title: Emergence of multidrug-resistant Salmonella Gloucester and Salmonella typhimurium in Bangladesh.
abstract: Infections due to non-typhoid Salmonella, resistant to antibiotics, have recently emerged as an important health problem worldwide. Antibiotic resistance was studied by the disc-diffusion method among 3,876 (2.78%) non-typhoid Salmonella isolates cultured from 139,279 faecal samples in a diarrhoea treatment centre in Dhaka, Bangladesh, during 1989-1996. Of 499 salmonellae isolated in 1989, serogroup C (1.12%) was the most common, followed by Salmonella Typhi (0.72%) and serogroup B (0.71%). Isolation rate of serogroup B increased significantly to 2.18% (p < 0.01) in 1992 compared to 0.56% in 1991, 2.86% in 1995, and 2.48% in 1996. Serotyping of 194 serogroup B isolates revealed Salmonella Typhimurium (52%) and Salmonella Gloucester (45%) as predominant serotypes. Resistance to ampicillin (A), chloramphenicol (C), and trimethoprim-sulphamethoxazole (Sxt) (R type-ACSxt) increased to 89-100% during 1992-1996 from 20-28% during 1989-1991 (p < 0.01) among S. Typhimurium and S. Gloucester isolates. In 1993, 8-10% of the strains of both the serotypes, resistant to ampicillin, chloramphenicol, and trimethoprim-sulphamethoxazole, acquired resistance to ceftriaxone (Cr) (R type-ACSxtCr), which increased to 85-92% in 1996 (p < 0.01). All were susceptible to ciprofloxacin. A 157-kb conjugative plasmid transferred R type-ACSxt from both the serotypes to Escherichia coli K-12. The findings of the study suggest the emergence of multidrug-resistant S. Gloucester and S. Typhimurium for the first time as a significant health problem in Bangladesh, and surveillance is essential to monitor the resistant non-typhoid Salmonella and identify its sources and modes of transmission.
authors.affiliation: Laboratory Sciences Division, ICDDR,B: Centre for Health and Population Research, GPO Box 128, Dhaka 1000, Bangladesh. mahbubur@icddrb.org
authors.forename: M
authors.initials: M
authors.lastname: Rahman
authors.forename: H
authors.initials: H
authors.lastname: Islam
authors.forename: D
authors.initials: D
authors.lastname: Ahmed
authors.forename: R B
authors.initials: RB
authors.lastname: Sack
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001459:Bangladesh / Q000453:epidemiology; D021821:Communicable Diseases, Emerging / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D005243:Feces / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D012475:Salmonella / Q000187:drug effects / Q000302:isolation & purification; D012480:Salmonella Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents