Transient or persistent norovirus infection does not alter the pathology of Salmonella typhimurium induced intestinal inflammation and fibrosis in mice

Murine noroviruses (MNV) are currently the most prevalent viruses infecting mouse research colonies. Concurrent infection of research mice with these viruses can dramatically alter the experimental outcome in some research models, but not others. In this report, we investigated the effect of MNV1 and MNV4 on a murine model of intestinal inflammation and fibrosis induced by Salmonella typhimurium infection in C57BL/6 mice. Subsequent co-infection of these mice with MNV1 or MNV4 did not lead to major changes in histopathology, the inflammatory response, or the fibrotic response. Thus, MNV does not substantially alter all gastrointestinal research models, highlighting the importance of investigating potential alterations in the research outcome by MNV on an individual basis. We hypothesize that this is particularly important in cases of research models that use immunocompromised mice, which could be more sensitive to MNV infection-induced changes.     

Protective role of murine norovirus against Pseudomonas aeruginosa acute pneumonia

The murine norovirus (MNV) is a recently discovered mouse pathogen, representing the most common contaminant in laboratory mouse colonies. Nevertheless, the effects of MNV infection on biomedical research are still unclear. We tested the hypothesis that MNV infection could alter immune response in mice with acute lung infection. Here we report that co-infection with MNV increases survival of mice with Pseudomonas aeruginosa acute lung injury and decreases in vivo production of pro-inflammatory cytokines. Our results suggest that MNV infection can deeply modify the parameters studied in conventional models of infection and lead to false conclusions in experimental models.     

Prevalence of Bordetella hinzii in mice in experimental facilities in Japan

To reveal the current status of the prevalence of Bordetella hinzii in mice in experimental facilities in Japan, a survey of this agent was performed by culture of tracheal swabs from a total of 12,923 mice from 1699 facilities (12,192 mice from 1572 facilities in universities and research institutes and 731 mice from 127 facilities in pharmaceutical companies) in total. In the results, 195 out of 12,192 mice (1.6%) from 44 out of 1572 facilities (2.8%) in universities and research institutes were positive for B. hinzii. No B. hinzii-positive mice were found in 127 pharmaceutical companies surveyed. Gross lesions in the lungs with isolation of B. hinzii were observed in seven mice from four universities, and the lesions were identified as bronchopneumonia histopathologically. To our knowledge, this is the first report to reveal the prevalence of B. hinzii in laboratory mice.     

The prevalence of serum antibodies to Toxoplasma gondii in Ontario mammals.

The prevalence of seropositive reactions to Toxoplasma gondii was studied in farm animals, companion animals, wild rodents and birds. Of the animals tested, 17% of cattle, 65% of sheep, 45% of pigs, 9% of horses, 33% of dogs and 20% of cats were seropositive by the Sabin-Feldman dye test. In addition 11% of mice (Mus musculus), 5% of deer mice (Peromyscus), 3% of rats (Rattus norvegicus) and less than 2% of sparrows (Passer domestcus) were seropositive. All samples from short-tailed field mice (Microtus pennsylvanicus), squirrels (Sciurus carolinensis), chipmunks (Tamias striatus), meadow jumping mice (Zapus hudsonius) and starlings (Sturnus vulgaris) were seronegative. The significance of these findings in relation to the epizootiology of toxoplasmosis in Ontario is discussed.     

Corynebacterium pseudotuberculosis infection in goats. IV. Course of the infection in two recently infected goat herds

Adult animals from 2 herds were examined clinically and serologically, 5 (Herd A) and 4 (Herd B) times during the same period of 3% years.Serum samples were examined for antibodies against Gorynebac-terium pseudotuberculosis using the bacterial agglutination test (BAT) and the hemolysis inhibition test (HIT).The results of the first examination showed that no animal in Herd A was seropositive, while in Herd B 1 animal showed a high positive titre in BAT. The prevalence of animals with superficial swellings was then 2 % in Herd A and 4 % in Herd B. In both herds, the prevalence of animals with superficial swellings and seropositive reactions increased during the following 1–2 yeairs. About 30 % of animals had superficial lesions and close to 100 % were seropositive. The proportion, of animals with superficial swellings and seropositive reactions was almost constant on subsequent examinations.In some of the animals, superficial swellings were found during 2 or more of the examinations, a few animals having such lesions at the same site on both or all occasions.Animals in Herd A became infected through grazing together with goats from infected herds. Caseous lymphadenitis was introduced into Herd B by animals obtained from infected herds.     

In vitro expression of the 50-kDa and 30-kDa fragments of the P97 adhesin of Mycoplasma hyopneumoniae in Escherichia coli and their use for serodiagnosis

This article reports the cloning and expression of 2 fragments of the P97 adhesin of Mycoplasma hyopneumoniae for use in serodiagnosis: a 50-kDa fragment (including the N-terminal cleavage site) and a 30-kDa fragment (including the C-terminal R1 and R2 repeats, which are essential for adherence). The genes encoding the fragments were amplified, cloned, and expressed in the Escherichia coli expression system BL21 (DE3)pLysS. Antiserum against the purified recombinant proteins reacted with the mycoplasmal 97-kDa intact protein and the 66-kDa major cleavage fragment, confirming that both cloned fragments could induce antigen-specific antibodies in mice. Of 70 serum samples from nonvaccinated pigs, 26 (37%) were seropositive when the 30-kDa fragment was used as an antigen for enzyme-linked immunosorbent assay, suggesting that natural mycoplasmal infection is quite common in Korea. However, only 4 samples were seropositive when the 50-kDa fragment was used; this fragment was therefore deemed unsuitable for serodiagnosis. The 30-kDa fragment protein might be useful for measuring antibody response to vaccination and for detecting mycoplasmal infection.     

Seroprevalence of bovine immunodeficiency virus in dairy and beef cattle herds in Korea.

Infection of bovine immunodeficiency virus (BIV), a lentivirus, is thought to sporadically occur throughout the world, but seroepidemiological surveys concerning the incidence of BIV are limited and have not been undertaken in Korea. A total of 266 sera from different twenty dairy (Holstein) and twenty-six Korean native beef (Hanwoo) farms of the south-western part of Korea was analyzed for the presence of anti-BIV antibodies by Western blotting. Thirty five percent and 33% of dairy and beef cattle, respectively, were BIV-seropositive. By nested polymerase chain reaction, it was confirmed that these seropositive cows had provirus in the peripheral blood mononuclear cells. To demonstrate the correlation with BIV and bovine leukemia virus (BLV) infection, these sera were also analyzed for anti-BLV antibodies by immunodiffusion test, resulting in high prevalence of BLV infection but relatively a few dual infections. We report herein the first serological detection of antibodies to BIV in Korea.     

Isolation and molecular characterization of Toxoplasma gondii from chickens and ducks from Egypt

The prevalence of Toxoplasma gondii in free range chickens is a good indicator of the prevalence of T. gondii oocysts in the environment because chickens feed from the ground. In the present study, prevalence of T. gondii in 121 free range chickens (Gallus domesticus) and 19 ducks (Anas sp.) from a rural area surrounding Giza, Egypt was assessed. Blood, heart, and brain from each animal were examined for T. gondii infection. Antibodies to T. gondii, assayed with the modified agglutination test (MAT), were found in 49 (40.4%) chickens in titers of 1:5 in 11, 1:10 in four, 1:20 in four, 1:40 in eight, 1:80 in 10, and 1:160 or more in 12 chickens. Antibodies were found in three ducks each with a titer of 1:80. Hearts and brains of seropositive (MAT > or = 1:5) chickens and ducks were bioassayed in mice. Additionally, hearts and brains of seronegative (MAT<1:5) animals were bioassayed in T. gondii-free cats. T. gondii was isolated from 19 of 49 seropositive chickens (one with a titer of 1:5, two with a titer of 1:20, one with a titer of 1:40, five with a titer of 1:80, three with a titer of 1:160, and seven with a titer of > or = 1:360). One cat fed tissues pooled from 15 seronegative chickens shed T. gondii oocysts, while two cats fed tissues of 34 seronegative chickens did not shed oocysts. T. gondii was isolated from one of the seropositive ducks by bioassay in mice. The two cats fed tissues from 16 seronegative ducks did not shed oocysts. Genotyping of 20 chicken isolates of T. gondii using the SAG 2 locus indicated that 17 isolates were type III and three were type II. The duck isolate of T. gondii was type III. The mice inoculated with tissue stages of all 21 isolates of T. gondii from chickens and ducks remained asymptomatic, indicating that phenotypically they were not type I because type I strains are lethal for mice. Infections with mixed genotypes were not found.     

Prevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in sheep from Mossoró, Rio Grande do Norte, Brazil

Toxoplasma gondii is an obligate intracellular parasite with a variety of hosts, responsible for reproductive problems and economic losses in sheep flocks. Neospora caninum was recently identified and its clinical presentation in sheep is similar to that of toxoplasmosis, which can cause repeated abortions, though less frequently in this species. In order to confirm the prevalence of these agents in the city of Mossoró, Rio Grande do Norte, Brazil, 409 serum samples from adult sheep (364 females and 45 males) were tested by the indirect immunofluorescence antibody test, using cut-off point at a dilution of 1:64 and 1:50 for T. gondii and N. caninum, respectively. From the 35 properties examined, 23 (65.7%) had at least one seropositive animal for T. gondii and six (17.1%) for N. caninum. The prevalence of seropositive animals for T. gondii was 20.7% and for N. caninum 1.8%. There was no association between the presence of the agent’s antibody and gender, reports of reproductive problems and presence of dogs and/or cats in the properties. T. gondii is well distributed and N. caninum has low prevalence in sheep and in the properties of the studied region.     

A survey for Toxoplasma gondii antibodies in deer and other wildlife on a sheep range.

Blood samples were obtained from native mammals and birds on a sheep range (Hopland Field Station) in northern California. Serums were tested for antibodies to Toxoplasma gondii by the indirect hemagglutination test. Of 382 deer that were tested from 1964 to 1973, 77 (20%) were seropositive for T gondii. Among 36 serums representing 6 species of wild carnivores (badgers, bobcats, coyotes, foxes, raccoons, and skunks), 18 (50%) were seropositive. All of the 5 bobcats tested were seropositive, with antibody titers ranging from 1:65,536. The testing of 175 serums from small wild mammals indicated antibody prevalence of 8% among jackrabbits, 6% among brush rabbits, and 2% among squirrels. None of the native mice tested was seropositive for T gondii. Of 120 native birds tested, 6 (5%) were seropositive. Of the resident domestic species of animals tested, antibodies were found in 1 of 7 domestic cats, 1 of 5 feral cats, 1 of 2 dogs, and 54 (13%) of 405 sheep.     

Survey of Toxoplasma antibodies among sheep in western United States

A survey was conducted to determine the prevalence of toxoplasma antibodies among breeding ewes and among lambs slaughtered for food in western United States. Each serum was tested by the indirect hemaglutination method, using microtiter technique. Agglutination (greater than or equal to 2 +) at the 1:64 dilution was considered to be a positive reaction. Of 2,164 ewes from 18 flocks tested in California, 523 (24%) were seropositive for Toxoplasma gondii, with prevalence rates among flocks ranging from 4 to 51%. In 9 of those flocks, 1,495 ewes were stratified by whether ewes had lambed or were barren. On an overall basis, the antibody prevalence was similar (about 25%) in both groups, but there was a significant difference (P less than 0.05) in 1 flock in which 30% of the nursing ewes were seropositive, compared with 21% of the barren ewes. Of 1,056 market lambs from 19 lots tested, 85 (8%) were seropositive. The antibody prevalence in lambs tested at slaughter in California, by state of origin, were: Oregon, 11/51 (22%); Nevada, 32/159 (20%); Idaho, 12/147 (5%), and California, 30/699 (4%).     

Characterization of Toxoplasma gondii isolates from free range chickens from Paraná, Brazil

The prevalence of Toxoplasma gondii in free range chickens is a good indicator of the prevalence of T. gondii oocysts in the environment because chickens feed from the ground. In the present study, prevalence of T. gondii in 40 free range chickens (Gallus domesticus) from a rural area surrounding Paraná, Brazil was assessed. Blood, heart, and brain from each chicken were examined for T. gondii infection. Antibodies to T. gondii, assayed with the modified agglutination test (MAT> or =1:5) were found in 16 chickens. Hearts and brains of seropositive (MAT> or =1:5) chickens were bioassayed in mice. Additionally, hearts and brains of seronegative (MAT<1:5) chickens were bioassayed in two T. gondii-free cats (12 chickens per cat). T. gondii was isolated from 13 of 16 (81%) seropositive chickens. Of the two cats fed tissues pooled form seronegative chickens, one shed T. gondii oocysts. Nine of the 13 T. gondii isolates killed 100% of infected mice. The T. gondii isolate from the cat was also virulent for mice. Genotyping of 13 chicken isolates of T. gondii using the SAG2 locus indicated that seven isolates were type I and six were type III; three of these type III isolates killed all infected mice suggesting that all strains virulent for mice are not type I. The isolate from the feces of the cat fed chicken tissues was type I.     

Seroprevalence of antibodies against Lawsonia intracellularis among growing pigs raised in indoor versus outdoor units

OBJECTIVE: To determine change over time in sero-prevalence of antibodies against Lawsonia intracellularis among growing-finishing pigs housed in indoor versus outdoor facilities. DESIGN: Serologic survey. ANIMALS: 93 pigs born to seropositive gilts and raised in indoor (n = 49) or outdoor (44) growing-finishing facilities. PROCEDURE: Blood samples were collected from the pigs 2, 6, 10, 14, 18, 22, and 26 weeks after birth and tested for antibodies against L intracellularis with an indirect immunofluorescence assay. RESULTS: None of the pigs were seropositive 2 or 6 weeks after birth.Ten weeks after birth, 74% and 76% of pigs in indoor and outdoor growing-finishing facilities were seropositive, respectively, whereas 14 weeks after birth, the percentage of pigs in indoor growing-finishing facilities that were seropositive was substantially higher than the percentage of pigs in outdoor facilities that were. From 18 weeks after birth to the end of the study, none of the pigs in outdoor growing-finishing facilities were seropositive, whereas low percentages of pigs in indoor facilities were seropositive 18, 22, and 26 weeks after birth. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that seroprevalence of antibodies against L intracellularis decreases faster among growing-finishing pigs housed in outdoor facilities than among growing-finishing pigs housed in indoor facilities.     

Seroprevalence of Coxiella burnetii infections among cats in different living environments

The seroprevalence of Coxiella burnetii infection among pet cats in Japan and Korea and stray cats in Japan was investigated by an indirect fluorescent antibody technique and PCR test. Forty-four (14.2%) of 310 pet cats in Japan were seropositive, as were 15 (41.7%) of 36 stray cats in Japan and 10 (8.6%) of 116 pet cats in Korea. The antibody positive rate in stray cats was significantly higher than that in pet cats, but there was no correlation between the rates in Japanese and Korean pet cats. In this study, the prevalence of C. burnetii infection among cats in different living environments was found and it is difficult to deny that stray cats would be one of the important sources of infection for human Q fever.     

Enzyme immunoassay for surveillance of Q fever

An enzyme-linked immunosorbent assay (ELISA) was developed to monitor antibodies against Coxiella burnetii among animal populations used in research and teaching facilities. Various antigenic components of C burnetii prepared from phase I and phase II whole cells and commercially available antigens were evaluated. A trichloroacetic acid extract was selected for routine use. There was a linear relationship between the transformed absorbance readings of the ELISA results and microagglutination (MA) titers. Comparison between positive or negative results of the MA test and ELISA gave 98.6% concordance. Using the MA test as the standard, ELISA results were 97.8% sensitive and 100% specific. The efficacy of ELISA was evaluated by testing ruminants with known histories of C burnetii infection. Antibody prevalence was 0 in 117 sheep with no history of C burnetii infection, 22% in 145 naturally infected sheep used for research, and 53% in 115 sheep used for vaccine field trials. Forty-eight percent of 120 dairy cows and 52% of 79 goats from endemically infected herds were seropositive. These results indicate that ELISA should be the test of choice for mass screening and surveillance of animals when Q fever is a suspected biohazard.     

The rate of Salmonella spp. infection in zoo animals at Seoul Grand Park, Korea

Salmonellosis is an important zoonotic disease that affects both people and animals. The incidence of reptile-associated salmonellosis has increased in Western countries due to the increasing popularity of reptiles as pets. In Korea, where reptiles are not popular as pets, many zoos offer programs in which people have contact with animals, including reptiles. So, we determined the rate of Salmonella spp. infection in animals by taking anal swabs from 294 animals at Seoul Grand Park. Salmonella spp. were isolated from 14 of 46 reptiles (30.4%), 1 of 15 birds (6.7%) and 2 of 233 mammals (0.9%). These findings indicate that vigilance is required for determining the presence of zoonotic pathogen infections in zoo animals and contamination of animal facilities to prevent human infection with zoonotic diseases from zoo facilities and animal exhibitions. In addition, prevention of human infection requires proper education about personal hygiene.     

Mass screening of cattle sera against 14 infectious disease agents, using an ELISA system for monitoring health in livestock.

Mass screening ELISA methods were developed for testing cattle serum for antibodies against 14 common livestock diseases simultaneously. The absorbance values were transformed to a %ELISA (spectrophotometric antibody end point) by a computer interfaced with a microplate reader. A histogram indicating a cutoff point and a report for the veterinarian also was generated. The computer program produced a print-out of the antibody profile for each animal tested, the antibody concentration against each disease, and a histogram (antibody profile) showing the prevalence of each disease in the herd. Serum samples were obtained from 1,953 cattle, including 880 dairy cattle from 10 herds and 1,073 beef cattle from 20 herds. These samples were obtained from June 1988 through June 1989. The highest antibody prevalence was against bluetongue virus. Of the 1,953 cattle tested, 1,223 (63%) were seropositive for bluetongue virus, including 502 (57%) of the dairy cattle and 721 (67%) beef cattle. Other antibody prevalences, in descending order, were: rotavirus (44%), Pasteurella spp (25%), Leptospira spp and Haemophilus spp (22%), Mycoplasma spp (18%), parainfluenza virus (17%), Campylobacter spp (16%), Anaplasma marginale (15%), bovine leukosis virus (13%), Brucella spp (8%), Mycobacterium paratuberculosis (8%), bovine viral diarrhea virus (3%), and infectious bovine rhinotracheitis virus (3%). Major differences in antibody prevalence between dairy and beef cattle were that only 4% of the dairy cattle were seropositive for A marginale, compared with 25% of the beef cattle, and conversely, 29% of the dairy cattle were seropositive for bovine leukosis virus, compared with 1% of the beef cattle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Investigation of pseudorabies virus latency in nervous tissues of seropositive pigs exposed to field strain

The prevalence and quantity of latent pseudorabies virus (PrV) in nervous tissues of pigs exposed to field strain in Korea was investigated by nested and real-time PCR. Nervous tissues including trigeminal ganglion (TG), olfactory bulb (OB), and brain stem (BS) were collected from 94 seropositive pigs. PrV latent infection in nervous tissues was initially investigated by nested PCR targeting three glycoprotein genes (gB, gE, and gG). Based on the obtained result, latent infection was detected in 95.7% of screened animals. Furthermore, it was revealed that the examined tissues harbored different copy numbers of latent PrV genome ranging from <10(2.0) to 10(7.1) copies per microgram of genomic DNA in real-time PCR analysis. These results show that under normal conditions, levels of latent PrV in the nervous tissues of pigs can vary across a wide range. Therefore, the data presented here provides information regarding control of the endemic state of PrV in Korea.     

Seroprevalence of Anaplasma marginale in 2 Iowa feedlots and its association with morbidity, mortality, production parameters, and carcass traits

A prospective cohort observational study was conducted to investigate the seroprevalence of Anaplasma marginale in Iowa feedlots and its association with morbidity, mortality, and treatment costs. Blood samples were taken from 659 calves from 31 consigners at processing and classified as seropositive to A. marginale using a competitive enzyme-linked immunosorbent assay (cELISA) with a 30% cutoff. Health and production parameters were modeled by A. marginale serostatus with mixed model regression analysis. The apparent prevalence of seropositive cattle was 15.17% (100/659). When the cELISA positive cutoff was at 42% inhibition, the apparent prevalence was 5.00% (33/659). There was no significant association between A. marginale serostatus and production parameters; however, seropositive status had a weak positive association with undifferentiated fever (P = 0.17). Although prevalence of anaplasmosis in Iowa feedlots is higher than reported in Montana-sourced calves arriving in Canadian feedlots, this was not associated with increased production costs.     

Factors associated with the seroprevalence of pseudorabies virus in breeding swine from quarantined herds.

Strategies for the elimination of pseudorabies virus (PRV) from swine herds include test and removal, offspring segregation, and depopulation/repopulation. The prevalence of PRV in a herd is a major factor in selection of the most appropriate strategy. The purpose of the study reported here was to describe the prevalence of PRV in adult swine in PRV quarantined herds in Minnesota, and to determine herd factors associated with the seroprevalence. Questionnaires describing the health history of the herd, management practices, and design of the swine facilities were obtained from the owners of 142 quarantined herds. Blood was collected from 29 finishing pigs over the age of 4 months, up to 29 adult females, and all herd boars. Factors considered to be significant in a bivariate analysis were combined in a stepwise multiple logistic regression analysis. The prevalence of PRV-seropositive adults in each herd was bimodally distributed among the 142 herds. In 42 (30%) of the herds, none of the females tested was seropositive, which represented the lower mode. At least 90% of the adults tested were seropositive in 30 (21%) of the herds and represented the higher mode. The odds of the breeding swine of a given herd having a PRV seroprevalence of greater than or equal to 20% as compared with having a seroprevalence of less than 20% was 1.654 times higher per 50 adults in the herd, 13.550 times higher if the finishing pigs were seropositive, 2.378 times higher if sows were housed inside during gestation, and 1.481 times lower per number of years since the imposition of quarantine.(ABSTRACT TRUNCATED AT 250 WORDS)