title: Deciphering the Contribution of Biofilm to the Pathogenesis of Peritoneal Dialysis Infections: Characterization and Microbial Behaviour on Dialysis Fluids.
abstract: Infections are major complications in peritoneal dialysis (PD) with a multifactorial etiology that comprises patient, microbial and dialytic factors. This study aimed at investigating the contribution of microbial biofilms on PD catheters to recalcitrant infections and their interplay with PD related-factors. A prospective observational study was performed on 47 patients attending Centro Hospitalar of Porto and Vila Nova de Gaia/Espinho to whom the catheter was removed due to infectious (n = 16) and non-infectious causes (n = 31). Microbial density on the catheter was assessed by culture methods and the isolated microorganisms identified by matrix-assisted laser desorption/ionization time-of-flight intact cell mass spectrometry. The effect of conventional and three biocompatible PD solutions on 16 Coagulase Negative Staphylococci (CNS) and 10 Pseudomonas aeruginosa strains planktonic growth and biofilm formation was evaluated. Cultures were positive in 87.5% of the catheters removed due infectious and 90.3% removed due to non-infectious causes. However, microbial yields were higher on the cuffs of catheters removed due to infection vs. non-infection. Staphylococci (CNS and Staphylococcus aureus) and P. aeruginosa were the predominant species: 32% and 20% in the infection and 43.3% and 22.7% in the non-infection group, respectively. In general, PD solutions had a detrimental effect on planktonic CNS and P. aeruginosa strains growth. All strains formed biofilms in the presence of PD solutions. The solutions had a more detrimental effect on P. aeruginosa than CNS strains. No major differences were observed between conventional and biocompatible solutions, although in icodextrin solution biofilm biomass was lower than in bicarbonate/lactate solution. Overall, we show that microbial biofilm is universal in PD catheters with the subclinical menace of Staphylococci and P. aeruginosa. Cuffs colonization may significantly contribute to infection. PD solutions differentially impact microbial species. This knowledge is important for the development of infection diagnosis, treatment and preventive strategies.
authors.affiliation: CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Campus de Gualtar, Braga, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Sampaio
authors.affiliation: CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Campus de Gualtar, Braga, Portugal.
authors.forename: Diana
authors.initials: D
authors.lastname: Machado
authors.affiliation: Serviço Nefrologia, Centro Hospitalar Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia, Portugal.
authors.forename: Ana Marta
authors.initials: AM
authors.lastname: Gomes
authors.affiliation: LEPABE, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal.
authors.forename: Idalina
authors.initials: I
authors.lastname: Machado
authors.affiliation: Department of Chemical Sciences and Natural Resources, CIBAMA, BIOREN-UFRO Universidad de La Frontera, Temuco, Chile.
authors.forename: Cledir
authors.initials: C
authors.lastname: Santos
authors.affiliation: CEB - Centre of Biological Engineering, Micoteca da Universidade do Minho, Campus de Gualtar, Braga, Portugal.
authors.forename: Nelson
authors.initials: N
authors.lastname: Lima
authors.affiliation: Serviço Nefrologia, Centro Hospitalar Porto, Largo Prof. Abel Salazar Porto, Porto, Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Carvalho
authors.affiliation: Serviço Nefrologia, Centro Hospitalar Porto, Largo Prof. Abel Salazar Porto, Porto, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Cabrita
authors.affiliation: Serviço Nefrologia, Centro Hospitalar Porto, Largo Prof. Abel Salazar Porto, Porto, Portugal.|Unidade Multidisciplinar de Investigação Biomédica, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto - UMIB/ICBAS/UP, Porto, Portugal.
authors.forename: Anabela
authors.initials: A
authors.lastname: Rodrigues
authors.affiliation: CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Campus de Gualtar, Braga, Portugal.
authors.forename: Margarida
authors.identifier: http://orcid.org/0000-0002-4979-7634
authors.initials: M
authors.lastname: Martins
mesh_terms: D000328:Adult; D000368:Aged; D058491:Bacterial Load; D018441:Biofilms; D018533:Biomass; D002404:Catheterization / Q000009:adverse effects; D002408:Catheters, Indwelling / Q000009:adverse effects; D015897:Comorbidity; D015314:Dialysis Solutions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010538:Peritonitis / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology* / Q000401:mortality
chemical_list: D015314:Dialysis Solutions