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Biofilm inhibitory efficiency of phytol in combination with cefotaxime against nosocomial pathogen Acinetobacter baumannii
Author(s) -
Ramanathan S.,
Arunachalam K.,
Chandran S.,
Selvaraj R.,
Shunmugiah K.P.,
Arumugam V.R.
Publication year - 2018
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.13741
Subject(s) - acinetobacter baumannii , biofilm , cefotaxime , microbiology and biotechnology , virulence , biology , bacteria , chemistry , antibiotics , gene , biochemistry , pseudomonas aeruginosa , genetics
Aims This study aimed to evaluate the antibiofilm potential of phytol and cefotaxime combinations ( PCC s) against Acinetobacter baumannii and to elucidate the molecular mechanism of their antibiofilm potential through the transcriptomic approach. Methods and Results Phytol and cefotaxime combination(s) ( PCC (s) [160 μ g ml −1 + 8 μ g ml −1 for microbial type culture collection ( MTCC ) strain and 160 μ g ml −1 + 0.5 μ g ml −1 for clinical isolate] effectively inhibited the A. baumannii biofilm formation. Additionally, light, confocal laser scanning and scanning electron microscopic analyses validated the antibiofilm potential of PCC s. Furthermore, PCC s treated A. baumannii cells showed a decreased level of hydrophobicity index compared to their respective controls. Fourier‐transform infrared ( FT ‐ IR ) spectra of exopolysaccharide matrix extracted from PCC s‐treated A. baumannii cells showed a visible decrease in absorbance of polysaccharides, nucleic acids and protein regions compared to the spectra of untreated controls. In the blood sensitivity assay, the PCC s‐treated A. baumannii plates showed reduced a number of bacterial colonies compared to their control plates. Reduced level of catalase production was also observed in the PCC s treatment compared to their controls. Transcriptomic analysis revealed the downregulation of bfmR, bap, csuA/B, ompA, pgaA, pgaC and katE biofilm virulence genes in both the A. baumannii strains on treatment with PCC s. Conclusion The obtained results of this study indicate that PCC s have potent antibiofilm activity and downregulate the biofilm‐related virulence genes expression in A. baumannii . Significance and Impact of the Study To the best of our knowledge, this is the pioneering study, which shows the antibiofilm effect of PCC s against A. baumannii along with their molecular mechanism. The antibiofilm effect of PCC s could be a successful strategy for eradicating infections related to A. baumannii biofilms in nosocomial settings.