In vitro synergistic activities of cefazolin and nisin A against mastitis pathogens

The Journal of Veterinary Medical Science

Kohei KITAZAKI¹  Takeshi ZENDO²  Shoko KOGA³  Kenji SONOMOTO⁴  Hitoshi ANO⁴  Jiro NAKAYAMA⁴  Hiromu KATAMOTO⁵  Koichi KUWANO⁶  Kohei NAGATOSHI⁶ 

[1] Department of Animal Production, Fukuoka Agriculture and Forestry Research Center, 587 Oaza-Yoshiki, Chikushino, Fukuoka 818-8549, Japan;Division of Microbiology, Department of Infectious Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan;Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan;Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan;Laboratory of Veterinary Internal Medicine, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai-nishi, Miyazaki 889-2192, Japan;Research and Development Division, Omu Milk Products Co., Ltd., 1-38-1 Shinkatsudati-machi, Omuta, Fukuoka 836-0895, Japan

关键词: cattle;    cephalosporin;    mastitis;    nisin;    synergism;   

DOI  :  10.1292/jvms.17-0180

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

First-generation cephalosporins such as cefazolin (CEZ) have been widely used for mastitis treatment in dairy cattle. However, the use of antibiotics results in the presence of antibiotic residues in milk, which is used for human consumption. Nisin A, a bacteriocin produced by Lactococcus lactis, has been used as a broad-spectrum food preservative for over 50 years. Therefore, a combination of CEZ and nisin A might provide an extended activity spectrum against mastitis pathogens and reduce the antibiotic dose for mastitis treatment. This study aimed to evaluate the combined effect of CEZ and nisin A against mastitis pathogens using the checkerboard and time-kill assays. In the checkerboard assay, the CEZ-nisin A combination exhibited a synergistic effect against Staphylococcus aureus (n=20/20) and Enterococcus faecalis (n=13/18), and meanwhile exhibited a mostly additive effect against Staphylococcus intermedius (n=12/20), Streptococcus agalactiae (n=10/10), Streptococcus dysgalactiae (n=18/18), and Escherichia coli (n=14/18). There were no indifferent or antagonistic effects between CEZ and nisin A. In the time-kill assay, the CEZ-nisin A combination at 0.5 × or 1 × minimum inhibitory concentration exhibited synergistic reduction of bacterial growth by over 3 log10 colony forming units per ml relative to that observed with either antimicrobial substance alone. These results suggest that the CEZ-nisin A combination can be used for developing an intramammary infusion for mastitis treatment, with lower antibiotic concentrations than normal.

【 授权许可】

Unknown