Open AccessHigh Prevalence of Antimicrobial Resistance among Shigella Isolates in the United States Tested by the National Antimicrobial Resistance Monitoring System from 1999 to 2002
Author(s) -
Sumathi Sivapalasingam,
Jennifer Nelson,
Kevin Joyce,
Robert M. Hoekstra,
Frederick J. Angulo,
Eric D. Mintz
Publication year - 2006
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.50.1.49-54.2006
Subject(s) - shigella , ampicillin , microbiology and biotechnology , shigella flexneri , ciprofloxacin , shigella sonnei , shigella boydii , nalidixic acid , antibiotic resistance , amp resistance , antimicrobial , trimethoprim , shigella dysenteriae , biology , ceftriaxone , salmonella , antibiotics , bacteria , escherichia coli , biochemistry , genetics , gene
Shigella spp. infect approximately 450,000 persons annually in the United States, resulting in over 6,000 hospitalizations. Since 1999, the National Antimicrobial Resistance Monitoring System (NARMS) for Enteric Bacteria has tested every 10thShigella isolate from 16 state or local public health laboratories for susceptibility to 15 antimicrobial agents. From 1999 to 2002, NARMS tested 1,604 isolates. Among 1,598 isolates identified to species level, 1,278 (80%) wereShigella sonnei , 295 (18%) wereShigella flexneri , 18 (1%) wereShigella boydii , and 7 (0.4%) wereShigella dysenteriae . Overall, 1,251 (78%) were resistant to ampicillin and 744 (46%) were resistant to trimethoprim-sulfamethoxazole (TMP-SMX). Prevalence of TMP-SMX- or ampicillin- and TMP-SMX-resistantShigella sonnei isolates varied by geographic region, with lower rates in the South and Midwest regions (TMP-SMX resistance, 27% and 30%, respectively; ampicillin and TMP-SMX resistance, 25% and 22%, respectively) and higher rates in the East and West regions (TMP-SMX resistance, 66% and 80%, respectively; ampicillin and TMP-SMX resistance, 54% and 65%, respectively). Nineteen isolates (1%) were resistant to nalidixic acid (1% ofS. sonnei and 2% ofS. flexneri isolates); 12 (63%) of these isolates had decreased susceptibility to ciprofloxacin. OneS. flexneri isolate was resistant to ciprofloxacin. All isolates were susceptible to ceftriaxone. Since 1986, resistance to ampicillin and TMP-SMX has dramatically increased.Shigella isolates in the United States remain susceptible to ciprofloxacin and ceftriaxone.