On Disagreement between Antibacterial Activity of a New Nitrofuran Derivative MKM and its Therapeutic Effect Against Fish Infected Intramuscularly

Abstract

The present paper deals with the antibacterial activity, the therapeutic effect on red sea bream (Chrysophyrys major) infected with pathogene, the property of metal chelation and the residue in fish tissues of a new nitrofuran derivative MKM, 1-methyl-1, 4-dihydro-7-[1- methyl-2-(5-nitro-2-fury1)-vinyl]-4-oxo-1, 8-naphthyridine-3-carboxylic acid potassium salt.
The results obtained can be summarized as follows:
1) The antibacterial activities of MKM against the pathogenes of fish were superior to those of other nitrofuran derivatives, antibiotics and sulfonamides (Table 1).
2) On the contrary, the therapeutic effects of MKM by bathing on red sea bream infected intramuscularly with the pathogenes were inferior to those of a nitrofuran derivative P-7138 having secondary antibacterial activity (Table 2 and 3).
3) Nitrofuran derivative MKM is supposed to be a metal-chelate compound according to its chemical structure and the emission of fluorescece in the presence of Al, Mg, Ag, Ba, K and Ca (Table 4).
4) After 2 hour-bathing in MKM or P-7138 sea water solution at 0.5 and 5 ppm levels, MKM was not detected in the blood, liver, kidney and muscle of the fish, but a considerable quantity of P-7138 was detected in these tissues (Table 5).
5) The therapeutic effect of MKM by bathing on red sea breath infected percutaneously with pathogene SP-1 was equal to that of P-7138 in effectiveness (Table 6).