|
|||||
|
|
Host adaptation of bovine Staphylococcus aureus seems associated with bacteriological cure after lactational antimicrobial treatment |
|
| Authors: | BHP van den Borne M Nielen MB Melchior RN Zadoks |
| Affiliation: | * Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands † GD Animal Health Service, PO Box 9, 7400 AA Deventer, the Netherlands ‡ Central Veterinary Institute (CVI), Wageningen UR, PO Box 2004, 8203 AA Lelystad, the Netherlands § Dutch Udder Health Centre, PO Box 2030, 7420 AA Deventer, the Netherlands # Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, EH26 0PZ, United Kingdom || Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, EH25 9RG, United Kingdom |
| Abstract: | Staphylococcus aureus causes a wide range of diseases in multiple species. Some sequence types (ST) are observed in a variety of hosts, whereas other strains are mainly associated with bovine mastitis, suggesting host adaptation. We propose that host adaptation of Staph. aureus may influence bacteriological cure of bovine subclinical mastitis after antimicrobial treatment. To test this hypothesis, multilocus sequence typing was performed on Staph. aureus isolates from 60 treated and 79 untreated control quarters that were obtained from well-defined cohorts of dairy cows from a recently conducted randomized field trial on early treatment of subclinical mastitis. Bovine-associated ST were distinguished from non-bovine-associated ST based on the literature and public databases. The association between host adaptation and bacteriological cure was investigated using population-averaged logistic regression models. Thirteen ST were identified, with approximately 80% of isolates belonging to bovine-associated ST. The odds for cure were around 2.5 times as high for non-bovine-associated ST as for bovine ST in treated quarters, whereas no difference in spontaneous cure was observed in untreated control quarters. In addition, host adaptation was related to known predictors of cure, such as penicillin susceptibility and somatic cell count. All isolates belonging to non-bovine-associated ST were resistant to penicillin, whereas the majority of isolates belonging to bovine-associated ST were penicillin susceptible. Penicillin-resistant bovine-associated strains were associated with high somatic cell counts compared with other strains. The correlation between penicillin resistance, cell counts, and host adaptation may affect the association between host adaptation and cure. For diagnostic purposes, a simple and fast alternative to multilocus sequence typing of Staph. aureus to determine host adaptation may be valuable. |
| Keywords: | Staphylococcus aureus subclinical mastitis antimicrobial treatment genotyping |
| 本文献已被 ScienceDirect 等数据库收录！ | |