IDENTIFICATION AND TYPING OF PROTEUS-PENNERI AND PROTEUS-VULGARIS BIOGROUP-2 AND BIOGROUP-3, FROM CLINICAL SOURCES, BY COMPUTERIZED ANALYSIS OF ELECTROPHORETIC PROTEIN-PATTERNS

Seventy-six strains of the Proteus vulgaris complex (Pr. penneri and P r. vulgaris biogroups 2 and 3) were characterized by one-dimensional S DS-PAGE of cellular proteins. The protein patterns were highly reprodu cible. The strains came from various countries and were mainly of huma n origin: urine (28), respiratory tract (13), wounds (8), faeces (7), blood (3), miscellaneous sources (6) and unknown sources (11). The pat terns of these strains, together with those of the type strains of sev en Morganella, Proteus and Providencia species were subjected to two n umerical analyses. In the first, in which the principal protein bands (in the 35.0-42.0 kDa range) were excluded, the strains of the Pr. vul garis complex formed four clusters at the 83% similarity level. These corresponded to Pr. penneri, Pr. vulgaris biogroup 2, and two clusters (3a and 3b) represented biogroup 3. Each of these clusters was distin ct from the Morganella, Proteus and Providencia reference strains. In the second analysis, which included all the protein bands, the 41 Pr. penneri strains showed little heterogeneity but 17 subphenons could be recognized among the 35 strains of Pr. vulgaris biogroups 2 and 3. Th ese results support the division of biogroup 3 strains into at least t wo separate taxa. Other results indicate that biogroup 3 is heterogene ous and may contain further genomic groups. The method also provides a basis for typing clinical strains of Pr. vulgaris biogroups 2 and 3.