THE NATURAL OCCURRENCE OF PHASE 2 OF SALMONELLA 

 PARATYPHI A 1 



P. R. EDWARDS 



Laboratory Division, Communicable Disease Center, Public Health Service, Federal Security 

 Agency, Atlanta, Georgia, 



AND 



L. A. BARNES and MARY C. BABCOCK 



Bacteriology Division, Naval Medical Research Institute, Bethesda, Maryland 



Received for publication October 24, 1949 



By a modification of the Gard technique, Bruner and Edwards (J. Bact., 

 42, 467, 1941) obtained from typical cultures of Salmonella paratyphi A 

 (I, II, XII: a) a variant having the formula I, II, XII: 1, 5. This experimental 

 evidence supported the hypothesis of White (Med. Research Council, Brit., 

 Special Rept. Series, No. 103, 1926) that S. paratyphi A, as well as other mono- 

 phasic Salmonella types, was a loss variant of an originally diphasic ancestral 

 form. In the isolation of the 1,5 phase and its reversion to the original form, 

 two "artificial" phases that did not correspond to any of the known naturally 

 occurring antigens of the genus were produced. These were designated as z 5 

 and zn, respectively. The natural occurrence of phase 2 (I, II, XII :1 ,5) has not 

 been reported heretofore. 



In 1948 a culture isolated by the United States Naval Medical Research Unit 

 No. 3 in Egypt from the urine of a patient affected with enteric fever of 49 days' 

 duration was forwarded to the Naval Medical Research Institute and subse- 

 quently to the Communicable Disease Center for study. Examination revealed 

 that the bacterium was a motile rod that possessed the tinctorial and cultural 

 properties of Salmonella. 



The organism reduced nitrates but failed to utilize citrate or D-tartrate. 

 Acid and gas were formed in the butt of triple-sugar iron agar slants; the medium 

 was not blackened. Indole was not formed in peptone water. Glucose, mannitol, 

 arabinose, rhamnose, maltose, and trehalose were fermented with the production 

 of acid and gas within 24 hours; dulcitol was fermented in 48 hours. Xylose, 

 cellobiose, lactose, sucrose, raffinose, inositol, and salicin were not attacked. 

 The biochemical properties described above are typical of S. paratyphi A. 



Upon serological examination it was found that the organism was agglutinated 

 strongly by O serum derived from S. paratyphi A and possessed somatic antigens 

 I , II , XII. In absorption tests it removed all somatic agglutinins from two serums 

 derived from S. paratyphi A. When the H antigens were examined, it was found 



1 The opinions or assertions contained herein are the private ones of the writers and are 

 not to be construed as official or reflecting the views of the Navy Department or the Naval 

 Service at large. 



135 



[Reprinted by permission of The Williams & Wilkins Company from Journal of 

 Bacteriology 59: (1) 135-136, January. 1950] 



u6 



