Antimicrobial activity of bioactive molecules produced by Streptomyces parvulus DPUA 1573 against Staphylococcus spp. multi-drug resistant isolates from mastitis buffalo

Abstract:

Mastitis is an inflammation in one or more mammary glands which can lead to reduction in production and quality of milk causing economic losses to dairy farming. The use of antibiotics is the key for the treatment of this disease, but in many cases ineffective due to bacterial resistance already known for this condition. The aim of this study was to select strains of Streptomyces spp. producing biomolecules with antimicrobial activity against multidrug-resistant Staphylococcus isolated from buffaloes with mastitis, as well as to determine the best production parameters to the evaluation of simultaneous production of clavulanic acid. Thirty species of Streptomyces spp. were used to selecting the greatest producer spectrum of antimicrobial activity (agar block technique), with selection of Streptomyces parvulus DPUA 1573, and 7 multidrug-resistant Staphylococcus spp. sensitive to its biocompounds. The selected strain of Streptomyces parvulus DPUA 1573 was cultured in different conditions predetermined by the factorial design 2⁴, where the independent variables were: soybean concentration (0.5, 1.0, 1.5%), glucose (0, 0.5, 1g/L), agitation (150, 200, 250rpm) and temperature (28, 32, 37°C); all the tests were monitored up to 120 hours of cultivation. All independent variables influenced positively the cell growth, while for antimicrobial activity only the variables temperature and agitation showed positive effects. The antimicrobial bio compounds showed activity against seven multidrug-resistant Staphylococcus spp under the conditions: temperature 37°C, agitation 250rpm, with 72 hours of production process. In the tests which showed antimicrobial activity, was also assessed the production of clavulanic acid along with the cultivation. The highest concentration of clavulanic acid was 269.84g/L obtained under the conditions of 1.5% of soybean flour and absence of glucose in 96 hours. The strain Streptomyces parvulus DPUA 1573 was effective against multidrug-resistant strains of Staphylococcus spp. of mastitis from buffaloes, still showing concomitantly production of clavulanic acid for pharmaceutical use.

Index Terms:
Streptomyces parvulus DPUA 1573; Staphylococcus spp.; antimicrobial; buffaloes mastitis; multi-drug resistance