Proticine typing of serologically defined Proteus strains

Serologically defined Proteus strains including 120 P. vulgaris, 356 P. mirabilis, 47 P. morganii, 36 P. rettgeri and 66 P. inconstans cultures isolated from a wide variety of sources, were classified by proticine (bacteriocine) typing. Using Cradock-Watson's set of indicator and producer strains, the isolates were tested for proticine production (P type) and for proticine sensitivity (S type). P. vulgaris was typable by the P method in 4.1%, by the S method in 41.6%. The respective percentages for P. mirabilis were 60.1 and 48.9. Most strains of P. morganii, P. rettgeri and P. inconstans were untypable by both methods. A correlation has been demonstrated between P/S types and certain serogroups and serotypes of P. mirabilis. It has been concluded that, in combination with the determination of O and H antigens, the P/S method of proticine typing has a high differentiating value in the epidemiological tracing of P. vulgaris and P. mirabilis.