title: Etiologies of community-onset urinary tract infections requiring hospitalization and antimicrobial susceptibilities of causative microorganisms.
abstract: BACKGROUND
  Community-onset urinary tract infections (CoUTIs) are the most common bacterial infections, and a decline in antibiotic susceptibility causes many clinical challenges. Adequate empiric antibiotic treatment can decrease unnecessary hospital stays and complications, while reducing the antimicrobial resistance progression.
  
  
  METHODS
  From October 2014 to April 2015, we retrospectively enrolled patients who were at least 18 years old and required hospitalization for CoUTIs. Demographic variables of these patients, and uropathogens and their antimicrobial susceptibilities were evaluated.
  
  
  RESULTS
  In total, 457 patients were enrolled in this study. Their mean age was 71.9 years, and 35.2% of the patients were male. Escherichia coli (54.5%) was the most common uropathogen, followed by Klebsiella pneumoniae (13.1%), Enterococcus spp. (7.1%), Pseudomonas aeruginosa (4.6%), and Proteus mirabilis (3.5%). Bacteremia was present in 25.2% of patients. Diabetes mellitus and acute kidney injury at admission were risk factors for CoUTIs with concomitant bacteremia. Among the UTI-associated bloodstream strains, E. coli (53.1%) was also the most predominant pathogen, followed by K. pneumoniae (11.3%), Staphylococcus aureus (6.1%), and P. mirabilis (4.3%). The overall susceptibility of cefazolin was 62.8%, ceftriaxone 71.4%, ceftazidime 82.8%, flomoxef 82%, cefepime 94.5%, ampicillin-sulbactam 41.6%, piperacillin-tazobactam 85%, levofloxacin 65.2%, trimethoprim-sulfamethoxazole 61.5%, imipenem 92.3%, gentamicin 76.1%, and amikacin 97.5%. Cefazolin-susceptible isolates could be found more frequently among patients who are less than 65 years of age and without diabetes mellitus, had no UTI episode in the past year, and have no bacteremia risk. Patients with nasogastric tube retention more commonly experienced antimicrobial resistance to all the third-generation cephalosporins.
  
  
  CONCLUSIONS
  Third-generation cephalosporins effectively treated CoUTIs. However, patients with nasogastric tube retention more commonly experienced cephalosporin resistance. Cefepime, imipenem, and amikacin may be used in patients with higher antimicrobial resistance. In selected patients, cefazolin may still be an adequate drug of choice for CoUTIs.
authors.affiliation: Department of Internal Medicine, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan; Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chih-Chien
authors.initials: CC
authors.lastname: Chiu
authors.affiliation: Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Department of Internal Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan.
authors.forename: Tzu-Chao
authors.initials: TC
authors.lastname: Lin
authors.affiliation: Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Rui-Xin
authors.initials: RX
authors.lastname: Wu
authors.affiliation: Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Ya-Sung
authors.initials: YS
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan.
authors.forename: Po-Jen
authors.initials: PJ
authors.lastname: Hsiao
authors.affiliation: Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Jung-Chung
authors.initials: JC
authors.lastname: Lin
authors.affiliation: Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. Electronic address: fychang@mail.ndmctsgh.edu.tw.
authors.forename: Feng-Yee
authors.initials: FY
authors.lastname: Chang
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002511:Cephalosporins / Q000627:therapeutic use; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000209:etiology / Q000382:microbiology*; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000302:isolation & purification; D016983:Enterococcus / Q000187:drug effects / Q000302:isolation & purification; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D012189:Retrospective Studies; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000209:etiology / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins
keywords: antibiotic susceptibility; cefazolin; community onset; third-generation cephalosporin; urinary tract infection