title: Prevalence of multidrug-resistant gram-negative bacilli producing extended-spectrum β-lactamases (ESBLs) and ESBL genes in solid organ transplant recipients.
abstract: BACKGROUND
  Multidrug-resistant (MDR) gram-negative bacilli pose a serious and rapidly emerging threat to recipients of solid organ transplants (SOTs). However, extended-spectrum β-lactamases (ESBLs), as one of the cardinal mechanisms of resistance to antimicrobial agents in SOT recipients, remain obscure. The aim of this study was to investigate the prevalence of strains producing ESBLs in SOT patients with MDR gram-negative bacilli infections and to identify the ESBL genes carried by them.
  
  
  METHODS
  Isolates from various clinical specimens of SOT recipients were identified using the VITEK 2 system, and their antibiotic sensitivity was determined by the 2-fold agar dilution method. Isolates suspected of producing ESBL enzymes were tested by an ESBL phenotypic confirmatory method, and the ESBL genotypes were determined by the polymerase chain reaction and sequencing.
  
  
  RESULTS
  A total of 80 MDR gram-negative strains were isolated from 350 SOT recipients. Among these strains, 42 (52.5%) had an ESBL-positive phenotype; 33 (42.3%) patients with ESBL-positive infection were found. Molecular analysis showed that most of the isolates harbored blaCTX-M-9 (78.6%), blaTEM (81.0%), and blaSHV (69.0%) genes. All the ESBL-producing strains were susceptible to carbapenems.
  
  
  CONCLUSIONS
  MDR gram-negative isolates from SOT recipients are frequently ESBL producers. TEM and CTX-M9 were the predominant ESBL types.
authors.affiliation: Department of Urology, Shandong University Affiliated Shandong Province Qianfoshan Hospital, Jinan, China.
authors.forename: T-Y
authors.initials: TY
authors.lastname: Men
authors.forename: J-N
authors.initials: JN
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Gu
authors.forename: T-H
authors.initials: TH
authors.lastname: Xing
authors.forename: Z-H
authors.initials: ZH
authors.lastname: Peng
authors.forename: L
authors.initials: L
authors.lastname: Zhong
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004269:DNA, Bacterial / Q000032:analysis; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D016030:Kidney Transplantation; D016031:Liver Transplantation; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D015995:Prevalence; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases