Downloaded from www.microbiologyresearch.org by IP: 54.157.140.51 On: Wed, 20 Apr 2016 08:10:48 Case Report Ciprofloxacin treatment failure in a case of typhoid fever caused by Salmonella enterica serotype Paratyphi A with reduced susceptibility to ciprofloxacin Tzonyo Dimitrov, 1 Edet E. Udo, 2 Osama Albaksami, 3 Abdul A. Kilani 4 and El-Din M. R. Shehab 4 Correspondence Tzonyo Dimitrov dimitrov_varn90@hotmail.com 1 Department of Medical Laboratories, Microbiology Section, Infectious Diseases Hospital, PO Box 4710, Safat 13048, Kuwait 2 Department of Microbiology, Faculty of Medicine, Kuwait University, PO Box 24923, Safat 13110, Kuwait 3 Department of Pediatrics, Infectious Diseases Hospital, PO Box 4710, Safat 13048, Kuwait 4 Department of Medicine, Infectious Diseases Hospital, PO Box 4710, Safat 13048, Kuwait Received 11 June 2006 Accepted 6 October 2006 This report describes a case of ciprofloxacin treatment failure in a patient with enteric fever caused by Salmonella enterica serotype Paratyphi A. The organism was isolated from a blood culture from a patient who was treated with oral ciprofloxacin (500 mg every 12 h) for 13 days. The organism showed reduced susceptibility to ciprofloxacin (MIC 0.75 mg ml ”1 ) and was resistant to nalidixic acid. The patient was then placed on intravenous ceftriaxone (1 g every 12 h) and responded within 3 days. The patient was discharged after 9 days on ceftriaxone with no relapse on follow-up. This case adds to the increasing incidence of treatment failures with ciprofloxacin in typhoid fever caused by typhoid salmonellae with reduced susceptibility to ciprofloxacin. It also highlights the inadequacy of current laboratory methods for fluoroquinolone susceptibility testing in adequately predicting in vivo activity of ciprofloxacin against typhoid salmonellae and supports calls for new guidelines for fluoroquinolone susceptibility testing of these organisms. Introduction Typhoid fever is a major health concern in the developing world. More than 16 million new cases occur worldwide annually, resulting in approximately 600 000 deaths per year (Parry et al., 2002). Previously, typhoid fever was success- fully treated with chloramphenicol, co-trimoxazole and ampicillin; however, resistance to these agents has emerged in the last two decades, especially in South and Southeast Asia (Chandel et al., 2000). These developments resulted in the use of fluoroquinolones as the antimicrobial agents of choice for the treatment of typhoid fever (Parry et al., 2002). Subsequently, fluoroquinolone resistance has been reported in some parts of the world (Wain et al., 1997; Threlfall & Ward, 2001; Hakanen et al., 2001). We now report ciprofloxacin treatment failure in a case of enteric fever caused by Salmonella enterica serotype Paratyphi A (Salmonella Paratyphi A) in Kuwait in a traveller returning from South Asia. Case report An 18-year-old female returned to Kuwait from India on 19 May 2005. On 21 May 2005 she developed low-grade fever, mild abdominal discomfort and passed loose motions once or twice daily. She did not seek medical help until 1 June 2005, when she started to run a high temperature (>38 uC) and presented at the outpatient clinic of a Kuwaiti hospital. A provisional diagnosis of fever of unknown origin was made, and blood was taken for culture and sensitivity testing. The blood culture yielded growth of S. Paratyphi A. Antimicrobial susceptibility testing, performed by the disc diffusion method, reported the isolate as sensitive to ciprofloxacin. On 4 June 2005 the patient was prescribed oral ciprofloxacin in doses of 500 mg twice daily. The patient’s clinical condition did not improve after 7 days on ciprofloxacin, and she was referred to the Infectious Diseases Hospital on 11 June 2005 for admission with a 10 day history of continuous fever (>38 u C), poorly localized abdominal discomfort, myalgia and hepatomegaly. Blood culture, total blood count, urinalysis, Widal test and blood film for malaria parasites were ordered on admission. Her total leucocyte count was 8.5610 9 l 21 . Urinalysis was normal, and thin and thick film examinations of the Abbreviation: CLSI, Clinical and Laboratory Standards Institute. 46773 G 2007 SGM Printed in Great Britain 277 Journal of Medical Microbiology (2007), 56, 277–279 DOI 10.1099/jmm.0.46773-0