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Prototheca Zopfii? Mastitis in Holstein Dairy Herds and Its Characteristics of Insufficient Elimination from the Udder
© The Author(s); licensee BioMed Central Ltd. 2003
Published: 31 March 2003
Prototheca spp cause sporadic cases of bovine mastitis as well as serious herd mastitis problems. Clinical mastitis caused by Prototheca zopfii (P. zopfii) occurred in 2 Holstein dairy herds. Epidemiological, bacteriological, pathological studies and therapeutic trials were performed to find the effective control measures for P. zopfii mastitis. Serum antibody to P. zopfii was monitored to evaluate the efficacy of drug therapy. Further, in vitro responsiveness of phagocytic cells to P. zopfii was also evaluated. P. zopfii was isolated from 46 quarters from 28 cows in 2 herds of 75 lactating cows by culturing quarter milk samples. Chemiluminescent response of bovine neutrophils against large size(13?20 um) of P. zopfii was 52% of those of small size (6?8 um). Phagocytic activity of neutrophils to P. zopfii was 35%. Pathological findings showed the chronic granulomatous changes of the inflamed mammary glands. Therapeutic trials using kanamycin (600 mg/day, IMI) and/or cellulase (MacerozymeR 10%, 300 ml/day, IMI), which were proved to be effective to P. zopfii in vitro, for 5 days, were not efficacious to treat clinical P. zopfii mastitis. However, beneficial effects of Kanamycin infusion into infected glands, for 5 days, were observed in cases of subclinical mastitis. Difference in serum antibody to P. zopfii was found in cows between clinical and subclinical mastitis. This suggests that serum P. zopfii?anti-body level is a possible parameter to determine whether anti?microbial therapy is efficacious or not.
Poor responsiveness of neutrophils to P. zopfii was demonstrated. Under insufficient sensitivity to antibiotics and the lack of effective control measures for P. zopfii, proper handling of milking procedures may play a key role for prevention of the spreading of P. zopfii pathogen.
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