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Title:	Antimicrobial activity of marine actinomycetes species against bacteria from fish, sediment and water in west costal of Peninsular Malaysia
Authors:	Orooba Meteab Faja (P79855)
Supervisor:	Asmat Ahmad, Assoc. Prof. Dr.
Keywords:	Marine bacteria Fishes -- Diseases
Issue Date:	Jul-2018
Description:	Most fish diseases are commonly caused by bacteria present in fish ponds. In the present study, marine bacteria Actinomycetes from (Kukup-Johor, Balik Pulau-Penang and Kuala Linggi-Melaka) were isolated and screened to examine antibacterial activites against bacteria originating from pond sediments, water and fish sources with n=22, 28 and 40 respectively . A total of ninety bacteria isolates were extracted from the sources inhabited by sea bass, snapper, grouper and tilapia. Two most widespread genera found were Vibrio spp. and Aeromonas spp. The former marine species (Vibrio spp.) yielded 23%, 29% and 28% and the latter (Aeromonas spp.) 23%, 18% and 20% from sediments, water and fish samples respectively. The target bacteria isolates showed wide differences in antibiotic susceptibility and ability to form biofilm. Bacteria isolated from sediments showed high resistance toward novobiocin, kanamycin, ampicillin and streptomycin, while those isolated from water samples showed high resistance to vancomycin, penicillin, streptomycin and tetracycline. Isolates from fish were highly resistant to vancomycin, ampicillin, streptomycin and tetracycline. Isolates from sediments produced high biofilm of which 68% were strong biofilm formers. Pathogenicity of A. hydrophila SFT3 isolate was tested on carp (Cyprinus carpio L.) by intraperitoneal (IP) and intramuscular (IM) routes with a standard dose of 1.2 x 107 cfu/ml. Clinical symptoms observed comprised of petechiae and reddening of the abdomen, hemorrhage and large ulcerative lesions at the injection sites. Microscopically, predominant histopathological lesions in the liver, kidney and gills were observed. Mortality of up to 100% and 85% were recorded within 14-15 days post inoculation in the IP and IM groups respectively. Out of eleven isolates of Actinomycetes, only four (M1, SDJ1, SDJ9 and SDJ10) displayed significant antibacterial activities against selected fish bacteria. The optimum growth conditions for the most active isolates of Actinomycetes, Streptomyces sp. SDJ10 was starch casein broth (SCB)medium, at a tempearture of 28oC and pH 7. Ethyl acetate crude extract of Streptomyces sp. SDJ10 isolate was further subjected to extraction and purification by TLC, GC-MS, HPLC and NMR. The most active compound for Streptomyces sp. isolate against fish isolate of A. hydrophila SFT3 was identified as Eicosane. The species A. hydrophila SFT3 was selected as a target for antibacterial activity of Streptomyces sp. SDJ10 because of its multiple antibiotic resistance and strongest biofilm formation compared with other bacteria in the study. In conclusion, the antibacterial activity of the Actinomycete isolate of Streptomyces sp. SDJ10 is remarkably promising and has the potentiality of being as antibacterial agent against fish bacteria A. hydrophila (SFT3).,'Certification of Master's/Doctoral Thesis' is not available,Ph.D.
Pages:	238
Call Number:	SH171.F335 2018 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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