| Full text | |
| Author(s): |
Martins, Larissa
[1, 2]
;
Goncalves, Juliano L.
[2]
;
Leite, Renata F.
[2]
;
Tomazi, Tiago
[3]
;
Rall, Vera L. M.
[4]
;
Santos, V, Marcos
Total Authors: 6
|
| Affiliation: | [1] V, Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Nutr & Anim Prod, BR-13635900 Pirassununga, SP - Brazil
[2] Univ Calgary, Dept Prod Anim Hlth, Calgary, AB T2N 4N1 - Canada
[3] Cornell Univ, Coll Vet Med, Dept Populat Med & Diagnost Sci, Ithaca, NY 14850 - USA
[4] Sao Paulo State Univ, Inst Biosci, Dept Chem & Biol Sci, Rua Dr Plinio Pinto e Silva, BR-18618691 Botucatu, SP - Brazil
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | JOURNAL OF DAIRY SCIENCE; v. 104, n. 11, p. 12030-12041, NOV 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
It is unknown whether overuse of antimicrobials against clinical mastitis (CM) from Streptococcus uberis is associated with increased antimicrobial resistance (AMR). Therefore, the aim of this study was to evalu-ate the association between antimicrobial use (AMU) and AMR in relation to the Strep. uberis causing CM in dairy herds. A total of 83 Strep. uberis isolates were se-lected from a collection created during a previous study evaluating the epidemiology of CM in dairy herds (n = 17) of southeastern Brazil. For each case of CM identi-fied on farm, the following information was recorded: cow's identification number, affected mammary quar-ter, date of CM diagnosis, antimicrobial commercial names, number of administrations, and descriptions of protocol changes during the treatment. Streptococcus uberis isolates were confirmed by conventional culture, MALDI-TOF mass spectrometry, and quantitative multiplex PCR analyses. Thus, a total of 8 antimicro-bials commonly used for CM treatment were evaluated for antimicrobial activity against Strep. uberis isolates. The minimum inhibitory levels of antimicrobials were determined at the lowest concentrations able to inhibit 50 and 90%, respectively, of Strep. uberis isolates. Data related to the antibiotics used for treatment of CM was used to calculate the frequency of administered antimi-crobials as the number of defined daily doses (DDD). The highest frequencies of resistant Strep. uberis were observed for erythromycin (80.7% resistant, R), tet-racycline (R = 59%), and penicillin G (R = 57.8%), whereas against ceftiofur only 10.8% of Strep. uberis isolates were resistant, and only 1.2% of the Strep. uberis isolates were resistant to enrofloxacin. Regarding the evaluation of resistance for antimicrobial classes, the highest frequency was observed for macrolides (R = 80.7%; 19.3% susceptible, S). Additionally, a fre-quency of 18.7% of Strep. uberis isolates were resistant to cephalosporins (S = 81.3%), respectively. Further, 94% of Strep. uberis isolates were multiresistant; all these isolates presented resistance to at least 3 different antimicrobial classes. The overall monthly average of antimicrobial treatment incidence (ATI) among the 17 herds enrolled in the study was 23.7 DDD per 1,000 lactating dairy cows {[}standard deviation (SD) = 13.9], ranging from 5.0 to 55.4 DDD per 1,000 cows in lacta-tion-day. Cephalosporins and penicillins were the most commonly used antimicrobial classes among the evalu-ated herds (n = 16; 94.1%), followed by tetracyclines (n = 15 herds; 88.2%), fluoroquinolones (n = 14; 82.3%), and sulfonamides (n = 14; 82.3%). The tetracycline class had the highest ATI mean (5.0 DDD per 1,000 lactating cow-days, SD = 5.8), followed by fluoroqui-nolones (4.7 DDD per 1,000 lactating cow-days, SD = 6.0) and cephalosporins (3.8 DDD per 1,000 lactating cow-days, SD = 6.0). The overall use of antimicrobials was associated with the resistance of Strep. uberis to the antimicrobial tetracycline. (AU) | |
| FAPESP's process: | 13/23613-8 - Impact of subclinical mastitis on cost of production and milk quality in dairy herds |
| Grantee: | Juliano Leonel Gonçalves |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 18/23040-1 - Association between antimicrobial use and resistance of Streptococcus uberis causing clinical mastitis |
| Grantee: | Larissa Martins |
| Support Opportunities: | Scholarships in Brazil - Scientific Initiation |
| FAPESP's process: | 14/17411-6 - Economic impact and profile of etiologic agents of bovine mastitis |
| Grantee: | Marcos Veiga dos Santos |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 13/22286-3 - Profile of etiologic agents causing clinical mastitis and antimicrobial use in dairy herds |
| Grantee: | Tiago Tomazi |
| Support Opportunities: | Scholarships in Brazil - Doctorate |