title: Frequency and predictors of colonization of the respiratory tract by VIM-2-producing Pseudomonas aeruginosa in patients of a newly established intensive care unit.
abstract: The aim of this study was to examine the frequency and predictors of colonization of the respiratory tract by metallo-beta-lactamase (MBL)-producing Gram-negative bacteria in patients admitted to a newly established intensive care unit (ICU) of a tertiary care hospital. Specimens of tracheobronchial aspirates for microbiological studies were obtained every day for the first 3 days of the ICU stay and subsequently every third day for the rest of the ICU stay. PCR analysis and nucleotide sequencing were performed to identify bacteria that had MBL genes. Thirty-five patients (20 male, 15 female) were hospitalized during the initial 3 month period of functioning of the ICU. Colonization of the lower respiratory tract by Gram-negative bacteria was found in 29 of 35 patients (83 %) during the first 6-20 days (median 13 days) following admission to the ICU (13 patients with Acinetobacter baumannii, ten with Pseudomonas aeruginosa, three with Enterobacter aerogenes, two with Klebsiella pneumoniae and one with Stenotrophomonas maltophilia). Six of 29 patients (21 %) colonized with Gram-negative bacteria had bla(VIM-2)-positive P. aeruginosa isolates; one of these patients developed clinical infection due to this micro-organism. Previous use of carbapenems (P=0.01) or other beta-lactams (P=0.03), as well as a stay in the ICU of >20 days (P<0.001), were associated with colonization with bla(VIM-2)-producing P. aeruginosa. In conclusion, colonization by Gram-negative bacteria of the respiratory tract of patients in this newly established ICU was common (83 %). Use of beta-lactams, including carbapenems, was associated with subsequent colonization of the respiratory tract with MBL-positive P. aeruginosa.
authors.forename: Maria
authors.initials: M
authors.lastname: Horianopoulou
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, Greece.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Legakis
authors.forename: Maria
authors.initials: M
authors.lastname: Kanellopoulou
authors.forename: Sotiris
authors.initials: S
authors.lastname: Lambropoulos
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, Greece.
authors.forename: Athanassios
authors.initials: A
authors.lastname: Tsakris
authors.affiliation: Department of Medicine, Tufts University School of Medicine, Boston, MA, USA.|Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, Marousi 151 23, Athens, Greece.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Falagas
mesh_terms: D000208:Acute Disease; D001980:Bronchi / Q000382:microbiology*; D015780:Carbapenems / Q000008:administration & dosage; D002353:Carrier State / Q000382:microbiology / Q000517:prevention & control; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology* / Q000517:prevention & control; D005260:Female; D005798:Genes, Bacterial; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006115:Greece / Q000453:epidemiology; D006769:Hospitals, General; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology* / Q000517:prevention & control; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D012307:Risk Factors; D013997:Time Factors; D014132:Trachea / Q000382:microbiology*; D014505:Urban Population; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics; D047090:beta-Lactams / Q000008:administration & dosage
chemical_list: D015780:Carbapenems; D047090:beta-Lactams; C425108:beta-lactamase bla(vim-2); D001618:beta-Lactamases