cartilage or secreted total protein production between injected and control joints. There were also no significant differences in cartilage or secreted proteoglycan production between joints. Morphometric evaluation of articular tissues following massive haemarthrosis has quantified a temporary hyperplastic reaction. A significant decrease in cartilage hexosamine concentration in haemarthrotic joints suggests this is a crucial biochemical event in the pathogenesis of blood-induced cartilage destruction.

Attaching and effacing Escherichia coli infection as a cause of diarrhea in young calves.

A form of enteric Escherichia coli infection was identified in 60 calves from 59 farming operations. The E coli responsible for these infections principally colonized the colon, inducing a distinctive lesion described as attaching and effacing. Hemorrhagic enterocolitis or blood in the feces was observed on 40% of the farms. Of affected calves, 86.6% were dairy calves (average age, 11.8 days). Forty-four calves were infected concurrently with other enteropathogens (cryptosporidia, rotavirus, coronavirus, enterotoxigenic E coli, bovine viral diarrhea virus, coccidia). Verotoxin-producing E coli was recovered from 31 calves; 8 were serotype O111:NM isolates, 3 were serotype O5:NM, and 1 was serotype O26:NM.

Macroscopic, microscopic and ultrastructural findings in experimental haemarthrosis of rhesus monkeys.

The effects of a single episode of massive haemarthrosis in rhesus monkeys were studied morphologically. Autologous whole blood was injected into a femorotibial joint of 16 anaesthetized monkeys, equally divided into four groups and killed 7 days, 2, 3 and 6 months post injection (PI). Synovial membrane and articular cartilage were examined for macroscopic, microscopic and ultrastructural changes. Haemarthrosis was only evident in one monkey by 7 days PI. Slight yellow-brown discoloration of synovium and cartilage was evident in groups killed early after injection. Histologically, a hyperplastic and inflammatory reaction was present in the synovium at 7 days PI. Ultrastructural examination of synoviocytes in this group revealed numerous cytoplasmic vacuoles and prominent microplicae compatible with increased phagocytic activity. Erythrophagocytosis by synoviocytes was observed by light microscopy and confirmed by transmission EM. Results of scanning EM suggested that red cells might also pass through the synovial intima. Transmission EM also revealed mild degenerative changes in superficial chondrocytes. Rhesus monkeys reacted morphologically to haemarthrosis in the same way as dogs and rabbits, with mild morphological changes that resolved by 2 months PI.

Morphometric evaluation of rhesus articular cartilage: correlation of hexosamine and 35SO4 = incorporation.

Morphometric evaluation of 20 rhesus articular cartilage samples were correlated with hexosamine and an 18-hour incorporation of 35SO4- as a measure of proteoglycan production on samples from the same joint. Reduced chondrocyte cellularity was the basis of the reduced maintenance of the matrix by the chondrocyte. In the more cellular cartilage, the matrix/lacunae area ratio was less than 25, and the less cellular group had a ratio of greater than 40. An inverse correlation existed between morphometric cartilage matrix/lacunar area ratio and hexosamine content. A significant difference of 35SO4 incorporation was not seen between the three morphometric grades. Morphometric assessment reduces the subjectivity of articular cartilage evaluation.

Attaching and effacing Escherichia coli infections in calves, pigs, lambs, and dogs.

Attaching and effacing Escherichia coli (AEEC) adhere to mucosal epithelium in both small and large intestine and induce a distinctive lesion characterized by an irregular scalloped appearance of the epithelial layer. Infection with attaching and effacing E. coli was detected in 14 calves, 7 pigs, 2 lambs, and 3 dogs. Affected animals were from farms and kennels in South Dakota, Minnesota, Iowa, Nebraska, and Wisconsin. Ages of affected animals were calves, 2 days to 4 months; pigs, 1-6 weeks; lambs, 1 week; and dogs, 7-8 weeks. Clinical signs included diarrhea in all animals, but other nonenteric disease problems were present in some animals. Concurrent infection with other enteropathogens was detected in 9 calves and 5 pigs. Infection with AEEC appeared to be the sole cause of illness and death in some animals. There was evidence of intestinal hemorrhage in 5 of the calves and in all 3 dogs. Attaching and effacing lesions varied from small scattered foci to widespread involvement of large areas of intestinal mucosa. Verotoxin was produced by E. coli strains isolated from 9 calves, but not by strains from pigs, lambs, or dogs.

Scrotal cestodiasis in a dog.

Scrotal cestodiasis was diagnosed from a surgical biopsy specimen from an 8-year-old Miniature Poodle. Peritoneal cestodiasis with secondary scrotal cestodiasis was suspected and could be explained by migration of the parasite along the vaginal tunics. Subsequent necropsy confirmed severe peritoneal cestodiasis due to Mesocestoides sp. It appears that scrotal cestodiasis may be an early indicator of peritoneal cestodiasis in male dogs and diagnostic pathologists and clinicians should be aware of this condition.