Spread of bla(CTX-M-type) and bla(PER-2) beta-lactamase genes in clinical isolates from Bolivian hospitals.
OBJECTIVE
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.
Celenza
Giuseppe
G
Dipartimento di Scienze e Tecnologie Biomediche, Università di L'Aquila, I-67100 L'Aquila, Italy.
Pellegrini
Cristina
C
Caccamo
Marisa
M
Segatore
Bernardetta
B
Amicosante
Gianfranco
G
Perilli
Mariagrazia
M
D000150:Acinetobacter / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D001838:Bolivia; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D005798:Genes, Bacterial; D006769:Hospitals, General; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases