Extraintestinal focal infections in adults with Salmonella enterica serotype Choleraesuis bacteremia.

BACKGROUND AND PURPOSE: Salmonella enterica serotype Choleraesuis, which is associated with severe human infections and multidrug resistance, poses a serious problem in Taiwan. The aim of the study was to investigate the epidemiology and clinical features of S. Choleraesuis bacteremia.

METHODS

Medical records and antimicrobial susceptibility of blood isolates were investigated for 43 adults (> or =18 years old) with S. Choleraesuis bacteremia from 1999 to 2005.

RESULTS

The proportion of S. Choleraesuis in non-typhoidal Salmonella bacteremia increased in the latter three years (2003-2005). The elderly with aged-related disorders, and younger patients receiving immunosuppressive therapy for their underlying diseases were two high-risk groups. Twenty cases (47%) had extraintestinal focal infections, including 10 cases of mycotic aneurysm, six of osteomyelitis, and 4 pleuropulmonary infections. Univariate analysis revealed that age > or =50 years was associated with occurrence of endovascular infection (p=0.008), while immunosuppressive therapy was negatively associated with endovascular infection (p=0.043). Significant resistance to first-line antimicrobial agents (i.e., ampicillin, trimethoprim-sulfamethoxazole or chloramphenicol) was noted. All strains were resistant to nalidixic acid, and 56% were resistant to ciprofloxacin. Few (<5%) isolates were resistant to ceftriaxone, and all were susceptible to cefepime, aztreonam, imipenem, meropenem and ertapenem. Multivariate analysis showed that shock (odds ratio [OR], 20.6; 95% confidence interval [CI], 1.8-239.4; p=0.016) and apyrexia (OR, 36.2; 95% CI, 3.7-358.2; p=0.002) were independent risk factors for mortality.

CONCLUSION

S. Choleraesuis bacteremia was usually complicated with extraintestinal focal infections in the elderly. With a high level of resistance among S. Choleraesuis, fluoroquinolones should be avoided for critically ill patients with suspected Salmonella bacteremia.