title: Propensity for biofilm formation by clinical isolates from urinary tract infections: developing a multifactorial predictive model to improve antibiotherapy.
abstract: A group of biofilm-producing bacteria isolated from patients with urinary tract infections was evaluated, identifying the main factors contributing to biofilm formation. Among the 156 isolates, 58 (37.2%) were biofilm producers. The bacterial species (P<0.001), together with patient's gender (P = 0.022), were the factors with the highest influence for biofilm production. There was also a strong correlation of catheterization with biofilm formation, despite being less significant (P = 0.070) than species or gender. In fact, some of the bacteria isolated were biofilm producers in all cases. With regard to resistance profile among bacterial isolates, β-lactam antibiotics presented the highest number of cases/percentages--ampicillin (32/55.2%), cephalothin (30/51.7%), amoxicillin/clavulanic acid (22/37.9%)--although the carbapenem group still represented a good therapeutic option (2/3.4%). Quinolones (nucleic acid synthesis inhibitors) also showed high resistance percentages. Furthermore, biofilm production clearly increases bacterial resistance. Almost half of the biofilm-producing bacteria showed resistance against at least three different groups of antibiotics. Bacterial resistance is often associated with catheterization. Accordingly, intrinsic (age and gender) and extrinsic (hospital unit, bacterial isolate and catheterization) factors were used to build a predictive model, by evaluating the contribution of each factor to biofilm production. In this way, it is possible to anticipate biofilm occurrence immediately after bacterial identification, allowing selection of a more effective antibiotic (among the susceptibility options suggested by the antibiogram) against biofilm-producing bacteria. This approach reduces the putative bacterial resistance during treatment, and the consequent need to adjust antibiotherapy.
authors.affiliation: CBQF-Escola Superior de Biotecnologia, Universidade Católica Portuguesa Porto, Rua Dr António Bernardino de Almeida, 4200-072 Porto, Portugal.|Centro de Investigação de Montanha (CIMO), ESA, Instituto Politécnico de Bragança, Campus de Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal.|Escola Superior de Saúde, Instituto Politécnico de Bragança, Av. D. Afonso V, 5300-121 Bragança, Portugal.|Centro Hospitalar de Trás-os-Montes e Alto Douro - Unidade de Chaves, Av. Dr Francisco Sá Carneiro, 5400-249 Chaves, Portugal.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Alves
authors.affiliation: REQUIMTE/Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira no. 228, 4050-313 Porto, Portugal.|Centro de Investigação de Montanha (CIMO), ESA, Instituto Politécnico de Bragança, Campus de Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal.
authors.forename: João C M
authors.initials: JCM
authors.lastname: Barreira
authors.affiliation: Escola Superior de Saúde, Instituto Politécnico de Bragança, Av. D. Afonso V, 5300-121 Bragança, Portugal.
authors.forename: Inês
authors.initials: I
authors.lastname: Carvalho
authors.affiliation: Escola Superior de Saúde, Instituto Politécnico de Bragança, Av. D. Afonso V, 5300-121 Bragança, Portugal.
authors.forename: Luis
authors.initials: L
authors.lastname: Trinta
authors.affiliation: Escola Superior de Saúde, Instituto Politécnico de Bragança, Av. D. Afonso V, 5300-121 Bragança, Portugal.
authors.forename: Liliana
authors.initials: L
authors.lastname: Perreira
authors.affiliation: Centro de Investigação de Montanha (CIMO), ESA, Instituto Politécnico de Bragança, Campus de Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal.
authors.forename: Isabel C F R
authors.initials: ICFR
authors.lastname: Ferreira
authors.affiliation: CBQF-Escola Superior de Biotecnologia, Universidade Católica Portuguesa Porto, Rua Dr António Bernardino de Almeida, 4200-072 Porto, Portugal.
authors.forename: Manuela
authors.initials: M
authors.lastname: Pintado
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development*; D002648:Child; D002675:Child, Preschool; D004755:Enterobacteriaceae / Q000187:drug effects / Q000502:physiology; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000502:physiology; D012189:Retrospective Studies; D014546:Urinary Catheterization / Q000009:adverse effects; D014552:Urinary Tract Infections / Q000382:microbiology*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents