Abstract

Recent statistics compiled by the Pet Industry Joint Advisory Council indicate that 10% of United States households (9.4 million) maintain freshwater aquaria with an additional 0.6 million households containing marine aquaria.¹ A filter with bacteriocidal activity that is also safe for pet fish is highly desirable and could possibly reduce the practice of indiscriminate shotgun antimicrobial usage. Such a filter would also have potential value to recirculating food fish and invertebrate aquaculture operations.

Aeromonas salmonicida is an important pathogen of fishes and is typically treated with a variety of antimicrobial compounds.^{2,3,4,5,6,7,8} This study utilized the in vitro shaker flask method to test in vitro antimicrobial activity of the Environmental Products Group (EPG) Masterflow Aquarium Management System with Aegis Microbe Shield. The Dow Corning Shaker Flask method was used with modifications to accommodate A. salmonicida.⁹ In two separate in vitro trials the EPG filter out performed the control filter in removing bacteria from a 100 ml water sample. In the first trial, the mean number of bacteria (three replicates) decreased from 3.02 bacteria/ml to 2.07 bacteria/ml after an hour of incubation in the shaker flask with the EPG sample while the control filter sample showed an increase from 2.31 bacteria/ml to 3.02 bacteria/mi. In the second trial, the EPG filter outperformed the control filter, but both samples showed gains in bacteria/ml after the one hour incubation period.

Acknowledgements

This work was supported by a grant from Bon-Aire Filters, Inc., Marietta, NC.

References

1.  Pet Industry Joint Advisory Council (PIJAC), 1997. PIJAC National Office Suite 400, 1220 19th Street, NW, Washington, DC 20036

2.  Barnes AC, Lewin CS, Hastings TS, SGB Amyes, 1990. In vitro activities of 4quinolones against the fish pathogen Aeromonas salmonicida. Antimicrobial Agents and Chemotherapy, 34(9):1819-1820.

3.  Fukui H, Fujihara Y, T Kano, 1987. In vitro and in vivo antibacterial activities of florfenicol, a new fluorinated analog of thiamphenicol, against fish pathogens. Fish Pathol., 22:201-207.

4.  Inglis V, RH Richards, 1991. The in vitro susceptibility of Aeromonas salmonicida and other fish pathogenic bacteria to 29 antimicrobial agents. J. Fish Dis., 14:641-650.

5.  Inglis V, Richards, RH, Varma, KJ, Sutherland, I, and ES Brokken, 1991. Florfenicol in Atlantic salmon, Salmo salar L., parr: tolerance and assessment of efficacy against furunculosis. J. Fish Dis., 14:343-351.

6.  Martinsen B, Oppegaard H, Wichstrom R, E Myhr, 1992. Temperature-Dependent in vitro antimicrobial activity of four 4-quinolones and oxytetracycline against bacteria pathogenic to fish. Antimicrobial Agents and Chemotherapy, 36(8): 1738-1743.

7.  Stoffregen DA, Chako AJ, Backman S, JG Babish, 1993. Successful therapy of furunculosis in Atlantic Salmon, Salmo salar L., using the floroquinolone antimicrobial agent enrofloxacin. J. Fish Dis., 16:219-228.

8.  Tsoumas A, Alderman DJ, CJ Rogers, 1989. Aeromonas salmonicida: development of resistance to 4-quinolone antimicrobials. J. Fish Dis., 12:493-507.

9.  Dow Coming Report. Antimicrobial Activity--Dynamic Test of Surfaces, Dow Corning Corporation, Midland, MI 48640, CTM-0923, Nov. 20, 1979.