title: Metallo-β-lactamase and genetic diversity of Pseudomonas aeruginosa in intensive care units in Campo Grande, MS, Brazil.
abstract: Infection by Pseudomonas aeruginosa has spread worldwide, with limited options for treatment. The purpose of this study was to investigate metallo-β-lactamase-producing P. aeruginosa strains and compare their genetic profile using samples collected from patients in intensive care units. Forty P. aeruginosa strains were isolated from two public hospitals in Campo Grande, Mato Grosso do Sul State, from January 1st, 2007 to June 31st, 2008. Profiles of antimicrobial susceptibility were determined using the agar diffusion method. Metallo-β-lactamase was investigated using the double-disk diffusion test and PCR. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE). Respiratory and urinary tracts were the most common isolation sites. Of the 40 samples tested, 72.5% (29/40) were resistant to ceftazidime and 92.5% (37/40) to imipenem, whereas 65% (26/40) were resistant to both antimicrobials. Fifteen pan-resistant samples were found. Five percent (2/40) of samples were positive for metallo-β-lactamase on the phenotype test. No metallo-β-lactamase subtype was detected by PCR. Macrorestriction analysis revealed 14 distinct genetic patterns. Based on the superior accuracy of PCR, it can be inferred that P. aeruginosa isolates from the investigated hospitals have alternative mechanisms of carbapenem resistance. The results also suggest clonal spread of P. aeruginosa between the studied hospitals.
authors.affiliation: Health and Development Post-graduation Program, Central-West Region, Universidade Federal de Mato Grosso do Sul, MS, Brazil. anaclaurod@yahoo.com.br
authors.forename: Ana Claudia Souza
authors.initials: AC
authors.lastname: Rodrigues
authors.forename: Marilene Rodrigues
authors.initials: MR
authors.lastname: Chang
authors.forename: Gabriela Dorn
authors.initials: GD
authors.lastname: Nóbrega
authors.forename: Mayara Souza
authors.initials: MS
authors.lastname: Rodrigues
authors.forename: Nadia Cristina Pereira
authors.initials: NC
authors.lastname: Carvalho
authors.forename: Beatriz Garcia
authors.initials: BG
authors.lastname: Gomes
authors.forename: Dênio Lopes de
authors.initials: DL
authors.lastname: Almeida
authors.forename: Karyne Rangel
authors.initials: KR
authors.lastname: Carvalho
authors.forename: Marise Dutra
authors.initials: MD
authors.lastname: Asensi
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D052978:Disk Diffusion Antimicrobial Tests; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D007362:Intensive Care Units; D058889:Molecular Typing; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases