title: The emerging strains of Shigella dysenteriae type 2 in Bangladesh are clonal.
abstract: A total of 113 strains of Shigella dysenteriae type 2 isolated from patients attending the Dhaka diarrhoea treatment centre of ICDDR,B: Centre for Health and Population Research during the period 1999-2004 were studied. Serotype of the isolates was confirmed using commercially available antisera. Except for arabinose fermentation, all the strains had similar biochemical reactions. More than 60% of the strains were sensitive to commonly used antibiotics; only 6% (n=7) of the strains were resistant to nalidixic acid, and none of the strains were resistant to mecillinam and ciprofloxacin. All strains were invasive as demonstrated by the presence of a 140 MDa plasmid, ial, sen and ipaH genes, Congo Red absorption ability and by the Sereny test performed on representative strains. Plasmid patterns were heterogeneous but more than 50% of strains were confined to a single pattern. All strains possessed a 1.6 MDa plasmid and 87% of the strains contained a 4 MDa plasmid. Middle-range plasmids (90 MDa to 30 MDa) present in 36% of the strains were not associated with antibiotic resistance. All the strains were clustered within a single type with four subtypes by pulsed-field gel electrophoresis while ribotyping patterns of all the strains were identical.
authors: ICDDR, B: Centre for Health and Population Research, Dhaka, Bangladesh. kaisar@icddrb.org
authors: K A
authors: KA
authors: Talukder
authors: B K
authors: BK
authors: Khajanchi
authors: M A
authors: MA
authors: Islam
authors: D K
authors: DK
authors: Dutta
authors: Z
authors: Z
authors: Islam
authors: S I
authors: SI
authors: Khan
authors: G B
authors: GB
authors: Nair
authors: D A
authors: DA
authors: Sack