1. Threlfall, EJ, et al. Ciprofloxacin-resistant Salmonella typhi and treatment failure. Lancet 1999; 353: 1590–1591.
2. Capoor, MR, et al. Salmonella enterica serovar Typhi: molecular analysis of ciprofloxacin decreased susceptibility and resistant isolates from India (2001–2003). Brazilian Journal of Infectious Diseases 2007; 11: 423–425.
3. Levy, DD, Sharma, B, Cebula, TA. Single-nucleotide polymorphism mutation spectra and resistance to quinolones in Salmonella enterica serovar enteritidis with a mutator phenotype. Antimicrobial Agents and Chemotherapy 2004; 48: 2355–2363.
4. Nair, S, et al. Molecular analysis of fluoroquinolone-resistant Salmonella Paratyphi A isolate, India. Emerging Infectious Diseases 2006 12: 489–491.
5. Hirose, K, et al. DNA sequence analysis of DNA gyrase and DNA topoisomerase in the quinolone resistance determining regions of Salmonella enterica serovar Typhi and serovar Paratyphi A. Antimicrobial Agents and Chemotherapy 2002; 46: 3249–3252.
6. Lindgren, PK, Karlsson, ASA, Hughes, D. Mutation rate and evolution of fluroquinolone resistance in E. coli isolates from patients in urinary tract infections. Antimicrobial Agents and Chemotherapy 2003; 47: 3222–3232.
7. Eaves, DJ, et al. Prevalence of mutations within the quinolone resistance determining region of gyrA, gyrB, parC, and parE and association with antibiotic resistance in quinolone-resistance Salmonella enterica. Antimicrobial Agents and Chemotherapy 2004; 48: 4012–4015.
8. Baucheron, S, et al. High level resistance to fluoroquinolones linked to mutations in gyr A, par C and par E in Salmonella enterica serovar Schwarzengrund isolated from humans in Taiwan. Antimicrobial Agents and Chemotherapy 2005; 49: 862–863.
9. Ling, JM, et al. Mutations in topoisomerase genes of fluoroquinolone resistant Salmonella in Hong Kong. Antimicrobial Agents and Chemotherapy 2003; 47: 3567–3573.
10. Sanders, CC. Mechanisms responsible for cross-resistance and dichotomous resistance among quinolones. Clinical Infectious Diseases 2001; 32: 81–88.
11. Crump, JA, et al. Clinical response and outcome of infection with Salmonella enterica serotype Typhi with decreased susceptibility to fluoroquinolones: a United Stat FoodNet Multicenter Retospective Cohort study. Antimicrobial Agents and Chemotherapy 2008; 52: 1278–1284.
12. Yamane, K, et al. New plasmid-mediated fluoroquinolone efflux pump, QepA, found in an Escherichia coli clinical isolate. Antimicrobial Agents and Chemotherapy 2007; 51: 3354–3360.
13. Renuka, K, et al. High-level ciprofloxacin resistance in Salmonella enterica serovar Typhi in India. Journal of Medical Microbiology 2005; 54: 999–1000.
14. Capoor, MR, et al. Enteric fever perspective in India: emergence of high-level ciprofloxacin resistance and rising MIC to cephalosporins. Journal of Medical Microbiology 2007; 56: 1131–1132.
15. Kownhar, H, et al. Emergence of nalidixic acid-resistant Salmonella enterica serovar Typhi resistant to ciprofloxacin in India. Journal of Medical Microbiology 2007; 56: 136–137.
16. Adachi, T, et al. Fluoroquinolone-resistant Salmonella enterica serovar Paratyphi A. Emerging Infectious Diseases 2005; 11: 172–174.
17. Saha, SK, et al. Molecular basis of resistance displayed by highly-ciprofloxacin resistant Salmonella enterica serovar Typhi in Bangladesh. Journal of Clinical Microbiology 2006; 44: 3811–3813.
18. Gaind, R, et al. Molecular characterization of ciprofloxacin-resistant Salmonella enterica serovar Typhi and S. Paratyphi A causing enteric fever in India. Journal of Antimicrobial Chemotherapy 2006; 58: 1139–1144.
19. Old, DC. Salmonella. In: Collee, JG, Fraser, AG, Marmion, BP, Simmons, A eds. Mackie and McCartney Practical Medical Microbiology, 14th edn. New York: Churchill Livingstone, 1996, pp. 385–404.
20. Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing. CLSI document (M100-S16), p. 26. Clinical and Laboratory Standards Institute, 2007. Wayne, Pennsylvania.
21. Giraud, E, et al. Comparative study of animal isolates and experimental in vitro- and in vivo-selected mutants of Salmonella spp. suggest a counterselection of highly fluoroquinolone-resistant strains in the field. Antimicrobial Agents and Chemotherapy 1999; 43: 2131–2037.
22. Wang, M, et al. Plasmid-mediated Quinolone resistance in clinical isolated in clinical isolates of Escherichia coli from Shanghai, China. Antimicrobial Agents and Chemotherapy 2003; 47: 2242–2248.
23. Mammarei, H, et al. Emergence of plasmid-mediated quinolone resistance in Escherichia coli in Europe. Antimicrobial Agents and Chemotherapy 2005; 49: 71–76.
24. Kariuki, S, et al. Genotypic analysis of multidrug-resistant Salmonella enterica serovar Typhi, Kenya. Emerging Infectious Diseases 2000; 6: 649–651.
25. Friedman, SM, Lu, T, Drlica, K. Mutation in the DNA Gyrase A gene of Escherichia coli that expands the quinolone resistance-determining region. Antimicrobial Agents and Chemotherapy 2001; 45: 2378–2380.
26. Capoor, MR, et al. In vitro activity of azithromycin, newer quinolones and cephalosporins in ciprofloxacin resistant Salmonella causing enteric fever. Journal of Medical Microbiology 2007; 58: 1490–1494.
27. Marano, NK, et al. Emerging quinolone and extended spectrum cephalosporin resistant Salmonella in the United States. American Society for Microbiology, 99th General Meeting. Chicago, IL, May 1999.