Effect of High-Dose Antimicrobials on Biofilm Growth of Achromobacter Species Isolated from Cystic Fibrosis Patients

Sean K Tom; Yvonne C W Yau; Trevor Beaudoin; John J LiPuma; Valerie Waters

doi:10.1128/AAC.02240-15

Effect of High-Dose Antimicrobials on Biofilm Growth of Achromobacter Species Isolated from Cystic Fibrosis Patients

Antimicrob Agents Chemother. 2015 Nov 2;60(1):650-2. doi: 10.1128/AAC.02240-15. Print 2016 Jan.

Authors

Sean K Tom¹, Yvonne C W Yau², Trevor Beaudoin¹, John J LiPuma³, Valerie Waters⁴

Affiliations

¹ Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
² Division of Microbiology, Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
³ Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, Michigan, USA.
⁴ Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Canada valerie.waters@sickkids.ca.

Abstract

MICs and biofilm inhibitory concentrations (BICs) were measured for 68 cystic fibrosis (CF) Achromobacter isolates for amikacin, aztreonam, colistin, levofloxacin, and tobramycin. With the exception of colistin and levofloxacin, the remaining antibiotics had MIC90s, BICs at which 50% of the isolates were susceptible (BIC50s), and BICs at which 90% of the isolates were susceptible (BIC90s) equal to or above the highest concentrations tested. In a biofilm model, tobramycin was able to significantly increase killing of bacterial cells compared to controls, for intermediate-resistant strains only, at concentrations of 1,000 and 2,000 μg/ml.

MeSH terms

Achromobacter / drug effects*
Achromobacter / isolation & purification
Achromobacter / physiology
Amikacin / pharmacology
Anti-Bacterial Agents / pharmacology*
Aztreonam / pharmacology
Biofilms / drug effects*
Biofilms / growth & development
Colistin / pharmacology
Cystic Fibrosis / complications
Cystic Fibrosis / microbiology*
Gram-Negative Bacterial Infections / complications
Gram-Negative Bacterial Infections / microbiology*
Humans
Levofloxacin / pharmacology
Microbial Sensitivity Tests
Plankton / drug effects
Plankton / growth & development
Tobramycin / pharmacology

Substances

Anti-Bacterial Agents
Levofloxacin
Amikacin
Aztreonam
Tobramycin
Colistin

Grants and funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.