Nalidixic acid-resistant Salmonella typhi (NARST) was first isolated in Viet Nam in 1993.
Analysis of the quinolone resistance-determining region of gyrA in 20 NARST isolates by
polymerase chain reaction and single-stranded conformational polymorphism yielded two
novel patterns: pattern II corresponding to a point mutation at nucleotide 87 Asp→ Gly (n=
17), and pattern III corresponding to a point mutation at nucleotide 83 Ser→ Phe (n= 3). In
trials of short-course ofloxacin therapy for uncomplicated typhoid, 117 (78%) of 150 patients …

SIR—We share the worries of DA Murdoch and colleagues (Jan 31, p 339) 1 about the
spread of quinoloneresistant Salmonella typhi in Asia. Typhoid fever has been endemic in
Vietnam for many years and is a common cause of admission to the Centre for Tropical
Diseases (CTD) in Ho Chi Minh City, an infectious disease referral centre for the south of the
country. 2 80% of blood culture isolates of S typhi at this centre carry plasmidmediated
resistance to chloramphenicol, ampicillin, and trimethoprimsulphamethoxazole (co …