title: Characterization of Shigella strains in Iran by plasmid profile analysis and PCR amplification of ipa genes.
abstract: To characterize Shigella clinical strains, we studied 82 Shigella strains recovered from 719 stool samples of patients with bloody diarrhea in Shiraz, Iran, over the period from April to October 2003. Serological assay classified the Shigella isolates as follows: 61 (74.39%) Shigella sonnei isolates, 16 (19.51%) Shigella flexneri isolates, 3 (3.65%) Shigella boydii isolates, and 2 (2.43%) Shigella dysenteriae isolates. In an antibiogram test, all Shigella strains were susceptible to ceftazidime, ciprofloxacin, and ceftriaxone. They showed high degrees of sensitivity to nalidixic acid, gentamicin, cephalothin, and amikacin. Approximately 90.24% of the Shigella isolates were resistant to co-trimoxazole. The plasmid profile patterns of all strains were determined by a modified alkaline lysis method. The average number of plasmid bands for each strain was 9.5. By plasmid profile analysis we identified 56 genotypes among all isolates and 42, 14, 3, and 2 genotypes among the S. sonnei, S. flexneri, S. boydii, and S. dysenteriae strains, respectively. PCR assays showed that all isolates were positive for two virulence genes, ipaBCD and ipaH. In conclusion, these data mandate local monitoring of drug resistance and its consideration in the empirical therapy of Shigella infections. These results also demonstrate that plasmid profile analysis is more reliable than antibiotic susceptibility pattern analysis for the identification of Shigella epidemic strains isolated in Iran.
authors.affiliation: Prof. Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Nemazi Hospital, Shiraz 71937-11351, Iran. s_farshad@yahoo.com
authors.forename: Shohreh
authors.initials: S
authors.lastname: Farshad
authors.forename: Raheleh
authors.initials: R
authors.lastname: Sheikhi
authors.forename: Aziz
authors.initials: A
authors.lastname: Japoni
authors.forename: Ezzatollah
authors.initials: E
authors.lastname: Basiri
authors.forename: Abdolvahab
authors.initials: A
authors.lastname: Alborzi
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004405:Dysentery, Bacillary / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007492:Iran; D008297:Male; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D016133:Polymerase Chain Reaction; D012703:Serotyping; D012760:Shigella / Q000145:classification* / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial