Comparison of the antibiotic resistance patterns among Shigella species isolated from pediatric hospital between 1995-1999 and 2009-2013 in North-West of Iran

Introduction: This study was conducted to determine the frequency and pattern of antimicrobial susceptibility of Shigella spp. isolated from pediatric hospital in two different time periods between March 1995 to March 1999 and March 2009 to March 2013 in North-West of Iran.
Methods: The stool specimens were collected and examined for shigellosis by biochemical tests, and antibiogram was conducted according to Clinical and Laboratory Standards Institute protocol. One hundred and thirty-nine Shigella spp. isolated from year 1995 to 1999 and 38 Shigella spp. isolates collected from year 2009 to 2013 and examined for serotyping and antibiotic resistance pattern.
REsults: According to serotyping results Shigella flexneri isolated in 98.6% of isolates in the first time period, followed by Shigella boydii and Shigella sonnei (0.7%) but in the second time period just 47.3% were S. flexneri and 39.5% were S. sonnei, 7.9% were S. boydii and 5.3% of isolates were Shigella dysenteriae. Results indicated significantly increase in resistance to ceftizoxime, chloramphenicol, and amikacin (P = 0.004, 0.010, and 0.004 respectively), also, in Shigella isolates isolated in the second time period showed an increase in multidrug resistant (MDR) isolate and frequency of MDR isolates increased to 95.0% in the second time period.
Conclusion: We are facing with the increase in resistance to antibiotics in Shigella spp. especially MDR isolates. These results showed changing pattern of resistance in Shigella isolates and needs for planning and design antibiotics stewardships for controlling Shigellosis, especially in pediatric hospitals