Initial Pseudomonas aeruginosa infection in patients with cystic fibrosis: characteristics of eradicated and persistent isolates

TY - JOUR

T1 - Initial Pseudomonas aeruginosa infection in patients with cystic fibrosis

T2 - characteristics of eradicated and persistent isolates

AU - Tramper-Stranders, G A

AU - van der Ent, C K

AU - Molin, S

AU - Yang, L

AU - Hansen, S K

AU - Rau, M H

AU - Ciofu, Oana

AU - Johansen, H K

AU - Wolfs, T F W

N1 - © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

PY - 2012/6

Y1 - 2012/6

N2 - Despite intensive eradication therapy, some CF patients with early Pseudomonas aeruginosa infection rapidly develop a chronic infection. To elucidate factors associated with this persistence, bacterial characteristics of early P. aeruginosa isolates were analysed that were either eradicated rapidly or persisted despite multiple antimicrobial treatments. Eighty-six early infection episodes were studied. First P. aeruginosa isolates from patients with eradication (36) or persistent infection (16) were included; isolates from patients with intermittent infection (34) were omitted from the study. Virulence assays, antimicrobial resistance, cytotoxicity and mutation frequencies were analysed in vitro. P. aeruginosa was genotyped by SNP-array. Transcriptomic profiles of two eradicated and two persistent strains were compared. Nineteen per cent of patients developed persistent infection; 42% achieved eradication. Secretion of virulence factors and mutation frequencies were highly variable among both eradicated and persistent isolates and were not different between the groups. Cytotoxicity was present in 57% of eradicated vs. 100% of persistent isolates (p <0.01). None of the isolates were resistant to antibiotics. The isolates were genotypically highly diverse. Multivariate analysis showed that in vitro determined bacterial characteristics could not predict persistence after first P. aeruginosa infection. Preliminary transcriptomic data showed increased expression of some genes related to a metabolic pathway. The early onset of chronic infection was not associated with (in vitro determined) bacterial characteristics only. Although the persistent isolates were more often cytotoxic, for the individual patient it was not possible to predict the risk of persistence based on bacterial characteristics. Unknown factors such as host-pathogen and pathogen-pathogen interactions should be further explored.

AB - Despite intensive eradication therapy, some CF patients with early Pseudomonas aeruginosa infection rapidly develop a chronic infection. To elucidate factors associated with this persistence, bacterial characteristics of early P. aeruginosa isolates were analysed that were either eradicated rapidly or persisted despite multiple antimicrobial treatments. Eighty-six early infection episodes were studied. First P. aeruginosa isolates from patients with eradication (36) or persistent infection (16) were included; isolates from patients with intermittent infection (34) were omitted from the study. Virulence assays, antimicrobial resistance, cytotoxicity and mutation frequencies were analysed in vitro. P. aeruginosa was genotyped by SNP-array. Transcriptomic profiles of two eradicated and two persistent strains were compared. Nineteen per cent of patients developed persistent infection; 42% achieved eradication. Secretion of virulence factors and mutation frequencies were highly variable among both eradicated and persistent isolates and were not different between the groups. Cytotoxicity was present in 57% of eradicated vs. 100% of persistent isolates (p <0.01). None of the isolates were resistant to antibiotics. The isolates were genotypically highly diverse. Multivariate analysis showed that in vitro determined bacterial characteristics could not predict persistence after first P. aeruginosa infection. Preliminary transcriptomic data showed increased expression of some genes related to a metabolic pathway. The early onset of chronic infection was not associated with (in vitro determined) bacterial characteristics only. Although the persistent isolates were more often cytotoxic, for the individual patient it was not possible to predict the risk of persistence based on bacterial characteristics. Unknown factors such as host-pathogen and pathogen-pathogen interactions should be further explored.

KW - Adolescent

KW - Anti-Bacterial Agents

KW - Bacterial Toxins

KW - Bronchopneumonia

KW - Cell Survival

KW - Child

KW - Child, Preschool

KW - Chronic Disease

KW - Cystic Fibrosis

KW - Epithelial Cells

KW - Female

KW - Humans

KW - Infant

KW - Male

KW - Microbial Sensitivity Tests

KW - Pseudomonas Infections

KW - Pseudomonas aeruginosa

KW - Transcriptome

KW - Virulence

KW - Virulence Factors

KW - Young Adult

U2 - 10.1111/j.1469-0691.2011.03627.x

DO - 10.1111/j.1469-0691.2011.03627.x

M3 - Journal article

C2 - 21883670

SN - 1469-0691

VL - 18

SP - 567

EP - 574

JO - Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases

JF - Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases

IS - 6

ER -