In-vitro antimicrobial activity of marine actinobacteria against multidrug resistance Staphylococcus aureus

Objective:To investigate the antibacterial aclivily of marine actinobacteria against multidrug resistance Staphylococcus aureus(MDRSA).Methods:Fifty one actinobacterial strains were isolated from salt pans soil,costal area in Kothapattanam,Ongole,Andhra Pradesh.Primary screening was done using cross-streak method against MDRSA.The bioaclive compounds are extracted from efficient actinobacteria using solvent extraction.The antimicrobial activity of crude and solvent extracts was perfomied using Kirby-Bauer method.MIC for ethyl acetate extract was determined by modified agar well diffusion method.The potent actinobacteria are identified using Nonomura key,Shirling and Gottlieb 1966 with Bergey's manual of determinative bacteriology.Results:Among the fifty one isolates screened for antibacterial activity,SRB25were found efficient against MDRSA.The ethyl acetate extracts showed high inhibition against test organism.MIC test was performed with the ethyl acetate extract against MDRSA and found to be 1 000μg/mL.The isolaled actinobacteria are identified as Streptomyces sp with the help of Nonomura key.Conclusions:The current investigation reveals that the marine actinobacteria from salt pan environment can be able to produce new drug molecules against drug resistant microorganisms.

金黄色葡萄球菌外毒素及荚膜特异性卵黄抗体联合治疗奶牛乳房炎效果研究

本研究目的是评价金黄色葡萄球菌外毒素特异性卵黄抗体(IgY-toxins)及5、8、336型金黄色葡萄球菌荚膜特异性卵黄抗体(IgY-T5、IgY-T8及IgY-T336)联合使用对奶牛乳房炎的治疗效果。乳酸脱氢酶试验表明,IgYtoxins能够有效中和外毒素对乳腺上皮细胞MAC-T的破坏作用。荧光显微镜观察发现,5mg·mL-1的IgYT336可有效阻断金黄色葡萄球菌RN6390对MAC-T的侵袭。与单独使用IgY-T336相比,5mg·mL-1的IgYT336和0.5mg·mL-1的IgY-toxins联合使用能够更加有效地保护MAC-T细胞,同时显著改善细胞的生长形态。临床型乳房炎试验表明,与PBS对照相比,对金黄色葡萄球菌感染乳池每天注射各20mg的IgY-T5、IgY-T8、IgYT336及IgY-toxins可显著降低(P<0.001)病牛乳汁的体细胞数(SCC),20mg的IgY-T5、IgY-T8、IgY-T336或者20mg的IgY-toxins虽然也可降低体细胞数,但是降低幅度显著低于联合治疗组(P<0.01)。所有治疗组奶牛乳汁的凝块水平都显著低于对照组(P<0.05)。本研究表明,荚膜及外毒素特异性卵黄抗体联合使用比其单独使用对乳房炎的治疗效果更好,在应用卵黄抗体治疗乳房炎时应该将荚膜和外毒素都列为抗体的靶点。