In vitro efficacy of the combination of ciprofloxacin and cefotaxime against nalidixic acid-resistant Salmonella enterica serotype Typhi

• Published in: International journal of antimicrobial agents Vol. 36; no. 2; pp. 155 - 158
• Main Authors: Kim, Dong-Min, Neupane, Ganesh Prasad, Jang, Sook Jin, Kim, Sung Hun, Lee, Bok Kwon
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2010; Elsevier
• Subjects: Anti-Infective Agents - pharmacology; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Azithromycin; Bacterial diseases; Bacterial diseases of the digestive system and abdomen; Biological and medical sciences; Cefotaxime; Cefotaxime - pharmacology; Ciprofloxacin; Ciprofloxacin - pharmacology; Drug Resistance, Bacterial; Drug Synergism; Human bacterial diseases; Humans; Infectious Disease; Infectious diseases; Medical sciences; Microbial Sensitivity Tests; Nalidixic Acid - pharmacology; Pharmacology. Drug treatments; Salmonella enterica; Salmonella Typhi; Salmonella typhi - drug effects; Typhoid fever; Typhoid Fever - microbiology; Typhoid fever; Cefotaxime; Ciprofloxacin; Salmonella Typhi; Azithromycin; Salmonella typhi; Fluoroquinolone derivatives; Bacteria; Salmonellosis; Naphtyridine derivatives; Protein synthesis inhibitor; Serotype; Quinolone derivatives; Enterobacteriaceae; Typing; β-Lactams; Treatment efficiency; Typhoid; Macrolide; In vitro; Infection; Resistance; Cephalosporin derivatives; Antibiotic; Nalidixic acid; Bacteriosis; Digestive diseases; Antibacterial agent
• ISSN: 0924-8579; 1872-7913
• DOI: 10.1016/j.ijantimicag.2010.03.022

Abstract Typhoid fever is a systemic intracellular infection caused by Salmonella enterica serotype Typhi. The emergence and spread of nalidixic acid-resistant S. Typhi (NARST) is challenging for clinicians in many countries owing to the lack of suitable treatment options. The aim of this study was to identify in vitro synergistic combinations of antibiotics against S. Typhi. In vitro time–kill studies were performed on three clinical NARST isolates and one type strain of nalidixic acid-susceptible S. Typhi (NASST) ATCC 9992 with ciprofloxacin, cefotaxime and azithromycin in various combinations. The combination of ciprofloxacin (0.012–0.375 μg/mL) and cefotaxime (0.063–0.125 μg/mL) against all three NARST strains and the NASST strain was significantly more effective in vitro in reducing bacterial counts by ≥3 log10 colony-forming units at 24 h and showed synergistic effects. Combination therapy with ciprofloxacin and cefotaxime might be the treatment of choice for patients with typhoid fever. The combination of a fluoroquinolone and a β-lactam, which are directed against different targets, may improve efficacy compared with a fluoroquinolone alone and may reduce the chance of fluoroquinolone-resistant mutants emerging in patients with severe typhoid fever.