[Molecular characterization of carbapenem-resistant and metallo-beta-lactamase-producing Pseudomonas aeruginosa isolated from blood cultures from children and teenagers with cancer].
BACKGROUND
The objective of this study was to evaluate the prevalence and dissemination of carbapenem-resistant and metallo-beta-lactamase-producing Pseudomonas aeruginosa isolated from blood-stream samples (2000-2005) that were collected from patients admitted to the Institute of Pediatric Oncology, UNIFESP (IOP-GRAACC).


RESULTS
Fifty-six P. aeruginosa samples were isolated from 49 patients. Thirty-two of these samples were classified as carbapenem-resistant using the disc diffusion method and were subjected to the PCR reaction in order to detect MBL genes. Eighteen of these 32 isolates showed the blaSPM-1 gene. Eight samples selected in different years over the study period presented the same genetic profile according to pulsed-field gel electrophoresis. The antimicrobial therapy was considered adequate for only 23.5% of the patients with bacteremia due to P. aeruginosa carrying the blaSPM-1 gene, and a high lethality rate of 70.6% was observed during the 30-day period after bacteremia and an inadequate initial antibiotic regimen.


CONCLUSIONS
We detected the presence of a clone of carbapenem-resistant P. aeruginosa carrying blaSPM-1 that persisted in blood culture samples over a six-year period at the institution, with high lethality, thus justifying rigorous epidemiological surveillance and a rearrangement of the antimicrobial therapy regimens at the institution.
Fernandes
Thais Avila
TA
Laboratório Especial em Microbiologia Clínica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP.
Pereira
Carlos Alberto Pires
CA
Petrili
Antônio Sergio
AS
Pignatari
Antônio Carlos Campos
AC
D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000382:microbiology*; D001938:Brazil; D015780:Carbapenems / Q000494:pharmacology*; D002648:Child; D052978:Disk Diffusion Antimicrobial Tests; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D012189:Retrospective Studies; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics
D000900:Anti-Bacterial Agents; D015780:Carbapenems; C476155:beta-lactamase SPM-1, Pseudomonas aeruginosa; D001618:beta-Lactamases