Cefotaxime-Ciprofloxacin Combination Therapy for Nontyphoid Salmonella Bacteremia and Paravertebral Abscess After Failure of Monotherapy Chia-Ming Chang, M.D., Hsin-Chun Lee, M.D., Nan-Yao Lee, M.D., Guan-Cheng Huang, M.D., I-Wen Lee, M.D., and Wen-Chien Ko, M.D. Therapeutic failure of monotherapy with either a third-generation cephalosporin or a fluoroquinolone against nontyphoid salmonellae has been observed in clinical practice. Combination therapy with both agents is recommended in the literature for treating life-threatening infections. However, we know of no published case reports that indicate a therapeutic advantage of this combination therapy for nontyphoid salmonellae infections. We describe a 60-year-old man who had breakthrough bacteremia with vertebral osteomyelitis and paravertebral abscess caused by Salmonella enterica serotype Choleraesuis. This was not controlled with sequential monotherapy but was eventually cured with cefotaxime-ciprofloxacin combination therapy. The Etest showed that the strain was susceptible to cefotaxime and ciprofloxacin, but resistant to nalidixic acid. Cefotaxime and ciprofloxacin in combination may be considered as an option for difficult-to- treat salmonellosis. Key Words: Salmonella enterica serotype Choleraesuis, S. Choleraesuis, Salmonella typhi, nontyphoid salmonellosis, cephalosporin, fluoroquinolone, cefotaxime-ciprofloxacin combination treatment. (Pharmacotherapy 2006;26(11):1671–1674) Despite improvements in sanitation, human nontyphoid salmonellae infections continue to occur when food is not well processed. These infections may occur in patients with various clinical disorders, such as gastroenteritis, enteric fever, chronic carrier state, bacteremia, or extraintestinal localized infections. 1 Among more than 2000 nontyphoid salmonellae serotypes, Salmonella enterica serotype Choleraesuis (S. Choleraesuis) is highly invasive and is usually associated with bacteremia and extraintestinal infections. 2 Although S. Choleraesuis is an infrequent serotype isolated from human sources in the United States, 3 Canada 4 and the United Kingdom, 5 the epidemiologic pattern differs in Asian countries. 6 In Taiwan, S. Choleraesuis represents the second most common nontyphoid salmonellae serotype isolated from human sources in two independent epidemiologic surveys. 7, 8 Antimicrobial resistance in nontyphoid salmonellae has become a major public health concern worldwide. 9 As resistance to ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol has increased, 10–12 the third- generation cephalosporins and fluoroquinolones have become the drugs of choice for empiric treatment in endemic areas with high prevalence of antimicrobial resistance. 9, 13 However, because of reduced susceptibility to fluoroquinolones, monotherapy with a fluoroquinolone against From the Division of Infectious Diseases, Department of Internal Medicine (Drs. Chang, H.-C. Lee, N.-Y. Lee, and Ko), and the Department of Obstetrics and Gynecology, (Dr. I.-W. Lee), National Cheng Kung University Hospital, Tainan, Taiwan; and the Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan (Dr. Huang). Address reprint requests to Wen-Chien Ko, M.D., Department of Internal Medicine, National Cheng Kung University Hospital, 138 Sheng Li Road, Tainan, 70403, Taiwan; e-mail: winston@mail.ncku.edu.tw.