Association of the M blood group system with bovine mastitis

Associations of the 11 bovine blood group systems with mastitis were examined in Red Danish dairy cattle. The mastitis status was followed during three lactational periods. A significant effect of the M blood group system on mastitis incidence was observed in the first and second lactation periods and a lower frequency of mastitis is found among animals lacking the M' factor as compared to those having the M' blood group factor. The significance of these results are discussed in view of the close relation between the M blood group system and the bovine lymphocyte antigens (BoLA), and the expected effect of eliminating the M' gene from the breed is estimated. Among the remaining 10 blood group systems, the T' system was the only system showing an overall effect on mastitis, and only in first and third lactation. However, the T' system was inconsistent with regard to the effect of the T' gene on the various mastitis diagnoses.     

Quantification of antigens with haemolysing antibodies exemplified by the bovine J blood group system*

• 1 The J blood group activity of red cells is measured in terms of 50 % haemolysis (‘direct test’), that of dissolved or suspended samples in terms of 50 % haemolysis inhibition (‘indirect test’) in a standardized bovine J system.
• 2 The volume of J-containing sample required for a 50% haemolysis inhibition decreases with increasing J activity.
• 3 The volume of anti-J required for a 50% haemolysis of J-positive erythrocytes also decreases with increasing J activity.
• 4 The use of antigen units (U_Ag) was introduced to serve as a measure of J activity of dissolved or suspended samples.
• 5 Antigen units were also used to characterize J-containing red cells. This was made possible by measuring the relation of the direct test (on red cells). Thus, a relatively simple method of determination of red cell U_Ag is obtained.
• 6 It was confirmed by absorption experiments that erythrocytes containing high concentrations of antigen require relatively low amounts of antibody to bring about a 50 % haemolysis, but are able to bind a relatively high excess of antibody.

     

Serological relationships among antigens of the BoLA and the bovine M blood group systems

Alloimmunizations with either lymphocytes or red cells from donor cows positive for BoLA w16 and blood group M' antigens into recipients negative for these antigens produced antisera reactive in the cytotoxic test with w16-positive lymphocytes and in the haemolytic test with M'-positive erythrocytes. Similarly, alloimmunizations of blood group M1-negative recipients with either lymphocytes or red cells from donor cows possessing the M1 blood group factor produced antisera specifically reactive with lymphocytes and erythrocytes from M1-positive cattle. Absorptions with either lymphocytes or erythrocytes from individual animals of the same M antigenic type as the donor removed all haemolytic and cytotoxic reactivity. The results indicate that blood group M' and BoLA w16 share a similar antigenic structure. Likewise, blood group M1 has an antigenically similar counterpart which is also part of the BoLA system.     

Structural studies of the M blood group determinant

Structural studies of homozygous glycophorin A^M were undertaken by monitoring the ¹³C methyl resonances of ¹³C reductively methylated glycophorin A^M (contains five $\text{N}{}^{\mathrm{?}}\text{,N-[}{}^{13}\text{C}\text{]}\text{dimethyl}$ Lys residues, and the N-terminal $\text{N}{}^{\mathrm{\alpha }}\text{,N-[}{}^{13}\text{C]}\text{dimethyl}$ Ser residues) in various forms of glycosylation. The results indicate that removal of the α-d-NeuAc residues does not affect the structure about the N-terminal Ser residue. However, removal of the fifteen O-linked oligosaccharide units results in a structural effect about the N-terminal Ser residue. Partial methylation experiments performed on native glycophorin A^M and deglycosylated glycophorin A^M indicate that methylation of the lysine residue(s) may influence the structure about the N-terminal Ser residue, especially in the case of deglycosylated A^M.     

On the bovine F blood group system

The F system of three Danish cattle breeds as determined by four specific anti-sera is described. In the Jersey breed three alleles are recognised. In the Danish cattle breeds there was no indication of a null allele. However, the phenotypes observed in zebu cattle by means of four reagents suggest the presence of at least six alleles in the bovine F system. Furthermore, the data show that the factors V₁ and V₂ do not form a linear subtype system in all cattle breeds.     

Mm, a new factor in the porcine M blood group system

By means of a new antiserum, Mm, the Mae phenotype can be shown to be controlled by the Maem allele, the Mef phenotype by either the original Mef or a new Mefm allele, and the Mbe(f) phenotype by the Mbe(f)m allele. The complexity of the porcine M system is now extended to 13 internationally recognized blood group factors controlled by at least 19 alleles.     

Confirmation of the F2 allele in the bovine F blood group system

Serological evidence is presented to prove the presence of an F₂ allele in the F system of British Friesian cattle.     

Mapping of the bovine blood group systems J,N', R', and Z show evidence for oligo-genetic inheritance

Genes determining the bovine erythrocyte antigens were mapped by linkage analysis. In total 9591 genotypes of 20 grandsire families with 1074 sires from a grand-daughter design were elucidated for the genes determining the erythrocyte antigens EAA, EAB, EAC, EAF, EAJ, EAL, EAM, EAN', EAR', EAS, EAT', and EAZ according to standard paternity testing procedures in the blood typing laboratories. Linkage analyses were performed with 248 microsatellite markers, eight SSCP markers and four polymorphic proteins and enzymes covering the 29 autosomes and the pseudoautosomal region of the sex chromosomes. The number of informative meioses for the blood group systems ranged from 76 to 947. Blood group systems EAM and EAT' were non-informative. Most of the erythrocyte antigen loci showed significant linkage to a single chromosome and were mapped unequivocally. The genes determining erythrocyte antigen EAA, EAB, EAC, EAL, and EAS were mapped to chromosomes 15, 12, 18, 3, and 21, respectively. Lod-score values ranged from 11.43 to 107.83. Moreover, the EAF system could be mapped to chromosome 17. However, the EAN' system previously known as part of the EAF system could be mapped to chromosome 5. In addition, the blood group systems EAJ, the new EAN', EAR', and EAZ, showed significant linkage to microsatellite markers on various chromosomes and also to other blood groups. The appearance of a single blood group system might be therefore either dependent on the existence of other blood group systems or because of an interaction between different loci on various chromosomes as is known in humans and in pigs.     

Isolation and characterization of glycosphingolipids with J blood group activity from bovine spleen1,2

Two glycosphingolipids with J blood group activity were found in J-positive bovine spleen. They were tentatively identified as ceramide deca- and dodecahexosides containing galactose, glucose, N -acetylgalactosamine and N -acetylglucosamine in a molar ratio of 5:3:1:1 and 6:3:2:1, respectively. Fucose was not present. Ceramide decahexosides without J activity were also found in J-negative bovine spleen. The principal component fatty acids of the J-active glycosphingolipids were saturated even-numbered long-chain acids with 16 to 24 C atoms. Their principal long-chain bases were sphingosine and dihydrosphingosine with smaller amounts of phy-tosphingosine.
Both J-active glycosphingolipids were readily water-soluble and showed strong activity in the bovine J and in the porcine A blood group system. They exhibited no cross-reactivity in the human A system. However, a J-negatiye glycosphingolipid fraction - also from J-negative spleen - with shorter carbohydrate chain-length showed strong activity in the human A system.     

Multiplex PCR assay for species identification of bovine mastitis pathogens

Aim: To develop and evaluate a multiplex PCR (mPCR) assay for simultaneous detection of 10 bacterial species causing bovine mastitis namely, Staphylococcus aureus, Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus sciuri, Staphylococcus haemolyticus, Staphylococcus simulans, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis and Escherichia coli in milk. Methods and Results: A two‐tube mPCR assay was developed. The accuracy of the mPCR was evaluated using 56 standard reference strains and 705 strains comprising of E. coli (n = 99), staphylococci (n = 522) and streptococci (n = 84). The threshold of detection of the mPCR assay was 10 fg of genomic DNA and <10³ CFU ml^?1. A comparative evaluation of mPCR with culture method using 115 milk samples from subclinical mastitis showed mPCR to be more efficacious. Subsequently, the mPCR showed successful detection of target bacteria, when applied directly for the assessment of 36 bulk milk samples. Conclusion: The developed mPCR assay was found to be simple, rapid, reliable and specific in species identification of 10 bacteria at a time. Significance and Impact of the Study: The assay will be useful for the detection of mastitis, testing bacteriological safety of milk and for species level differentiation. The assay will be of value in the dairy sector for diagnosis and research. The early and accurate identification of pathogens will enable timely interventions for the treatment and control of bovine mastitis.     

Staphylococcus aureus persistence properties associated with bovine mastitis and alternative therapeutic modalities

Staphylococcus aureus is an important agent of contagious bovine intramammary infections in dairy cattle. Its ability to persist inside the udder is based on the presence of important mechanisms such as its ability to form biofilms, polysaccharide capsules small colony variants, and their ability to invade professional and nonprofessional cells, which will protect S. aureus from the innate and adaptive immune response of the cow, and from antibiotics that are no longer considered to be sufficient against S. aureus bovine mastitis. In this review, we present the recent research outlining S. aureus persistence properties inside the mammary gland, including its regulation mechanisms, and we highlight alternative therapeutic strategies that were tested against S. aureus isolated from bovine mastitis such as the use of probiotic bacteria, bacteriocins and bacteriophages. Overall, the persistence of S. aureus inside the mammary gland remains a pressing veterinary problem. A thorough understanding of staphylococcal persistence mechanisms will elucidate novel ways that can help in the identification of novel treatments.     

The AB blood group system of cats

Holmes (1950) and Eyquem. Podliachouk & Milot (1962) classified feline erythrocytes into two types according to their reactions with naturally occurring antibodies in cats' plasmas. Eyquem et al. (1962) designated the two antigens, A and B. and this nomenclature has been retained in the present study. The blood group system. AB. was investigated in more detail, both genetically and serologically. Frequencies of 73.3 % A and 26.3 % B were found in a survey of 1895 Brisbane cats and in addition, a new phenotype. AB. was discovered with a low incidence of 0.4 %.The results of the serological testing and limited family information suggested that the AB phenotype is inherited and not due to blood chimaerism. Preliminary genetic studies indicated that the A gene is dominant to the B in the usual situation and hypotheses to explain the occurrence of the AB phenotype are discussed.
The incidence of naturally occurring antibodies was investigated in cats, with 1895 of blood type B having anti-A and only 35 % of type A having anti-B. No subgroups of the A and B antigens were detected and no blood group substances were found in the salivas of 37 cats. There was no evidence of any serological relationship of the feline A and B antigens with the human ABO antigens.     

Investigation of the lytic ability of South African bacteriophages specific for Staphylococcus aureus,associated with bovine mastitis

Bovine mastitis is an infectious disease of the mammary glands of dairy cattle primarily causaled by the bacterium, Staphylococcus aureus subsp. aureus Rosenbach1884. Traditional control of this organism was through the use of antibiotics. However, S. aureus is developing resistance towards these chemotherapeutic agents faster than they are being developed. Bacteriophages can serve as an alternative control measure for the disease. This study investigated the prevalence of phages and S. aureus within the South African dairy environment, as well as infectivity of phage isolates against antibiotic-resistant S. aureus. The four S. aureus strains used in the study displayed resistance to representative antibiotics from both the β-lactamases and non-β-lactamases, macrolides, aminoglycosides and glycopeptides. Susceptibility was only noted towards the tetracycline antibiotics. Twenty-eight phages were isolated and screened against four strains of S. aureus. Only six phages showed biocontrol potential based on their wide host range, high titres and common growth requirements. Morphological and preliminary genomic analysis was carried out on the three best performing phages. At an optimal titre of between 6.2 × 10⁷ and 2.9 × 10⁸ pfu.ml^?1, the phages were able to reduce live bacterial cell counts between 64% and 95%. In addition, these six phages showed further infectivity towards S. aureus strains that were isolated from different milk-producing regions during a farm survey. The phages isolated in this study show reasonable potential for in vivo applications.     

The inactivation of the bovine J blood group substance by the periodate ion

• 1 Treatment of J-positive (JR) bovine erythrocytes with periodate (0.25 mmol/1 final concentration, 1 hour, room temperature) has no effect on the J activity. Higher periodate concentrations cause spontaneous haemolyses.
• 2 Treatment of the lipids extracted from (and containing all J activity of) J^cs erythrocytes with periodate leads to a decrease of J activity even with lower periodate concentrations.
• 3 Treatment of the stroma prepared from J^cs erythrocytes with periodate demonstrated the relative stability of the J antigen up to 0.25 mmol/l periodate. At the same time the sialic acid concentration of stroma is reduced to about 13 % of the initial concentration.
• 4 Desialylation of J^cs erythrocytes or J^cs stroma with sialidase does not affect the J activity thus confirming previous findings. On the other hand, the J activity of desialylated J^cs stroma is much more susceptible to periodate.
• 5 It is concluded that membrane-bound sialic acid shields the membrane-bound J antigen from being attacked by periodate.

     

Isolation of Prothoteca zopfii from a case of bovine mastitis in Brazil

The isolation of Prothoteca zopfii, an algae lacking chlorophyll, from bovine mastitic milk, is described herein. The isolation was performed on 8% sheep blood agar, following incubation at 37 °C for 48 h. Based on biochemical tests, susceptibility to clotrimazole, and light and electron microscopic observation of cellular morphology the algae was identified as P. zopfii . The affected animal did not improve following treatment and had to be eliminated. This revised version was published online in June 2006 with corrections to the Cover Date.     

Expansion of the canine A blood group system

A detailed study of the canine A blood group system was undertaken, resulting in the expansion of this system into a three-factor, four-allelic one with the recognition of an additional subtype, a3. The serological and extensive family data supported the proposed genetic theory of four alleles with dominance with the order being Aa1, Aa2, Aa3 and A-. Gene frequencies of the alleles were determined in various breeds of dogs with frequencies in the general Brisbane population being 0.244 (Aa1), 0.042 (Aa2), 0.045 (Aa3) and 0.669 (A-).