Open AccessIn vitro interference of cefotaxime at subinhibitory concentrations on biofilm formation by nontypeable Haemophilus influenzae
Author(s) -
Sudarat Baothong,
Sutthirat Sitthisak,
Duangkamol Kunthalert
Publication year - 2016
Publication title -
asian pacific journal of tropical biomedicine/asian pacific journal of tropical biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 61
eISSN - 2588-9222
pISSN - 2221-1691
DOI - 10.1016/j.apjtb.2016.07.003
Subject(s) - cefotaxime , haemophilus influenzae , microbiology and biotechnology , haemophilus , in vitro , biofilm , medicine , biology , antibiotics , chemistry , bacteria , genetics
ObjectiveTo investigate the in vitro interference of cefotaxime at subinhibitory concentrations [sub-minimal inhibitory concentrations (MIC)] on biofilm formation by nontypeable Haemophilus influenzae (NTHi).MethodsThe interference of subinhibitory concentrations of cefotaxime on biofilm formation of the clinical strong-biofilm forming isolates of NTHi was evaluated by a microtiter plate biofilm formation assay. The effect of sub-MIC cefotaxime on bacterial cell-surface hydrophobicity was determined using a standard microbial adhesion to n-hexadecane test. Additionally, the effects on bacterial adherence to human fibronectin and expression of bacterial adhesins were also investigated.ResultsSubinhibitory concentrations of cefotaxime, both at 0.1× and 0.5× MIC levels, efficiently reduced the NTHi biofilm formation, and this effect was independent of decreasing bacterial viability. Sub-MIC cefotaxime also decreased bacterial cell-surface hydrophobicity and reduced adherence to human fibronectin. Inhibition in the P2 and P6 gene expressions upon exposure to sub-MIC cefotaxime was also noted.ConclusionsTaken together, our results indicate that sub-MIC cefotaxime interferes with the formation of NTHi biofilm, and this effect is feasibly related to the interference with cell-surface hydrophobicity, fibronectin-binding activity as well as alteration of the P2 and P6 gene expression. The findings of the present study therefore provide a rationale for the use of subinhibitory concentrations of cefotaxime for treatment of NTHi-related diseases