Transferable drug resistance plasmids in fish-pathogenic bacteria.
9718511490_p031-033.pdf (44.45Kb)Abstract
Chemotherapeutic agents have been developed for treating bacterial infections and have been widely used for cultured fish for the last 30 years in Japan. The extensive use of chemotherapeutants has resulted in an increase in the occurrence of drug resistance in fish-pathogenic bacteria and also in the bacterial flora of the intestinal tract of cultured fish. The kinds of chemotherapeutants used are correlated with the occurrence of the corresponding drug-resistant genes in fish-pathogenic bacteria. Almost all multiple-drug resistant strains are carried on the transferable R plasmid, although resistance in fish pathogens to nitrofuran derivatives and pyridonecarboxylic acids is associated with a chromosomal gene. The DNA sequences of R plasmids generally differ depending on the species of fish pathogen. Exceptions are the R plasmids of Aeromonas hydrophila and A. salmonicida, which have the same resistance markers as chloramphenicol, streptomycin, and sulfonamides (SA); and the R plasmids of A. hydrophila and Edwardsiella tarda, which have the same resistance markers as SA and tetracycline. The fish pathogens A. hydrophila, A. salmonicida, E. tarda, Enterococcus seriolicida, Pasteurella piscicida, and Vibrio anguillarum are all widely distributed in fish farms in various areas, and within each species the R plasmid has an identical DNA sequence. The chloramphenicol resistance (cat) gene of the R plasmid from Gram-negative bacteria was classified into CAT I, II, III, and IV according to the DNA sequence. The cat gene of P. piscicida was classified as CAT I, those of A. salmonicida and E. tarda were classified as CAT II, and that of V. anguillarum was classified as CAT II or IV, depending on the time the strains were isolated. The tetracycline-resistance determinants (Tet), which occur in six classes (Tet A through Tet G), were class D in the R plasmids obtained from strains of V. anguillarum that were isolated from 1989 to 1991. The Tet for strains of V. anguillarum isolated from 1973 to 1977 was classified as Tet B, while for strains isolated from 1980 to 1983 it was classified as Tet G.
Citation
Aoki, T. (2000). Transferable drug resistance plasmids in fish-pathogenic bacteria. In: J.R. Arthur, C.R. Lavilla-Pitogo, & R.P. Subasinghe (Eds.) Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines (pp. 31-33). Tigbauan, Iloilo, Philippines: Aquaculture Department, Southeast Asian Fisheries Development Center.
Publisher
Aquaculture Department, SEAFDECSubject
Type
Conference paperISBN
9718511490Collections
Related items
Showing items related by title, author, creator and subject.
-
Conference paper
The use of chemicals in aquaculture in Thailand
- In JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.), Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, Southeast Asian Fisheries Development CenterIn Thailand, many chemicals are used to treat diseases of cultured aquatic animals and to improve water quality in culture facilities. Along with the intensification of aquaculture practices that has occurred in recent years in Thailand, chemical use has also increased, particularly in marine shrimp culture. This paper summarizes information on the types of chemotherapeutants commonly used in Thailand, their sources and costs, the treatment regimes used, the adverse impacts that have resulted and the hazards posed. Also included is information on national regulations, a summary of on-going research, and recommendations to aquaculturists, producers and suppliers of chemicals, government agencies and scientists. It is concluded that although chemicals and drugs will continue to play an important role in the development of Thai aquaculture, they must be used with caution to avoid adverse effects such as environmental damage and the development of resistant strains of pathogens. To minimize chemical usage, additional emphasis needs to be placed on developing good management practices for aquaculture systems. -
Book | Conference publication
Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia.
- 2000 - Aquaculture Department, Southeast Asian Fisheries Development CenterThe use of chemicals is common in various aquaculture systems, as it is in many agricultural practices. However, with growing worldwide awareness of the need for responsible practices in aquaculture, governments and aquaculturists are increasingly concerned with the effects of the use of chemicals in aquaculture, especially those which appear likely to be hazardous to man, cultured stock and/or the environment. The need to synthesize and disseminate information on the use and management of double prime aquachemicals double prime was recognized by the Fishery Resources Division of the Food and Agriculture Organization of the United Nations (FAO) and the Southeast Asian Fisheries Development Center (SEAFDEC) Aquaculture Department, who convened double prime The Expert Meeting on the Use of Chemicals in Aquaculture in Asia, double prime which was held 20-22 May 1996 at the SEAFDEC facilities in Tigbauan, Iloilo, the Philippines. Support was provided by FAO, SEAFDEC and the Canadian International Development Agency s (CIDA) ASEAN Fund. The World Health Organization (WHO) supported the participation of a human health expert. The meeting was attended by 27 participants and more than 70 observers from the public and private sectors of 20 countries. Among the attendees were representatives from the Network of Aquaculture Centres in Asia-Pacific (NACA), the Fish Health Section of the Asian Fisheries Society (FHS/AFS), the Japan International Research Center for Agricultural Sciences (JIRCAS), the GESAMP Working Group on Environmental Impacts of Coastal Aquaculture, and the ICES Working Group on Environmental Interactions of Mariculture. The results of this expert workshop are presented in this volume. They include the texts of presentations on a wide range of topics (thematic reviews) related to the use of chemicals in aquaculture, with emphasis on the Asian Region, as well as country overview papers summarizing the use of aquachemicals in Asian countries. The contributions of the selected participants during the meeting are contained in this volume. -
Article
Changes induced in the gills of milkfish (Chanos chanos Forsskål) fingerlings after acute exposure to nifurpirinol (Furanace; P-7138)
-Bulletin of Environmental Contamination and Toxicology , 1995 - Springer VerlagThe need for a chemotherapeutant used specifically for fish disease became increasingly apparent with intensive fish culture practices, and with the possibility of bacterial resistance against drugs used for human and animal medicine (Austin 1985). With this in mind, Nifurpirinol (trade name Furanace; P-7138) was developed by the Dainippon Pharmaceutical Co., Ltd., Japan, and is currently manufactured in the United States as Prefuran. Studies have proven that the drug is effective against bacterial and fungal pathogens in a wide variety of aquatic animals. Most of the Nifurpirinol studies done in the past have dealt on its antimicrobial activity, tissue uptake, and effective treatment levels ranging from 0.5-2.5 mg/L. The 96-hr median lethal concentration (LC50) to channel catfish (Ictalurus punctatus Rafinesque) has also been determined at 0.945-1.90 mg/L, and at 1.70 mg/L for milkfish, Chanos chanos Forsskaal. However, there have only been two studies that have examined the histological effects on treated fish. Histopathologically, Mitchell et al. (1978) found hypertrophy and hyperplasia of the lamellar epithelium in channel catfish gills exposed to 0.5 mg/L for 4 d or longer at 24 plus or minus 2 degree C, while Amend and Ross (1970) working at 21 plus or minus 1 degree C observed no apparent changes in the gills of coho salmon (Oncorhynchus kisutch) exposed intermittently to 1 mg/L of Nifurpirinol. This paper describes the histological changes observed in the gills of milkfish fingerlings used in static, 96-hr Nifurpirinol toxicity tests. Milkfish was used because of its economic importance as a widely cultured food fish in Asia. The gills were chosen as target organs.
