Displaying publications 101 - 120 of 227 in total

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  1. Alongi DM, Chong VC, Dixon P, Sasekumar A, Tirendi F
    Mar Environ Res, 2003 May;55(4):313-33.
    PMID: 12517423
    The impact of floating net cages culturing the seabass, Lates calcarifer, on planktonic processes and water chemistry in two heavily used mangrove estuaries in Malaysia was examined. Concentrations of dissolved inorganic and particulate nutrients were usually greater in cage vs. adjacent (approximately 100 m) non-cage waters, although most variability in water-column chemistry related to water depth and tides. There were few consistent differences in plankton abundance, production or respiration between cage and non-cage sites. Rates of primary production were low compared with rates of pelagic mineralization reflecting high suspended loads coupled with large inputs of organic matter from mangrove forests, fishing villages, fish cages, pig farms and other industries within the catchment. Our preliminary sampling did not reveal any large-scale eutrophication due to the cages. A crude estimate of the contribution of fish cage inputs to the estuaries shows that fish cages contribute only approximately 2% of C but greater percentages of N (32-36%) and P (83-99%) to these waters relative to phytoplankton and mangrove inputs. Isolating and detecting impacts of cage culture in such heavily used waterways--a situation typical of most mangrove estuaries in Southeast Asia--are constrained by a background of large, highly variable fluxes of organic material derived from extensive mangrove forests and other human activities.
    Matched MeSH terms: Aquaculture*
  2. Ng WK
    Asia Pac J Clin Nutr, 2002;11 Suppl 7:S473-6.
    PMID: 12492637
    One key ingredient used in the formulation of aquafeed is fish oil, which is produced from small marine pelagic fish and represents a finite fishery resource. At the present time, global fish oil production has reached a plateau and is not expected to increase beyond current levels. Recent estimates suggest that fish oils may be unable to meet demands from the rapidly growing aquaculture industry by as early as 2005. Therefore, there is currently great interest within the aquafeed industry in evaluating alternatives to fish oils. The ever-expanding oil palm cultivation in Malaysia and other tropical countries offers the possibility of an increased and constant availability of palm oil products for aquafeed formulation. Research into the use of palm oil in aquafeed begun around the mid-1990s and this review examines some of the findings from these studies. The use of palm oil in fish diets has generally shown encouraging results. Improved growth, feed efficiency, protein utilisation, reproductive performance and higher concentrations of alpha-tocopherol in fish fillets have been reported. Recent evidence for the ability of palm oil to substitute for fish oil in catfish diets is reviewed. The potential of palm oil use in aquafeed and future experimental directions are suggested. The aquaculture feed industry offers a great avenue to increase and diversify the use of palm oil-based products.
    Matched MeSH terms: Aquaculture*
  3. Shekhar KC
    PMID: 9656350
    Epidemiological studies have been conducted to determine the association between fish and disease. The fish were obtained from rivers, streams, ponds and lakes but few from aquaculture farms. While no defined studies have been carried out in Malaysia, baseline data show that fish obtained from aquaculture farms (mixed farming) contributed to cases of opisthorchiasis and clonorchiasis.
    Matched MeSH terms: Aquaculture*
  4. Székely C, Shaharom-Harrison F, Cech G, Mohamed K, Molnár K
    Dis Aquat Organ, 2009 Jan 28;83(1):49-57.
    PMID: 19301636 DOI: 10.3354/dao01990
    We describe new myxosporean species from Malaysian fishes cultured in pond farms and net-cages. Myxobolus omari sp. nov. and M. leptobarbi sp. nov. were found in the muscles of Pangasianodon hypophthalmus and Leptobarbus hoevenii, respectively, while plasmodia and spores of Thelohanellus zahrahae sp. nov. and Henneguya daoudi sp. nov. were detected in the gills of Barbonymus gonionotus and Trichogaster trichopterus, respectively. Plasmodia and spores found in these fishes differed from the known myxosporean species in respect of their morphology, tissue tropism and 18S rDNA structure. No major pathological changes were found, but in the future these species might pose a potential threat to more intensified fish culture.
    Matched MeSH terms: Aquaculture*
  5. Ismail NAH, Aris AZ, Wee SY, Nasir HM, Razak MR, Kamarulzaman NH, et al.
    Food Chem, 2021 May 30;345:128806.
    PMID: 33352402 DOI: 10.1016/j.foodchem.2020.128806
    The presence and distribution of endocrine-disrupting chemicals (EDCs) in the mariculture fish from Pulau Kukup, Johor of Malaysia have been studied along with the impact on human health. Six different species of mariculture fish were collected, due to their high consumption in the Asian region-especially Malaysia, to assess their levels of EDCs. The highest concentration of EDCs detected in the muscle was dexamethasone (2.37-15.84 ng/g) and (0.77-13.41 ng/g), in the liver was dexamethasone (<2.54-43.56 ng/g) and progesterone (2.23-9.78 ng/g), and in the reproductive organ are dexamethasone (<2.54-37.23 ng/g) and caffeine (0.21-18.92 ng/g). The human health risk assessment in the current study suggested that there is no potential risk to the consumer because the hazard index was below 1 (HI 
    Matched MeSH terms: Aquaculture*
  6. Akter R, Yagi N, Sugino H, Thilsted SH, Ghosh S, Gurung S, et al.
    Nutrients, 2020 Sep 04;12(9).
    PMID: 32899764 DOI: 10.3390/nu12092705
    The consumption of high-quality diverse diets is crucial for optimal growth, health, and wellbeing.

    OBJECTIVE: This study assessed the diet quality of households by their type of engagement in homestead aquaculture and/or horticulture. Socio-demographic determinants of diet quality were also studied.

    METHOD: Diet quality was assessed using a nutrient adequacy ratio (NAR), based on the preceding 7 days' dietary recall at the household level. Adult male equivalent units (AMEs) were used for age- and sex-specific intra-household distribution of household intakes. Mean adequacy ratios (MAR) were computed as an overall measure of diet quality, using NAR.

    RESULTS: Better diet quality (mean ± SD) was associated with households engaged in both homestead aquaculture and horticulture (0.43 ± 0.23; p < 0.001) compared to only one type of agriculture (0.38 ± 0.20) or none (0.36 ± 0.20). Tukey's post-hoc test confirmed significant differences in diet quality between both and either engagement (0.05 ± 0.01, p < 0.001), both and no engagement (0.07 ± 0.01, p < 0.001), and either and no engagement households (0.02 ± 0.01, p < 0.001). Beyond farm production of nutrient-rich foods, generalized estimating equations showed that diet quality was influenced by the higher educational level and occupation of adult household members, higher daily per capita food expenditure, sex, family size and region.

    CONCLUSIONS: Projects that promote and support household engagement in both homestead aquaculture and horticulture have the potential to improve the diet quality of households.

    Matched MeSH terms: Aquaculture/statistics & numerical data*
  7. Okomoda VT, Mithun S, Chatterji A, Effendy MAW, Oladimeji AS, Abol-Munafi AB, et al.
    Fish Physiol Biochem, 2020 Aug;46(4):1497-1505.
    PMID: 32378001 DOI: 10.1007/s10695-020-00807-7
    This study was designed to optimize the culture conditions of juvenile Epinephelus fuscoguttatus (Forsskål, 1775) under laboratory conditions. To this effect, the rate of oxygen consumption was monitored as an index of stress under different temperature, salinity, pH, photoperiod, and urea concentrations. The result obtained after 12 h of exposure suggests the preference of the juvenile E. fuscoguttatus to a temperature range of 15-25 °C and salinity of 30 ppt. Based on this study, temperature was found to be the most lethal as 100% mortality was observed after 6 h in fish exposure to temperatures above the optimal (≥ 30 °C). However, the oxygen consumption rate was similar under the different pH, photoperiod, and urea concentration tested. It was concluded that water temperature was most critical in terms of respiration physiology of the juvenile E. fuscoguttatus given the range and levels of environmental factors tested in this study.
    Matched MeSH terms: Aquaculture/standards*
  8. Mohamed Ramli N, Giatsis C, Md Yusoff F, Verreth J, Verdegem M
    PLoS One, 2018;13(4):e0195862.
    PMID: 29659617 DOI: 10.1371/journal.pone.0195862
    The experimental set-up of this study mimicked recirculating aquaculture systems (RAS) where water quality parameters such as dissolved oxygen, pH, temperature, and turbidity were controlled and wastes produced by fish and feeding were converted to inorganic forms. A key process in the RAS was the conversion of ammonia to nitrite and nitrite to nitrate through nitrification. It was hypothesized that algae inclusion in RAS would improve the ammonia removal from the water; thereby improving RAS water quality and stability. To test this hypothesis, the stability of the microbiota community composition in a freshwater RAS with (RAS+A) or without algae (RAS-A) was challenged by introducing an acute pH drop (from pH 7 to 4 during three hours) to the system. Stigeoclonium nanum, a periphytic freshwater microalga was used in this study. No significant effect of the algae presence was found on the resistance to the acute pH drop on ammonia conversion to nitrite and nitrite conversion to nitrate. Also the resilience of the ammonia conversion to the pH drop disruption was not affected by the addition of algae. This could be due to the low biomass of algae achieved in the RAS. However, with regard to the conversion step of nitrite to nitrate, RAS+A was significantly more resilient than RAS-A. In terms of overall bacterial communities, the composition and predictive function of the bacterial communities was significantly different between RAS+A and RAS-A.
    Matched MeSH terms: Aquaculture*
  9. Ng C, Chen H, Goh SG, Haller L, Wu Z, Charles FR, et al.
    Mar Pollut Bull, 2018 Oct;135:475-480.
    PMID: 30301062 DOI: 10.1016/j.marpolbul.2018.07.055
    Poor microbial water quality jeopardizes the health and safety of food produced by aquaculture farms. Three fish farms and transect sites in Singapore were assessed for microbial water quality and antimicrobial resistance determinants. Of the 33 multidrug resistant E. coli isolated from surface waters of the Johor Straits, 81.8% were ESBL producers. The relative abundance of sul1, qnrA and intI1 genes were higher in sediments than surface waters. Among the surface water samples, higher concentrations (10-1-101) of beta-lactamases (blaSHV, blaOXA, blaCTX-M) were detected in the transect sites. This study highlights a potential antimicrobial resistance transmission chain from environmental waters, to animal carriers and humans.
    Matched MeSH terms: Aquaculture*
  10. Ismail NAH, Wee SY, Haron DEM, Kamarulzaman NH, Aris AZ
    Mar Pollut Bull, 2020 Jan;150:110735.
    PMID: 31784268 DOI: 10.1016/j.marpolbul.2019.110735
    Endocrine-disrupting compounds (EDCs) such as hormones, pesticides, phenolic compounds, and pharmaceuticals compounds can cause adverse effects on humans, animals, and other living organisms. One of the largest mariculture areas situated in Pulau Kukup, Johor, Malaysia, is actively involved in exporting marine fish to other countries worldwide. This paper aims to provide baseline data on the level of EDC pollutants found in mariculture sediments in Malaysia since no reports have investigated this issue. Calculated samples recovered are between 50.39 and 129.10% at 100 ng/g spiking level. The highest concentration in the sediment samples was bisphenol A (0.072-0.389 ng/g dry weight) followed by diethylstilbestrol (<0.208-0.331 ng/g dry weight) and propranolol (<0.250-0.275 ng/g dry weight). Even though the concentrations of the targeted compounds obtained were low, their effects could become more evident longer term, which raises not only environmental health concerns but the potential risk to humans.
    Matched MeSH terms: Aquaculture*
  11. Sun F, Wang C, Chen H, Zheng Z
    Curr Microbiol, 2020 May;77(5):816-825.
    PMID: 31927597 DOI: 10.1007/s00284-019-01862-x
    Enteromorpha prolifera blooms considerably affected coastal environments in recent years. However, the effects of E. prolifera on microbial ecology and function remained unknown. In this study, metagenomic sequencing was used to investigate the effect of E. prolifera bloom on the microbial communities and functional genes in an aquaculture environment. Results showed that E. prolifera bloom could significantly alter the microbial composition and abundance, and heterotrophic bacteria comprised the major groups in the E. prolifera bloom pond, which was dominated by Actinomycetales and Flavobacteriales. The study indicated that viruses played an important role in shaping the microbial community and diversity during E. prolifera bloom. These viruses affected various dominant microbial taxa (such as Rhodobacteraceae, Synechococcus, and Prochlorococcus), which produced an obvious impact on potential nutrient transformation. Functional annotation analysis indicated that E. prolifera bloom would considerably shift the metabolism function by altering the structure and abundance of the microbial community. E. prolifera bloom pond had the low ability of potential metabolic capabilities of nitrogen, sulfur, and phosphate, whereas promoted gene abundance of genetic information processing. These changes in the microbial community and function could produce serious effect on aquaculture ecosystem.
    Matched MeSH terms: Aquaculture*
  12. Yao Ang C, Sano M, Dan S, Leelakriangsak M, M Lal T
    Biocontrol Sci, 2020;25(1):1-7.
    PMID: 32173662 DOI: 10.4265/bio.25.1
    Aquaculture is developing so fast that infectious disease outbreak happens regularly. Antibiotic treatment results in development of antibiotic resistance pathogens, thus cause urgent action in searching of other alternative treatment method. Postbiotic was one of the explored strategies among various proposed alternatives. Due to its benefits in agriculture industry, it may be useful in aquaculture industry. Although many reviews were reported on other alternative strategies, the review on postbiotic in aquaculture is limited. This mini review provides an overview of different postbiotics as aquaculture disease control agents. Peptides and exopolysaccharides have antimicrobial properties against bacterial pathogens. Then, short chain fatty acids have both antimicrobial activities against bacterial pathogens and immunostimulating effects to aquatic organism. Vitamins, peptidoglycan and lipopolysaccharide are reported as immunostimulants. Finally, cell surface proteins and teichoic acid can act as vaccine.
    Matched MeSH terms: Aquaculture/methods
  13. Lee PT, Yamamoto FY, Low CF, Loh JY, Chong CM
    Front Immunol, 2021;12:773193.
    PMID: 34975860 DOI: 10.3389/fimmu.2021.773193
    The gastrointestinal immune system plays an important role in immune homeostasis regulation. It regulates the symbiotic host-microbiome interactions by training and developing the host's innate and adaptive immunity. This interaction plays a vital role in host defence mechanisms and at the same time, balancing the endogenous perturbations of the host immune homeostasis. The fish gastrointestinal immune system is armed with intricate diffused gut-associated lymphoid tissues (GALTs) that establish tolerance toward the enormous commensal gut microbiome while preserving immune responses against the intrusion of enteric pathogens. A comprehensive understanding of the intestinal immune system is a prerequisite for developing an oral vaccine and immunostimulants in aquaculture, particularly in cultured fish species. In this review, we outline the remarkable features of gut immunity and the essential components of gut-associated lymphoid tissue. The mechanistic principles underlying the antigen absorption and uptake through the intestinal epithelial, and the subsequent immune activation through a series of molecular events are reviewed. The emphasis is on the significance of gut immunity in oral administration of immunoprophylactics, and the different potential adjuvants that circumvent intestinal immune tolerance. Comprehension of the intestinal immune system is pivotal for developing effective fish vaccines that can be delivered orally, which is less labour-intensive and could improve fish health and facilitate disease management in the aquaculture industry.
    Matched MeSH terms: Aquaculture/methods*
  14. Fan S, Ji B, Abu Hasan H, Fan J, Guo S, Wang J, et al.
    Bioprocess Biosyst Eng, 2021 Aug;44(8):1733-1739.
    PMID: 33772637 DOI: 10.1007/s00449-021-02556-0
    Microalgal-bacterial granular sludge (MBGS) process has become a focal point in treating municipal wastewater. However, it remains elusive whether the emerging process can be applied for the treatment of aquaculture wastewater, which contains considerable concentrations of nitrate and nitrite. This study evaluated the feasibility of MBGS process for aquaculture wastewater treatment. Result showed that the MBGS process was competent to remove respective 64.8%, 84.9%, 70.8%, 50.0% and 84.2% of chemical oxygen demand, ammonia-nitrogen, nitrate-nitrogen, nitrite-nitrogen and phosphate-phosphorus under non-aerated conditions within 8 h. The dominant microalgae and bacteria were identified to be Coelastrella and Rhodobacteraceae, respectively. Further metagenomics analysis implied that microbial assimilation was the main contributor in organics, nitrogen and phosphorus removal. Specifically, considerable nitrate and nitrite removals were also obtained with the synergy between microalgae and bacteria. Consequently, this work demonstrated that the MBGS process showed a prospect of becoming an environmentally friendly and efficient alternative in aquaculture wastewater treatment.
    Matched MeSH terms: Aquaculture*
  15. Yasin IM, Razak NF, Natrah FMI, Harmin SA
    J Environ Biol, 2016 07;37(4 Spec No):791-800.
    PMID: 28779739
    A total of 58 Gram-positive bacteria strains were isolated from the marine environment and screened for potential probiotics for disease prevention and improving the productivity of tiger grouper Epinephelus fuscoguttatus larvae and juveniles. The bacteria were identified as Bacillus licheniformis, B. subtilis, B. circulans, B. sphaericus, B. cereus, Brevibacillus brevis, Corynebacterium propinquum, Leifsonia aquatica and Paenibacillus macerans. Only 24 strains showed antagonistic activities against four pathogenic strains; Vibrio alginolyticus, V. harveyi, V. parahaemolyticus and Aeromonas hydrophila, where two of the Bacillus strains, B12 and B45 demonstrated intermediate to highest level of inhibitory activity against these pathogenic strains, respectively. Further assessment by co-culture assay showed that Bacillus strain B12 exhibited a total inhibition of V. alginolyticus, while B45 strain displayed no inhibitory activity. Mixed culture of Bacillus B12 and B45 strains to outcompete V. alginolyticus was observed at a cell density of 10(7) CFU ml(-1). Molecular identification and phylogenetic tree analysis have categorized Bacillus strain B12 to the reference strains GQ340480 and JX290193 of? B. amyloliquafaciens, and Bacillus strain B45 with a reference strain JF496522 of B. subtilis. Safety tests of probionts by intraperitoneal administration of B12 and B45 strains at cell densities of 103, 105 and 10(7) CFU ml(-1) revealed no abnormalities and cent percent survival for healthy Epinephelus fuscoguttatus juveniles within 15 days of experimental period. Overall, the study revealed that Bacillus B12 strain possesses tremendous probiotic potential that could be used as a feed supplement in tiger grouper diets. ?
    Matched MeSH terms: Aquaculture*
  16. Rizan N, Yew CY, Niknam MR, Krishnasamy J, Bhassu S, Hong GZ, et al.
    Sci Rep, 2018 01 17;8(1):896.
    PMID: 29343758 DOI: 10.1038/s41598-017-18825-6
    The exciting discovery of the semiconducting-like properties of deoxyribonucleic acid (DNA) and its potential applications in molecular genetics and diagnostics in recent times has resulted in a paradigm shift in biophysics research. Recent studies in our laboratory provide a platform towards detecting charge transfer mechanism and understanding the electronic properties of DNA based on the sequence-specific electronic response, which can be applied as an alternative to identify or detect DNA. In this study, we demonstrate a novel method for identification of DNA from different shrimp viruses and bacteria using electronic properties of DNA obtained from both negative and positive bias regions in current-voltage (I-V) profiles. Characteristic electronic properties were calculated and used for quantification and further understanding in the identification process. Aquaculture in shrimp industry is a fast-growing food sector throughout the world. However, shrimp culture in many Asian countries faced a huge economic loss due to disease outbreaks. Scientists have been using specific established methods for detecting shrimp infection, but those methods do have their significant drawbacks due to many inherent factors. As such, we believe that this simple, rapid, sensitive and cost-effective tool can be used for detection and identification of DNA from different shrimp viruses and bacteria.
    Matched MeSH terms: Aquaculture/methods
  17. Er HH, Lee LK, Lim ZF, Teng ST, Leaw CP, Lim PT
    Environ Sci Pollut Res Int, 2018 Aug;25(23):22944-22962.
    PMID: 29858995 DOI: 10.1007/s11356-018-2389-0
    Effects of aquaculture activities on the environmental parameters and phytoplankton community structure were investigated in a semi-enclosed lagoon located at Semerak River, Malaysia. Elevated concentrations of phosphate and ammonia were observed at the aquaculture area and the inner lagoon. Relatively low dissolved oxygen, high total chlorophyll a, and high phytoplankton abundances but low species richness were recorded. Chaetoceros, Pseudo-nitzschia brasiliana, Blixaea quinquecornis, and Skeletonema blooms were observed, and some were associated with anoxia condition. Eutrophication level assessed by UNTRIX suggests that the water quality in the lagoon is deteriorating. Dissolved inorganic phosphorus and nitrogen at the impacted area were 15 and 12 times higher than the reference sites, respectively. Such trophic status indices could provide a useful guideline for optimal aquaculture management plan to reduce the environmental impact caused by aquaculture.
    Matched MeSH terms: Aquaculture/methods*
  18. Kasan NA, Ghazali NA, Ikhwanuddin M, Ibrahim Z
    Pak J Biol Sci, 2017;20(6):306-313.
    PMID: 29023055 DOI: 10.3923/pjbs.2017.306.313
    BACKGROUND AND OBJECTIVE: A new green technology to reduce environmental damages while optimizing production of Pacific Whiteleg shrimp, Litopenaeus vannamei was developed known as "Biofloc technology". Microbial communities in biofloc aggregates are responsible in eliminating water exchange and producing microbial proteins that can be used as supplemented feed for L. vannamei. This study aimed to isolate and identify potential bioflocculant-producing bacteria to be used as inoculum for rapid formation of biofloc.

    MATERIALS AND METHODS: For the purpose of this study, bacterial communities during 0, 30 and 70 days of culture (DOC) of L. vannamei grow-out ponds were isolated and identified through phenotypic and 16S rDNA sequences analysis. Phylogenetic relationships between isolated bacteria were then evaluated through phylogenetic tree analysis. One-way analysis of variance (ANOVA) was used to compare the differences of microbial communities at each DOC.

    RESULTS: Out of 125 bacterial isolates, nine species of bacteria from biofloc were identified successfully. Those bacteria species were identified as Halomonas venusta, H. aquamarina, Vibrio parahaemolyticus, Bacillus infantis, B. cereus, B. safensis, Providencia vermicola, Nitratireductor aquimarinus and Pseudoalteromonas sp., respectively. Through phylogenetic analysis, these isolates belong to Proteobacteria and Firmicutes families under the genera of Halomonas sp., Vibrio sp., Bacillus sp., Providencia sp., Nitratireductor sp. and Pseudoalteromonas sp.

    CONCLUSION: In this study, bioflocculant-producing bacteria were successfully identified which are perfect candidates in forming biofloc to reduce water pollution towards a sustainable aquaculture industry. Presence of Halomonas sp. and Bacillus sp. in all stages of biofloc formation reinforces the need for new development regarding the ability of these species to be used as inoculum in forming biofloc rapidly.

    Matched MeSH terms: Aquaculture/methods*
  19. Samarakoon J
    Ambio, 2004 Feb;33(1-2):34-44.
    PMID: 15083648
    This article is based on the findings of the Global International Waters Assessment (GIWA) Subregion 53, Bay of Bengal. It introduces the Subregion. The wide disparity in development indicators in the Bay of Bengal Subregion (BOBSR) is presented. The large population of poor people living in South Asia is presented as a factor that needs special attention. The article focuses on the 3 geographic sites selected for detailed analysis: i) the Ganges-Brahmaputra-Meghna river systems; ii) the Merbok Estuary mangroves, Malaysia; and iii) the Sunderbans mangroves, Bangladesh. Integrated water management based upon regional cooperation among Bangladesh, India and Nepal holds opportunities for mutual benefit. Policy options are proposed. For mangrove ecosystems, the impacts of urbanization in Malaysia and the unmanaged expansion of shrimp farming in Bangladesh are analyzed. Improved governance was seen to hold promise for enhancing economic benefits from shrimp farming while safeguarding the natural ecological system. However, these measures need to be a part of national efforts to achieve the UN Millennium Development Goals.
    Matched MeSH terms: Aquaculture/economics
  20. Letchumanan V, Pusparajah P, Tan LT, Yin WF, Lee LH, Chan KG
    Front Microbiol, 2015;6:1417.
    PMID: 26697003 DOI: 10.3389/fmicb.2015.01417
    High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio sp; however, tox-R assay showed that only 44.4% (200/450) of these were V. parahaemolyticus. Out of these 200 samples, 6.5% (13/200) were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all V. parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR) was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin,70.5% to kanamycin, 73% to cefotaxime, and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to five antibiotics). Among the 13 trh-positive strains, almost 70% (9/13) demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all V. parahaemolyticus isolates revealed that 86.5% (173/200) contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2 kb to greater than 10 kb. 6/13 of the pathogenic V. pathogenic strains contained plasmid. After plasmid curing, the plasmid containing pathogenic strains isolated in our study have chromosomally mediated ampicillin resistance while the remaining resistance phenotypes are plasmid mediated. Overall, our results indicate that while the incidence of pathogenic V. parahaemolyticus in shellfish in Selangor still appears to be at relatively reassuring levels, antibiotic resistance is a real concern and warrants ongoing surveillance.
    Matched MeSH terms: Aquaculture
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