Spread of bla(CTX-M-type) and bla(PER-2) beta-lactamase genes in clinical isolates from Bolivian hospitals

J Antimicrob Chemother. 2006 May;57(5):975-8. doi: 10.1093/jac/dkl055. Epub 2006 Mar 1.


Objectives: To assess the prevalence and types of genes encoding extended-spectrum beta-lactamases (ESBLs) in clinical isolates of Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter spp. from Bolivia.

Methods: A total of 642 clinical isolates were collected consecutively during a 4 month period (September to December 2004). Resistance or reduced susceptibility to cefotaxime and/or ceftazidime and/or aztreonam was assessed using double disc synergy tests using clavulanic acid, cefotaxime, ceftazidime and aztreonam to identify putative ESBL-producing isolates. The ESBL determinants were characterized by colony blot hybridization, PCR and DNA sequencing.

Results: Of the 642 isolates, 220 (34.3%) showed resistance or reduced susceptibility to cefotaxime and/or ceftazidime and/or aztreonam, and 150 (23.4%) were putative ESBL producers. A total of 106 ESBL-producing isolates contained the bla(CTX-M-2) gene, and 32 isolates had a novel allele, bla(CTX-M-43). bla(CTX-M) alleles were detected in all P. aeruginosa and Acinetobacter spp. studied. In contrast, only 12 ESBL-producing isolates had bla(PER-2), mainly Enterobacteriaceae, although it was also found in a strain of P. aeruginosa.

Conclusions: This is the first study on ESBL-producing strains in Bolivia and it reveals a high prevalence of bla(CTX-M) genes. The PER-2 enzyme was less prevalent, but its gene was detected in several species, including P. aeruginosa, which is consistent with horizontal transfer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter / drug effects
  • Acinetobacter / enzymology
  • Acinetobacter / genetics*
  • Acinetobacter / isolation & purification
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Bolivia
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Enterobacteriaceae / drug effects
  • Enterobacteriaceae / enzymology
  • Enterobacteriaceae / genetics*
  • Enterobacteriaceae / isolation & purification
  • Genes, Bacterial
  • Hospitals, General
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / enzymology
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / isolation & purification
  • beta-Lactamases / genetics*


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • beta-Lactamases