title: Antimicrobial resistance among invasive nontyphoidal Salmonella enterica isolates in the United States: National Antimicrobial Resistance Monitoring System, 1996 to 2007.
abstract: Nontyphoidal salmonellae (NTS) are important causes of community-acquired bloodstream infection. We describe patterns of antimicrobial resistance among invasive NTS in the United States. We compared bloodstream NTS isolates with those from stool submitted to the National Antimicrobial Resistance Monitoring System (NARMS) from 1996 to 2007. We describe antimicrobial resistance among invasive strains by serogroup and serotype. Of the 19,302 NTS isolates, 17,804 (92.2%) were from stool or blood. Of these, 1,050 (5.9%) were bloodstream isolates. The median ages (ranges) of patients with and without bacteremia were 36 (<1 to 97) years and 20 (<1 to 105) years, respectively (P < 0.001). Males (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.06 to 1.38) and those ≥65 years of age were at greater risk for invasive disease. Salmonella enterica serotypes Enteritidis, Typhimurium, and Heidelberg were the most common serotypes isolated from blood; S. enterica serotypes Dublin, Sandiego, and Schwarzengrund were associated with the greatest risk for bloodstream isolation. Of invasive isolates, 208 (19.8%) were resistant to ampicillin, 117 (11.1%) to chloramphenicol, and 26 (2.5%) to trimethoprim-sulfamethoxazole; 28 (2.7%) isolates were resistant to nalidixic acid and 26 (2.5%) to ceftriaxone. Antimicrobial resistance to traditional agents is common. However, the occurrence of nalidixic acid and ceftriaxone resistance among invasive NTS is cause for clinical and public health vigilance.
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, MS A-38, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30329, USA. jcrump@cdc.gov
authors.forename: John A
authors.initials: JA
authors.lastname: Crump
authors.forename: Felicita M
authors.initials: FM
authors.lastname: Medalla
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Joyce
authors.forename: Amy L
authors.initials: AL
authors.lastname: Krueger
authors.forename: R Michael
authors.initials: RM
authors.lastname: Hoekstra
authors.forename: Jean M
authors.initials: JM
authors.lastname: Whichard
authors.forename: Ezra J
authors.initials: EJ
authors.lastname: Barzilay
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000667:Ampicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology; D002443:Ceftriaxone / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002701:Chloramphenicol / Q000627:therapeutic use; D017714:Community-Acquired Infections / Q000188:drug therapy; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009268:Nalidixic Acid / Q000627:therapeutic use; D012480:Salmonella Infections / Q000382:microbiology; D019779:Salmonella enterica / Q000187:drug effects*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use; D014481:United States; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D009268:Nalidixic Acid; D002701:Chloramphenicol; D002443:Ceftriaxone; D000667:Ampicillin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination