PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “CATTLE DISEASES”

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.

At least 703 records · Page 39Linked to original sources
PubMed1995

Characterization of a novel Mycobacterium bovis secreted antigen containing PGLTS repeats.

Serum from naturally infected cattle was used to identify a novel Mycobacterium bovis antigen from an expression library. The first recombinant product identified was a fusion protein with lacZ (55 kDa). A clone containing the whole gene was also obtained. This clone expressed a 38-kDa protein. A rabbit serum against the recombinant antigen reacts in M. bovis supernatants with two proteins of 36 and 34 kDa. The new protein was called P36/P34. The gene cloned has a deduced amino acid sequence with a predicted molecular mass of 28 kDa, showing a characteristic signal sequence for exportation. The protein bears partial homology to a 28-kDa protein from M. leprae. An interesting feature of the P36/P34 sequence is that it contains several PGLTS repeats, which are not present in the M. leprae protein. Antigenic determinants seem also to be conserved between the two proteins because sera from leprosy patients recognized the recombinant M. bovis protein. The discrepancy among the molecular mass deduced from the sequence (28 kDa), that of the recombinant protein in Escherichia coli (38 kDa), and that of the native protein in M. bovis (36 and 34 kDa) could be attributed to posttranslational modifications or to the high proline content that may alter the migration properties of the protein. This antigen seems to be immunodominant during bovine tuberculosis, because 8 of 9 serum specimens from diseased cattle are reactive. The homology among the M. leprae 28-kDa protein, the protein described in this article, and a recently described M. tuberculosis protein suggests the existence of a new protein family in mycobacteria.

Amino Acid Sequence↗
PubMed2005

Mycoplasma mycoides ssp. mycoides biotype small colony-secreted components induce apoptotic cell death in bovine leucocytes.

Contagious bovine pleuropneumonia, caused by Mycoplasma mycoides ssp. mycoides biotype small colony (MmmSC), is one of the most serious cattle diseases in Africa. Several observations suggested that MmmSC had evolved an efficient way to escape the bovine immune responses by triggering host-cell cytotoxicity. This study was implemented to determine whether the cytotoxic effect was due to apoptotic cell death. To that end, bovine blood cells were cultured for up to 3 days in the presence of viable or heat-killed MmmSC compared to unstimulated cultures. The findings provided evidence for a viable MmmSC-induced, time-dependent apoptosis in bovine blood leucocytes, whereas heat-killed MmmSC had no effect. Morphological and physiological changes (evidenced by TUNEL and annexin V staining) typical of apoptosis were observed in response to viable MmmSC. All the lymphocyte subsets as well as the monocyte/granulocyte subset exhibited extensive apoptosis after exposure to viable MmmSC. Our results demonstrated a potential role for MmmSC-secreted components as pathogenic factors able to induce programmed cell death in bovine blood leucocytes.

Animals↗
PubMed1992

Activation of bovine immunodeficiency-like virus expression by bovine herpesvirus type 1.

Bovine immunodeficiency-like virus (BIV) is a recently identified lentivirus that infects cattle. The virus has structural and genetic similarities to human HIV. The present study demonstrates that BIV can be activated by bovine herpesvirus type 1 (BHV-1), a pathogen frequently associated with cattle diseases. Activation of BIV expression can be detected as increased BIV reverse transcriptase activity, increased in the number of syncytia induced by BIV, and increased in the steady state level of BIV-specific RNA upon BHV-1 super-infection. Additional transactivation studies using the BIV-LTR (long terminal repeat) were conducted. The BIV-LTR was linked to the chloramphenicol acetyl transferase gene (CAT) and transfected into bovine cell cultures in order to quantitate the levels of BIV-LTR expression. When the transfected cells were infected by BHV-1, there was an increase in CAT expression, indicating transactivation of the BIV-LTR by BHV-1. Most of the transactivation activities were abolished with an LTR construct that has deleted the NF-kappa B-like sequence located in the U3 region of the LTR. In order to further demonstrate that activation of the BIV-LTR involves factors that may bind to the LTR sequences, gel retardation assays were carried out using the BIV-LTR U3 region as probe. Our results showed that BHV-1 infection resulted in an induction of factor(s) that binds to the NF-kappa B-like sequence on the BIV-LTR. This suggests that transactivation of BIV by BHV-1 may be mediated by a bovine NF-kappa B-like protein that binds to the target sequence in the BIV promoter region.

Animals↗
PubMed2006

Viable Mycoplasma mycoides ssp. mycoides small colony-mediated depression of the bovine cell responsiveness to the mitogen concanavalin A.

Mycoplasma mycoides ssp. mycoides biotype Small Colony (MmmSC) is the causative agent of contagious bovine pleuropneumonia (CBPP), which is still a major tropical cattle disease. Development of an efficient vaccine requires an understanding of the immunopathology of CBPP as MmmSC presents a strong ability to escape the host immune response. The objective of this study was to determine whether the presence of MmmSC can modulate the immune response induced by the mitogen Concanavalin A (ConA) on bovine immune cells [peripheral blood mononuclear cells (PBMC) and lymph node (LN) cells]. Comparative analysis of the immunomodulating properties of viable versus heat-killed MmmSC on ConA-stimulated immune cells revealed that while heat-killed MmmSC had no effect, viable MmmSC strongly depressed, in a concentration-dependent manner, the ConA mitogenic activity (blastogenesis and interferon-gamma production). Both B-cell and T-cell activation were affected with the highest impact on the CD4 T cells. The phenotypic analysis showed that the ConA-induced proliferation of CD25(+) cells was strongly reduced when co-exposed to viable MmmSC, confirming that events associated with ConA-induced cell activation were suppressed by the pathogen. This study thus demonstrated that viable MmmSC is able to inhibit the polyclonal mitogenic activity of the ConA on bovine PBMC and LN cells. This finding strongly suggests that the persistence of viable MmmSC may also thus inhibit the bovine immune response directed towards inactivated MmmSC, whether dead or in the form of antigens, also present during infection. This study confirmed that MmmSC has evolved an efficient mechanism to prevent its elimination from the host.

Animals↗
PubMed1989

Experimental autoimmune motoneuron disease.

An animal model of disease of the lower motoneurons has been developed by inoculating guinea pigs with bovine motoneurons. Four of 9 immunized female animals and 4 of 5 immunized male animals developed symptoms of neuromuscular degeneration marked by weakness, evidence of denervation by electromyographic and morphological criteria, and a loss of motoneurons within the spinal cord. No inflammatory foci were noted within parenchyma or meninges of the central nervous system. The immunized guinea pigs developed high serum titers of IgG class antibodies to motoneurons. Immunohistochemical studies demonstrated the presence of IgG within spinal cord motoneurons and at the end-plates of immunized animals. This experimental autoimmune motoneuron disease may provide important insights into the cause and pathogenesis of amyotrophic lateral sclerosis, a human motoneuron disease.

Animals↗
PubMed1994

Identification of a new group of bovine viral diarrhea virus strains associated with severe outbreaks and high mortalities.

New BVDV strains associated with very high mortalities, which killed about 25% of the veal calves in Quebec in 1993, have been isolated. In this study, characterization of the last two-thirds of the 5' untranslated region (5'UTR) of their genome and virus neutralization experiments with polyvalent antisera raised in different animals both demonstrated that these strains formed a distinct group. Despite a difference of about 25% in the 5'UTR sequence with that of the classical strains, these 5'UTRs maintained the same secondary structure albeit with a higher stability. Serological crossreactivity between the classical and new BVDV strains was relatively low and suggest that new strains should also be included to obtain efficient BVDV vaccines. Based upon the distinct characteristics of these new BVDV strains, we propose to divide BVDV into two groups. Group I comprises the classical BVDV isolates including commonly used laboratory and vaccine strains, and group II comprises the newly described BVDV strains and those associated with thrombocytopenia and hemorrhaging.

Animals↗
PubMed1995

Delayed onset postvaccinal mucosal disease as a result of genetic recombination between genotype 1 and genotype 2 BVDV.

Bovine viral diarrhea viruses (BVDV) are segregated into two genotypes, BVDV 1 and BVDV 2. Viruses within both genotypes may exist as one of two biotypes, cytopathic or noncytopathic. A highly fatal form of BVDV termed mucosal disease (MD) occurs when an animal persistently infected with noncytopathic BVDV becomes superinfected with cytopathic BVDV. In this study, we characterized a noncytopathic (BVDV2-125nc)/cytopathic (BVDV2-125c) viral pair isolated from an animal that died of MD 3 months after vaccination with modified-live BVDV1-NADL. In comparison to BVDV2-125nc, BVDV2-125c contained a 366-nucleotide insertion. The insertion was in the correct reading frame for the large open reading frame of the BVDV genome and occurred in the portion of the genome that codes for the p125 viral polypeptide. There was a 99% identity between the inserted sequences found in BVDV2-125c and sequences from the vaccine virus BVDV1-NADL. These data suggest that MD was induced after a recombination between noncytopathic BVD2-125nc and cytopathic vaccine virus BVDV1-NADL created the cytopathic virus BVDV2-125c.

Amino Acid Sequence↗
PubMed1991

Clinical and virological observations of a mucosal disease outbreak with persistently-infected seropositive survivors.

A group of 14 four to nine month old calves, clinically healthy but persistently infected with bovine virus diarrhoea virus (BVDV), was obtained from a single farm, and reared as a group. Ten of them were male and were castrated soon after arrival. Signs of mucosal disease (MD) developed within a month and eight of the males had died or been killed on humane grounds by 2 months after purchase. The other two males and one of the females developed more chronic but progressive signs of MD and were killed during the next four months. The remaining three females showed only transient signs of MD followed by clinical recovery. They subsequently remained healthy up to slaughter at 2, 2.5 and 5 years respectively. These three survivors were persistently infected with BVDV, and shed virus in their mucous secretions, although two of them were also seropositive to the virus with fluctuating neutralizing antibody titres (at times as high as 1/960) to a range of BVDV strains including their own persisting virus.

Animals↗
PubMed1982

Increased incidence of bovine papular stomatitis in neonatal calves.

A high incidence of bovine papular stomatitis (BPS) occurred in neonatal calves following neonatal thymectomy and antilymphocyte globulin treatment, sham thymectomy, treatment with normal horse globulin and in untreated calves. The source of BPS virus was not identified but was suspected to be latent in the calves and activated by thymectomy although no experimental evidence directly supported this conclusion. The potential for activation of a latent BPS infection was indicated by an apparent relationship between the stress of surgery or foreign protein inoculation and the severity of lesions. Subsequent bovine viral diarrhea virus infection did not result in recrudescence.

Animals↗