Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 17, Number 6—June 2011
Dispatch

Ciprofloxacin-Resistant Salmonella enterica Serotype Typhi, United States, 1999–2008

Felicita MedallaComments to Author , Maria Sjölund-Karlsson, Sanghyuk Shin, Emily Harvey, Kevin Joyce, Lisa Theobald, Benjamin L. Nygren, Gary Pecic, Kathryn Gay, Jana Austin, Andrew Stuart, Elizabeth Blanton, Eric D. Mintz, Jean M. Whichard, and Ezra J. Barzilay
Author affiliations: Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (F. Medalla, M. Sjölund-Karlsson, K. Joyce, L. Theobald, B.L. Nygren, G. Pecic, K. Gay, J. Austin, A. Stuart, E. Blanton, E.D. Mintz, J.M. Whichard, E.J. Barzilay); California Emerging Infections Program, Oakland, California, USA (S. Shin); Massachusetts Department of Public Health, Jamaica Plain, Massachusetts, USA (E. Harvey)

Main Article

Table 1

MICs of antimicrobial agents tested for 9 ciprofloxacin-resistant Salmonella enterica serotype Typhi isolates detected in the National Antimicrobial Resistance Monitoring System, United States, 1999–2008

Antimicrobial class and agent* MIC, µg/mL,* by patient no. (isolate)
Patient 1 (MA-03) Patient 2† (CA-05) Patient 3 (CA-06) Patient 4 (TX-06) Patient 5 (AZ-06) Patient 6 (NY-07) Patient 7 (CA-07) Patient 8 (NJ-07) Patient 9 (LAC-07)
Quinolones
Ciprofloxacin >4 >4 >4 >4 >4 >4 >4 >4 >4
Nalidixic acid
>32
>32
>32
>32
>32
>32
>32
>32
>32
Aminoglycosides
Amikacin <0.5 1 1 1 1 1 1 1 1
Gentamicin <0.25 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25
Kanamycin <8 <8 <8 <8 <8 <8 <8 <8 <8
Streptomycin
<32
<32
<32
>64
<32
<32
<32
<32
<32
β-lactam–β-lactamase inhibitor
Amoxicillin-clavulanic acid
<1/0.5
<1/0.5
<1/0.5
8/4
<1/0.5
<1/0.5
<1/0.5
<1/0.5
<1/0.5
Cephems
Cefoxitin 4 4 4 4 2 4 4 4 4
Ceftiofur 0.5 0.5 0.5 0.5 0.25 0.5 0.5 0.5 0.5
Ceftriaxone
<0.25
<0.25
<0.25
<0.25
<0.25
<0.25
<0.25
<0.25
<0.25
Folate pathway inhibitors
Sulfonamide‡ >512 >256 <16 >256 >256 <16 >256 <16 <16
Trimethoprim-
sulfamethoxazole
>4/76
>4/76
<0.12/ 2.38
>4/76
>4/76
<0.12/ 2.38
>4/76
<0.12/ 2.38
<0.12/ 2.38
Penicillins
Ampicillin
2
<1
<1
>32
<1
<1
<1
<1
<1
Phenicols
Chloramphenicol
4
4
4
>32
4
4
4
4
4
Tetracyclines
Tetracycline >32 >32 <4 <4 >32 <4 >32 <4 <4

*Classes of antimicrobial agents defined by the Clinical and Laboratory Standards Institute (CLSI) were used to categorize agents (7,13). MICs were interpreted by using CLSI criteria when available (7,13): ciprofloxacin (resistance breakpoint, >4 µg/mL); nalidixic acid (>32); amikacin (>64); gentamicin (>16); kanamycin (>64); amoxicillin-clavulanic acid (>32/16); cefoxitin (>32); ceftiofur (>8); ceftriaxone (>4); sulfamethoxazole/sulfisoxazole (>512); trimethoprim-sulfamethoxazole (>4/76); ampicillin (>32); chloramphenicol (>32); and tetracycline (>16). For streptomycin, resistance was defined as MIC >64 µg/mL (7). If growth was not inhibited by the highest concentration of the agent in the panel, the MIC was reported as above the highest concentration.
†Isolate was cultured from a blood specimen. Another isolate was cultured from fecal samples, which had MIC <0.5 µg/mL for amikacin and same MICs for other agents tested.
‡Sulfamethoxazole was used during 1999–2003 and sulfisoxazole since 2004 to represent sulfonamides.

Main Article

References
  1. Mermin  JH, Townes  JM, Gerber  M, Dolan  N, Mintz  ED, Tauxe  RV. Typhoid fever in the United States, 1985–1994: changing risks of international travel and increasing antimicrobial resistance. Arch Intern Med. 1998;158:6338. DOIPubMedGoogle Scholar
  2. Connor  BA, Schwartz  E. Typhoid and paratyphoid fever in travelers. Lancet Infect Dis. 2005;5:6238. DOIPubMedGoogle Scholar
  3. Centers for Disease Control and Prevention. Summary of notifiable diseases—United States, 2006. MMWR. 2008;55:32,77.
  4. Ackers  ML, Puhr  ND, Tauxe  RV, Mintz  ED. Laboratory-based surveillance of Salmonella serotype Typhi infections in the United States: antimicrobial resistance on the rise. JAMA. 2000;283:266873. DOIPubMedGoogle Scholar
  5. Lynch  MF, Blanton  EM, Bulens  S, Polyak  C, Vojdani  J, Stevenson  J, Typhoid fever in the United States, 1999–2006: trends in quinolone-resistant cases among international travelers. JAMA. 2009;302:85965. DOIPubMedGoogle Scholar
  6. Crump  JA, Kretsinger  K, Gay  K, Hoekstra  RM, Vugia  DJ, Hurd  S, Clinical response and outcome of infection with Salmonella enterica serotype Typhi with decreased susceptibility to fluoroquinolones: a United States FoodNet multicenter retrospective cohort study. Antimicrob Agents Chemother. 2008;52:127884. DOIPubMedGoogle Scholar
  7. Centers for Disease Control and Prevention. National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS): human isolates final report, 2008. Atlanta: US Department of Health and Human Services; 2010.
  8. Cooke  FJ, Wain  J. The emergence of antibiotic resistance in typhoid fever. Travel Med Infect Dis. 2004;2:6774. DOIPubMedGoogle Scholar
  9. Parry  CM, Ho  VA, Phuong le  T, Bay  PV, Lanh  MN, Tung le  T, Randomized controlled comparison of ofloxacin, azithromycin, and an ofloxacin-azithromycin combination for treatment of multidrug-resistant and nalidixic acid-resistant typhoid fever. Antimicrob Agents Chemother. 2007;51:81925. DOIPubMedGoogle Scholar
  10. Hopkins  KL, Davies  RH, Threlfall  EJ. Mechanisms of quinolone resistance in Escherichia coli and Salmonella: recent developments. Int J Antimicrob Agents. 2005;25:35873. DOIPubMedGoogle Scholar
  11. Gaind  R, Paglietti  B, Murgia  M, Dawar  R, Uzzau  S, Cappuccinelli  P, Molecular characterization of ciprofloxacin-resistant Salmonella enterica serovar Typhi and Paratyphi A causing enteric fever in India. J Antimicrob Chemother. 2006;58:113944. DOIPubMedGoogle Scholar
  12. Turner  AK, Nair  S, Wain  J. The acquisition of full fluoroquinolone resistance in Salmonella Typhi by accumulation of point mutations in the topoisomerase targets. J Antimicrob Chemother. 2006;58:73340. DOIPubMedGoogle Scholar
  13. Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing: twentieth informational supplement. Wayne (PA): The Institute; 2010.
  14. Ribot  EM, Fair  MA, Gautom  R, Cameron  DN, Hunter  SB, Swaminathan  B, Standardization of pulsed-field gel electrophoresis protocols for the subtyping of Escherichia coli O157:H7, Salmonella, and Shigella for PulseNet. Foodborne Pathog Dis. 2006;3:5967. DOIPubMedGoogle Scholar
  15. Crump  JA, Mintz  ED. Global trends in typhoid and paratyphoid fever. Clin Infect Dis. 2010;50:2416. DOIPubMedGoogle Scholar

Main Article

Page created: August 03, 2011
Page updated: August 03, 2011
Page reviewed: August 03, 2011
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
file_external