title: Efficacy of nisin in treatment of clinical mastitis in lactating dairy cows.
abstract: Nisin is an antimicrobial polypeptide produced by Lactococcus lactis and is believed nontoxic to humans. The objective of this study was to evaluate a nisin-based formulation for the treatment of bovine clinical mastitis in lactating dairy cattle. A total of 92 cows with 107 clinically mastitic quarters were randomly assigned to nisin- (48 cows with 51 quarters) and gentamicin (GM)-treated (44 cows with 56 quarters) groups. In the nisin-treated group, cows received an intramammary infusion of nisin at a dose of 2,500,000 IU; in the GM-treated group, intramammary infusion of GM was administered at a dose of 0.8 g. Results indicated that nisin offered a clinical cure rate similar to GM (90.2 vs. 91.1%) and no difference in bacteriological cure rate than GM-treated group (60.8 vs. 44.6%, respectively). Proportion of the quarters with milk somatic cell counts <500,000 cells/mL was not different in the nisin-treated group (50.0 and 47.8%) compared with the GM-treated group (33.3 and 37.3%) 1 and 2 wk after treatment. Of 17 Staphylococcus aureus isolates, 82.5% were resistant to penicillin, and 35.3% to GM, but none of them to nisin. Nisin therapy eliminated 54.5% (6 of 11) of S. aureus IMI, whereas GM eliminated 33.3% (2 of 6). Nisin in milk (4.5 +/- 0.8 IU/mL) was detected only at 12 h following intramammary infusion, which was much lower than the upper limit (500 mg/mL) allowed as preservative in milk by the China authority. Because of its efficacy in the treatment of bovine clinical mastitis, especially resistant Staph. aureus-caused IMI, as well as its safety in humans, nisin deserves further study to clarify its effects on mastitis caused by different mastitis pathogens on a larger scale.
authors.affiliation: Department of Veterinary Medicine, Zhejiang University, Hangzhou 310029, China.
authors.forename: L T
authors.initials: LT
authors.lastname: Cao
authors.forename: J Q
authors.initials: JQ
authors.lastname: Wu
authors.forename: F
authors.initials: F
authors.lastname: Xie
authors.forename: S H
authors.initials: SH
authors.lastname: Hu
authors.forename: Y
authors.initials: Y
authors.lastname: Mo
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use*; D002417:Cattle; D002452:Cell Count / Q000662:veterinary; D024881:Drug Resistance, Bacterial; D005260:Female; D005285:Fermentation / Q000187:drug effects; D005839:Gentamicins / Q000008:administration & dosage / Q000627:therapeutic use; D006863:Hydrogen-Ion Concentration; D036502:Infusions, Intralesional / Q000662:veterinary; D007774:Lactation; D013294:Lactococcus lactis / Q000737:chemistry; D008414:Mastitis, Bovine / Q000188:drug therapy*; D008892:Milk / Q000737:chemistry / Q000166:cytology / Q000382:microbiology; D009561:Nisin / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D013290:Streptococcal Infections / Q000188:drug therapy / Q000662:veterinary*; D013292:Streptococcus agalactiae / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D009561:Nisin