The impact of chlortetracycline residue from fresh chicken manure on pond ecosystem | |
| Author | Weena Koeypudsa |
| Call Number | AIT Diss. no.AQ-05-02 |
| Subject(s) | Integrated agricultural systems Fishes--Feeding and feeds Fish ponds |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctoral of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AQ-05-02 |
| Abstract | Integrated chicken-fish farming, where chicken manure is used to fertilized fish ponds, is well established in Asia for a long time. The antibiotics are used in chicken feed as prophylactic or curative measures and to promoting growth. There are environmental and public health concerns on the use of contaminated fecal matter as a pond input due to potential contamination of aquatic environment and fish with antibiotic residue, as well as the potential for aquatic bacteria to develop resistance to the particular antibiotic group. This study was designed to investigate the use of chlortetracycline (CTC) in chicken feed and the effects of CTC contaminated manure to the aquatic environment, bacteria, and fish. The study consisted of four experiments. The first experiment was conducted to evaluate residue level in chicken manure when CTC is added into chicken feed. Integrated chicken-fish culture system was simulated during the second experiment to investigate the effects of CTC contaminated chicken manure on aquatic microorganisms, fish (sexreversed Nile tilapia; Oreochromis niloticus), water column and sediments. The third experiment was conducted to investigate the virulence of Aeromonas hydrophila isolated from fish ponds fertilized with CTC residue contaminated chicken manure and its resistance to other type of antibiotics. Effect of A. hydrophila isolations on the blood clotting time of hybrid catfish (Clarias gariepinus Burchell x C. macrocephalus Gunther) was investigated during the fourth experiment. CTC residue in chicken manure, aquatic environment and fish body was measured by using radio-immuno microbial receptor assay (Charm II test). Results showed that when chickens were fed with CTC added feeds at rate of 50, 200 and 800 mg kg', CTC residue was detected in the manure on the first day after feeding. Residue levels for chicken fed 50, 200 and 800 mg kg' CTC feed were 0, 1.5 and 5.1 ppb, respectively. After the cessation of CTC-added feed, the residue was dramatically dropped to a negligible level. Results of the investigation on integrated chicken-fish culture system showed that when CTC contaminated chicken manure was used to fertilized fish ponds, CTC can be detected in the water column by the 20th day. CTC concentration in water then gradually increased from 0.26 to 12.13 ppb at the end of experiment. CTC concentration in edible fish muscle, intestinal tract, and sediments of CTC contaminated manure treatments were 7.21, 22.104 and 1.788 ppb, respectively, at the end of the experiment. CTC residue was not detected in the control treatment. The results showed the potential for antibiotic residue accumulation in fish, water and sediments when CTC contaminated chicken manure is used for fertilization fishponds. Bacteria from chicken feed, manure, water column, sediments, fish muscle, and viscera were isolated and identified using API 20E strips (BioMerieux, France). Total viable count showed that bacteria in chicken manure were higher than counts from chicken feed and water column. Enterobacter cloacae, Escherichia coli, Klebsiella ornithiolytica, K. pneumonae, K. terrigina, Proteus vulgaris, Pseudomonas spp., Ps. putrifaciens, Ps. jluorescense, Salmonella spp., S. ari-onae and A. hydrophila were identified in chicken feed, manure, water column, sediments, fish muscle, and viscera. A. hydrophila was the dominant bacteria in all samples. Minimal inhibitory concentration (MIC) of CTC was determined by exposing isolated A. hydrophila to different concentrations of CTC. The MIC that inhibits 100% A. hydrophila isolations from the control group and CTC contaminated group were 10 and 100 ppm, respectively. The result showed that approximately 10-fold higher dose of CTC is required to inhibit A. hydrophila isolates from CTC contaminated fish tanks. Each A. hydrophila isolate from CTC contaminated tanks was resistant to CTC, oxytetracycline, doxycycline, and tetracycline but susceptible to the rest of antibiotic agents. The experiment investigated the virulence of A. hydrophila isolated from simulated chickenfish integrated farming system showed that the majority of isolations were virulent against catfish. Median lethal dose (LD50) was ranged from 4.41 x 107 to 4.32 x 108 colony forming unit ml,'. However, prior exposure to CTC residue did not make A. hydrophila more virulent. Hemolysis reaction (on sheep blood agar) showed that hemolysin is involved in fish pathogenicity. Blood-clotting time of catfish infected with A. hydrophila after 6 and 24 hr was found to be 127.55 and 273.78 second, respectively. The results showed that blood-clotting time of control fish was ranged from 39 to 43 second. Infected catfish had approximately 3 to 7-fold prolong blood-clotting time compared with non-infected fish. There was no effect on the blood clotting time of fish injected with A. In druphilLl isolated from the control and CTC contaminated treatment tanks. Hemorrhage and blood congestion was developed within 24 hr after injection of A. hydrophila inoculations. Histopathological examination indicated that spleen and kidney contained the most of phagocytic cells and macrophages and blood was congested in the liver. In conclusion, the results demonstrate the presence of antibiotic residue in fish and aquatic environment when CTC contaminated chicken manure is used for pond fertilization. However, the observed CTC levels in fish, water, and sediments were lower than the recommended MRL. CTC residue in manure makes aquatic bacteria resistance to tetracycline group of antibiotics. It may be unrealistic to expect farmers to abandon the use of antibacterial compounds in animal husbandry but a reduction and the safe use of antibiotics should be encouraged. Fish farmers should be encouraged to take measures to withdraw animal manure applications to fish ponds for a sufficient period of time before harvesting fish. |
| Year | 2005 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AQ-05-02 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Yakupitiyage, Amararatne |
| Examination Committee(s) | Rakshit, Sudip Kumar;Jirasak Tangtrongpiros;Hatai, Kishio; |
| Scholarship Donor(s) | Royal Thai Government; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2005 |