title: Genetic characteristics and changing antimicrobial resistance among Shigella spp. isolated from hospitalized diarrhoeal patients in Kolkata, India.
abstract: To study the prevalence pattern and trends in the phenotypic and genetic characteristics of shigellae, we tested 212 isolates isolated from diarrhoeal patients admitted to the Infectious Diseases Hospital, Kolkata, India, from November 2007 to October 2010. Prevalence of Shigella spp. was higher in the >5 years age group (69 %) than in children in the <5 years age group (31 %). Serotypes 2a, 3a and untypable isolates of Shigella flexneri were frequently detected. An increase in the isolation of Shigella sonnei (15 %) is a novel trend in this region. Fluoroquinolone resistance among S. flexneri serotypes 2a, 3a and other serogroups of shigellae is another evolving trend. The set gene was exclusively present in S. flexneri 2a, and the sen gene was detected in all serogroups. PFGE revealed the grouping of S. flexneri isolates according to their serotypes with approximately 80-100 % similarity, whilst Shigella dysenteriae type 2 and S. sonnei were clonal in nature. There was no demarcation in the prevalence of serotypes, antimicrobial resistance or clonality between the two age groups.
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: Santanu
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: G P
authors.initials: GP
authors.lastname: Pazhani
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: Goutam
authors.initials: G
authors.lastname: Chowdhury
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: Sucharita
authors.initials: S
authors.lastname: Guin
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: Sanjucta
authors.initials: S
authors.lastname: Dutta
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: K
authors.initials: K
authors.lastname: Rajendran
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Bhattacharya
authors.affiliation: Collaborative Research Center of Okayama University for Infectious Diseases in India, National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: Y
authors.initials: Y
authors.lastname: Takeda
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Niyogi
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: G Balakrish
authors.initials: GB
authors.lastname: Nair
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: T
authors.initials: T
authors.lastname: Ramamurthy
mesh_terms: D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D004405:Dysentery, Bacillary / Q000453:epidemiology* / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D007194:India; D007223:Infant; D058889:Molecular Typing; D010641:Phenotype; D015995:Prevalence; D012703:Serotyping; D012762:Shigella dysenteriae / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D012763:Shigella flexneri / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D012764:Shigella sonnei / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents