The Serological Types of Vibrios Isolated from Cholera Patients in Calcutta

Venkatraman and Pandit (1938) have recently reviewed the literature bearing on the serological types of Vibrio cholerce and the few observations on the types of vibrios in relation to different epidemics. These workers record a severe epidemic of cholera in Periyakuluin range of the Madura district in South India. They examined stools from 131 cases of cholera and studied 84 strains of vibrios isolated from 97 cases. These 84 strains of vibrios were all of the Ogawa type. Maitra, Sen Gupta and Thant (1938) examined 52 agglutinable strains of V. cholerce isolated in Rangoon, and found that 51 of these strains were of the Inaba type and only 1 strain of the Ogawa type. During the year ending 28th February, 1939, the stools from 959 clinical cases of cholera were examined. Vibrios were isolated from 438 or 45.7 per cent of the patients examined. Biochemically all the O-agglutinable strains were arabinose-negative and belonged to Heiberg s groups I and II. The serological type was determined by agglutination test with rabbit sera prepared with Bruce-White's standard dried Inaba and Ogawa ' 0' antigens and with a living suspension of V. cholerce (Inaba). The results are given in table I. The Inaba O and Ogawa 0 sera used were completely differential and the agglutination with these sera was to titre. The titre of the differ' ent sera with their homologous strains were, Inaba 1 O ' ?2,500, Ogawa ' 0 ' ?1,000 and Inaba ' H & O ' ?2,500. The Inaba type of V. cholerce was isolated from 60.7 per cent of the bacteriologically' positive cholera cases. The Ogawa type was found in 25.8 per cent of such cases. The Ogawa type of V. cholerce was present throughout the year, and there was no appreciable preponderance of the Ogawa type at any particular time of the year or the cholera epidemic. The H-agglutinable vibrios, i.e., vibrios in' agglutinable with Inaba O or Ogawa O sera bu agglutinable with Inaba H & O serum, were found in 2.8 per cent of the patients from whotf1 vibrios were recovered. The inagglutinable vibrios were found in 10.7 per cent of the cases-