scholarly journals Single-Chain Fragment Variables Targeting Leukocidin ED Can Alleviate the Inflammation of Staphylococcus aureus-Induced Mastitis in Mice

2021 ◽  
Vol 23 (1) ◽  
pp. 334
Author(s):  
Lei Zhang ◽  
Xin Ye ◽  
Yan Jia ◽  
Manling Cheng ◽  
Dangjin Wu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Chemokine Receptors ◽  
Bovine Mastitis ◽  
Economic Losses ◽  
Single Chain ◽  
Necrosis Factor Alpha ◽  
Chain Fragment ◽  
Single Chain Fragment

Staphylococcus aureus is a vital bovine mastitis pathogen causing huge economic losses to the dairy industry worldwide. In our previous studies, leukotoxin ED (LukED) was detected in most S. aureus strains isolated from bovine mastitis. Here, four single-chain fragment variables (scFvs) (ZL8 and ZL42 targeting LukE, ZL22 and ZL23 targeting LukD) were obtained using purified LukE and LukD proteins as the antigens after five rounds of bio-panning. The complementarity-determining region 3 (CDR3) of the VH domain of these scFvs exhibited significant diversities. In vitro, the scFvs significantly decreased LukED-induced cell killing by inhibiting the binding of LukED to chemokine receptors (CCR5 and CXCR2) and reduced the death rates of bovine neutrophils and MAC-T cells caused by LukED and S. aureus (p < 0.05). In an S. aureus-induced mouse mastitis model, histopathology and MPO results revealed that scFvs ameliorated the histopathological damages and reduced the infiltration of inflammatory cells (p < 0.05). The ELISA and qPCR assays showed that scFvs reduced the transcription and expression levels of Tumor Necrosis Factor-alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-8 and IL-18 (p < 0.05). The overall results demonstrated the protective anti-inflammatory effect of scFvs in vitro and in vivo, enlightening the potential role of scFvs in the prevention and treatment of S. aureus-induced mastitis.

scholarly journals Anti-Staphylococcus aureus Single-Chain Fragment Variables Play a Protective Anti-Inflammatory Role In Vitro and In Vivo

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1300
Author(s):  
Lei Zhang ◽  
Xin Ye ◽  
Yan Zhang ◽  
Fengqing Wang ◽  
Fanqing Zhang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
T Cells ◽  
Virulence Factors ◽  
Economic Losses ◽  
Single Chain ◽  
Chain Fragment ◽  
Anti Inflammatory ◽  
Single Chain Fragment

Staphylococcus aureus is a causative agent of bovine mastitis, capable of causing significant economic losses to the dairy industry worldwide. This study focuses on obtaining single-chain fragment variables (scFvs) against the virulence factors of S. aureus and evaluates the protective effect of scFvs on bovine mammary epithelial (MAC-T) cells and mice mammary gland tissues infected by S. aureus. After five rounds of bio-panning, four scFvs targeting four virulence factors of S. aureus were obtained. The complementarity-determining regions (CDRs) of these scFvs exhibited significant diversities, especially CDR3 of the VH domain. In vitro, each of scFvs was capable of inhibiting S. aureus growth and reducing the damage of MAC-T cells infected by S. aureus. Preincubation of MAC-T cells with scFvs could significantly attenuate the effect of apoptosis and necrosis compared with the negative control group. In vivo, the qPCR and ELISA results demonstrated that scFvs reduced the transcription and expression of Tumor Necrosis Factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-8, and IL-18. Histopathology and myeloperoxidase (MPO) results showed that scFvs ameliorated the histopathological damages and reduced the inflammatory cells infiltration. The overall results demonstrated the positive anti-inflammatory effect of scFvs, revealing the potential role of scFvs in the prevention and treatment of S. aureus infections.

scholarly journals Immunotoxins Containing Recombinant Anti-CTLA-4 Single-Chain Fragment Variable Antibodies and Saporin: In Vitro Results and In Vivo Effects in an Acute Rejection Model

2001 ◽  
Vol 167 (8) ◽  
pp. 4222-4229 ◽  
Author(s):  
Pier-Luigi Tazzari ◽  
Letizia Polito ◽  
Andrea Bolognesi ◽  
Maria-Pia Pistillo ◽  
Paolo Capanni ◽  
...  
Keyword(s):  
Acute Rejection ◽  
Single Chain ◽  
Chain Fragment ◽  
Single Chain Fragment Variable ◽  
In Vivo Effects ◽  
Single Chain Fragment

scholarly journals Efficacy of natural formulations in bovine mastitis pathology: alternative solution to antibiotic treatment

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Claudia Pașca ◽  
Liviu Alexandru Mărghitaș ◽  
Daniel Severus Dezmirean ◽  
Ioana Adriana Matei ◽  
Victorița Bonta ◽  
...  
Keyword(s):  
Natural Products ◽  
Therapeutic Potential ◽  
Dairy Product ◽  
Bovine Mastitis ◽  
Antimicrobial Effect ◽  
Economic Losses ◽  
Standard Plate ◽  
Conventional Antibiotics

AbstractIntroductionBovine mastitis is an inflammatory disease of the udder that causes important economic losses in the animal breeding and dairy product industries. Nowadays, the conventional livestock antibiotic treatments are slowly being replaced by alternative treatments. In this context, the main aim of this study was to evaluate the efficacy of natural products in alternative treatment of bovine mastitis.Material and MethodsTwo natural formulations with previously suggested in vitro antimicrobial effect were tested in vivo on mastitic cows. Animals with a positive diagnosis for mastitis (n = 20) were divided into three treatment groups: two groups (n = 8) were administered formulations of propolis, alcoholic extracts of Brewers Gold and Perle hops, plum lichen, common mallow, marigold, absinthe wormwood, black poplar buds, lemon balm, and essential oils of oregano, lavender, and rosemary designated R4 and R7 (differing only in the latter being more concentrated) and one group (n = 4) a conventional antibiotic mixture. In vivo efficacy of treatments was evaluated by somatic cell and standard plate counts, the treatment being considered efficacious when both parameters were under the maximum limit.ResultsR7 was effective in the most cases, being therapeutically bactericidal in six out of eight cows, while R4 gave good results in three out of eight cows, and conventional antibiotics cured one out of four.ConclusionThese results suggest the possible therapeutic potential of these natural products in bovine mastitis.

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.

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.

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