Intestinal carriage of extended-spectrum beta-lactamase–producing Enterobacteriaceae at admission in a Portuguese hospital

Marta Aires-de-sousa, Elizeth Lopes, Maria Luísa Gonçalves, Ana Luísa Pereira, Augusto Machado E Costa, Hermínia De Lencastre, Laurent Poirel

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7 Citations (Scopus)


To evaluate the prevalence of extended-spectrum β-lactamase (ESBL)–producing Enterobacteriaceae fecal carriers at admission in a Portuguese hospital and to determine the epidemiology and antimicrobial resistance patterns of ESBL-producing isolates. During a 2-month period, rectal swabs were collected at hospital admission from 151 at-risk patients. In addition, 48 rectal swabs were obtained from weekly screenings of 37 patients hospitalized for > 48 h. All ESBL/carbapenemase-producing isolates were tested for antimicrobial susceptibility and characterized by PFGE and MLST. The prevalence of ESBL producers at hospital admission was 17% and 24% among at-risk patients hospitalized for > 48 h, while the prevalence of carbapenemase producers was 3% in both cases. Most of the isolates were Escherichia coli (54%) and Klebsiella pneumoniae (41%). The most common ESBL identified was CTX-M-15 (n = 17/34; 50%), followed by CTX-M-27 (n = 10; 29%), CTX-M-33 (n = 4; 12%), SHV-12 (n = 2), and CTX-M-55 (n = 1). The 20 E. coli isolates were distributed into 16 PFGE types and nine sequence types (ST), with 60% of the isolates belonging to ST131. The 15 K. pneumoniae were grouped into 12 PFGE types and nine STs, with three STs (ST17, ST449, ST147) corresponding to 60% of the isolates. A high proportion of isolates showed resistance to ciprofloxacin (86%), trimethoprim-sulfamethoxazole (68%), tobramycin (57%), and gentamicin (43%). All isolates remained susceptible to fosfomycin. A high prevalence of ESBL-producing Enterobacteriaceae was found at hospital admission among at-risk patients and > 50% of the isolates showed resistance to first-line antibiotics for the treatment of lower urinary tract infections, leaving fosfomycin as an alternative.

Original languageEnglish
Pages (from-to)783-790
Number of pages8
JournalEuropean Journal of Clinical Microbiology & Infectious Diseases
Issue number4
Publication statusPublished - 1 Apr 2020


  • ESBL
  • Enterobacteriaceae
  • Escherichia coli
  • Hospital admission
  • Klebsiella pneumoniae
  • Portugal


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