scholarly journals Directed Expression of Tracheal Antimicrobial Peptide as a Treatment for Bovine-Associated Staphylococcus Aureus-Induced Mastitis in Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhipeng Zhang ◽  
Daijie Chen ◽  
Xubin Lu ◽  
Ruifeng Zhao ◽  
Zhi Chen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mammary Gland ◽  
Antimicrobial Peptide ◽  
Expression Vector ◽  
Bovine Mastitis ◽  
Specific Expression ◽  
Mammary Gland Tissue ◽  
Gland Tissue

Bovine mastitis is perplexing the dairy industry since the initiation of intensive dairy farming, which has caused a reduction in the productivity of cows and an escalation in costs. The use of antibiotics causes a series of problems, especially the formation of bacterial antimicrobial resistance. However, there are limited antibiotic-free therapeutic strategies that can effectively relieve bacterial infection of bovine mammary glands. Hence, in this study, we constructed a mammary gland tissue-specific expression vector carrying the antimicrobial peptide of bovine-derived tracheal antimicrobial peptide (TAP) and evaluated it in both primary bovine mammary epithelial cells (pBMECs) and mice. The results showed that the vector driven by the β-lactoglobulin gene (BLG) promoter could efficiently direct the expression of TAP in pBMECs and the mammary gland tissue of mice. In addition, significant antibacterial effects were observed in both in vitro and in vivo experiments when introducing this vector to bovine-associated Staphylococcus aureus-treated pBMECs and mice, respectively. This study demonstrated that the mammary gland tissue-specific expression vector could be used to introduce antimicrobial peptide both in in vitro and in vivo and will provide a new therapeutic strategy in the treatment of bovine mastitis.

Expression and characterization of a lysine rich protein in cow milk

2018 ◽  
Author(s):  
Xin Ma ◽  
Li Su ◽  
Peng Zhang ◽  
Sheng Zhang ◽  
Bo Tang ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Amino Acid ◽  
Expression Vector ◽  
Cow Milk ◽  
Specific Expression ◽  
Mammary Gland Tissue ◽  
Gland Tissue ◽  
Negative Controls ◽  
Mammary Gland Expression

The lysine is considered as the most important essential amino acid, because it is the most limiting in the cereals grains. In this study, a lysine-rich (LR) gene, and the expression vector pcDNA3.1-LR and pBC1-LR were constructed. The LR was expressed in 293T cells driven by the vector pcDNA3.1-LR and checked by RT-PCR and WB. The mammary gland tissue-specific expression vector carrying the LR was injected directly into the lactating mammary glands of cows and the milk samples were checked by a complete amino acid analysis. The results showed that the LR protein was expressed successfully in cells and in cow milk; the expression of LR lasted for 6 d, and the lysine level of the injection group was significantly higher than that of negative controls (p Lass Than 0.05). This study provide a better understanding of how mammary gland expression systems increase the lysine content of milk that can be applied to transgenic dairy cow.

scholarly journals Efficacy of Bacteriophages Against Staphylococcus aureus Isolates from Bovine Mastitis

2020 ◽  
Vol 13 (3) ◽  
pp. 35 ◽  
Author(s):  
Isabel Titze ◽  
Tatiana Lehnherr ◽  
Hansjörg Lehnherr ◽  
Volker Krömker
Keyword(s):  
Staphylococcus Aureus ◽  
Host Range ◽  
Bacterial Infections ◽  
Plaque Assay ◽  
Bovine Milk ◽  
Bovine Mastitis ◽  
Raw Milk ◽  
Pasteurized Milk

The lytic efficacy of bacteriophages against Staphylococcus aureus isolates from bovine milk was investigated in vitro, regarding possible applications in the therapy of udder inflammation caused by bacterial infections (mastitis). The host range of sequenced, lytic bacteriophages was determined against a collection of 92 Staphylococcus (S.) aureus isolates. The isolates originated from quarter foremilk samples of clinical and subclinical mastitis cases. A spot test and a subsequent plaque assay were used to determine the phage host range. According to their host range, propagation and storage properties, three phages, STA1.ST29, EB1.ST11, and EB1.ST27, were selected for preparing a bacteriophage mixture (1:1:1), which was examined for its lytic activity against S. aureus in pasteurized and raw milk. It was found that almost two thirds of the isolates could be lysed by at least one of the tested phages. The bacteriophage mixture was able to reduce the S. aureus germ density in pasteurized milk and its reduction ability was maintained in raw milk, with only a moderate decrease compared to the results in pasteurized milk. The significant reduction ability of the phage mixture in raw milk promotes further in vivo investigation.

scholarly journals Development of a heavy metal-inducible fish-specific expression vector for gene transfer in vitro and in vivo

Aquaculture ◽  
1993 ◽  
Vol 111 (1-4) ◽  
pp. 215-226 ◽  
Author(s):  
Yunhan Hong ◽  
Christoph Winkler ◽  
Gottfried Brem ◽  
Manfred Schartl
Keyword(s):  
Heavy Metal ◽  
Gene Transfer ◽  
Expression Vector ◽  
Specific Expression

Staphylococcus aureus leucocidin, a virulence factor in bovine mastitis

2005 ◽  
Vol 72 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Ahmed Younis ◽  
Oleg Krifucks ◽  
Gideon Fleminger ◽  
Elimelech D Heller ◽  
Natan Gollop ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mononuclear Cells ◽  
Gel Filtration ◽  
Bovine Mastitis ◽  
Culture Broth ◽  
Protein Sequencing ◽  
Staph Aureus ◽  
Proliferation Response

The involvement of Staphylococcus aureus exosecretions in bovine udder infection (Younis et al. 2003) suggests that four different monomer protein bands appearing between 36 and 31 kDa, are associated with the severity of the cow's infection response. Three out of these four bands have been identified by means of protein sequencing. Band B, with a MW of 35 kDa was identified as Panton-Valentaine leucocidin LukF'-PV chain- Staph. aureus; band C, with a MW of 32 kDa was identified as leucocidin chain LukM precursor- Staph. aureus; and band D was found to be similar, but not identical, to phosphatidylinositol-specific phospholipase-C-X. Bands B and C were purified by gel filtration using FPLC. The ability of these proteins to induce udder inflammation in vivo, and proliferation response in vitro and cytokine secretion were tested for both the crude exosecretions and purified bands. Three cows were inoculated intracisternally, with three quarters receiving either 0·007–0·008 mg (as total proteins) of Staph. aureus FR2449/1 bacterial exosecretion, pooled fraction 39–41 (bands B and C), or culture broth medium. The fourth quarter was left free as a control. Quarters that received fraction 39–41 of Staph. aureus FR2449/1, exhibited induced inflammation, which was indicated by increased somatic cell count and enhanced NAGase activity that was significantly higher than that of the original Staph. aureus FR2449/1 bacterial exosecretion. Proliferation tests of bovine blood lymphocytes in vitro showed that the pooled fraction 39–41 stimulated bovine proliferation of mononuclear cells much more than the original Staph. aureus FR2449/1 bacterial exosecretion. Secretion of TNF-α, IL-1β, IL-6 and IL-8 was in accordance with the contents of LukF'-PV and LukM precursor in the exosecretions. The results suggest that LukM/LukF' induce inflammation into the udder by a mechanism similar to that of LPS or by a unique mechanism(s) which requires further investigation.

Phagocytosis of Staphylococcus aureus by bovine mammary gland macrophages and intracellular protection from antibiotic action in vitro and in vivo

1984 ◽  
Vol 51 (4) ◽  
pp. 513-523 ◽  
Author(s):  
Neil Craven ◽  
James C. Anderson
Keyword(s):  
Staphylococcus Aureus ◽  
Mammary Gland ◽  
Antibiotic Therapy ◽  
Bovine Mammary Gland ◽  
Lactating Cows ◽  
Colony Forming Units ◽  
Subsequent Exposure ◽  
Increased Sensitivity

SummaryMacrophages isolated from the involuted bovine mammary gland were cultured in vitro. Phagocytosis of opsonized Staphylococcus aureus occurred rapidly, but intracellular killing of bacteria was slow. Many intracellular staphylococci survived for up to 4 d exposure to extracellular cloxacillin and emerged from within the macrophages to multiply extracellularly when the antibiotic was inactivated. Rifampicin was significantly more efficient than cloxacillin in killing intracellular S. aureus after 18 h incubation, but it too failed to sterilize the cultures within 3 d. Staphylococci, which had remained viable within macrophages during 20 h incubation with extracellular cloxacillin, showed an increased sensitivity to dilute lysostaphin on subsequent exposure. A 3 d course of intramammary therapy with cloxacillin, commencing simultaneously with an infecting inoculum of ∼108 colony forming units (c.f.u.) S. aureus, apparently eliminated the infection from one quarter of the udders of each of three lactating cows, but bacteria were re-isolated from two cows after a delay of several days. However, when other quarters of the same cows were infected with ∼108 c.f.u. S. aureus which had been phagocytosed by autologous mammary macrophages, similar simultaneous antibiotic therapy failed to affect these infections. The in vitro and in vivo findings indicate the significance of intracellular survival of S. aureus as a factor contributing to failure of antibiotic therapy.

Construction and in vivo evaluation of a mammary gland-specific expression vector for human lysozyme

Plasmid ◽  
2014 ◽  
Vol 76 ◽  
pp. 47-53 ◽  
Author(s):  
Guocai Li ◽  
Weiqing Shi ◽  
Gang Chen ◽  
Hongju Chen ◽  
Hongmei Jiao ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Expression Vector ◽  
Human Lysozyme ◽  
In Vivo Evaluation ◽  
Specific Expression
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