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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Antimicrobial activity of crude extracts from actinomycetes against mastitis pathogens

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Author(s):
Leite, R. F. [1] ; Goncalves, J. L. [1] ; Peti, A. P. F. [2] ; Figueiro, F. S. [2] ; Moraes, L. A. B. [2] ; Santos, V, M.
Total Authors: 6
Affiliation:
[1] V, Univ Sao Paulo, Dept Anim Sci, Sch Vet Med & Anim Sci, BR-13635900 Pirassununga, SP - Brazil
[2] Univ Sao Paulo, Dept Chem, BR-14040901 Ribeirao Preto, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF DAIRY SCIENCE; v. 101, n. 11, p. 10116-10125, NOV 2018.
Web of Science Citations: 1
Abstract

The emergence of antimicrobial resistance to commonly used antibiotics has necessitated the development of new antimicrobial products. Crude extracts produced by actinomycetes contain antimicrobial metabolites that can inhibit bacterial growth. The objective of our study was to evaluate the antimicrobial activity of crude extracts (Caat1-54 and CaatP5-8) produced by actinomycetes against isolates of Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, and Streptococcus uberis, which were obtained from the milk of cows affected by mastitis in 23 dairy herds. Twenty isolates of each bacterial species were used to define minimum inhibitory concentrations (MIC) of both crude extracts and ceftiofur (positive control). The MIC50 and MIC90 were defined at the concentration required to inhibit the growth of 50 and 90% of bacterial isolates tested, respectively. The MIC results were evaluated by survival analysis. Staphylococcus aureus isolates presented MIC90 of Caat 1-54 >= 6.25 mu g/mL, ceftiofur >= 12.5 mu g/mL, and Caat P5-8 >= 100 mu g/mL. Streptococcus uberis presented MIC90 of ceftiofur >= 0.39 mu g/mL, Caat 1-54 >= 50 mu g/mL, and Caat P5-8 >= 100 mu g/mL. Staphylococcus chromogenes isolated from subclinical mastitis presented MIC90 of Caat 1-54 >= 0.78 mu g/mL and ceftiofur and Caat P5-8 of >= 6.25 and >= 100 mu g/mL, respectively. Streptococcus dysgalactiae isolated from clinical mastitis presented similar MIC90 values between antimicrobials tested (ceftiofur, Caat 1-54, and Caat P-58), but these values (>= 100 mu g/mL) were higher than the values obtained from other pathogens evaluated in the present study. Our results indicate that Caat 1-54 and Caat P5-8 crude extracts present in vitro antimicrobial activity against isolates of Staph. aureus, Staph. chromogenes, Strep. dysgalactiae, and Strep. uberis isolated from clinical and subclinical mastitis. (AU)

FAPESP's process: 16/22023-0 - Activation of the Cryptic Secondary Metabolite Biosynthetic Gene Clusters in Actinomycetes by Antibiotics Resistance
Grantee:Luiz Alberto Beraldo de Moraes
Support Opportunities: Regular Research Grants