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Published on: September 4, 2012
Dynamics of milk leukocytes in response to a biological response modifier during bovine subclinical mastitis
Ujjwal Kumar De1, Reena Mukherjee
1Division of Medicine, Indian Veterinary Research Institute, Izatnagar 243122, Uttar Pradesh, India. ujjwalde@gmail.com
Insights
This study shows a biological response modifier (BRM) effectively primes cow milk leukocytes against subclinical mastitis (SCM). BRM treatment enhanced immune cell activity and reduced bacterial counts, offering a novel therapeutic approach.
Area of Science:
- Veterinary Immunology
- Bovine Mastitis Research
- Microbial Therapeutics
Background:
- Subclinical mastitis (SCM) in cows significantly impacts milk production and udder health.
- Current treatments often rely on antibiotics, contributing to antimicrobial resistance.
- Novel therapeutic strategies are needed to manage bovine mastitis effectively.
Purpose of the Study:
- To evaluate the immune response dynamics in bovine milk leukocytes following intramammary infusion of a biological response modifier (BRM).
- To assess the efficacy of BRM against subclinical mastitis (SCM) by measuring key indicators of infection and inflammation.
- To explore a non-antibiotic therapeutic option for bovine SCM.
Main Methods:
- Intramammary infusion of a BRM derived from Nocardia globerula into SCM-affected quarters.
- Monitoring of somatic cell count (SCC), total bacterial count (TBC), cyclooxygenase (COX) activity, phagocytic activity, hydrogen peroxide (H2O2) production, and myeloperoxidase (MPO) activity in milk leukocytes.
- Comparative analysis of these parameters before and after BRM treatment.
Main Results:
- BRM infusion led to an initial increase in SCC, followed by a reduction by day 7.
- Cyclooxygenase (COX) activity peaked on day 3, while total bacterial count (TBC) decreased from day 3 onwards.
- Significant enhancement in milk leukocyte phagocytic activity, H2O2 production, and MPO activity was observed post-BRM treatment.
Conclusions:
- BRM treatment effectively primes resident milk leukocytes, boosting their phagocytic and microbicidal activities.
- The observed immunomodulatory effects suggest BRM's potential as a therapeutic agent for bovine SCM.
- This study highlights BRM as a promising alternative to antibiotics, potentially reducing drug resistance and milk contamination.
Abstract:
The objective of this study was to evaluate the dynamics of milk leukocyte in response to intramammary infusion of a biological response modifier (BRM) prepared from Nocardia globerula during bovine subclinical mastitis (SCM). The somatic cell count (SCC), total bacterial count (TBC) in milk, cyclooxygenase (COX) activity, phagocytic activity, production of hydrogen peroxide (H2O2) and myeloperoxidase (MPO) activity in milk leukocytes were evaluated after intramammary infusion of BRM in quarters inflicted with SCM. Intramammary infusion of BRM significantly enhanced the SCC in earlier phase with subsequent reduction on day 7 after initiation of treatment. Similarly, the COX activity in milk cell lysate increased on day 3 and reduced on day 5. However reduction in TBC could be observed from day 3 onwards. The phagocytic activity of milk leukocytes was lower in mastitic cows whereas, significant enhancement in phagocytic activity was recorded in post treated cows with BRM. Similarly, the H2O2 production and MPO activities in milk leukocytes were enhanced significantly in diseased cows in response to BRM infusion. Significant enhancement of phagocytic activity, H2O2 and MPO activities indicate the priming of resident milk leukocytes in response to BRM infusion. Initial influx of SCC and raised COX activity also indicate the immunomodulatory activity of BRM. Reduction of TBC could be due to increased leukocytosis or direct microbicidal activity of activated milk cells. In the present study, the biological activity of BRM at standardized dose against bovine SCM is reported for the first time. Development of such therapy is warranted to reduce the drug resistance of microorganisms and contamination of milk with antibiotic residue.
