The “curative” agent for Schistosoma mansoni, occurring in the hemolymph of Biomphalaria glabrata, did not pass through either a dialysis membrane or millipore filter (0.22 µ). Thoroughly washed ameboid cells from the hemolymph were inactive. Among bacteria cultured from hemolymph, Proteus mirabilis decimated mature S. mansoni in mice, but it was not effective when injected 1 week after mice were exposed to cercariae. Moreover, the infectivity of cercariae was unaltered by mixing them with P. mirabilis 1 hour before exposure of the mice. Klebsiella pneumoniae cultured from hemolymph did not affect mature S. mansoni, but a laboratory strain of this bacterium killed some worms. P. mirabilis injected into normal mice did not produce abscesses. Cultures of P. mirabilis derived from worms, taken asseptically from hemolymph-treated mice, produced liver abscesses within 10 days in other mice infected with S. mansoni. Similarly, K. pneumoniae cultured from liver abscesses in hemolymph-treated mice and subinjected, produced abscesses in one of eight mice, and this mouse was cleared of a bonafide infection of S. mansoni. Possible clinical complications for man when enteric bacterial infections occur simultaneously with schistosomiasis may warrant consideration.
The Puerto Rico Nuclear Center is operated by the University of Puerto Rico under Contract AT-(40-1)-1833 for the U. S. Atomic Energy Commission.