Lysogenicity and prophage type of the strains of Vibrio cholerae O-1 isolated mainly from the natural environment.

Abstract

Listen

Translate article

Attention has recently been given to the increasingly frequent detection of atypical Vibrio cholerae O-1 in the natural environments throughout the world. Lysogenicity of V. cholerae O-1, mainly isolated from environmental sources in nine areas, including the United States, was studied by electron microscopy and a cross-lysis test between bacteria and the culture supernatants. A total of 38 strains isolated in Texas in 1973 and in Louisiana in 1978 were lysogenic, whereas there were no lysogenic strains among those isolated in Louisiana in 1979. Because these phages were identical in terms of serology and host range, the phage in them was named T-L phage. T-L phage differed in host range from the k type phage in the epidemic strain of the seventh cholera pandemic. Although the T-L phage was neutralized by antiserum to the k type phage and vice versa, the two phage types were not serologically identical. By a prophage typing method, strains of V. cholerae O-1 isolated from the environment in Guam, Bangladesh, and Japan were classified as either of the Celebes type (epidemic strain) or the Classic-Ubon type. All strains isolated in Brazil, the Chesapeake Bay, and England were nonlysogenic and classified as Classic-Ubon type.