Mastitis is still considered to be the most economically important infectious disease in dairy cattle breeding. The immune response in mammary gland tissues could help in developing support strategies to combat this disease. The role of neutrophils and macrophages in the innate response of mammary gland is well known. However, the immune response in mammary gland tissues, including levels of antimicrobial peptide transcripts, has not been well recognized. Moreover, most studies are conducted in vitro, on cell cultures, or on artificially infected animals, with analysis being done within a several dozen hours after infection. The aim of the study was to examine the in vivo transcript levels of beta-defensin and cathelicidins genes in cow mammary gland secretory tissue (parenchyma) with the chronic, recurrent and incurable mammary gland inflammation induced by coagulase-positive or coagulase-negative Staphyloccoci vs. bacteria-free tissue. The mRNA of DEFB1, BNBD4, BNBD5, BNBD10 and LAP genes, but not of TAP gene, were detected in all investigated samples regardless of the animals’ age and microbiological status of the mammary gland, but at different levels. The expression of most of the beta-defensin genes was shown to be much higher in tissues derived from udders infected with bacteria (CoPS or CoNS) than from bacteria-free udders, regardless of parity. Cathelicidins (CATH4, CATH5 and CATH6) showed expression patterns contrasting those of β-defensins, with the highest expression in tissues derived from bacteria-free udders. Increased expression of genes encoding β-defensins in the infected udder confirms their crucial role in the defense of the cow mammary gland against mastitis. On the other hand, the elevated cathelicidin transcripts in non-infected tissues indicate their role in the maintenance of healthy mammary tissues. The expression levels of investigated genes are likely to depend on the duration of the infection and type of bacteria.

/pdf/expression-patterns-of-b-defensin-and-cathelicidin-genes-in-25l2078axo.pdf

Expression patterns of β-defensin and cathelicidin genes in parenchyma of bovine mammary gland infected with coagulase-positive or coagulase-negative Staphylococci

Due to their activity against bacteria, viruses, and fungi, antimicrobial peptides are important factors in the innate resistance system of humans and animals. They are called "new generation antibiotics" for their potential use in preventive and therapeutic medicine. The most numerous group of antimicrobial peptides is a family of cationic peptides which include defensins and cathelicidins. Among them the most common are peptides with a beta-sheet structure containing three intra-molecular disulphide bonds, called defensins, comprising three classes: alpha, beta, and theta. The class of beta-defensins is the largest one. Their transcripts have been found in many tissues of humans and animals. The aim of this paper is to present the current knowledge about antimicrobial peptides from the defensin family in farm animals, their expression, polymorphism, as well as the potential of their use as genetic markers of health and production traits.

/pdf/expression-and-polymorphism-of-defensins-in-farm-animals-543gdw0k11.pdf

Expression and polymorphism of defensins in farm animals.

Bovine neutrophils have similarities to those of other species with respect to mechanisms of their activation and migration into tissue, modulation of immune responses and the balance between microbial killing and host tissue damage. However, bovine neutrophils have biochemical and functional differences from those of other species, which may yield insights about the comparative biology of neutrophils. Neutrophils play protective and harmful roles in the infectious diseases of cattle that occur at times of transition: respiratory disease in beef calves recently arrived to feedlots and mastitis and other diseases of postparturient dairy cows. An important research focus is the mechanisms by which risk factors for these diseases affect neutrophil function and thereby lead to disease and the prospect of genetic or pharmacologic improvement of disease resistance. Further, in keeping with the One Health paradigm, cattle can be considered a model for studying the role of neutrophils in naturally occurring diseases caused by host-adapted pathogens and are thus an intermediary between studies of mouse models and investigations of human disease. Finally, the study of bovine neutrophils is important for agriculture, to understand the pathogenesis of these production-limiting diseases and to develop novel methods of disease prevention that improve animal health and reduce the reliance on antimicrobial use.

Bovine neutrophils in health and disease.

Genome-wide gene expression profiling allows for identification of genes involved in the defense response of the host against pathogens. As presented here, transcriptomic analysis and bioinformatics tools were applied in order to identify genes expressed in the mammary gland parenchyma of cows naturally infected with coagulase-positive and coagulase-negative Staphylococci. In cows infected with coagulase-positive Staphylococci, being in 1st or 2nd lactation, 1700 differentially expressed genes (DEGs) were identified. However, examination of the 3rd or 4th lactations revealed 2200 DEGs. Gene ontology functional classification showed the molecular functions of the DEGs overrepresented the activity of cytokines, chemokines, and their receptors. In cows infected with coagulase-negative Staphylococci, in the 1st or 2nd lactations 418 DEGs, while in the 3rd or 4th lactations, 1200 DEGs were identified that involved in molecular functions such as protein, calcium ion and lipid binding, chemokine activity, and protein homodimerization. Gene network analysis showed DEGs associated with inflammation, cell migration, and immune response to infection, development of cells and tissues, and humoral responses to infections caused by both types of Staphylococci. A coagulase-positive Staphylococci infection caused a markedly stronger host response than that of coagulase-negative, resulting in vastly increased DEGs. A significant increase in the expression of the FOS, TNF, and genes encoding the major histocompatibility complex proteins (MHC) was observed. It suggests these genes play a key role in the synchronization of the immune response of the cow’s parenchyma against mastitis-causing bacteria. Moreover, the following genes that belong to several physiological pathways (KEGG pathways) were selected for further studies as candidate genes of mammary gland immune response for use in Marker Assisted Selection (MAS): chemokine signaling pathway (CCL2, CXCL5, HCK, CCR1), cell adhesion molecules (CAMs) pathway (BOLA-DQA2, BOLA-DQA1, F11R, ITGAL, CD86), antigen processing and presentation pathway (CD8A, PDIA3, LGMN, IFI30, HSPA1A), and NOD-like receptor signaling pathway (TNF, IL8, IL18, NFKBIA).

/pdf/transcriptome-profiling-of-staphylococci-infected-cow-bzge3jopf7.pdf

Transcriptome profiling of Staphylococci-infected cow mammary gland parenchyma

mastitis is one of the most important mammary gland diseases impacting lactating animals. re- sistance to this disease could be improved by breeding. there are several selection methods for mastitis resistance. t o improve the natural genetic resistance of cows in succeeding generations, current breeding programmes use somatic cell count and clinical mastitis cases as resistance traits. However, these methods of selection have met with limited success. this is partly due to the com- plex nature of the disease. the limited progress in improving udder health by conventional selec- tion procedures requires applying information on molecular markers of mastitis susceptibility in marker-assisted selection schemes. mastitis is under polygenic control, so there are many genes that control this trait in many loci. This review briefly describes genome-wide association studies which have been carried out to identify quantitative trait loci associated with mastitis resistance in dairy cattle worldwide. it also characterizes the candidate gene approach focus on identifying genes that are strong candidates for the mastitis resistance trait. in the conclusion of the paper we focus our attention on future research which should be conducted in the field of the resistance to mastitis.

/pdf/genetic-basis-of-mastitis-resistance-in-dairy-cattle-a-5ed8o3bgt1.pdf

Genetic Basis of Mastitis Resistance in Dairy Cattle – A Review / Podstawy Genetyczne Odporności Krów Mlecznych Na Zapalenie Wymienia – Artykuł Przeglądowy

Lactoferrin is an iron-binding protein present in many mammalian biological fluids, such as tears, saliva and milk, widely investigated due to its multiple activities. Human milk contains 1 to 5 mg of lactoferrin /ml, contrary to bovine milk, where lactoferrin concentration reaches maximum level of 0.1 mg/ml. Dramatic increase of lactoferrin content has been noticed in colostrum, mammary gland secretion during involution, and in milk yielded by females suffering from udder inflammation. Lactoferrin gene has developed during evolutional mutations in transferrin gene. It was mapped to bovine chromosome 22, contains 17 exons and spreads out on about 34.5 kilo base pairs (kbp) of genomic DNA. There are many polymorphisms in lactoferrin gene. Polymorphisms occurring in gene regulatory region seem to be particularly interesting, as they may affect a gene expression. It has been claimed, that lactoferrin gene expression in mouse and human uterus appeared under estrogen stimulation, but for bovine species the regulation of its expression has not been fully understood yet. Another possibility to find functional polymorphisms is to search for them in exons which code for lactoferrin antimicrobial peptides. Due to its relation to the innate immunity, lactoferrin gene is supposed to be a promising candidate gene for mastitis resistance trait.

Bovine lactoferrin gene polymorphism and expression in relation to mastitis resistance - a review

The innate immune response plays an important role in the course of bacterial infections. Innate immunity effectiveness relies on the expression of many genes, connected, among others, to the activity of neutrophils. Interleukin 8 (IL-8) receptor α, coded by the CXCR1 gene, is present on the neutrophil surface and binds pro-inflammatory IL-8 with high affinity. This is why the bovine CXCR1 gene carries a potential for use as a dairy cattle mastitis marker. To date, several studies on the CXCR1 polymorphism brought out contradictory results. The aim of this study was to analyse the association between two SNPs of the CXCR1 gene, which is potentially important for the protein function and animal phenotype for mastitis susceptibility. A total of 554 Polish Holsteins were genotyped, and 140 among them were bacteriologically tested. The differences between animals carrying different genotypes and haplotypes of CXCR1 in test day somatic cell count (SCC) and Staphylococcus aureus mastitis susceptibility were estimated. We found that test day SCC was significantly related to CXCR1+472 SNP but not to CXCR1+735 SNP. No statistically significant association between CXCR1 polymorphism and susceptibility to S. aureus mastitis was found in the studied herd.

https://www.termedia.pl/Journal/-10/pdf-25451-10?filename=Association between.pdf

Association between interleukin 8 receptor α gene (CXCR1) and mastitis in dairy cattle.

Staphylococci are the main aetiological factor of bovine mastitis in many dairy herds. Traditionally, coagulase-negative staphylococci (CNS) were considered a normal skin microbiota. Lately the role of CNS in bovine mastitis has increased, as in some countries these pathogens had started to outnumber other mastitis aetiological factors. Given the scale of mastitis problems, the intensive use of antibiotics in dairy cattle, the number of animals and the consumption of milk products there is an urgent need to highlight the threat to both human and animal health originating from CNS. The knowledge of how CNS mastitis develops, spreads in herd and persists is limited. Bovine strains of CNS are poorly characterised; moreover, they are characterised mainly in terms of phenotypes. This review summarises knowledge on the characterisation of CNS strains, stressing the role of the bacterial genotype, in the context of the risk to human and animal health. Selected CNS virulence factors that play a role during mastitis in dairy cattle are listed and described in this paper. They have been selected subjectively by the authors in view of their significance for public health (toxins, antimicrobial resistance) and their importance for animal health (formation of biofilm, prevention of phagocytosis intracellular survival) and mastitis outcome.

Current concepts on the impact of coagulase-negative staphylococci causing bovine mastitis as a threat to human and animal health - a review

Lactoferrin gene (LF) is regarded as one of the potential markers of mastitis susceptibility/resistance in dairy cattle The study’s aim was therefore, to investigate the feasibility of two single nucleotide polymorphisms (SNP), placed in the 5′-flanking region and 3′-untranslated region of the LF gene, to serve as mastitis markers The associations between these SNP and the expression of LF, both on mRNA and protein level, were estimated in the milk of Polish Holstein-Friesian cows The relationships between polymorphisms and cows’ estimated breeding values (EBV) for somatic cell count were also calculated It was shown that both polymorphisms have a significant impact on lactoferrin content in milk, and that LF+32 SNP is associated with the cow’s EBV for somatic cell count No association between SNP chosen for the study and lactoferrin mRNA abundance in milk somatic cells was observed We propose LF+32 SNP for a molecular marker of mastitis resistance in dairy cows

Adrianna Pawlik

Papers

Genetic Basis of Mastitis Resistance in Dairy Cattle – A Review / Podstawy Genetyczne Odporności Krów Mlecznych Na Zapalenie Wymienia – Artykuł Przeglądowy

Bovine lactoferrin gene polymorphism and expression in relation to mastitis resistance - a review

Association between interleukin 8 receptor α gene (CXCR1) and mastitis in dairy cattle.

Current concepts on the impact of coagulase-negative staphylococci causing bovine mastitis as a threat to human and animal health - a review

Lactoferrin gene variants, their expression in the udder and mastitis susceptibility in dairy cattle