title: Comparison of a repetitive extragenic palindromic sequence-based PCR method and clinical and microbiological methods for determining strain sources in cases of nosocomial Acinetobacter baumannii bacteremia.
abstract: Using a repetitive extragenic palindromic PCR (REP-PCR), we genotypically characterized strains causing nosocomial Acinetobacter baumannii infections and analyzed the source of bacteremia in 67 patients from an institution in which infections by this bacterium were endemic. Six different genotypes were found, including 21, 27, 3, 9, 3, and 4 strains. The probable source of bacteremia, according to clinical and/or microbiological criteria, was known in 42 patients (63%): respiratory tract (n = 19), surgical sites (n = 12), intravascular catheters (n = 5), burns (n = 3), and urinary tract (n = 3). The definite source of bacteremia, according to REP-PCR, could be established in 30 (71%) out of the 42 patients with strains from blood and other sites; in these cases clinical and microbiological criteria for the source of bacteremia were thus confirmed. In the remaining 12 patients (29%) the probable source was refuted by the REP-PCR method. The definite sources of bacteremia according to genotype were as follows: respiratory tract in 13 patients (31%), surgical sites in 8 (19%), intravascular catheters in 4 (9%), burns in 3 (7%), and urinary tract in 2 (5%). A comparison of strains from blood cultures and other sites with regard to their REP-PCR and antimicrobial resistance profiles was also made. Taking the REP-PCR as the "gold standard," the positive predictive value of antibiotype was 77% and the negative predictive value was 42%. In summary, the utility of the diagnosis of the source of nosocomial A. baumannii bacteremia using clinical and/or microbiological criteria, including antibiotyping, is limited, as demonstrated by REP-PCR.
authors.affiliation: Infectious Diseases Service, Virgen del Rocío University Hospitals, Seville, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Martín-Lozano
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Cisneros
authors.forename: Berta
authors.initials: B
authors.lastname: Becerril
authors.forename: Lucila
authors.initials: L
authors.lastname: Cuberos
authors.forename: Trinidad
authors.initials: T
authors.lastname: Prados
authors.forename: Carlos
authors.initials: C
authors.lastname: Ortíz-Leyba
authors.forename: Elías
authors.initials: E
authors.lastname: Cañas
authors.forename: Jerónimo
authors.initials: J
authors.lastname: Pachón
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000145:classification* / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D001769:Blood / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000382:microbiology*; D003470:Culture Media; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media