title: Clinical characteristics in adult patients with Salmonella bacteremia and analysis of ciprofloxacin-nonsusceptible isolates.
abstract: OBJECTIVE
  The purpose of this study is to describe clinical characteristics of Salmonella bacteremia in adult patients and analyze ciprofloxacin-nonsusceptible isolates.
  
  
  METHODS
  A total of 101 Salmonella blood isolates from adult patients were collected from January 2011 to December 2013 in MacKay Memorial Hospital. Eight ciprofloxacin-nonsusceptible Salmonella blood isolates were screened for carbapenemase and other β lactamase genes. Isolates were examined by PCR for the quinolone resistance-determining region (QRDR) of all subunits for DNA gyrase (gyrA and gyrB) genes and topoisomerase IV (parC and parE) genes.
  
  
  RESULTS
  There were 22 (21.78%) S. enterica serovar B, 5 (4.95%) S. enterica serovar C1, 7 (6.93%) S. enterica serovar C2, 65 (64.36%) S. enterica serovar D, and 2 (1.98%) S. enterica serovar Typhi (S. typhi) isolates. β-lactamase gene screening and sequencing yielded only one blaCMY-2-positive isolate. In multivariate risk factor analysis, renal insufficiency [odds ratio (OR) 3.774; p = 0.020] and heart disease (OR 2.922; p = 0.027) were more common among elderly patients (≥65 years). Independent risk factors for ciprofloxacin-nonsusceptible strains included S. enterica serovar C2 (OR 28.430; p = 0.032), renal insufficiency (OR 13.927; p = 0.032), and immunosuppression agent usage (OR 60.082; p = 0.006). 87.50% (7/8) of isolates had gyrA mutation, 62.50% (5/8) had parC mutation, and none had gyrB and parE mutations. Isolates with both Ser83Phe/Asp87Asn gyrA and Thr57Ser/Ser80Ile parC mutation genes were highly ciprofloxacin-resistant (minimum inhibitory concentration ≥4 mg/L).
  
  
  CONCLUSIONS
  Elderly patients with renal insufficiency and heart disease were at risk for Salmonella bacteremia. Those for ciprofloxacin-nonsusceptible strains included S. enterica serovar C2, renal insufficiency, and immunosuppression agent usage. The 8 ciprofloxacin-nonsusceptible isolates carried gyrA and parC mutations, which cause resistance that poses a major concern.
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan.
authors.forename: Ming-Wei
authors.initials: MW
authors.lastname: Cheng
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan; MacKay College of Medicine, Nursing and Management, Taipei, Taiwan; Infection Control Committee, MacKay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Lee
authors.affiliation: Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan.
authors.forename: Nai-Yu
authors.initials: NY
authors.lastname: Wang
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan.
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Wu
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chih-Chen
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan.
authors.forename: Li-Chuan
authors.initials: LC
authors.lastname: Weng
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan; MacKay College of Medicine, Nursing and Management, Taipei, Taiwan; Infection Control Committee, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan. Electronic address: joeliu5929@hotmail.com.tw.
authors.forename: Chang-Pan
authors.initials: CP
authors.lastname: Liu
authors.affiliation: Department of Medicine, MacKay Medical College, New Taipei City, Taiwan; MacKay College of Medicine, Nursing and Management, Taipei, Taiwan; Infection Control Committee, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Division of Gastroenterology, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan. Electronic address: shihshou@gmail.com.
authors.forename: Shou-Chuan
authors.initials: SC
authors.lastname: Shih
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000453:epidemiology; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002939:Ciprofloxacin / Q000627:therapeutic use*; D027081:DNA Gyrase / Q000235:genetics; D027101:DNA Topoisomerase IV / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D051437:Renal Insufficiency / Q000150:complications; D012475:Salmonella / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D012480:Salmonella Infections / Q000188:drug therapy* / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D002939:Ciprofloxacin; D001618:beta-Lactamases; C063912:carbapenemase; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase
keywords: Salmonella bacteremia; ciprofloxacin; gyrA mutation; parC mutation; risk factors