Antibody isotypes against the surface glycoproteins of porcine coronavirus in the milk of orally infected sows.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Colostrum of cows immunized with a polyvalent vaccine against enteropathogenic strains of Escherichia coli gave good protection to piglets and calves against enteric coli infections. Bovine immunoglobulin (IgG1) and its precipitable fragments persisted in the small intestine of piglets for 6 hours after oral administration. The proteolytic breakdown of porcine colostral IgG2, which occurs predominantly in the small intestine proceeded at a higher rate than that of heterologous bovine colostral IgG1. Colostrum of cows immunized with transmissible gastroenteritis (TGE) virus by intramammary administration protected newborn piglets from virulent TGE virus on oral administration. The prevention of enteric coli infections in suckling piglets and calves in Czechoslovakia is based on vaccination of pregnant cows and sows and on additional passive protection of weanlings by oral administration of dried or liquid immune colostrum or serum of cows vaccinated with polyvalent vaccines prepared from enteropathogenic strains of E. Coli.
Explore the source record for details and available documents.
An enteric coronavirus that is antigenically closely related to feline infectious peritonitis virus (FIPV) is ubiquitous in the cat population. This virus has been designated feline enteric coronavirus to differentiate it from FIPV. The virus is shed in the feces by many seropositive cats; in catteries it is a cause of inapparent to mildly severe enteritis in kittens 6 to 12 weeks of age. The virus may produce a more severe enteritis in young specific-pathogen-free kittens. Feline enteric coronavirus selectively infects the apical columnar epithelium of the intestinal villi, from the caudal part of the duodenum to the cecum. In severe infections, there are sloughing of the tips of the villi and villous atrophy. Many cats recovering from the disease remain carriers of the virus. Recovered cats, observed for 3 to 24 months, remained healthy and did not develop peritonitis, pleuritis, or granulomatous disease. The relationship of feline enteric coronavirus and FIPV was studied. Although the viruses were antigenically similar, they were distinctly different in their pathogenicities. The enteric coronavirus did not cause feline infectious peritonitis in coronavirus antibody-negative cats inoculated orally or intraperitoneally nor in coronavirus antibody-positive cats inoculated intraperitoneally or intratracheally. Serologic tests, using FIPV, canine coronavirus, and transmissible gastroenteritis virus of swine as substrate antigens in fluorescent antibody procedures may not accurately identify FIPV infection. These tests do not appear to distinguish between FIPV and this feline enteric coronavirus.
A heterologous neutralization assay for feline infectious peritonitis virus serology was developed using a single continuous cell line of canine origin, A-72, which is susceptible to cytopathic infection with both transmissible gastroenteritis virus of pigs and canine coronavirus. Of several coronavirus isolates tested, the 1-71 isolate of canine coronavirus demonstrated the most effective neutralization by serum and body fluids of cats with histopathologically confirmed feline infectious peritonitis.
Environmental stressors are involved in the etiology of important livestock diseases, including transmissible gastroenteritis in young pigs, Newcastle's and Marek's disease in chickens and shipping fever in cattle. Unfortunately, very little research has been conducted to learn how stress alters host resistance, although it is generally assumed that the immune system of the host is affected. This paper identifies eight stressors that typically occur in modern livestock production units: heat, cold, crowding, mixing, weaning, limit-feeding, noise and restraint. All of these stressors have been shown to alter the immune system of animals. These changes in immune function may ultimately explain the physiological basis of disease-environment interactions. A thorough understanding of stress-induced changes in host resistance will also provide the scientific basis for effective prophylactic therapy. More controlled experiments are needed to learn how stress alters the susceptibility of animals to infectious and noninfectious diseases.
Molecular mimicry has been characterized as the presence of common epitopes, either linear or conformational, shared by host and microbial determinants. Such cross-reactivity may lead to an autoimmune disease. On the other hand molecular mimicry between certain viral proteins and host determinant may protect invading virus to be eliminated by immune system and may promote persistence. In this mini-review I discuss the molecular mimicry of S peplomer protein of mouse hepatitis virus, strain JHM (MHV-JHM) to the host Fc gamma receptor (Fc gamma R). MHV-JHM induces in rodents acute encephalomyelitis and surviving animals develop demyelinating disease with concomitant persistent infection. We have demonstrated that rabbit IgG, but not is F(ab')2 fragments, monoclonal rat and mouse IgG and the rat 2.4G2 anti-Fc gamma R mab immunoprecipitated natural and recombinant S peplomer protein of several strains of MHV. Furthermore, MHV-JHM infected cells formed rosettes with anti-sheep red blood cell (SRBC) - antibody coated SRBC. The 2.4G2 anti-Fc gamma R mab are able to neutralize several strains of MHV, presumably by binding to S peplomer protein. Therefore, the Fc binding site of S is present on the surface of MHV-infected cells. This molecular mimicry between S peplomer protein of MHV-JHM and Fc gamma R has been extended to other members of Coronaviridae, namely bovine coronavirus and transmissible gastroenteritis virus but not to infectious bronchitis virus. The molecular mimicry of viral antigens to Fc receptors has been described also for members of Herpesviridae, namely Herpes simplex, cytomegalovirus and Varicella zoster.(ABSTRACT TRUNCATED AT 250 WORDS)
A modified method of the reverse transcription followed by polymerase chain reaction (RT-PCR) was developed in order to examine the genome of a recently discovered virus, the porcine epidemic diarrhoea virus (PEDV), which resembled morphologically the coronaviruses. The published sequences of the genomes of various coronaviruses were compared. On the level of the amino acid sequence, conserved regions, common to all coronaviruses, were found in the gene encoding the nonstructural protein 1b as well as in the genes coding for the major structural proteins (S, M, and N). Due to the degeneration of the genetic code, some amino acids may be encoded by different nucleotide triplets. In order to compensate for this degeneration, mixtures of primers were synthesized, containing a variety of nucleotide sequences which together represented all possible codons for the conserved amino acid sequences. This method allowed to amplify and clone approximately 4000 base pairs of the genome of PEDV. An analysis of the genomic sequences revealed that PEDV holds an interesting intermediate position between human coronavirus 229E and Transmissible Gastroenteritis virus. We postulate that the method presented in this contribution may be useful to study and characterize other unknown viruses, especially viruses for which no cell cultures for propagation are available.
Coronaviruses and arteriviruses infect multiple species of mammals, including humans, causing diseases that range from encephalitis to enteritis. Several of these viruses infect domestic animals and cause significant morbidity and mortality, leading to major economic losses. In this category are included such pathogens as transmissible gastroenteritis virus, porcine respiratory and reproductive virus and infectious bronchitis virus. The feline coronaviruses (FECV) generally do not cause infections with high morbidity but in a small percentage of cases, the virus mutates to become more virulent. This virus, feline infectious peritonitis virus (FIPV), causes severe disease in young cats. This disease is in large part immunopathological and understanding it is a major goal of coronavirus research.
A low frequency leukocyte subpopulation, referred to as natural interferon producing cells (NIPC) is able to produce high amounts of interferon alpha (IFN-alpha) following contact with noninfectious viral structures. In order to examine the possible leukocytic nature and bone marrow origin of NIPC, severe combined immunodeficiency (SCID) mice were reconstituted with porcine leukocyte populations, including bone marrow cells. At different times after reconstitution, enriched CD4 and CD45 positive porcine cells were isolated from various mouse organs and tested for the presence of porcine NIPC by porcine IFN-alpha specific ELISPOT assay, after in vitro stimulation by UV inactivated transmissible gastroenteritis virus (TGEV). Although engraftment of porcine cells in SCID mice was shown by flow cytometry and by the production of pig immunoglobulins, no IFN-alpha secreting cells could be detected. This result suggests that NIPC do not derive from bone marrow precursor cells, or that growth factors needed for in vivo expansion of porcine NIPC were absent in mice.
BACKGROUND: Outbreaks of salmonella gastroenteritis in nursing homes are common. Person-to-person transmission to nursing home personnel occurs occasionally, but infection of laundry staff as a result of handling soiled linen rarely has been reported. OBJECTIVE: To examine the nosocomial transmission of infection to laundry staff during an outbreak of salmonellosis in a nursing home. SETTING: A 250-bed nursing home in a rural Tennessee county. METHODS: Residents and staff of the nursing home were interviewed and cultures of stool samples examined for enteric pathogens. RESULTS: Stool cultures from 32 residents and 8 employees were positive for Salmonella hadar. Infection among the residents was food-borne, but infection among employees likely represented secondary transmission, as none of the employees ate food prepared in the kitchen and their onset of symptoms occurred seven to 10 days after that of ill residents. Three laundry personnel who had no contact with residents were infected. Most of the ill residents (81%) were incontinent, which led to an increase in both the degree of fecal soiling and the amount of soiled linen received by the laundry during the outbreak. Laundry personnel regularly ate in the laundry room, did not wear protective clothing, and did not wear gloves consistently while handling soiled laundry. CONCLUSIONS: This investigation implicates linen soiled with feces as the source of nosocomial S hadar infection in laundry workers and underscores the importance of using appropriate precautions when handling linen.
A pooled suspension of rotavirus was prepared from the stools of eight children with acute non-bacterial gastroenteritis. The suspension was infused into the duodenum and stomach of an infant monkey (Nemestrina macaque). Biopsy samples of duodenal mucosa were taken at several intervals after inoculation, examined by light and electron microscopy, and assayed for lysosomal activity. Virus-like particles were seen within and around microvilli and intracellularly within vesicles as early as 20 minutes after the infusion. On the fourth and fifth days, large lysosomal bodies containing numerous virus-like particles were found within epithelial cells of the duodenal villi. No such particles were seen in the pre-inoculation sample or at days 16 or 25 after infection. The present study would appear to be the first demonstration of the transmission of this human virus to another species.
Explore the source record for details and available documents.
There is an inseparable correlation between higher livestock performance and animal health with many visible repercussions in terms of further intensification of livestock farming. This is the background against which immunobiological action is defined as a major element of all efforts which are undertaken for the purpose of ensuring high-stability and high-continuity and no-problem production. Underlined in this paper is the great role played by legal provisions for immunisation concepts as well as by straight-forward guidance, organisation, and documentation of all uses of live vaccines. Practical experience so far obtained from the use of vaccines and its effects under conditions of industrialised livestock farming is reported in this paper, with particular reference being made to swine fever and transmissible gastro-enteritis of swine.
We conducted a 19-month prospective study of children attending 20-day-care centers to determine the occurrence, causes, and transmission of gastroenteritis among children, staff, and family members. Nine centers had 15 outbreaks of diarrhea involving 195 patients. An enteropathogen was identified in all outbreaks. Shigella was detected in five outbreaks, rotavirus in two, giardia in one, and in the remaining seven multiple enteropathogens were identified. Rotavirus and Giardia occurred only in children less than 3 years of age; shigellosis occurred at all ages. In six DCC 68 single cases of diarrhea were not associated with an outbreak; an enteropathogen was identified in only three (4%) persons. Thirty-four family members (11%) developed diarrhea associated with the occurrence of gastroenteritis in children in six DCC evaluated for this problem. Secondary attack rates of diarrhea in families according to organisms identified in the DCC outbreaks were: Shigella 26%, rotavirus 15%, and G. lamblia 17%. DCC may play an important role in the epidemiology and transmission of gastroenteritis in the United States.
The epizootiology of transmissible gastro-enteritis (TGE) of swine in 1975 and 1976 in the Netherlands was studied. Diagnosis was made by the direct fluorescent antibody technique (FAT). Specimens from the small intestine of suspected animals were examined for this purpose. The results obtained by the direct FAT were proved to be reliable, if the specimens were derived from acutely sick animals and examination could be carried out as soon as possible. The results confirmed that TGE occured in any season of the year. The peaks of epizootic outbreaks were in the spring and winter of those years.