Effects of composite casein and [beta]-lactoglobulin genotypes on renneting properties and composition of bovine milk by assuming an animal model

Selostus: Kaseiinien yhdistelmägenotyyppien ja [beta]-laktoglobuliinin genotyyppien vaikutus maidon juoksettumisominaisuuksiin ja koostumukseen

Waddlia, Parachlamydia and Chlamydiaceae in bovine abortion.

The etiology remains unknown in many cases of bovine abortion in Switzerland. Bacteria of the Chlamydiales order are known abortive agents, therefore cases of bovine abortion from three representative regions of Switzerland were investigated in this study. Particularly Chlamydiaceae as well as the Chlamydia-like organisms Waddlia and Parachlamydia were of interest, especially because of their possible zoonotic potential. Placenta samples (n=343) were tested for these bacteria by different PCR-methods, immunohistochemistry and serology for Chlamydia abortus. Additionally an attempt for the isolation of Waddlia and Parachlamydia was made by co-cultivation in amoebae. In 67.3% of the 343 cases a necrotizing and/or purulent placentitis was found histologically. By real-time PCR, 0.9% (3/343) of the cases were positive for Waddlia, 13.4% (46/343) positive for Parachlamydia and 14.6% (50/343) positive or questionable positive for Chlamydiaceae. Of these samples, confirmation by immunohistochemistry was possible in 2/3 cases for Waddlia, 25/46 for Parachlamydia and 4/50 for Chlamydiaceae. Of the 50 cases positive or questionable positive for Chlamydiaceae, species-identification by ArrayTube Microarray or 16S rRNA PCR resulted in 41 cases positive for C. abortus whereas the presence of Chlamydia suis was confirmed in four and Chlamydia pecorum in one case. This study brought evidence for the importance of different members of Chlamydiales in different regions of Switzerland although Waddlia is not occurring in a high prevalence. On the other hand mixed infections with different Chlamydiales as well as with other abortigenic agents could be found.

Peptides from Lactobacillus hydrolysates of bovine milk caseins inhibit prolyl-peptidases of human colon cells.

Prolyl-rich peptides derived from hydrolysates of bovine caseins have been previously shown to inhibit angiotensin converting enzyme (ACE) activity, suggesting that they may also be able to inhibit the enzymatic activities of prolyl-specific peptidases. This study shows that peptides derived from α(S1)-casein and β-casein inhibited the enzymatic activities of purified recombinant matrix metalloprotease (MMP)-2, MMP-7, and MMP-9. The inhibitory efficacy was sequence-dependent. These peptides also selectively inhibited the enzymatic activities of prolyl-amino-peptidases, prolyl-amino-dipeptidases, and prolyl-endopeptidases in extracts of HT-29 and SW480 human colon carcinoma cells, but not in intact cells. They were not cytotoxic or growth inhibitory for these cells. Thus, the prolyl-rich selected peptides were good and selective inhibitors of MMPs and post-proline-cleaving proteases, demonstrating their potential to control inadequate proteolytic activity in the human digestive tract, without inducing cytotoxic effects.

Peroxynitrite cytotoxicity on bovine retinal pigmented epithelial cells in culture.

Peroxynitrite induced in vitro a dose dependent toxicity on retinal pigmented epithelial (RPE) cells. Cell death was partially mediated by apoptosis as demonstrated by nuclear fragmentation and TdT-mediated dUTP nick-end labeling assay. Peroxynitrite-induced tyrosine nitration was revealed by immunocytochemistry, both in the cytoplasm and in the nucleus of the cells. Nitration was not observed in RPE cells, producing nitric oxide (NO) after stimulation by lipopolysacharide and interferon-g (IFN-gamma), suggesting that peroxynitrite was not formed in vitro in such conditions. Peroxynitrite could be responsible for the retinal damages observed in pathological conditions in which NO has been demonstrated to be involved. In this context, EGb761, identified as a free radical scavenger, was showed herein to protect RPE cells against peroxynitrite injury.

Prevalence of articular chondrocalcinosis in elderly subjects in a rural area of Catalonia

The occurrence of rheumatic disorders did not differ significantly between subjects with articular chondrocalcinosis and those without. CONCLUSIONS--Articular chondrocalcinosis is an age related disorder, which could partly explain the discrepancies in its prevalence reported in previous studies. In most subjects with articular chondrocalcinosis recruited from an unselected population the clinical manifestations are probably mild or even absent.

Staphylococcus aureus host range and human-bovine host shift.

Staphylococcus aureus is a major agent of bovine mastitis. The concomitant emergence of pig-associated methicillin-resistant S. aureus (MRSA) in human carriage and infection requires a reexamination of the host range and specificity of human- and cow-associated S. aureus strains, something which has not been systematically studied previously. The genetic relatedness of 500 S. aureus isolates from bovine mastitis cases, 57 isolates from nasal carriage of farmers, and 133 isolates from nonfarmers was determined by amplified fragment length polymorphism (AFLP) analysis and spa typing. Multilocus sequence typing (MLST) was conducted on a subset of isolates to match AFLP clusters with MLST clonal complexes (CCs). This data set allowed us to study host range and host specificity and to estimate the extent of bovine-to-human transmission. The genotype compositions of S. aureus isolates from farmers and nonfarmers were very similar, while the mastitis isolates were quite distinct. Overall, transmission was low, but specific genotypes did show increased cow-to-human transmission. Unexpectedly, more than one-third of mastitis isolates belonged to CC8, a lineage which has not been considered to be bovine mastitis associated, but it is well known from human carriage and infection (i.e., USA300). Despite the fact that we did detect some transmission of other genotypes from cows to farmers, no transmission of CC8 isolates to farmers was detected, except for one tentative case. This was despite the close genetic relatedness of mastitis CC8 strains to nonfarmer carriage strains. These results suggest that the emergence of the new bovine-adapted genotype was due to a recent host shift from humans to cows concurrent with a loss of the ability to colonize humans. More broadly, our results indicate that host specificity is a lineage-specific trait that can rapidly evolve.

Dopamine receptors on dispersed bovine anterior pituitary cells

The dopamine antagonist [3H]-domperidone-[3H]-DOM-bound to a single class of high-affinity (Kd = 1.24 +/- 0.14 nM) and saturable receptors on dispersed bovine anterior pituitary (AP) cells. The binding of [3H]-DOM was stereoselective and reversible with agonists and antagonists. Dopamine competitions for [3H]-DOM binding modeled best for a single site consistent with an interaction with a homogeneous population of receptors. The mean number of specific binding sites labeled by [3H]-DOM was 53,000 per cell in dispersed AP cells consisting of 42% lactotrophs. Dispersed bovine AP cells attached to extracellular matrix within 3 h, and prolactin secretion from these cells was effectively inhibited by dopamine. Several observations suggested that [3H]-DOM-labeled receptors on dispersed bovine AP cells were restricted to the outer plasma membrane and not internalized. These included (1) the rapid and complete dissociation of specific [3H]-DOM binding; (2) the ability of treatment with acid or proteolytic enzymes to entirely remove specifically bound [3H]-DOM, and (3) the lack of effect of metabolic inhibitors on specific [3H]-DOM binding.

IgA with "secretory piece" in bovine colostrum and saliva.

We have shown that in bovine colostrum and saliva there is a secretory IgA with a sedimentation, coefficient of 11S and a secretory piece, previously unknown and comparable with the 11S IgA described in human and rabbit external secretions. These secretory IgA contain molecules of 7S IgA with an additional protein segment called the transport or secretory piece1-5. Furthermore, the free form of the secretory piece is identified in bovine colostrum and also in mature milk which contains very little IgA.

In vitro combination of human and bovine free secretory component with IgA of various species.

The free form of the secretory component usually associated with secretory IgA can be isolated from human and bovine milk. These free secretory components of different origin combine in vitro with human polymeric myeloma IgA, with mouse myeloma IgA, and with the serum IgA of nine different mammalian species.

BMP-2 and TGF-beta1 differentially control expression of type II procollagen and alpha 10 and alpha 11 integrins in mouse chondrocytes.

Bone morphogenetic protein (BMP)-2 and transforming growth factor (TGF)-beta1 are multifunctional cytokines both proposed as stimulants for cartilage repair. Thus it is crucial to closely examine and compare their effects on the expression of key markers of the chondrocyte phenotype, at the gene and protein level. In this study, the expression of alpha 10 and alpha 11 integrin subunits and the IIA/IIB spliced forms of type II procollagen have been monitored for the first time in parallel in the same in vitro model of mouse chondrocyte dedifferentiation/redifferentiation. We demonstrated that TGF-beta1 stimulates the expression of the non-chondrogenic form of type II procollagen, IIA isoform, and of a marker of mesenchymal tissues, i.e. the alpha 11 integrin subunit. On the contrary, BMP-2 stimulates the cartilage-specific form of type II procollagen, IIB isoform, and a specific marker of chondrocytes, i.e. the alpha 10 integrin subunit. Collectively, our results demonstrate that BMP-2 has a better capability than TGF-beta1 to stimulate chondrocyte redifferentiation and reveal that the relative expressions of type IIB to type IIA procollagens and alpha 10 to alpha 11 integrin subunits are good markers to define the differentiation state of chondrocytes. In addition, adenoviral expression of Smad6, an inhibitor of BMP canonical Smad signaling, did not affect expression of total type II procollagen or the ratio of type IIA and type IIB isoforms in mouse chondrocytes exposed to BMP-2. This result strongly suggests that signaling pathways other than Smad proteins are involved in the effect of BMP-2 on type II procollagen expression.

Human-to-bovine jump of Staphylococcus aureus CC8 is associated with the loss of a β-hemolysin converting prophage and the acquisition of a new staphylococcal cassette chromosome.

Staphylococcus aureus can colonize and infect both humans and animals, but isolates from both hosts tend to belong to different lineages. Our recent finding of bovine-adapted S. aureus showing close genetic relationship to the human S. aureus clonal complex 8 (CC8) allowed us to examine the genetic basis of host adaptation in this particular CC. Using total chromosome microarrays, we compared the genetic makeup of 14 CC8 isolates obtained from cows suffering subclinical mastitis, with nine CC8 isolates from colonized or infected human patients, and nine S. aureus isolates belonging to typical bovine CCs. CC8 isolates were found to segregate in a unique group, different from the typical bovine CCs. Within this CC8 group, human and bovine isolates further segregated into three subgroups, among which two contained a mix of human and bovine isolates, and one contained only bovine isolates. This distribution into specific clusters and subclusters reflected major differences in the S. aureus content of mobile genetic elements (MGEs). Indeed, while the mixed human-bovine clusters carried commonly human-associated β-hemolysin converting prophages, the bovine-only isolates were devoid of such prophages but harbored an additional new non-mec staphylococcal cassette chromosome (SCC) unique to bovine CC8 isolates. This composite cassette carried a gene coding for a new LPXTG-surface protein sharing homologies with a protein found in the environmental bacterium Geobacillus thermoglucosidans. Thus, in contrast to human CC8 isolates, the bovine-only CC8 group was associated with the combined loss of β-hemolysin converting prophages and gain of a new SCC probably acquired in the animal environment. Remaining questions are whether the new LPXTG-protein plays a role in bovine colonization or infection, and whether the new SCC could further acquire antibiotic-resistance genes and carry them back to human.

Genetic diversity and population structure of Brazilian native bovine breeds

Conservation and improvement strategies should be based on the association between genetic and phenotypic characteristics. The objective of this work was to characterize five native Brazilian cattle breeds (Caracu, Crioulo Lageano, Curraleiro, National Polled and Pantaneiro) and two commercial breeds (Holstein and Nellore) using RAPD technique to estimate genetic distances and variability between and within breeds. Genetic relationships were investigated using 22 primers which generated 122 polymorphic bands. Analysis of molecular variance indicated that most of the genetic variation lay among individuals within populations. The genetic variabilities between pairs of breeds were statistically significant. The smallest genetic divergence was between Crioulo Lageano and Curraleiro.The National Polled, although historically considered to be of Bos taurus aquitanicus origin,similar to theCaracu, was grouped together with the other breeds of Bos taurus ibericus origin. Generally, the individual breeds formed distinct clusters except the National Polled. The RAPD technique was capable to distinguish genetically between the breeds studied; the Caracu, Crioulo Lageano, Curraleiro and Pantaneiro may be considered distinct genetic entities thereby proving the uniqueness of the populations; the National Polled has not been able to re-establish itself after its decline in the 1950s, thereby losing its genetic identity.

Secretory IgA, a major immunoglobulin in most bovine external secretions.

Bovine secretory IgA (SIgA), recently identified in colostrum, was shown to be homologous to human SIgA by immunologic cross-reaction. A quantitative study indicated that bovine SIgA, a minor component of colostrum, is a major immunoglobulin in most other external secretions including saliva, spermatic fluid, lacrimal, nasal and gastrointestinal secretions. SIgA was isolated from saliva. The free form of secretory component was found to be abundant in milk. A normal lactating cow produces about 1.2 g of this protein per day. Two forms of IgA were identified in serum: a normal serum IgA with no secretory antigenic determinant, and a small amount of SIgA. In vitro synthesis of SIgA by the salivary gland was studied by tissue cultures with incorporation of labeled amino acids.

Alternative genotyping method for the single nucleotide polymorphism A2959G (AF159246) of the bovine CAST gene

The objective of this work was to genotype the single nucleotide polymorphism (SNP) A2959G (AF159246) of bovine CAST gene by PCR-RFLP technique, and to report its use for the first time. For this, 147 Bos indicus and Bos taurus x Bos indicus animals were genotyped. The accuracy of the method was confirmed through the direct sequencing of PCR products of nine individuals. The lowest frequency of the meat tenderness favorable allele (A) in Bos indicus was confirmed. The use of PCR-RFLP for the genotyping of the bovine CAST gene SNP was shown to be robust and inexpensive, which will greatly facilitate its analysis by laboratories with basic structure.