Ciprofloxacin treatment failure in a case of typhoid fever caused by Salmonella enterica serotype Paratyphi A with reduced susceptibility to ciprofloxacin

Abstract

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.

Typhoid fever in sub-Saharan Africa: Challenges of diagnosis and management of infections

“…The emergence of multi-drug resistant S. Typhi strains subsequently led to the widespread use of fluoroquinolones, such as ciprofloxacin and ofloxacin, in countries where MDR is a problem. However, outbreaks of nalidixic acid-resistant typhoid with isolates showing reduced susceptibility to fluoroquinolones started to occur in Vietnam [10] and Tajikistan [23] in the early 1990s and then spread to Pakistan and India and several other countries in Southeast Asia [12,24,25,26], Kuwait [27], and Nepal [28]; often treatment of these infections with a fluoroquinolone resulted in a delay in clinical response and sometimes treatment failure. Fluoroquinolone resistance is now common in countries such as India [29] and Bangladesh [30].…”

Epidemiology, Clinical Presentation, Laboratory Diagnosis, Antimicrobial Resistance, and Antimicrobial Management of Invasive Salmonella Infections

“…Although nalidixic acid is not used for treatment, development of resistance to this drug is of clinical importance since it may be associated with reduced clinical effectiveness of fluoroquinolone treatments (370,371). Reports of quinolone resistance among nontyphoidal Salmonella strains followed soon after the introduction of fluoroquinolones.…”

Ciprofloxacin-Resistant Salmonella enterica Serovar Typhi from Kuwait with Novel Mutations in gyrA and parC Genes

“…Such strains have also been reported from other parts of the world (26,27). Consequently, there is treatment failure with ciprofloxacin in patients infected with these organisms (11,26,27).…”

“…We have previously reported enteric fever isolates that are either multiresistant or with reduced susceptibility to ciprofloxacin from expatriate workers of South Asian origin from Kuwait (9,10,11). Although there are reports from India (13,24), Bangladesh (1,25), and Nepal (5) of Salmonella enterica serovar Typhi strains fully resistant to ciprofloxacin (MICs Ն 4 mg/liter), infection with such strains is rare.…”