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Title:	Characterization of Vibrio And Aeromonas species in selected Malaysian waters
Authors:	Ashraf Abbas Drais (P72593)
Supervisor:	Asmat Ahmad, Assoc. Prof. Dr.
Keywords:	Vibrio Pathogenic bacteria -- Physiology Bacteria -- Physiology Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	10-Feb-2019
Description:	This study was conducted to identify the potentially pathogenic, the prevalence of antibiotic resistance and genetic diversity of Vibrio and Aeromonas species. A total of 32 sediments and 30 water samples were collected between March 2014 and February 2016 from 12 locations in Malaysia (Mersing, Johor; Bachok, Kelantan; Port Klang, Selangor; Port Dickson, Negeri Sembilan and Kota Kinabalu, Sabah). A total of 582 presumptive Vibrio spp. isolates and 441 Aeromonas spp. were isolated. Thiosulfate-citrate-bile salts-sucrose (TCBS) and Chromogenic Vibrio Agar were used to isolate Vibrio spp. while mRS Agar medium was used to isolate Aeromonas spp. Identification on species level was done by biochemical tests and specific gene markers ( gyrB, ompW, toxRvf, toxRvh, gyrBVp, gyrBVv, gyrBAc, gyrBAh, asa1 and rpoBAv genes). A total of 507 isolates were confirmed as Vibrio spp. and 346 were confirmed as Aeromonas spp. Of the Vibrio spp., 84 isolates were confirmed as Vibrio alginolyticus, 81 isolates were V. cholerae, 56 isolates were V. fluvialis, 55 isolates were V. harveyi, 129 isolates were V. parahaemolyticus, and 93 isolates were V. vulnificus. For Aeromonas spp., 69 isolates were Aeromonas caviae, 141 isolates were A. hydrophila, 79 isolates were A. sobria, and 38 isolates were A. veronii. A combination of standard culture methods and molecular approaches were used to investigate the occurrence of 9 virulence characteristics (protease, elastase, phospholipase, lipase, amylase, DNase, gelatinase, β-hemolysis and biofilm production).The antibiotic resistance test performed for 14 antibiotics by the disc diffusion method showed a high level of Multi-Antibiotic resistance (MAR) index. Characterization of antibiotic resistance was conducted using a phenotypic antibiogram analysis (antibiotic resistance patterns) and a genotypic analysis by detection of 7 antibiotic resistant genes including Streptomycin (strB), β-lactamase (blaP1), Chloramphenicol (floR), Tetracycline (tetA), Erythromycin (ermA and ermB), Quinolone resistance protein (qnrA) and Aminoglycosides (aac-3-IIa and aac-6-Ib). High MAR index (> 0.2) was observed among all the tested bacteria. Plasmids were detected in 61 % of the isolates and having one to five different molecular weights of plasmid bands that ranged in size from 1.2 to 33.5 kb. Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) and Enterobacterial Repetitive Interogenic Consensus-PCR (ERIC-PCR) were carried out for all pathogenic isolates. High level of local geographical genetic variation in all isolates found in this study showed that both the RAPD-PCR and ERIC-PCR typing methods to be useful for subspecies discrimination. The presence of Vibrio and Aeromonas spp. populations in a coastal area with a high value of MAR index and virulence characteristics pose a human health risk. Therefore, the need to determine the prevalence of Vibrio and Aeromonas spp., their antibiotic resistance as well as their genetic diversity from selected marine water in Malaysia becomes imperative.,Certification of Masters/Doctoral Thesis is not available,Ph.D.
Pages:	411
Call Number:	QR82.S6A834 2019 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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