the organism. Both 01 and non-O1 V. cholerae strains were isolated from the fecal specimens. Isolates from eight birds (representing five species) agglutinated in 0 group 1 antiserum. Supernatants of broth cultures from three isolates which typed as V. cholerae 01 serotype Ogawa gave reactions typical of cholera toxin when tested on Y-1 mouse adrenal cell cultures. Several serovars of non-O1 V. cholerae were isolated from the fecal specimens; serovar 22 was the most prevalent type. All non-Ol isolates were cytotoxic to Y-1 mouse adrenal cells. Only non-O1 V. cholerae was detected in water samples collected from the habitat of the birds. The results of this study suggest that aquatic birds serve as carriers and disseminate V. cholerae over a wide area.
A facil synthesis of benzophenanthridinium salts has been developed and used for preparing a number of these compounds. The antitumor activities in mouse leukemia L1210 (LE) and P388 (PS) were determined as well as some selected antimicrobial activities. Although antitumor activity was exhibited by several of the derivatives, none was as active as the naturally occurring alkaloid fagaronine. Fagaronine was made available as a synthetic by an improved procedure. Some structure-activity relationships among antitumor benzophenanthridinium salts are discussed.
Phage infection of Vibrio cholerae resulted in antigenic changes. A strain of biotype cholerae serotype Ogawa was converted into serotype Hikojima and gained the ability to synthesize antigenic factor C. Some phage-converted strains remained stable after subculture and were immune to superinfection with the same phage. The stable converted strains were lysogenic and released phage having a host range similar to the phage of the donor strain. Reinfection of unstable converted strains which had "lost" antigen C yielded types able to again synthesize this antigen. The polymyxin resistance character was expressed in the biotype cholerae strain after infection with some phage preparations. These polymyxin-resistant strains possessed three main characteristics of El Tor vibrios. The phage-induced changes described provide V. cholerae with the potential for innumerable genetic combinations.
Evidence was obtained for general transduction in Vibrio cholerae. Transduction of three amino acid markers and three antibiotic resistance characters was demonstrated using strains of biotype eltor and biotype cholerae. Some of the genetic characters were transduced from a biotype eltor donor (and its mutant derivatives) to biotype cholerae and eltor recipients. For the genetic traits
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