Intensive fish farming systems in Brazil have increased the disease incidence, mainly of bacterial origin, due to higher stocking density, high organic matter levels and poor quality of the aquatic environment that ca...Intensive fish farming systems in Brazil have increased the disease incidence, mainly of bacterial origin, due to higher stocking density, high organic matter levels and poor quality of the aquatic environment that causes high mortality rates during outbreaks. The identification of pathogenic species using a fast and reliable method of diagnosis is essential for successful epidemiological studies and disease control. The present study evaluated the use of direct colony PCR in combination with 16S rRNA gene sequencing to diagnose fish bacterial diseases, with the goal of reducing the costs and time necessary for bacterial identification. The method was successful for all 178 isolates tested and produced bands with the same intensity as the standard PCR performed using pure DNA. In conclusion, the genetics methods allowed detecting the most common and important pathogens in Aquaculture, including 12 species of occurrence in Brazilian fish farms. The results of the present study constitute an advance in the available diagnostic methods for bacterial pathogens in fish farms.展开更多
Objective:To investigate the antimicrobial activity of Clitoria ternatea(C.ternatea) against the fish pathogens viz.,Pseudomonas aeruginosa(P.aeruginosa),Escherichia coli(E.coli),Klebsiella pneumonia(K.pneumonia),Baci...Objective:To investigate the antimicrobial activity of Clitoria ternatea(C.ternatea) against the fish pathogens viz.,Pseudomonas aeruginosa(P.aeruginosa),Escherichia coli(E.coli),Klebsiella pneumonia(K.pneumonia),Bacillus subtilis(B.subtilis),Aeromonas formican(A.formicans)s, Aeromonas hydrophila(A.hydrophila) and Streptococcus agalactiae(S.agalactiae )isolated from diseased Tilapia(Oreochromis niloticus).Methods:The extracts of C.ternatea was tested against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S.agalactiae by the agar well diffusion method.Results:Different extracts of C.ternatea showed inhibitory effects against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S. agalactiae.Ethyl acetate extracts of C.ternatea showed maximum of zone of inhibition against A. formicans(18 mm),A.hydrophilia(19 mm),B.subtilis(19 mm) and P.aeruginosa(21 mm) next to that ethanol extract of C.ternatea showed A.formicans(18 mm) and E.coli(14 mm) followed by Acetone extract showed maximum zone of inhibition S.agalactiae(19 mm) and K.pneumonia(17 mm).Conclusions:The antimicrobial activities of all the four plant extracts are comparable and their potential as alternative in the treatment of infectious by these microorganisms was present in the fish.Susceptibility testing is conducted on isolates using drugs selected on the basis of their importance to human medicine and use in fish production.展开更多
Objective:To evaluate the antibacterial activity and immunostimulant of red seaweedChondrococcus hornemanni pathogens.Methods:(C.hornemanni)(Kuetzing,1847)against marine ornamental fish antimicrobial activity against ...Objective:To evaluate the antibacterial activity and immunostimulant of red seaweedChondrococcus hornemanni pathogens.Methods:(C.hornemanni)(Kuetzing,1847)against marine ornamental fish antimicrobial activity against two fish pathogens and the partially purified potential compound was characterized by GC-MS.Purified seaweed extract was injected to the clownfish,Amphiprion sebae to study the innate immune response of these fishes.Results:In the present study,seaweed extract of C.hornemanni showed significant Aeromonas hydrophila(20 mm)and Vibrio parahaemolyticus(19 mm)at a concentration(25 mg/mL)shown higher antimicrobial activity.The white blood cell count and respirator burst activity was significantly increased in the experimental tanks(E1)and(E2)when compared with control.The extracts was found effective and had more than 80%inhibitory activity against Conclusions:Hence,it is concluded that the seaweed extracts of C.hornemanni had potential bioactive compounds and act an immunostimulant and improve the immune response to fish.展开更多
Objective:To isolate bioactive molecules from marine seaweeds and check the antimicrobial activity against the fish pathogenic bacteria.Methods:Fresh marine seaweeds Gracilaria edulis,Kappaphycus spicifera,Sargassum w...Objective:To isolate bioactive molecules from marine seaweeds and check the antimicrobial activity against the fish pathogenic bacteria.Methods:Fresh marine seaweeds Gracilaria edulis,Kappaphycus spicifera,Sargassum wightii(S.wightii)were collected.Each seaweed was extracted with different solvents.In the study,test pathogens were collected from microbial type culture collection.Antibacterial activity was carried out by using disc diffusion method and minimum inhibition concentration(MIC)was calculated.Best seaweed was analysed by fourier transform infrared spectroscopy.The cured extract was separated by thin layer chromatography(TLC).Fraction was collected from TLC to check the antimicrobial activity.Best fraction was analysed by gas chromatography mass spectrometer(GCMS).Results:Based on the disc diffusion method,S.wightii showed a better antimicrobial activity than other seaweed extracts.Based on the MIC,methanol extract of S.wightii showed lower MIC than other solvents.S.wightii were separated by TLC.In this TLC,plate showed a two fraction.These two fractions were separated in preparative TLC and checked for their antimicrobial activity.Fraction 2 showed best MIC value against the tested pathogen.Fraction 2 was analysed by GCMS.Based on the GCMS,fraction 2 contains n-hexadecanoic acid(59.44%).Conclusions:From this present study,it can be concluded that S.wightii was potential sources of bioactive compounds.展开更多
Objective:To evaluate the antimicrobial capacity of fucoidan from the brown seaweed Turbinaria ornata against the marine ornamental fish bacterial pathogens.Methods:Fucoidan was isolated by the ethanol extraction meth...Objective:To evaluate the antimicrobial capacity of fucoidan from the brown seaweed Turbinaria ornata against the marine ornamental fish bacterial pathogens.Methods:Fucoidan was isolated by the ethanol extraction method and the functional groups were identified by Fourier Transform Infrared Spectroscopy analysis.Subsequently,structural characterization was done by 1H NMR analysis.In vitro antibacterial activity of fucoidan was performed by the agar plate diffusion method and Minimum Inhibitory Concentration.Results:The characteristic C-0-S bending vibration of sulfate substituent the axial C-4 was observed at 839 cm^(-1).Characterisitic signal of the fucoidan was detected in a different ppm of 1H NMR analysis.The maximum antibacterial activity(16.23±0.11)mm was obtained for Vibrio parahaemolyticus and the minimum activity(5.1±0.24)mm was recorded for Yersinia enterocolitica.The Minimum Inhibitory Concentration value was recorded between 2.5 to 10 mg/mL to the respective pathogens.Conclusions:The present study proved that fucoidan possessed the significant antibacterial activity against the tested fish bacterial pathogens.It could be further used as a natural antibiotic in an aquaculture system to control the bacterial diseases.However,the present study suggested that the further in vivo study is required to get the better understanding of the mode of action of fucoidan.展开更多
基金thank the State of Sao Paulo Research Foundation(FAPESP-Process 2011/07951-5)for the financial support.
文摘Intensive fish farming systems in Brazil have increased the disease incidence, mainly of bacterial origin, due to higher stocking density, high organic matter levels and poor quality of the aquatic environment that causes high mortality rates during outbreaks. The identification of pathogenic species using a fast and reliable method of diagnosis is essential for successful epidemiological studies and disease control. The present study evaluated the use of direct colony PCR in combination with 16S rRNA gene sequencing to diagnose fish bacterial diseases, with the goal of reducing the costs and time necessary for bacterial identification. The method was successful for all 178 isolates tested and produced bands with the same intensity as the standard PCR performed using pure DNA. In conclusion, the genetics methods allowed detecting the most common and important pathogens in Aquaculture, including 12 species of occurrence in Brazilian fish farms. The results of the present study constitute an advance in the available diagnostic methods for bacterial pathogens in fish farms.
文摘Objective:To investigate the antimicrobial activity of Clitoria ternatea(C.ternatea) against the fish pathogens viz.,Pseudomonas aeruginosa(P.aeruginosa),Escherichia coli(E.coli),Klebsiella pneumonia(K.pneumonia),Bacillus subtilis(B.subtilis),Aeromonas formican(A.formicans)s, Aeromonas hydrophila(A.hydrophila) and Streptococcus agalactiae(S.agalactiae )isolated from diseased Tilapia(Oreochromis niloticus).Methods:The extracts of C.ternatea was tested against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S.agalactiae by the agar well diffusion method.Results:Different extracts of C.ternatea showed inhibitory effects against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S. agalactiae.Ethyl acetate extracts of C.ternatea showed maximum of zone of inhibition against A. formicans(18 mm),A.hydrophilia(19 mm),B.subtilis(19 mm) and P.aeruginosa(21 mm) next to that ethanol extract of C.ternatea showed A.formicans(18 mm) and E.coli(14 mm) followed by Acetone extract showed maximum zone of inhibition S.agalactiae(19 mm) and K.pneumonia(17 mm).Conclusions:The antimicrobial activities of all the four plant extracts are comparable and their potential as alternative in the treatment of infectious by these microorganisms was present in the fish.Susceptibility testing is conducted on isolates using drugs selected on the basis of their importance to human medicine and use in fish production.
基金Supported by the Centre for Marine Living Resources and Ecology(Ministry of Earth Sciences),Kochi for financial assistance(Grant No.MoES/10MLR/2007).
文摘Objective:To evaluate the antibacterial activity and immunostimulant of red seaweedChondrococcus hornemanni pathogens.Methods:(C.hornemanni)(Kuetzing,1847)against marine ornamental fish antimicrobial activity against two fish pathogens and the partially purified potential compound was characterized by GC-MS.Purified seaweed extract was injected to the clownfish,Amphiprion sebae to study the innate immune response of these fishes.Results:In the present study,seaweed extract of C.hornemanni showed significant Aeromonas hydrophila(20 mm)and Vibrio parahaemolyticus(19 mm)at a concentration(25 mg/mL)shown higher antimicrobial activity.The white blood cell count and respirator burst activity was significantly increased in the experimental tanks(E1)and(E2)when compared with control.The extracts was found effective and had more than 80%inhibitory activity against Conclusions:Hence,it is concluded that the seaweed extracts of C.hornemanni had potential bioactive compounds and act an immunostimulant and improve the immune response to fish.
基金Supported by the Science and Engineering Research Board(SERB-F.No.SR/FT/LS-142/2009)Department of Science and Technology(DST),Government of India,New Delhi.
文摘Objective:To isolate bioactive molecules from marine seaweeds and check the antimicrobial activity against the fish pathogenic bacteria.Methods:Fresh marine seaweeds Gracilaria edulis,Kappaphycus spicifera,Sargassum wightii(S.wightii)were collected.Each seaweed was extracted with different solvents.In the study,test pathogens were collected from microbial type culture collection.Antibacterial activity was carried out by using disc diffusion method and minimum inhibition concentration(MIC)was calculated.Best seaweed was analysed by fourier transform infrared spectroscopy.The cured extract was separated by thin layer chromatography(TLC).Fraction was collected from TLC to check the antimicrobial activity.Best fraction was analysed by gas chromatography mass spectrometer(GCMS).Results:Based on the disc diffusion method,S.wightii showed a better antimicrobial activity than other seaweed extracts.Based on the MIC,methanol extract of S.wightii showed lower MIC than other solvents.S.wightii were separated by TLC.In this TLC,plate showed a two fraction.These two fractions were separated in preparative TLC and checked for their antimicrobial activity.Fraction 2 showed best MIC value against the tested pathogen.Fraction 2 was analysed by GCMS.Based on the GCMS,fraction 2 contains n-hexadecanoic acid(59.44%).Conclusions:From this present study,it can be concluded that S.wightii was potential sources of bioactive compounds.
基金Supported by the scheme of Centre with Potential for Excellence in Particular Area(CPEPA)[Grant No:F.No.8-2/2008(NS/PE)December 2011].
文摘Objective:To evaluate the antimicrobial capacity of fucoidan from the brown seaweed Turbinaria ornata against the marine ornamental fish bacterial pathogens.Methods:Fucoidan was isolated by the ethanol extraction method and the functional groups were identified by Fourier Transform Infrared Spectroscopy analysis.Subsequently,structural characterization was done by 1H NMR analysis.In vitro antibacterial activity of fucoidan was performed by the agar plate diffusion method and Minimum Inhibitory Concentration.Results:The characteristic C-0-S bending vibration of sulfate substituent the axial C-4 was observed at 839 cm^(-1).Characterisitic signal of the fucoidan was detected in a different ppm of 1H NMR analysis.The maximum antibacterial activity(16.23±0.11)mm was obtained for Vibrio parahaemolyticus and the minimum activity(5.1±0.24)mm was recorded for Yersinia enterocolitica.The Minimum Inhibitory Concentration value was recorded between 2.5 to 10 mg/mL to the respective pathogens.Conclusions:The present study proved that fucoidan possessed the significant antibacterial activity against the tested fish bacterial pathogens.It could be further used as a natural antibiotic in an aquaculture system to control the bacterial diseases.However,the present study suggested that the further in vivo study is required to get the better understanding of the mode of action of fucoidan.
