Ak. Mukhopadhyay et al., BIOTYPE TRAITS AND ANTIBIOTIC SUSCEPTIBILITY OF VIBRIO-CHOLERAE SEROGROUP O1 BEFORE, DURING AND AFTER THE EMERGENCE OF THE O139 SEROGROUP, Epidemiology and infection, 115(3), 1995, pp. 427-434
Sixty-nine strains of Vibrio cholerae O1 isolated at different times w
ere analysed to investigate if there were any differences among the O1
strains isolated before, during and after the advent of the O139 sero
group. Of the 69 O1 strains examined, 68 belonged to the Ogawa serotyp
e while one belonged to the Inaba serotype. With the exception of one
strain all other strains of V. cholerae O1 belonged to the eltor bioty
pe. A single O1 strain isolated before the emergence of the O139 serog
roup could not be classified as either eltor or classical biotype beca
use it was resistant to both classical and eltor specific bacteriophag
es. Marked variations in the susceptibility to antibiotics of V. chole
rae O1 isolated during the different periods were observed. In additio
n, strains of V. cholerae isolated after the epidemic of serogroup O13
9 in Calcutta showed an expanding R-type with resistance to a variety
of drugs as compared to the O1 strains isolated before the advent of t
he O139 serogroup. From this study, it is clear that there is a substa
ntial mobility in genetic elements of V. cholerae O1 which necessitate
s a continuous monitoring to keep abreast of the changing traits of th
e etiologic agent of cholera.